U.S. patent application number 09/304750 was filed with the patent office on 2002-01-31 for systems and methods for forming composite lesions to treat dysfunction in sphincters and adjoining tissue regions.
Invention is credited to CHIN, JAY, EDWARDS, STUART, GAISER, JOHN, UTLEY, DAVID S., WEST, SCOTT.
Application Number | 20020013581 09/304750 |
Document ID | / |
Family ID | 23177831 |
Filed Date | 2002-01-31 |
United States Patent
Application |
20020013581 |
Kind Code |
A1 |
EDWARDS, STUART ; et
al. |
January 31, 2002 |
SYSTEMS AND METHODS FOR FORMING COMPOSITE LESIONS TO TREAT
DYSFUNCTION IN SPHINCTERS AND ADJOINING TISSUE REGIONS
Abstract
Systems and methods manipulate a support structure to form a
composite lesion in a tissue region at or near a sphincter. The
support structure carries an array of electrodes attachable to a
source of energy capable of heating tissue when transmitted by the
electrodes. The systems and methods advance the electrodes to
penetrate the tissue region and form, when the energy is
transmitted, a first pattern of lesions. The systems and methods
retract the electrodes, and shift the position of the electrodes,
either rotationally, or axially, or both rotationally and axially.
The systems and methods advance the electrodes a second time to
form, when the energy is transmitted, a second pattern of lesions
either rotationally or axially or both rotationally and axially
shifted from the first pattern of lesions. The first and second
patterns of lesion together comprise the composite lesion.
Inventors: |
EDWARDS, STUART; (PORTOLA
VALLEY, CA) ; GAISER, JOHN; (MOUNTAIN VIEW, CA)
; UTLEY, DAVID S.; (SAN CARLOS, CA) ; WEST,
SCOTT; (LIVERMORE, CA) ; CHIN, JAY; (FREMONT,
CA) |
Correspondence
Address: |
RYAN KROMHOLZ & MSNION, S.C.
P.O. BOX26618
MILWAUKEE
WI
53226-0618
US
|
Family ID: |
23177831 |
Appl. No.: |
09/304750 |
Filed: |
May 4, 1999 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09304750 |
May 4, 1999 |
|
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09026296 |
Feb 19, 1998 |
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6009877 |
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Current U.S.
Class: |
606/41 |
Current CPC
Class: |
A61B 18/1477 20130101;
A61B 2018/00029 20130101; A61B 2018/046 20130101; A61B 2018/1475
20130101; A61B 2018/00755 20130101; A61B 2018/00702 20130101; A61B
2090/3782 20160201; A61B 2018/00898 20130101; A61B 2218/007
20130101; A61B 2018/00285 20130101; A61B 2018/00148 20130101; A61B
2018/00654 20130101; A61B 2018/00077 20130101; A61B 2018/0066
20130101; A61B 18/1206 20130101; A61B 18/1485 20130101; A61B
2018/00011 20130101; A61B 2018/00797 20130101; A61B 2018/00232
20130101; A61B 2018/1425 20130101; A61B 18/12 20130101; A61B
2018/00267 20130101; A61B 2018/00273 20130101; A61B 2218/002
20130101; A61B 2018/00791 20130101; A61B 18/1492 20130101; A61B
2018/00261 20130101; A61B 2018/00553 20130101; A61B 2018/00815
20130101; A61B 2018/00875 20130101; A61B 2018/00291 20130101; A61B
2018/00214 20130101 |
Class at
Publication: |
606/41 |
International
Class: |
A61B 018/14 |
Claims
We claim:
1. An assembly for forming a composite lesion in a tissue region at
or near a sphincter comprising a catheter tube having a proximal
end and a distal end, a support structure on the distal end, an
array of electrodes carried by the support structure and being
attachable to a source of energy capable of heating tissue when
transmitted by the electrodes, and a handle on the proximal end for
rotating the catheter tube to position the support structure in the
tissue region, including a mechanism to selectively advance the
electrodes in a path to penetrate the tissue region and form, when
the energy is transmitted, a first pattern of lesions, the
mechanism operating to selectively retract the electrodes to enable
rotation of the catheter tube by manipulation of the handle, to
thereby rotationally shift the position the support structure in
the tissue region, so that advancement of the electrodes a second
time forms, when the energy is transmitted, a second pattern of
lesions rotationally shifted from the first pattern of lesions,
together comprising the composite lesion.
2. An assembly for forming a composite lesion in a tissue region at
or near a sphincter comprising a catheter tube having a proximal
end and a distal end, a support structure on the distal end, an
array of electrodes carried by the support structure and being
attachable to a source of energy capable of heating tissue when
transmitted by the electrodes, and a handle on the proximal end for
axially moving the catheter tube to position the support structure
in the tissue region, including a mechanism to selectively advance
the electrodes in a path to penetrate the tissue region and form,
when the energy is transmitted, a first pattern of lesions, the
mechanism operating to selectively retract the electrodes to enable
axial movement of the catheter tube by manipulation of the handle,
to thereby axially shift the position the support structure in the
tissue region, so that advancement of the electrodes a second time
forms, when the energy is transmitted, a second pattern of lesions
axially shifted from the first pattern of lesions, together
comprising the composite lesion.
3. An assembly according to claim 1 or 2 wherein at least four
electrodes are carried in a circumferential, spaced apart
relationship by the support structure.
4. An assembly according to claim 1 or 2 wherein eight electrodes
are carried in a circumferentially spaced apart relationship by the
support structure.
5. An assembly according to claim 1 or 2 wherein the support
structure expands and collapses.
6. An assembly according to claim 1 or 2 further including at least
one temperature sensor on one of the electrodes.
7. An assembly according to claim 1 or 2 further including a
temperature sensor on the support structure.
8. An assembly according to claim 1 or 2 further including a
connector to couple the electrodes to a source of radio frequency
energy to ohmically heat tissue and create the composite lesion in
the tissue region.
9. An assembly for forming a composite lesion in a tissue region at
or near a sphincter comprising a catheter tube having a proximal
end and a distal end, a support structure on the distal end, an
array of electrodes carried by the support structure and being
attachable to a source of energy capable of heating tissue when
transmitted by the electrodes, and a handle on the proximal end to
position the support structure in the tissue region, including a
first mechanism to selectively advance the electrodes in a first
path outward of the support structure to penetrate the tissue
region and form, when the energy is transmitted, a first pattern of
lesions, and a second mechanism to advance the electrodes in a
second path axially along the support structure to axially shift
the position the electrodes in the tissue region, so that
advancement of the electrodes a second time forms, when the energy
is transmitted, a second pattern of lesions axially shifted from
the first pattern of lesions, together comprising the composite
lesion.
10. An assembly according to claim 9 wherein the support structure
includes an array of spines to support the electrodes, and wherein
the first and second mechanisms advance the electrodes along the
first and second paths without moving the spine.
11. An assembly according to claim 9 wherein the support structure
includes an array of movable spines to support the electrodes, and
wherein the second mechanism moves the spines to advance the
electrodes in the second path.
12. An assembly according to claim 11 wherein the first mechanism
moves the electrodes outward of the movable spines to advance the
electrodes in the first path.
13. An assembly according to claim 9 wherein the support structure
expands and collapses.
14. An assembly according to claim 9 further including at least one
temperature sensor on one of the electrodes.
15. An assembly according to claim 9 further including a
temperature sensor on the support structure.
16. An assembly according to claim 9 further including a connector
to couple the electrodes to a source of radio frequency energy to
ohmically heat tissue and create the composite lesion in the tissue
region.
17. An assembly for treating a tissue region at or near a sphincter
comprising a support structure, an electrode on the support
structure, a first mechanism to advance the electrode in a first
path outward of the support structure to penetrate the tissue
region, and a second mechanism to advance the electrode in a second
path along the support structure to select different locations
along the support structure for penetrating the tissue region.
18. An assembly according to claim 17 wherein the support structure
includes at least one spine to support the electrode, and wherein
the first and second mechanisms advance the electrode along the
first and second paths without moving the spine.
19. An assembly according to claim 17 wherein the support structure
includes at least one movable spine to support the electrode, and
wherein the second mechanism moves the spine to advance the
electrode in the second path.
20. An assembly according to claim 19 wherein the first mechanism
moves the electrode outward of the movable spine to advance the
electrode in the first path.
21. An assembly according to claim 17 wherein the support structure
expands and collapses.
22. An assembly according to claim 17 wherein the support structure
includes an expandable interior element and an exterior spine
carried by the interior element to support the electrode, and
wherein the first and second mechanisms advance the electrode along
the first and second paths without moving the exterior spine
relative to the interior element.
23. An assembly according to claim 17 wherein the support structure
includes an expandable interior element and an exterior spine
carried by the interior element to support the electrode, and
wherein the second mechanism moves the spine relative to the
support structure to advance the electrode in the second path.
24. An assembly according to claim 23 wherein the first mechanism
moves the electrode outward of the spine to advance the electrode
in the first path.
25. An assembly according to claim 17 further including a second
electrode on the support structure, and wherein the first mechanism
advances the electrodes in tandem in the first path outward of the
support structure to penetrate the tissue region.
26. An assembly according o claim 25 wherein the second mechanism
advances the electrodes in tandem in the second path along the
support structure to select different locations along the support
structure for penetrating the tissue region.
27. An assembly according to claim 17 further including a
temperature sensor on the electrode.
28. An assembly according to claim 17 further including a
temperature sensor on the support structure.
29. An assembly according to claim 17 further including a connector
to couple the electrode to a source of radio frequency energy to
ohmically heat tissue and create a lesion in the tissue region.
30. A method for forming a composite lesion in a tissue region at
or near a sphincter comprising the steps of manipulating a support
structure in the tissue region, the support structure carrying an
array of electrodes attachable to a source of energy capable of
heating tissue when transmitted by the electrodes, advancing the
electrodes in a path to penetrate the tissue region and form, when
the energy is transmitted, a first pattern of lesions, retracting
the electrodes, rotationally shifting the position of the support
structure in the tissue region, and advancing the electrodes a
second time to form, when the energy is transmitted, a second
pattern of lesions rotationally shifted from the first pattern of
lesions, together comprising the composite lesion.
31. A method for forming a composite lesion in a tissue region at
or near a sphincter comprising manipulating a support structure in
the tissue region, the support structure carrying an array of
electrodes attachable to a source of energy capable of heating
tissue when transmitted by the electrodes, advancing the electrodes
in a path to penetrate the tissue region and form, when the energy
is transmitted, a first pattern of lesions, retracting the
electrodes, axially shifting the position the support structure in
the tissue region, advancing the electrodes a second time to form,
when the energy is transmitted, a second pattern of lesions axially
shifted from the first pattern of lesions, together comprising the
composite lesion.
32. A method for treating a tissue region at or near a sphincter
comprising the steps of manipulating a support structure in the
tissue region, the support structure carrying an electrode
attachable to a source of energy capable of heating tissue when
transmitted by the electrode, advancing the electrode along the
support structure to select different locations along the support
structure for penetrating the tissue region, and advancing the
electrode outward of the support structure at a selected location
to penetrate the tissue region.
Description
RELATED APPLICATION
[0001] This application is a continuation-in-part of co-pending
U.S. patent application Ser. No. 09/026,296, filed Feb. 19, 1998,
and entitled "Method for Treating Sphincter."
FIELD OF THE INVENTION
[0002] In a general sense, the invention is directed to systems and
methods for treating interior tissue regions of the body. More
specifically, the invention is directed to systems and methods for
treating dysfunction in body sphincters and adjoining tissue, e.g.,
in and around the lower esophageal sphincter and cardia of the
stomach.
BACKGROUND OF THE INVENTION
[0003] The gastrointestinal tract, also called the alimentary
canal, is a long tube through which food is taken into the body and
digested. The alimentary canal begins at the mouth, and includes
the pharynx, esophagus, stomach, small and large intestines, and
rectum. In human beings, this passage is about 30 feet (9 meters)
long.
[0004] Small, ring-like muscles, called sphincters, surround
portions of the alimentary canal. In a healthy person, these
muscles contract or tighten in a coordinated fashion during eating
and the ensuing digestive process, to temporarily close off one
region of the alimentary canal from an other.
[0005] For example, a muscular ring called the lower esophageal
sphincter surrounds the opening between the esophagus and the
stomach. The lower esophageal sphincter (or LES) is a ring of
increased thickness in the circular, smooth-muscle layer of the
esophagus. Normally, the lower esophageal sphincter maintains a
high-pressure zone between fifteen and thirty mm Hg above
intragastric pressures inside the stomach.
[0006] When a person swallows food, muscles of the pharynx push the
food into the esophagus. The muscles in the esophagus walls respond
with a wavelike contraction called peristalsis. The lower
esophageal sphincter relaxes before the esophagus contracts, and
allows food to pass through to the stomach. After food passes into
the stomach, the lower esophageal sphincter constricts to prevent
the contents from regurgitating into the esophagus.
[0007] The stomach muscles churn the food and digestive juices into
a mass called chyme. Then the muscles squeeze the chyme toward the
pyloric (intestinal) end of the stomach by peristaltic waves, which
start at the top of the stomach and move downward. The pyloric
sphincter, another ringlike muscle, surrounds the duodenal opening.
The pyloric sphincter keeps food in the stomach until it is a
liquid. The pyloric sphincter then relaxes and lets some chyme pass
into the duodenum.
[0008] Dysfunction of a sphincter in the body can lead to internal
damage or disease, discomfort, or otherwise adversely affect the
quality of life. For example, if the lower esophageal sphincter
fails to function properly, stomach acid may rise back into the
esophagus. Unlike the stomach, the esophagus has no natural
protection against stomach acids. When the stomach contents make
contact with the esophagus, heartburn or other disease symptoms,
including damage to the esophagus, can occur.
[0009] Gastrointestinal reflux disease (GERD) is a common disorder,
characterized by spontaneous relaxation of the lower esophageal
sphincter. It has been estimated that approximately two percent of
the adult population suffers from GERD. The incidence of GERD
increases markedly after the age of 40, and it is not uncommon for
patients experiencing symptoms to wait years before seeking medical
treatment.
[0010] GERD is both a normal physiologic phenomenon that occurs in
the general population and a pathophysiologic phenomenon that can
result in mild to severe symptoms.
[0011] GERD is believed to be caused by a combination of conditions
that increase the presence of acid reflux in the esophagus. These
conditions include transient LES relaxation, decreased LES resting
tone, impaired esophageal clearance, delayed gastric emptying,
decreased salivation, and impaired tissue resistance. Since the
resting tone of the lower esophageal sphincter is maintained by
both myogenic (muscular) and neurogenic (nerve) mechanisms, some
believe that aberrant electrical signals in the lower esophageal
sphincter or surrounding region of the stomach (called the cardia)
can cause the sphincter to spontaneously relax.
[0012] Lifestyle factors can also cause increased risk of reflux.
Smoking, large meals, fatty foods, caffeine, pregnancy, obesity,
body position, drugs, hormones, and paraplegia may all exacerbate
GERD. Also, hiatal hernia frequently accompanies severe GERD. The
hernia may increase transient LES relaxation and delay acid
clearance due to impaired esophageal emptying. Thus, hiatal hernias
may contribute to prolonged acid exposure time following reflux,
resulting in GERD symptoms and esophageal damage.
[0013] The excessive reflux experienced by patients with GERD
overwhelms their intrinsic mucosal defense mechanisms, resulting in
many symptoms. The most common symptom of GERD is heartburn.
Besides the discomfort of heartburn, reflux results in symptoms of
esophageal inflammation, such as odynophagia (pain on swallowing)
and dysphagia (difficult swallowing). The acid reflux may also
cause pulmonary symptoms such as coughing, wheezing, asthma,
aspiration pneumonia, and interstitial fibrosis; oral symptoms such
as tooth enamel decay, gingivitis, halitosis, and waterbrash;
throat symptoms such as a soreness, laryngitis, hoarseness, and a
globus sensation; and earache.
[0014] Complications of GERD include esophageal erosion, esophageal
ulcer, and esophageal stricture; replacement of normal esophageal
epithelium with abnormal (Barrett's) epithelium; and pulmonary
aspiration.
[0015] Treatment of GERD includes drug therapy to reduce or block
stomach acid secretions. Still, daily drug therapy does not
eliminate the root cause of the dysfunction.
[0016] Invasive abdominal surgical intervention has also been tried
with success. One procedure, called Nissen fundoplication, entails
invasive, open abdominal surgery. The surgeon wraps the gastric
fundis about the lower esophagus, to, in effect, create a new
"valve." Less invasive laparoscopic tehniques have also been tried
to emulate Nissen fundoplication, also with success. Still, all
surgical intervention entails making an incision into the abdomen
and carry with it the usual risks of abdominal surgery.
SUMMARY OF THE INVENTION
[0017] The invention provides improved systems and methods for
treating a tissue region at or near a sphincter. The systems and
methods manipulate a support structure to form a composite lesion
in the tissue region, e.g. the lower esophageal sphincter and
adjoining cardia of the stomach.
[0018] One aspect of the invention provides an assembly for forming
a composite lesion in a tissue region at or near a sphincter. The
assembly comprises a catheter tube having a proximal end and a
distal end. A support structure on the distal end carries an array
of electrodes, being attachable to a source of energy capable of
heating tissue when transmitted by the electrodes.
[0019] In one embodiment, the assembly further includes a handle on
the proximal end for rotating the catheter tube, to position the
support structure in the tissue region. The handle includes a
mechanism to selectively advance the electrodes in a path to
penetrate the tissue region and form, when the energy is
transmitted, a first pattern of lesions. The mechanism also
operates to selectively retract the electrodes, to enable rotation
of the catheter tube by manipulation of the handle, to thereby
rotationally shift the position the support structure in the tissue
region. Advancement of the electrodes a second time forms, when the
energy is transmitted, a second pattern of lesions rotationally
shifted from the first pattern of lesions. Together, the first and
second patterns of lesions form the composite lesion.
[0020] In one embodiment, the assembly further includes a handle on
the proximal end for axially moving the catheter tube to position
the support structure in the tissue region. The handle includes a
mechanism to selectively advance the electrodes in a path to
penetrate the tissue region and form, when the energy is
transmitted, a first pattern of lesions. The mechanism also
operates to selectively retract the electrodes to enable axial
movement of the catheter tube by manipulation of the handle, to
thereby axially shift the position the support structure in the
tissue region. Advancement of the electrodes a second time forms,
when the energy is transmitted, a second pattern of lesions axially
shifted from the first pattern of lesions. Together, the first and
second patterns of lesions form the composite lesion.
[0021] Another aspect of the invention provides an electrode
carries by a support structure, which itself is carried by a
catheter tube. The catheter tube also has a handle. There are
different mechanisms on the handle. The first mechanism advances
the electrode in a first path outward of the support structure to
penetrate tissue. The second mechanism advances the electrode in a
second path along the support structure to select different
locations for penetrating the tissue region.
[0022] On one embodiment, the support structure includes a spine to
support the electrode. In one arrangement, the first and second
mechanisms advance the electrode along the first and second paths
without moving the spine. In another arrangement, the second
mechanism moves the spines to advance the electrodes in the second
path.
[0023] Another aspect of the invention provides various methods to
manipulate a support structure to form a composite lesion in a
tissue region at or near a sphincter. The support structure carries
an array of electrodes attachable to a source of energy capable of
heating tissue when transmitted by the electrodes. The methods
advance the electrodes to penetrate the tissue region and form,
when the energy is transmitted, a first pattern of lesions. The
methods retract the electrodes, and shift the position of the
electrodes, either rotationally, or axially, or both rotationally
and axially. The methods advance the electrodes a second time to
form, when the energy is transmitted, a second pattern of lesions
either rotationally or axially or both rotationally and axially
shifted from the first pattern of lesions. The first and second
patterns of lesion together comprise the composite lesion.
[0024] Features and advantages of the inventions are set forth in
the following Description and Drawings, as well as in the appended
Claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is an anatomic view of the esophagus and stomach;
[0026] FIG. 2 is a diagrammatic view of a system for treating body
sphincters and adjoining tissue regions, which embodies features of
the invention;
[0027] FIG. 3 is a perspective view, with portions broken away, of
a device usable in association with the system shown in FIG. 1
having an operative element for contacting tissue shown in a
collapsed condition;
[0028] FIG. 4 is a perspective view, with portions broken away, of
the device shown in FIG. 3, with the operative element shown in an
expanded condition;
[0029] FIG. 5 is a perspective view, with portions broken away, of
the device shown in FIG. 3, with the operative element shown in an
expanded condition and the electrodes extended for use;
[0030] FIG. 6 is an enlarged side view of the operative element
when collapsed, as also shown in FIG. 3;
[0031] FIG. 7 is an enlarged side view of the operative element
when expanded and with the electrodes extended for use, as also
shown in FIG. 5;
[0032] FIG. 8 is an enlarged perspective view of an embodiment the
operative element, when fully collapsed;
[0033] FIG. 9 is a side view of the deployment of a flexible
endoscope through an esophageal introducer into the stomach;
[0034] FIG. 10 is an enlarged view of the endoscope shown in FIG.
9, retroflexed for viewing the cardia and lower esophageal
sphincter;
[0035] FIG. 11 is a side view of the deployment of the device shown
in FIG. 3 after deployment of the flexible endoscope shown in FIG.
9, placing the operative element in the region of the lower
esophageal sphincter;
[0036] FIG. 12 is an enlarged view of the operative element shown
in FIG. 11, when placed in the region of the lower esophageal
sphincter;
[0037] FIG. 13 is an enlarged view of the operative element shown
in FIG. 11, when expanded into contact with muscosal tissue in the
region of the lower esophageal sphincter;
[0038] FIG. 14 is an enlarged view of the operative element shown
in FIG. 11, when expanded into contact with muscosal tissue in the
region of the lower esophageal sphincter and with the electrodes
extended to create lesions in the smooth muscle ring of the lower
esophageal sphincter;
[0039] FIG. 15 is an enlarged view of the operative element shown
in FIG. 11, when placed in the region of the cardia;
[0040] FIG. 16 is an enlarged view of the operative element shown
in FIG. 11, when expanded into contact with muscosal tissue in the
cardia;
[0041] FIG. 17 is an enlarged view of the operative element shown
in FIG. 11, when expanded into contact with muscosal tissue in the
cardia and with the electrodes extended to create lesions in the
smooth muscle of the cardia;
[0042] FIG. 18 is an enlarged view of the operative element shown
in FIG. 17, when fully deployed for creating lesions in the
cardia;
[0043] FIG. 19 is an enlarged view of the operative element shown
in FIG. 14 or FIG. 17, after being used to form lesions and in the
process of being removed from the targeted tissue site;
[0044] FIG. 20 is a top view of a targeted tissue region in the
cardia, showing a desired pattern of lesions;
[0045] FIG. 21 is a perspective view of a "pear-shaped" operative
element intended for deployment in the cardia, shown in a collapsed
condition;
[0046] FIG. 22 is a perspective view of the "pear-shaped" shown in
FIG. 21, shown in an expanded condition with the electrodes
extended for use in an antegrade orientation;
[0047] FIG. 23 is an enlarged view of the operative element shown
in FIG. 22, when expanded into contact with muscosal tissue in the
cardia and with the electrodes extended to create lesions in the
smooth muscle of the cardia;
[0048] FIG. 24 is a perspective view of the "pear-shaped" shown in
FIG. 21, shown in an expanded condition with the electrodes
extended for use in a retrograde orientation;
[0049] FIG. 25 is an enlarged view of the operative element shown
in FIG. 24, when expanded into contact with muscosal tissue in the
cardia and with the electrodes extended to create lesions in the
smooth muscle of the cardia;
[0050] FIG. 26 is an enlarged side view a "disk-shaped" operative
element intended for deployment in the cardia, when expanded into
contact with muscosal tissue in the cardia and with the electrodes
extended to create lesions in the smooth muscle of the cardia;
[0051] FIGS. 27 and 28 are an enlarged side views operative
elements having different "peanut" shapes intended for deployment
in the cardia, when expanded into contact with muscosal tissue in
the cardia and with the electrodes extended to create lesions in
the smooth muscle of the cardia;
[0052] FIG. 29 is an enlarged side view an operative element
expanded into contact with muscosal tissue in the cardia and with
"pig-tail" electrodes extended to create lesions in the smooth
muscle of the cardia;
[0053] FIG. 30 is a enlarged perspective section view of an
electrode having a cyindrical cross section;
[0054] FIG. 31 is a enlarged perspective section view of an
electrode having an elliptical cross section to resist
twisting;
[0055] FIG. 32 is a enlarged perspective section view of an
electrode having a rectilinear cross section to resist
twisting;
[0056] FIG. 33 is an enlarged side view of an electrode deployed
from an operative element in the region of the lower esophageal
sphincter and having a collar to control the depth of tissue
penetration;
[0057] FIG. 34 is a side section view of a stationary spine which
comprises a portion of an operative element and which carries a
movable electrode for creating lesion patterns;
[0058] FIG. 35 is a side section view of a stationary spine which
comprises a portion of an operative element and which carries a
pair of movable electrodes for creating lesion patterns; FIG. 34 is
a side section view of a stationary spine which comprises a portion
of an operative element and which carries a movable electrode for
creating lesion patterns;
[0059] FIGS. 36 and 37 are enlarged side views of operative
elements deployed in the cardia and having movable spines for
positioning either multiple electrodes or a single electrode in
different positions for creating lesion patterns;
[0060] FIG. 38 is an enlarged side view of an operative element
that carries a steerable electrode for creating lesions in body
sphincters and adjoining tissue;
[0061] FIG. 39 is an enlarged side view of an operative element
carrying surface electrodes for treating abnormal epithelial tissue
in the gastrointestinal tract, the operative element being shown in
a collapsed condition and deployed in the region of the lower
esophageal sphincter;
[0062] FIG. 40 is an enlarged side view of the operative element
shown in FIG. 39 and in an expanded condition contacting the
abnormal epithelial tissue for applying ablation energy;
[0063] FIG. 41 is a perspective view of an operative element
comprising a mechanically expandable basket shown in a collapsed
condition;
[0064] FIG. 42 is a perspective view of the operative element shown
in FIG. 41, with the operative element shown in an expanded
condition to extend the electrodes for use;
[0065] FIG. 43 is a side view showing a spine of the basket shown
in FIG. 41 as it is mechanically flexed for penetrating tissue;
[0066] FIG. 44 is a side view of another operative element
comprising a mechanically expandable basket shown in an expanded
condition with the electrodes extended for use shown;
[0067] FIG. 45 is a side view of the operative element shown in
FIG. 44 in a collapsed condition;
[0068] FIG. 46 is a perspective view of an operative element that
is deployed for use over a flexible endoscope, shown in a collapsed
condition;
[0069] FIG. 47 is a perspective view of the operative element shown
in FIG. 48 in an expanded condition and with the electrodes
extended for use;
[0070] FIG. 48 is an enlarged view of the operative element shown
in FIG. 47, when expanded into contact with muscosal tissue in the
cardia and with the electrodes extended to create lesions in the
smooth muscle of the cardia;
[0071] FIG. 49 is an end view of the operative element taken
generally along line 49-49 in FIG. 48, as viewed from the retroflex
endoscope over which the operative element is deployed for use;
[0072] FIG. 50 is a perspective view of the operative element of
the type shown in FIG. 47, deployed over a flexible endoscope, and
including a transparent region within the operative element to
permit endoscopic viewing from within the operative element;
[0073] FIG. 51 is a perspective view of the operative element shown
in FIG. 50, with the endoscope positioned within the operative
element for viewing;
[0074] FIG. 52 is an enlarged view of an operative element
comprising a mechanically expandable basket deployed over a
flexible endoscope and with the electrodes penetrating the lower
esophageal sphinter to create lesions;
[0075] FIG. 53 is a perspective view of an operative element for
treating body sphincters and adjoining tissue regions, shown in an
expanded condition with eight electrodes extended for use;
[0076] FIG. 54 is a perspective view of an operative element for
treating body sphincters and adjoining tissue regions, shown in an
expanded condition and four closely spaced electrodes extended for
use;
[0077] FIG. 55 a perspective distal facing view of an operative
element for treating body sphincters and adjoining tissue regions,
shown a spine structure with cooling and aspiration ports located
in the spines;
[0078] FIG. 56 a perspective proximal facing view of an operative
element shown in FIG. 56;
[0079] FIG. 57 is a perspective view of a handle for manipulating
the operative element shown in FIGS. 55 and 56;
[0080] FIG. 58A a perspective view of an operative element for
treating body sphincters and adjoining tissue regions, shown a
spine structure with cooling ports located in the spines and
aspiration ports located in an interior lumen;
[0081] FIG. 58B a perspective view of an operative element for
treating body sphincters and adjoining tissue regions, shown a
spine structure with an underlying expandable balloon structure
having pin hole ports which weep cooling liquid about the
electrodes;
[0082] FIG. 59 a perspective view of an operative element for
treating body sphincters and adjoining tissue regions, shown a
spine structure with cooling ports located in the spines and an
aspiration port located in its distal tip;
[0083] FIG. 60 a perspective view of the operative element shown in
FIG. 59, deployed over a guide wire that passes through its distal
tip;
[0084] FIG. 61 is a perspective view of a handle for manipulating
the operative element over the guide wire, as shown in FIG. 60;
[0085] FIG. 62 a perspective view of an operative element for
treating body sphincters and adjoining tissue regions, deployed
through an endoscope;
[0086] FIG. 63 is a perspective view of an extruded tube that, upon
further processing, will form an expandable basket structure;
[0087] FIG. 64 is a perspective view of the extruded tube shown in
FIG. 62 with slits formed to create an expandable basket
structure;
[0088] FIG. 65 is the expandable basket structure formed after
slitting the tube shown in FIG. 63;
[0089] FIG. 66 is a side section view of the esophagus, showing the
folds of mucosal tissue;
[0090] FIG. 67 is a perspective view of a device for treating body
sphincters and adjoining tissue regions, which applies a vacuum to
mucosal tissue to stabilize and present the tissue for the
deployment of electrodes delivered by a rotating mechanism;
[0091] FIG. 68 is a section view of the rotating mechanism for
deploying electrodes, taken generally along line 68-68 in FIG. 67
with the electrodes withdrawn;
[0092] FIG. 69 is a view of the rotating mechanism shown in FIG.
68, with a vacuum applied to muscosal tissue and the electrodes
extended;
[0093] FIG. 70 is a perspective view of a device for treating body
sphincters and adjoining tissue regions, which applies a vacuum to
mucosal tissue to stabilize and present the tissue for the
deployment of straight electrodes;
[0094] FIG. 71 is a side section view of the electrode deployment
mechanism of the device shown in FIG. 70;
[0095] FIGS. 72A and 72B are, respectively, left and right
perspective views of an integrated device for treating body
sphincters and adjoining tissue regions, and having graphical user
interface;
[0096] FIG. 73 is a front view of the device shown in FIGS. 72A and
72B showing the components of the graphical user interface;
[0097] FIG. 74 is a view of the graphical user interface shown in
FIG. 73 showing the Standby screen before connection of a treatment
device;
[0098] FIG. 75 is a view of the graphical user interface shown in
FIG. 73 showing the Standby screen after connection of a treatment
device;
[0099] FIG. 76 is a view of the graphical user interface shown in
FIG. 73 showing the Standby screen after connection of a treatment
device and after an electrode channel has been disabled by
selection;
[0100] FIG. 77 is a view of the graphical user interface shown in
FIG. 73 showing the Ready screen;
[0101] FIG. 78 is a view of the graphical user interface shown in
FIG. 73 showing the Ready screen while priming of cooling liquid
takes place;
[0102] FIG. 79 is a view of the graphical user interface shown in
FIG. 73 showing the RF-On screen;
[0103] FIG. 80 is a view of the graphical user interface shown in
FIG. 73 showing the RF-On screen after an electrode channel has
been disabled due to an undesired operating condition;
[0104] FIG. 81 is a view of the graphical user interface shown in
FIG. 73 showing the Pause screen;
[0105] FIG. 82 is a schematic view of the control architecture that
the integrated device and associated graphical user interface shown
in FIGS. 72A, 72B, and 73 incorporate; and
[0106] FIG. 83 is an anatomic view of the esophagus and stomach,
with portions broken away and in section, showing the location of a
composite lesion pattern effective in treating GERD.
[0107] The invention may be embodied in several forms without
departing from its spirit or essential characteristics. The scope
of the invention is defined in the appended claims, rather than in
the specific description preceding them. All embodiments that fall
within the meaning and range of equivalency of the claims are
therefore intended to be embraced by the claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0108] This Specification discloses various catheter-based systems
and methods for treating dysfunction of sphincters and adjoining
tissue regions in the body. The systems and methods are
particularly well suited for treating these dysfunctions in the
upper gastrointestinal tract, e.g., in the lower esophageal
sphincter and adjacent cardia of the stomach. For this reason, the
systems and methods will be described in this context.
[0109] Still, it should be appreciated that the disclosed systems
and methods are applicable for use in treating other dysfunctions
elsewhere in the body, which are not necessarily sphincter-related.
For example, the various aspects of the invention have application
in procedures requiring treatment of hemorrhoids, or incontinence,
or restoring compliance to or otherwise tightening interior tissue
or muscle regions. The systems and methods that embody features of
the invention are also adaptable for use with systems and surgical
techniques that are not necessarily catheter-based.
[0110] I. Anatomy of the Lower Esopageal Sphincter Region
[0111] As FIG. 1 shows, the esophagus 10 is a muscular tube that
carries food from the mouth to the stomach 12. The muscles in the
walls of the esophagus 10 contract in a wavelike manner, moving the
food down to the stomach 12. The interior wall of the esophagus
includes glands that secrete mucus, to aid in the movement of food
by providing lubrication. The human esophagus is about twenty-five
centimeters long.
[0112] The stomach 12, located in the upper left hand side of the
abdomen, lays between the esophagus 10 and the small intestine 14.
In people and most animals, the stomach 12 is a simple baglike
organ. A human being's stomach is shaped much like a J.
[0113] The average adult stomach can hold a little over one quart
(0.95 liter). The stomach 12 serves as a storage place for food.
Food in the stomach 12 is discharged slowly into the intestines 14.
The stomach 12 also helps digest food.
[0114] The upper end of the stomach connects with the esophagus 10
at the cardiac notch 16, at the top of the J-shape. The muscular
ring called the lower esophageal sphincter 18 surrounds the opening
between the esophagus 10 and the stomach 12. The funnel-shaped
region of the stomach 12 immediately adjacent to the sphincter 18
is called the cardia 20. The cardia 20 comprises smooth muscle. It
is not a sphincter.
[0115] The lower esophageal sphincter 18 relaxes, or opens, to
allow swallowed food to enter the stomach 12. The lower esophageal
sphincter 18, however, is normally closed, to keep the stomach 12
contents from flowing back into the esophagus 10.
[0116] Another sphincter, called the pyloric sphincter 22,
surrounds the duodenal opening of the stomach 12. The pyloric
sphincter 22 keeps non-liquid food material in the stomach 12 until
it is processed into a more flowable, liquid form. The time that
the stomach 12 retains food varies. Usually, the stomach 12 empties
in three to five hours.
[0117] In a person suffering from GERD, the lower esophageal
sphincter 18 is subject to spontaneous relaxation. The sphincter 18
opens independent of the normal swallowing function. Acidic stomach
contents surge upward into the esophagus 10, causing pain,
discomfort, and damage the mucosal wall of the esophagus 10.
[0118] The stomach 12 distends to accommodate various food volumes.
Over time, stomach distention can stretch the cardia 20 or
otherwise cause loss of compliance in the cardia 20. Loss of
compliance in the cardia 20 can also pull the lower esophageal
sphincter 18 open when the stomach 12 is distended, even absent
sphincter muscle relaxation. The same undesired results occur:
acidic stomach contents can surge upward into the esophagus 10 with
the attendant undesired consequences.
[0119] It should be noted that the views of the esophagus and
stomach shown in FIG. 1 and elsewhere in the drawings are not
intended to be strictly accurate in an anatomic sense. The drawings
show the esophagus and stomach in somewhat diagrammatic form to
demonstrate the features of the invention.
[0120] II. Systems for Sphincters or Adjoining Tissue Regions
[0121] A. System Overview
[0122] FIG. 2 shows a system 24 for diagnosing and/or treating
dysfunction of the lower esophageal sphincter 18 and/or the
adjoining cardia 20 of the stomach 12.
[0123] The system 24 includes a treatment device 26. The device 26
includes a handle 28 made, e.g., from molded plastic. The handle 28
carries a flexible catheter tube 30. The catheter tube 30 can be
constructed, for example, using standard flexible, medical grade
plastic materials, like vinyl, nylon, poly(ethylene), ionomer,
poly(urethane), poly(amide), and poly(ethylene terephthalate). The
handle 28 is sized to be conveniently held by a physician, to
introduce the catheter tube 30 into the esophagus 10. The details
of using the treatment device 28 will be described later.
[0124] The handle 28 and the catheter tube 30 can form an
integrated construction intended for a single use and subsequent
disposal as a unit. Alternatively, the handle 28 can comprise a
nondisposable component intended for multiple uses. In this
arrangement, the catheter tube 30, and components carried at the
end of the catheter tube 30 (as will be described), comprise a
disposable assembly, which the physician releasably connects to the
handle 28 at time of use and disconnects and discards after use.
The catheter tube 30 can, for example, include a male plug
connector that couples to a female plug receptacle on the handle
28.
[0125] The system 24 may include an esophageal introducer 32. The
esophageal introducer 32 is made from a rigid, inert plastic
material, e.g., poly(ethylene) or polyvinyl chloride. As will be
described later, the introducer 32 aids in the deployment of the
catheter tube 30 into the esophagus 10 through the mouth and throat
of a patient.
[0126] Alternatively, the catheter tube 30 may be deployed over a
guide wire through the patient's mouth and pharynx, and into the
esophagus 10, without use of an introducer 32, as will be described
later. Still alternatively, the catheter tube 30 may be passed
through the patient's mouth and pharynx, and into the esophagus 10,
without use of either a guide wire or introducer 32.
[0127] The catheter tube 30 has a distal end 34, which carries an
operative element 36. The operative element 36 can take different
forms and can be used for either therapeutic purposes, or
diagnostic purposes, or both.
[0128] The catheter tube 30 can carry a protection sheath 472 (see
FIG. 2) for the operative element 36. The sheath 472 slides along
the catheter tube 30 (as indicated by arrows 473 in FIG. 2) between
a forward position enclosing the operative element 36 and a
rearward position free of the operative element 36. When in the
forward position, the sheath 472 prevents contact between tissue
and the operative element 36, thereby aiding in the deployment and
removal of the operative element 36 through the patient's mouth and
pharynx. When in the rearward position, the sheath 472 frees the
operative element 36 for use.
[0129] As will be described in greater detail later, the operative
element 36 can support, for example, a device for imaging body
tissue, such as an endoscope, or an ultrasound transducer. The
operative element 36 can also support a device to deliver a drug or
therapeutic material to body tissue. The operative element 36 can
also support a device for sensing a physiological characteristic in
tissue, such as electrical activity, or for transmitting energy to
stimulate or form lesions in tissue.
[0130] According to the invention, one function that the operative
element 36 shown in the illustrated embodiment performs is to apply
energy in a selective fashion to a targeted sphincter or other body
region, which, for the purpose of illustration, are identified as
the lower esophageal sphincter 18, or cardia 20, or both. The
applied energy creates one or more lesions, or a prescribed pattern
of lesions, below the mucosal surface of the esophagus 10 or cardia
20. The subsurface lesions are formed in a manner that preserves
and protects the mucosal surface against thermal damage.
[0131] It has been discovered that natural healing of the
subsurface lesions leads to a physical tightening of the sphincter
18 and/or adjoining cardia 20. The subsurface lesions can also
result in the interruption of aberrant electrical pathways that may
cause spontaneous sphincter relaxation. In any event, the treatment
can restore normal closure function to the sphincter 18.
[0132] In this arrangement, the system 24 includes a generator 38
to supply the treatment energy. In the illustrated embodiment, the
generator 38 supplies radio frequency energy, e.g., having a
frequency in the range of about 400 kHz to about 10 mHz. Of course,
other forms of energy can be applied, e.g., coherent or incoherent
light; heated or cooled fluid; resistive heating; microwave;
ultrasound; a tissue ablation fluid; or cryogenic fluid.
[0133] A cable 40 extending from the proximal end of the handle 28
terminates with an electrical connector 42. The cable 40 is
electrically coupled to the operative element 36, e.g., by wires
that extend through the interior of the handle 28 and catheter tube
30. The connector 42 plugs into the generator 38, to convey the
generated energy to the operative element 36.
[0134] The system 24 also includes certain auxiliary processing
equipment. In the illustrated embodiment, the processing equipment
comprises an external fluid delivery apparatus 44 and an external
aspirating apparatus 46.
[0135] The catheter tube 30 includes one or more interior lumens
(not shown) that terminate in fittings 48 and 50, located on the
handle 28. One fitting 40 connects to the fluid delivery apparatus
44, to convey processing fluid for discharge by or near the
operative element 36. The other fitting 50 connects to the
aspirating apparatus 46, to convey aspirated material from or near
from the operative element 36 for discharge.
[0136] The system 24 also includes a controller 52. The controller
52, which preferably includes a central processing unit (CPU), is
linked to the generator 38, the fluid delivery apparatus 44, and
the aspirating apparatus 46. Alternatively, the aspirating
apparatus 46 can comprise a conventional vacuum source typically
present in a physician's suite, which operates continuously,
independent of the controller 52.
[0137] The controller 52 governs the power levels, cycles, and
duration that the radio frequency energy is distributed to the
operative element 36, to achieve and maintain power levels
appropriate to achieve the desired treatment objectives. In tandem,
the controller 52 also governs the delivery of processing fluid
and, if desired, the removal of aspirated material.
[0138] The controller 52 includes an input/output (I/O) device 54.
The I/O device 54 allows the physician to input control and
processing variables, to enable the controller to generate
appropriate command signals. The I/O device 54 also receives real
time processing feedback information from one or more sensors
associated with the operative element (as will be described later),
for processing by the controller 52, e.g., to govern the
application of energy and the delivery of processing fluid. The I/O
device 54 also includes a graphical user interface (GUI), to
graphically present processing information to the physician for
viewing or analysis. Further details regarding the GUI will be
provided later.
[0139] B. Operative Elements
[0140] The structure of the operative element 36 can vary. Various
representative embodiments will be described.
[0141] (i) Bipolar Devices
[0142] In the embodiment shown in FIGS. 3 to 7, the operative
element 36 comprises a three-dimensional basket 56. The basket 56
includes one or more spines 58, and typically includes from four to
eight spines 58, which are assembled together by a distal hub 60
and a proximal base 62. In FIG. 3, the spines 58 are equally
circumferentially spaced apart in side-by-side pairs.
[0143] Each spine 58 preferably comprises a flexible tubular body
made, e.g. from molded plastic, stainless steel, or nickel titanium
alloy. The cross sectional shape of the spines 58 can vary,
possessing, e.g., a circular, elliptical, square, or rectilinear
shape. In the illustrated embodiment, the spines 58 possess a
rectilinear shape to resist twisting. Further examples of specific
configurations for the spines 58 will be provided later.
[0144] Each spine 58 can be surrounded by a sleeve 64 (see FIG. 7)
that is preferably textured to impart friction. Candidate materials
for the sleeve 64 include knitted Dacron.RTM. material and
Dacron.RTM. velour.
[0145] Each spine 58 carries an electrode 66 (see FIGS. 5 and 7).
In the illustrated embodiment, each electrode 66 is carried within
the tubular spine 58 for sliding movement. Each electrode 66 slides
from a retracted position, withdrawn in the spine 58 (shown in
FIGS. 3, 4, and 6), and an extended position, extending outward
from the spine 58 (see FIGS. 5 and 7) through a hole in the spine
58 and sleeve 64.
[0146] A push-pull lever 68 on the handle 28 is coupled by one or
more interior wires to the sliding electrodes 66. The lever 68
controls movement electrodes between the retracted position (by
pulling rearward on the lever 68) and the extended position (by
pushing forward on the lever 68).
[0147] The electrodes 66 can be formed from various energy
transmitting materials. In the illustrated embodiment, for
deployment in the esophagus 10 or cardia 20, the electrodes 66 are
formed from nickel titanium. The electrodes 66 can also be formed
from stainless steel, e.g., 304 stainless steel, or, as will be
described later, a combination of nickel titanium and stainless
steel. The electrodes 66 have sufficient distal sharpness and
strength to penetrate a desired depth into the smooth muscle of the
esophageal or cardia 20 wall. The desired depth can range from
about 4 mm to about 5 mm.
[0148] To further facilitate penetration and anchoring in the
esophagus 10 or cardia 20, each electrode 66 is preferably biased
with a bend. Movement of the electrode 66 into the spine 58
overcomes the bias and straightens the electrode 66.
[0149] In the illustrated embodiment (see FIG. 5), each electrode
66 is normally biased with an antegrade bend (i.e., bending toward
the proximal base 62 of the basket 56). Alternatively, each
electrode 66 can be normally biased toward an opposite retrograde
bend (i.e., bending toward the distal hub 60 of the basket 58).
[0150] As FIG. 7 shows, an electrical insulating material 70 is
coated about the proximal end of each electrode 66. For deployment
in the esophagus 10 or cardia 20, the length of the material 70
ranges from about 80 to about 120 mm. The insulating material 70
can comprise, e.g., a Polyethylene Terephthalate (PET) material, or
a polyimide or polyamide material. For deployment in the esophagus
10 or cardia 20, each electrode 66 preferably presents an exposed,
non-insulated conductive length of about 8 mm, providing an exposed
surface area at the distal end of each electrode 66 of preferably
about 0.1 mm.sup.2 to 100 cm.sup.2.
[0151] When the distal end of the electrode 66 penetrating the
smooth muscle of the esophageal sphincter 18 or cardia 20 transmits
radio frequency energy, the material 70 insulates the mucosal
surface of the esophagus 10 or cardia 20 from direct exposure to
the radio frequency energy. Thermal damage to the mucosal surface
is thereby avoided. As will be described later, the mucosal surface
can also be actively cooled during application of radio frequency
energy, to further protect the mucosal surface from thermal
damage.
[0152] The ratio between exposed and insulated regions on the
electrodes 66 affects the impedance of the electrodes 66 during
use. Generally speaking, the larger the exposed region is compared
to the insulated region, a lower impedance value can be expected,
leading to a fewer incidences of power shut-offs due to high
impedance.
[0153] Of course, a greater or lesser number of spines 58 and/or
electrodes 66 can be present, and the geometric array of the spines
58 and electrodes 66 can vary.
[0154] In the embodiment shown in FIG. 3, an expandable structure
72 comprising a balloon is located within the basket 56. The
balloon structure 72 can be made, e.g., from a Polyethylene
Terephthalate (PET) material, or a polyamide (non-compliant)
material, or a radiation cross-linked polyethylene (semi-compliant)
material, or a latex material, or a silicone material, or a C-Flex
(highly compliant) material. Non-compliant materials offer the
advantages of a predictable size and pressure feedback when
inflated in contact with tissue. Compliant materials offer the
advantages of variable sizes and shape conformance to adjacent
tissue geometries.
[0155] The balloon structure 72 presents a normally, generally
collapsed condition, as FIGS. 3 and 6 show). In this condition, the
basket 56 is also normally collapsed about the balloon structure
72, presenting a low profile for deployment into the esophagus
10.
[0156] To aid in the collapse of the basket 56 (see FIG. 8), one
end (hub 60 or base 62) of the basket 56 can be arranged to slide
longitudinally relative to the other end of the basket 56, which is
accordingly kept stationary. A stylet 74 attached to the slidable
end of the basket 56 (which, in FIG. 8, is the base 62) is
controlled, e.g., by a push-pull mechanism on the handle 28. The
stylet 74, when pulled, serves to move the ends 58 and 60 of the
basket 56 apart when the balloon structure 72 is collapsed. A full
collapse of the basket 56 is thereby possible (as FIG. 8 shows) to
minimize the overall profile of the basket 56 for passage through
the esophagus 10. The push-pull mechanism can include a lock to
hold the stylet 74 stationary, to maintain the basket 56 in the
fully collapsed condition during deployment.
[0157] The catheter tube 30 includes an interior lumen, which
communicates with the interior of the balloon structure 72. A
fitting 76 (e.g., a syringe-activated check valve) is carried by
the handle 28. The fitting 76 communicates with the lumen. The
fitting 76 couples the lumen to a syringe 78 (see FIGS. 4 and 5).
The syringe 78 injects fluid under pressure through the lumen into
the balloon structure 72, causing its expansion.
[0158] Expansion of the balloon structure 72 urges the basket 56 to
open and expand (as FIGS. 4, 5, and 7 show). The force exerted by
the balloon structure 72, when expanded, is sufficient to exert an
opening force upon the tissue surrounding the basket 56.
Preferably, for deployment in the esophagus 10 or cardia 20, the
magnitude of the force exerted by the balloon structure 72 is
between about 0.01 to 0.5 lbs.
[0159] For deployment in the lower esophageal sphincter 18, the
diameter of the balloon structure 72, when expanded, can be
optimized at about 2 cm to 3 cm. For deployment in the cardia 20,
the diameter of the balloon structure 72, when expanded, can be
optimized at about 4 cm to about 6 cm.
[0160] In the illustrated embodiment, the controller 52 conditions
selected pairs of electrodes 66 to operate in a bipolar mode. In
this mode, one of the electrodes comprises the transmitter and the
other electrode comprises the return for the transmitted energy.
The bipolar electrode pairs can comprise adjacent side-by-side
electrodes 66 on a given spine, or electrodes 66 spaced more widely
apart on different spines.
[0161] In the illustrated embodiment (see FIG. 7), each electrode
66 carries at least one temperature sensor 80. Each electrode can
carry two temperature sensors 80, one to sense temperature
conditions near the exposed distal end of the electrode 66, and the
other to sense temperature conditions in the insulated material 70.
Preferably, the second temperature sensor 80 is located on the
corresponding spine 58, which rests against the muscosal surface
when the balloon structure 72 is inflated.
[0162] In use (see FIGS. 9 to 19), the patient lies awake in a
reclined or semi-reclined position. If used, the physician inserts
the esophageal introducer 32 through the throat and partially into
the esophagus 10. The introducer 32 is pre-curved to follow the
path from the mouth, through the pharynx, and into the esophagus
10. The introducer 32 also includes a mouth piece 82, on which the
patient bites to hold the introducer 32 in position. The introducer
32 provides an open, unobstructed path into the esophagus 10 and
prevents spontaneous gag reflexes during the procedure.
[0163] As before explained, the physician need not use the
introducer 32. In this instance, a simple mouth piece 82, upon
which the patient bites, is used.
[0164] The physician preferably first conducts a diagnostic phase
of the procedure, to localize the site to be treated. As FIGS. 9
and 10 show, a visualization device can be used for this purpose.
The visualization device can comprise an endoscope 84, or other
suitable visualizing mechanism, carried at the end of a flexible
catheter tube 86. The catheter tube 86 for the endoscope 84
includes measured markings 88 along its length. The markings 88
indicate the distance between a given location along the catheter
tube 86 and the endoscope 84.
[0165] As FIGS. 9 and 10 show, the physician passes the catheter
tube 86 through the patient's mouth and pharynx, and into the
esophagus 10, while visualizing through the endoscope 84. Relating
the alignment of the markings 88 to the mouth piece 82, the
physician can gauge, in either relative or absolute terms, the
distance between the patient's mouth and the endoscope 84 in the
esophagus 10. When the physician visualizes the desired treatment
site (lower esophageal sphincter 18 or cardia 20) with the
endoscope 84, the physician records the markings 88 that align with
the mouth piece 82.
[0166] The physician next begins the treatment phase of the
procedure. As FIGS. 11 and 12 show, the physician passes the
catheter tube 30 carrying the operative element 36 through the
introducer 32. For the passage, the expandable balloon structure 72
is in its collapsed condition, and the electrodes 66 are in their
retracted position. The physician can keep the endoscope 84
deployed for viewing the deployment of the operative element 36,
either separately deployed in a side-by-side relationship with the
catheter tube 30, or (as will be described later) by deployment
through a lumen in the catheter tube 30 or deployment of the
structure 72 through a lumen in the endoscope 84 itself. If there
is not enough space for side-by-side deployment of the endoscope
84, the physician deploys the endoscope 84 before and after
deployment of the structure 72.
[0167] In the illustrated embodiment, the catheter tube 30 includes
measured markings 90 along its length. The measured markings 90
indicate the distance between a given location along the catheter
tube 30 and the operative element 36. The markings 90 on the
catheter tube 30 correspond in spacing and scale with the measured
markings along the endoscope catheter tube 86. The physician can
thereby relate the markings 90 on the catheter tube 30 to gauge, in
either relative or absolute terms, the location of the operative
element 36 inside the esophagus 10. When the markings 90 indicate
that the operative element 36 is at the desired location (earlier
visualized by the endoscope 84), the physician stops passage of the
operative element 36. The operative element 36 is now located at
the site targeted for treatment.
[0168] In FIG. 12, the targeted site is shown to be the lower
esophageal sphincter 18. In FIG. 15, the targeted site is shown to
be the cardia 20 of the stomach 12.
[0169] Once located at the targeted site, the physician operates
the syringe 78 to convey fluid or air into the expandable balloon
structure 72. The structure 72, and with it, the basket 56, expand,
to make intimate contact with the mucosal surface, either with the
sphincter (see FIG. 13) or the cardia 20 (FIG. 16). The expanded
balloon structure 72 serves to temporarily dilate the lower
esophageal sphincter 18 or cardia 20, to remove some or all the
folds normally present in the mucosal surface. The expanded balloon
structure 72 also places the spines 58 in intimate contact with the
mucosal surface.
[0170] The physician pushes forward on the lever 68 to move the
electrodes 66 into their extended position. The electrodes 66
pierce and pass through the mucosal tissue into the smooth muscle
tissue of the lower esophageal sphincter 18 (FIG. 14) or cardia 20
(FIGS. 17 and 18).
[0171] The physician commands the controller 52 to apply radio
frequency energy between the transmitting and receiving electrodes
66 in each pair. The energy can be applied simultaneously by all
pairs of electrodes 66, or in any desired sequence.
[0172] The energy ohmically heats the smooth muscle tissue between
the transmitting and return electrodes 66. The controller 52
samples temperatures sensed by the sensors 80 to control the
application of energy. When each electrode 66 in a given pair
carries at least one temperature sensor 80, the controller 52 can
average the sensed temperature conditions or select the maximum
temperature condition sensed for control purposes.
[0173] The controller 52 processes the sensed temperatures in a
feedback loop to control the application of energy. The GUI can
also display the sensed temperatures and the applied energy levels.
Alternatively, the physician can manually control the energy levels
based upon the temperature conditions displayed on the GUI.
[0174] Preferably, for a region of the lower esophageal sphincter
18 or cardia 20, energy is applied to achieve tissue temperatures
in the smooth muscle tissue in the range of 55.degree. C. to
95.degree. C. In this way, lesions can typically be created at
depths ranging from one to four millimeters below the muscosal
surface. Typical energies range, e.g., between 100 and 1000 joules
per electrode pair.
[0175] It is desirable that the lesions possess sufficient volume
to evoke tissue healing processes accompanied by intervention of
fibroblasts, myofibroblasts, macrophages, and other cells. The
healing processes results in a contraction of tissue about the
lesion, to decrease its volume or otherwise alter its biomechanical
properties. The healing processes naturally tighten the smooth
muscle tissue in the sphincter 18 or cardia 20. The bipolar nature
of the energy path between the electrodes 66 creates, for a given
amount of energy, lesions of greater volume than is typically
created in a monopolar fashion.
[0176] To create greater lesion density in a given targeted tissue
area, it is also desirable to create a pattern of multiple lesions,
e.g., in rings along the targeted treatment site in the lower
esophageal sphincter 18 or cardia 20.
[0177] Various lesion patterns 92 can be achieved. A preferred
pattern (shown in FIG. 20 for the cardia 20) comprises several
rings 94 of lesions 96 about one centimeter apart, each ring 94
comprising at least eight lesions 96. For example, a preferred
pattern 92 comprise six rings 94, each with eight lesions 96. In
the cardia 20, as FIG. 20 shows, the rings 94 are concentrically
spaced about the opening funnel of the cardia 20. In the lower
esophageal sphincter 18, the rings 94 are axially spaced along the
esophagus 10.
[0178] The physician can create a given ring pattern 92 by
expanding the balloon structure 72 and extending the electrodes 66
at the targeted treatment site, to form a first set of four
lesions. The physician then withdraws the electrodes 66, collapses
the balloon structure 72, and rotates the catheter tube 30 by a
desired amount. The physician then again expands the structure 72
and again extends the electrodes 66, to achieve a second set of
four lesions. The physician repeats this sequence until a desired
ring 94 of lesions 96 is formed. Additional rings 94 of lesions 96
can be created by advancing the operative element axially, gauging
the ring separation by the markings 90 on the catheter tube 30.
[0179] Other, more random or eccentric patterns of lesions can be
formed to achieve the desired density of lesions within a given
targeted site.
[0180] The bipolar operative element 36 can be used in the manner
described to treat both the cardia 20 and the lower esophageal
sphincter 18 in a single procedure. Alternatively, the operative
element 36 can be used in the manner described to treat either the
cardia 20 or the lower esophageal sphincter 18 individually.
[0181] In one embodiment, at least one spine 58 (and preferably all
spines) includes an interior lumen 98 (see FIG. 7). The fluid
delivery apparatus 44 conveys processing fluid F through the lumen
98 for discharge at the treatment site. The processing fluid F can
comprise, e.g., saline or sterile water, to cool the mucosal
surface while energy is being applied by the electrode 66 to
ohmically heat muscle beneath the surface.
[0182] In this arrangement (see FIG. 5), the catheter tube 30
includes a distal tail 100, which extends beyond the hub 60 of the
basket 56. An interior lumen 102 extends through the tail 100 and
the interior of the balloon structure 72 to connect to the fitting
48. The aspirating apparatus 46 draws aspirated material and the
processing fluid through this lumen 102 for discharge. This
arrangement provides self-contained aspiration for the operative
element 36.
[0183] In an alternative embodiment suited for treatment of the
lower esophageal sphincter 18 outside the stomach 12 (see FIG. 11),
the mouth piece 82 of the esophageal introducer 32, if used,
includes an aspiration port 104. The aspiration apparatus 46 is
coupled to this port 104. In this arrangement, processing fluid
introduced at the treatment site is drawn through the introducer 32
surrounding the catheter tube 30 and into the aspiration apparatus
46 for discharge. In this embodiment, the operative element 36 need
not include the self contained, interior aspiration lumen 102.
[0184] (ii) Structures Shaped for the Cardia
[0185] As FIG. 1 shows, the cardia 20 presents a significantly
different topology than the lower esophageal sphincter 18. First,
the surface area of the cardia 20 is larger than the lower
esophageal sphincter 18. Second, the surface area of the cardia 20
expands with distance from the lower esophageal sphincter 18. The
cardia 20 is therefore "funnel" shaped, compared to the more
tubular shape of the lower esophageal sphincter 18.
[0186] The different topologies can be accommodated by using a
family of operative elements having different shapes. One such
operative element has a size and geometry better suited for
deployment in the lower esophageal sphincter 18 than the cardia 20,
if desired). Another such operative element has a larger size and
different geometry better suited for deployment in the cardia 20
than the lower esophageal sphincter. However, it is preferred to
provide a single operative element that can be effectively deployed
in both regions.
[0187] The location and the orientation of optimal, intimate
contact between an operative element and the targeted tissue also
differ in the cardia 20, compared to the lower esophageal sphincter
18. In the lower esophageal sphincter 18, optimal, intimate contact
occurs generally about the mid-region of the operative element, to
thereby conform to the generally tubular shape of the sphincter 18.
In the cardia 20, optimal, intimate contact occurs generally more
about the proximal end of operative device, to thereby conform to
the funnel shape of the cardia 20.
[0188] (a) Proximally Enlarged, Shaped Structures
[0189] FIGS. 21 to 23 show an operative element 106 having a shaped
geometry and electrode configuration well suited for use in the
cardia 20. The operative element 106 shares many features of the
operative element 36 shown in FIG. 5, and common reference numbers
are thus assigned.
[0190] Like the previously described element 36, the operative
element 106 comprises an array of spines 58 forming a basket 56,
which is carried at the distal end of a catheter tube 30. Like the
previously described element 36, the operative element 106 includes
electrodes 66 on the spines 58 that can be retracted (FIG. 21) or
extended (FIG. 22). As illustrated, the electrodes 66 are likewise
bent in an antegrade direction.
[0191] Like the previously described element 36, the operative
element 106 includes an inner balloon structure 72 that expands to
open the basket 56 and place it in intimate contact with the cardia
20 for extension of the electrodes 66.
[0192] The balloon structure 72, when expanded, as shown in FIG.
22, possesses a preformed shape achieved e.g., through the use of
conventional thermoforming or blow molding techniques. The
structure 72 possesses a "pear" shape, being more enlarged at its
proximal end than at its distal end. This preformed pear shape
presents an enlarged proximal surface for contacting the cardia 20
(see FIG. 23). The preformed pear shape better conforms to the
funnel shaped topography of the cardia 20 than a circular shape.
The pear shape, when in intimate contact with the cardia 20,
establishes a secure anchor point for the deployment of the
electrodes 66.
[0193] As also shown in FIGS. 22 and 23, the electrodes 66
themselves are repositioned to take advantage of the pear shape of
the underlying balloon structure 72. The electrodes 66 are
positioned proximally closer to the enlarged proximal base of the
structure 72 than to its distal end. As FIGS. 24 and 25 show, the
proximally located electrodes 66 can also be bent in a retrograde
bent direction on the pear-shaped element 106.
[0194] In use (as FIGS. 23 and 25 show), the physician deploys the
operative element 106 into the stomach 12. The physician expands
the element 106 and then pulls rearward on the catheter tube 30.
This places the enlarged proximal base of the structure 106 in
contact with the cardia 20. The physician next extends the
electrodes 66 into the cardia 20 and proceeds with the ablation
process. Multiple lesion patterns can be created by successive
extension and retraction of the electrodes, accompanied by rotation
and axial movement of the catheter tube 30 to reposition the
structure 106.
[0195] If enough space is present, the physician can retroflex an
endoscope, also deployed in the stomach 12, to image the cardia 20
as deployment of the electrodes 66 and lesion formation occur.
Typically, however, there is not enough space for side-by-side
deployment of the endoscope, and the physician views the cardia 20
before and after the lesion groups are formed.
[0196] As FIGS. 23 and 25 show, the purposeful proximal shaping of
the operative element 106 and the proximal location of the
antegrade or retrograde electrodes 66 make the operative element
106 well suited for use in the cardia 20.
[0197] In FIGS. 22 and 24, the electrodes 66 are not arranged in
bipolar pairs. Instead, for purposes of illustration, the
electrodes 66 are shown arranged in singular, spaced apart
relation. In this arrangement, the electrodes 66 are intended for
monopolar operation. Each electrode 66 serves as a transmitter of
energy, and an indifferent patch electrode (not shown) serves as a
common return for all electrodes 66. It should be appreciated,
however, the operative element 106 could include bipolar pairs of
electrodes 66 as shown in FIG. 5, if desired.
[0198] (b) Disk Shaped Expandable Structures
[0199] FIG. 26 shows another operative element 108 shaped for
deployment in the cardia 20. This element 108 shares many features
with the element 36 shown in FIG. 5, and common reference numbers
have also been assigned.
[0200] In FIG. 26, the expandable balloon structure 72 within the
element 108 has been preformed, e.g., through the use of
conventional thermoforming or blow molding techniques, to present a
disk or donut shape. The disk shape also provides an enlarged
proximal surface for contacting the cardia 20, to create a secure
anchor for the deployment of the electrodes 66.
[0201] The physician deploys the operative element 108 into the
stomach 12, preferably imaging the cardia 20 as deployment occurs.
The physician expands the disk-shaped element 108 and pulls
rearward on the catheter tube 30, to place the element 108 in
contact with the cardia 20. The physician extends the electrodes
into the cardia 20 and proceeds with the ablation process. Lesion
patterns are formed by successive extension and retraction of the
electrodes 66, accompanied by rotation and axial movement of the
catheter tube 30.
[0202] As FIG. 26 shows, antegrade bent electrodes 66 are
proximally mounted about the disk-shaped expandable element 108.
Retrograde bent electrodes could also be deployed.
[0203] (c) Complex Shaped Structures Providing Multiple Anchor
Points
[0204] FIGS. 27 and 28 show another operative element 110 having a
geometry well suited for deployment in the cardia 20. The balloon
structure 72 within the element 110 is preformed, e.g., through the
use of conventional thermoforming or blow molding techniques, to
possesses a complex peanut shape. The complex shape provides
multiple surface contact regions, both inside and outside the
cardia 20, to anchor the element 110 for deployment of the
electrodes 66.
[0205] In FIG. 27, a reduced diameter portion 112 of the expanded
structure 72 contacts the lower esophageal sphincter region. A
larger diameter main portion 114 of the expanded structure 72 rests
in intimate contact against the cardia 20 of the stomach 12.
[0206] In an alternative peanut shaped configuration (see FIG. 28),
the structure 72 includes a first reduced diameter portion 116 to
contact the esophagus 10 above the lower esophageal sphincter 18.
The structure 72 includes a second reduced portion 118 to contact
the lower esophageal sphincter 18 region of the esophagus 10. The
structure includes a third, larger diameter main portion 120 to
rest in intimate contact against the cardia 20 of the stomach
12.
[0207] The peanut shaped configurations shown in FIGS. 27 and 28
provide multiple points of support for operative element 110 both
inside and outside the stomach 12, to thereby stabilize the
electrodes.
[0208] In FIGS. 27 and 28, antegrade bent electrodes 66 are shown
deployed in the cardia 20. Retrograde bent electrodes could also be
deployed.
[0209] C. The Electrodes
[0210] (i) Electrode Shapes
[0211] Regardless of the shape of the operative element and its
region of deployment in the body, the electrodes 66 can be formed
in various sizes and shapes. As FIG. 30 shows, the electrodes 66
can possess a circular cross sectional shape. However, the
electrodes 66 preferably possess a cross section that provides
increased resistance to twisting or bending as the electrodes
penetrate tissue. For example, the electrodes 66 can possess a
rectangular cross section, as FIG. 32 shows. Alternatively, the
electrodes 66 can possess an elliptical cross section, as FIG. 31
shows. Other cross sections, e.g., conical or pyramidal, can also
be used to resist twisting.
[0212] The surface of the electrode 66 can, e.g., be smooth, or
textured, or concave, or convex. The preceding description
describes electrodes 66 bent in either an antegrade or retrograde
direction over an arc of ninety degrees or less. The bend provides
a secure anchorage in tissue. Retraction of the electrodes 66 into
the spines 58 overcomes the bias and straightens the electrode 66
when not in use.
[0213] In FIG. 29, the electrode 66 is biased toward a "pig-tail"
bend, which spans an arc of greater than ninety degrees. The
increased arc of the bend enhances the tissue-gripping force,
thereby providing a more secure anchorage in tissue. As before,
retraction of the electrodes 66 into the spines 58 overcomes the
bias and straightens the electrode 66 when not in use.
[0214] A given electrode 66 can comprise a hybrid of materials,
e.g., stainless steel for the proximal portion and nickel titanium
alloy for the distal portion. The nickel titanium alloy performs
best in a curved region of the electrode 66, due to its
super-elastic properties. The use of stainless steel in the
proximal portion can reduce cost, by minimizing the amount of
nickel titanium alloy required.
[0215] The different materials may be joined, e.g., by crimping,
swaging, soldering, welding, or adhesive bonding, which provide
electrical continuity between or among the various materials.
[0216] One or both of the materials may be flattened to an oval
geometry and keyed together to prevent mutual twisting. In a
preferred embodiment, the proximal portion comprises an oval
stainless steel tube, into which a distal curved region having a
round cross section and made of nickel titanium is slipped and
keyed to prevent mutual twisting.
[0217] (ii) Electrode Penetration Depth
[0218] The depth of electrode penetration can also be controlled,
to prevent puncture through the targeted tissue region.
[0219] In one embodiment, the push-pull lever 68 on the handle 28,
which controls movement electrodes 66, can include a rachet 118 or
detent mechanism (see FIG. 3) that provides a tactile indication of
electrode advancement. For each click of the rachet mechamism 118
as the lever 68 is moved forward or rearward, the physician knows
that the electrodes have traveled a set distance, e.g., 1 mm.
[0220] Alternatively, or in combination, the electrode 66 can carry
a limit collar 121 (see FIG. 33). The limit collar 121 contacts
surface tissue when a set maximum desired depth of electrode
penetration has been reached. The contact between the collar 121
and surface tissue resists further advancement of the electrode 66.
The physician senses the contact between the collar 121 and surface
tissue by the increased resistance to movement of the lever 68. The
physician thereby knows that the maximum desired depth of tissue
penetration has been reached and to extend the electrodes 66 no
further.
[0221] An electrical measurement can also be made to determine
penetration of an electrode 66 in tissue. For example, by applying
electrical energy at a frequency (e.g., 5 kHz) less than that
applied for lesion formation, impedance of a given electrode 66 can
be assessed. The magnitude of the impedance varies with the
existence of tissue penetration and the depth of tissue
penetration. A high impedance value indicates the lack of tissue
penetration. The impedance value is lowered to the extent the
electrode penetrates the tissue.
[0222] (iii) Movement of Electrodes
[0223] As before described, it is desirable to be able to create a
pattern of multiple lesions to create greater lesion density. The
previous discussions in this regard were directed to achieving
these patterns by successive extension and retraction of the
electrodes 66, accompanied by rotation and axial movement of the
catheter tube 30.
[0224] An alternative embodiment is shown in FIG. 34, which
achieves creation of lesion patterns movement without axial and, if
desired, rotational movement of the catheter tube 30. In this
embodiment, the basket 56 has an array of spines 58, as generally
shown, e.g., in FIG. 22 or 24. As FIG. 34 shows, each spine 58 in
the alternative embodiment includes an inner carrier 122 mounted
for axial sliding movement within a concentric outer sleeve 124. In
this arrangement, a push-pull stylet 126 controlled by another
lever on the handle (not shown) axially moves the carrier 122
within the outer sleeve 124 (as shown by arrows 125 in FIG.
34).
[0225] A tissue penetrating electrode 66 of the type already
described is supported by the carrier 122. The electrode 66 can be
moved by the operator (using the handle-mounted lever 68, as shown
in FIG. 5) from a retracted position within the carrier 122 and an
extended position, projecting from a guide hole 128 in the carrier
122 (which FIG. 34 shows). When in the extended position, the
electrode 66 also projects through a window 130 in the outer sleeve
124 for tissue penetration. The window 130 has a greater axial
length than the guide hole 128. The extended electrode 66 can
thereby be moved by moving the carrier 122 (as shown by arrows 127
in FIG. 34) and thereby positioned in a range of positions within
the window 130.
[0226] For example, in use, the physician moves the carrier 122 so
that the guide hole 128 is aligned with the leading edge of the
window 130. The push-pull stylet 126 can be controlled, e.g., with
a detent mechanism that stops forward advancement or otherwise
gives a tactile indication when this alignment occurs. External
markings on the handle can also visually provide this information.
The physician moves the electrodes 66 into their respective
extended position, to penetrate tissue. After energy sufficient to
form a first ring pattern of lesions is applied, the physician
withdraws the electrodes 66 into the carriers 122.
[0227] The physician now moves the electrodes 66 axially rearward,
without moving the catheter tube 30, by pulling the push-pull
stylet 126 rearward. If desired, the physician can rotate the
catheter tube 30 to achieve a different circumferential alignment
of electrodes 66. The detent mechanism or the like can click or
provide another tactile indication that the guide hole 128 in each
spine is aligned with a mid portion of the respective window 130.
Markings on the handle can also provide a visual indication of this
alignment. The physician extends the electrodes 66 through the
window 130. This time, the electrode 66 penetrate tissue in a
position axially spaced from the first ring of penetration. Energy
is applied sufficient to form a second ring pattern of lesions,
which likewise are axially spaced from the first ring. The
physician withdraws the electrodes 66 into the carriers.
[0228] The physician can now move the carriers 122 to move the
guide holes 128 to a third position at the trailing edge of each
window 130, still without axially moving the catheter tube 30. The
catheter tube 30 can be rotated, if desired, to achieve a different
circumferential orientation. The physician repeats the
above-described electrode deployment steps to form a third ring
pattern of lesions. The physician withdraws the electrodes 66 into
the carriers 122 and withdraws the basket 56, completing the
procedure.
[0229] As FIG. 35 shows, each carrier 122 can hold more than one
electrode 66. In this arrangement, the electrodes 66 on each
carrier 122 are extendable and retractable through axially
spaced-apart guide holes 128 in the carrier 122. In this
arrangement, the outer sleeve 124 includes multiple windows 130
registering with the electrode guide holes 128. In this
arrangement, the physician is able to simultaneously create
multiple ring patterns. Further, the physician can axially shift
the electrodes 66 and create additional ring patterns by shifting
the carrier 122, and without axial movement of the catheter tube
30.
[0230] In the foregoing descriptions, each spine 58 comprises a
stationary part of the basket 56. As FIGS. 36 and 37 show, an array
of movable spines 132, not joined to a common distal hub, can be
deployed along the expandable balloon structure 72. In FIGS. 36 and
37, the expandable structure 72 is shown to have a disk-shaped
geometry and is deployed in the cardia 20 of the stomach 12. Two
movable spines 132 are shown for the purpose of illustration, but
it should be appreciated that fewer or greater number of movable
spines 132 could be deployed.
[0231] In this embodiment, the proximal ends of the spines 132 are
coupled, e.g., to a push-pull stylet on the handle (not shown).
Under control of the physician, the spines 132 are advanced to a
desired position along the structure 72 in the tissue contact
region, as shown by arrows 133 in FIGS. 36 and 37. Each movable
spine 132 can carry a single electrode 66 (as FIG. 37 shows) or
multiple electrodes 66 (as shown in FIG. 36). Regardless, each
electrode 66 can be extended and retracted relative to the movable
spine 132.
[0232] In use, the physician positions the movable spines 132 and
deploys the electrode 66 or electrodes to create a first lesion
pattern in the contact region. By retracting the electrode 66 or
electrodes, the physician can relocate the movable spines 132 to
one or more other positions (with or without rotating the catheter
tube 30). By deploying the electrode 66 or electrodes in the
different positions by moving the spines 132, the physician can
form complex lesion patterns in the tissue contact region without
axial movement of the catheter tube 30.
[0233] In yet another alternative embodiment (see FIG. 38), an
operative element 134 can comprise a catheter tube 30 that carries
at its distal end a single mono-polar electrode 66 (or a bipolar
pair of electrodes), absent an associated expandable structure. The
distal end of the catheter tube 30 includes a conventional catheter
steering mechanism 135 to move the electrode 66 (or electrodes)
into penetrating contact with a desired tissue region, as arrows
137 in FIG. 38 show). The electrode 66 can carry a limit collar 121
(as also shown in FIG. 33) to resist advancement of the electrode
66 beyond a desired penetration depth. Using the operative element
134 shown in FIG. 38, the physician forms a desired pattern of
lesions by making a succession of individual mono-polar or bipolar
lesions.
[0234] (iv) Drug Delivery Through Electrodes
[0235] A given electrode 66 deployed by an operative device in a
sphincter or other body region can also be used to deliver drugs
independent of or as an adjunct to lesion formation. In this
arrangement, the electrode 66 includes an interior lumen 136 (as
FIG. 35 demonstrates for the purpose of illustration).
[0236] As before explained, a submucosal lesion can be formed by
injecting an ablation chemical through the lumen 136, instead of or
in combination with the application of ablation energy by the
electrode.
[0237] Any electrode 66 possessing the lumen 136 can also be used
to deliver drugs to the targeted tissue site. For example, tissue
growth factors, fibrosis inducers, fibroblast growth factors, or
sclerosants can be injected through the electrode lumen 136, either
without or as an adjunct to the application of energy to ablate the
tissue. Tissue bulking of a sphincter region can also be achieved
by the injection of collagen, dermis, cadaver allograft material,
or PTFE pellets through the electrode lumen 136. If desired, radio
frequency energy can be applied to the injected bulking material to
change its physical characteristics, e.g., to expand or harden the
bulking material, to achieve a desired effect.
[0238] As another example, the failure of a ring of muscle, e.g.,
the anal sphincter or the lower esophageal sphincter 18, called
achalasia, can also be treated using an electrode 66 having an
interior lumen 136, carried by an operative device previously
described. In this arrangement, the electrode 66 is deployed and
extended into the dysfunctional sphincter muscle. A selected
exotoxin, e.g., serotype A of the Botulinum toxin, can be injected
through the electrode lumen 136 to produce a flaccid paralysis of
the dysfunctional sphincter muscle.
[0239] For the treatment of achalasia of a given sphincter, the
electrode 66 carried by an operative device can also be conditioned
to apply stimulant energy to nerve tissue coupled to the
dysfunctional muscle. The stimulant energy provides an observable
positive result (e.g., a relaxation of the sphincter) when targeted
nerve tissue is in the tissue region occupied by the electrode 66.
the observable positive result indicates that position of the
electrode 66 should be maintained while applying ablation energy to
the nerve tissue. Application of the nerve ablation energy can
permanently eliminate the function of a targeted nerve branch, to
thereby inactivate a selected sphincter muscle. Further details of
the application of ablation energy to nerve tissue can be found in
co-pending application entitled "Systems And Methods For Ablating
Discrete Motor Nerve Regions."
[0240] (v) Surface Electrodes
[0241] As earlier mentioned, one of the complications of GERD is
the replacement of normal esophageal epithelium with abnormal
(Barrett's) epithelium. FIGS. 39 and 40 show an operative element
138 for the treatment of this condition.
[0242] The operative element 138 includes an expandable balloon
structure 140 carried at the distal end of a catheter tube 30. FIG.
39 shows the structure 140 deployed in a collapsed condition in the
lower esophageal sphincter 18, where the abnormal epithelium tissue
condition forms. FIG. 40 shows the structure 140 in an expanded
condition, contacting the abnormal epithelium tissue.
[0243] The structure 140 carries an array of surface electrodes
142. In the illustrated embodiment, the surface electrodes 142 are
carried by an electrically conductive wire 144, e.g., made from
nickel-titanium alloy material. The wire 144 extends from the
distal end of the catheter tube 30 and wraps about the structure
140 in a helical pattern. The electrodes 142 are electrically
coupled to the wire 144, e.g., by solder or adhesive.
Alternatively, the balloon structure 140 can have painted, coated,
or otherwise deposited on it solid state circuitry to provide the
electrical path and electrodes.
[0244] Expansion of the balloon structure 140 places the surface
electrodes 142 in contact with the abnormal epithelium. The
application of radio frequency energy ohmically heats the tissue
surface, causing necrosis of the abnormal epithelium. The desired
effect is the ablation of the mucosal surface layer (about 1 mm to
1.5 mm), without substantial ablation of underlying tissue. The
structure 140 is then collapsed, and the operative element 138 is
removed.
[0245] Absent chronic exposure to stomach 12 acid due to continued
spontaneous relaxation of the lower esophageal sphincter 18,
subsequent healing of the necrosed surface tissue will restore a
normal esophageal epithelium.
[0246] D. Electrode Structures to Minimize Lesion overlap
[0247] As before described, it is desirable to create one or more
symmetric rings of lesions with enough total volume to sufficiently
shrink the lower esophageal sphincter or cardia.
[0248] FIG. 83 shows a lesion pattern 500 that has demonstrated
efficacy in treating GERD. The lesion pattern 500 begins at the
Z-line 502, which marks the transition between esophageal tissue
(which is generally white in color) and stomach tissue (which is
generally pink in color). The tissue color change at or near the
Z-line 502 can be readily visualized using an endoscope.
[0249] The lower esophageal sphincter 18 (which is about 4 cm to 5
cm in length) extends above and below the Z-line 502. The Z-line
502 marks the high pressure zone of the lower esophageal sphincter
18. In the region of the Z-line 502, the physician may encounter an
overlap of sphincter muscle and cardia muscle.
[0250] As FIG. 83 shows, the lesion pattern 500 extends about 2 cm
to 3 cm from the Z-line 502 into the cardia 20. The pattern 500
comprises a high density of lesion rings 504, spaced apart by about
5 mm, with from four to sixteen lesions in each ring 504. Five
rings 504(1) to 504 (5) are shown in FIG. 83. The uppermost ring
504(1) (at or near the Z-line 502) contains eight lesions. The next
three rings 504(2) to 504 (4) each contains twelve lesions. The
lower most ring 504(5) contains eight lesions.
[0251] The lesion pattern 500 formed in this transition region
below the Z-line 502 creates, upon healing, an overall desired
tightening of the sphincter 18 and adjoining cardia 20 muscle,
restoring a normal closure function.
[0252] It is also believed that the pattern 500 formed in this
transition region may also create a neurophysiologic effect, as
well. The lesion pattern 500 may interrupt infra- and
supra-sphincter nerve conduction. The nerve pathway block formed by
the lesion pattern 500 may mediate pain due to high pH conditions
that accompany GERD and may in other ways contribute to the overall
reduction of spontaneous sphincter relaxation that the procedure
provides.
[0253] As before described, rotation or sequential movement of
electrodes 66 can achieve the desired complex lesion pattern 500.
However, in sequentially placing the lesions, overlapping lesions
can occur.
[0254] There are various ways to minimize the incidence of lesion
overlap.
[0255] (i) Full Ring Electrode Structures
[0256] To prevent overlapping lesions, the operative element 36
can, e.g., carry a number of electrodes 66 sufficient to form all
the desired lesions in a given circumferential ring with a single
deployment. For example, as FIG. 53 illustrates, when the desired
number of lesions for a given ring is eight, the operative element
36 carries eight electrodes 66. In this arrangement, the electrodes
66 are equally spaced about the circumference of the balloon
structure 72 on eight spines 58. As before described, each spine 58
preferably includes an interior lumen with a port 98 to convey a
cooling liquid like sterile water into contact with the mucosal
surface of the the targeted tissue site.
[0257] The generator 38 can include eight channels to supply
treatment energy simultaneously to the eight electrodes 66.
However, the generator 38 that supplies treatment energy
simultaneously in four channels to four electrodes 66 shown, e.g.,
in FIG. 22, can be readily configured by the controller 52 to
supply treatment energy to the eight electrodes 66 shown in FIG.
53.
[0258] (1) Monopolar/Hottest Temperature Control
[0259] In one configuration, pairs of electrodes 66 are shorted
together, so that each channel simultaneously powers two electrodes
in a monopolar mode. For simplicity, the shorted electrodes 66 are
preferably located on adjacent spines 58, but an adjacent
relationship for shorted electrodes is not essential.
[0260] Each electrode 66 carries a temperature sensor 80, coupled
to the I/O device 54 of the controller 52, as previously described.
The controller 52 alternatively samples the temperature sensed by
the sensors 80 for each shorted pair of electrodes 66. The
controller 52 selects the hottest sensed temperature to serve as
the input to control the magnitude of power to both electrodes.
Both electrodes receive the same magnitude of power, as they are
shorted together.
[0261] (2) Monopolar/Average Temperature Control
[0262] In one configuration, pairs of electrodes 66 are shorted
together, as described in the previous configuration, so that each
channel simultaneously powers two electrodes in a monopolar
mode.
[0263] Each electrode 66 carries a temperature sensor 80 and are
coupled to the I/O device 54 of the controller 52. In this
configuration, the temperature sensors 80 for each shorted pair of
electrodes 66 are connected in parallel. The controller 52 thus
receives as input a temperature that is approximately the average
of the temperatures sensed by the sensors 80 for each shorted pair
of electrodes 66. The controller 52 can include an algorithm to
process the input to achieve a weighted average. The controller 52
uses this approximate average to control the magnitude of power to
both electrodes. As previously stated, both electrodes receive the
same magnitude of power, as they are shorted together.
[0264] (3) Monopolar/Switched Control
[0265] In this configuration, the controller 52 includes a switch
element, which is coupled to each electrode 66 and its associated
temperature sensor 80 independently. In one position, the switch
element couples the four channels of the generator 38 to four of
the electrodes (Electrode Group A). In another position, the switch
element couples the four channels of the generator 38 to another
four of the electrodes (Electrode Group B).
[0266] The electrodes of Group A could be located on one side of
the element 36, and the electrodes of Group B could be located on
the opposite side of the element 36. Alternatively, the electrodes
66 of Groups A and B can be intermingled about the element 36.
[0267] The switch element can switch between Electrode Group A and
Electrode Group B, either manually or automatically. The switching
can occur sequentially or in a rapidly interspersed fashion.
[0268] In a sequential mode, Electrode Group A is selected, and the
controller samples the temperatures sensed by each sensor 80 and
individually controls power to the associated electrode 66 based
upon the sensed temperature. As tissue heating effects occur as a
result of the application of energy by Electrode Group A, the other
Electrode Group B is selected. The controller samples the
temperatures sensed by each sensor 80 and individually controls
power to the associated electrode 66 based upon the sensed
temperature. As tissue heating effects occur as a result of the
application of energy by Electrode Group B, the other Electrode
Group A is selected, and so on. This mode may minimize overheating
effects for a given electrode group.
[0269] In an interspersed fashion, the switching between Electrode
Groups A and B occurs at greater time intervals between the
application of energy, allowing tissue moisture to return to
dessicated tissue between applications of energy.
[0270] (4) Bipolar Control
[0271] In this configuration, the controller 52 conditions four
electrodes 66 to be transmitters (i.e., coupled to the four
channels of the generator 38) and conditions the other four
electrodes to be returns (i.e., coupled to the energy return of the
generator 38). For simplicity, the transmitter and return
electrodes are preferably located on adjacent spines 58, but this
is not essential.
[0272] In one arrangement, the four returns can be independent,
with no common ground, so that each channel is a true, independent
bipolar circuit. In another arrangement, the four returns are
shorted to provide a single, common return.
[0273] For each bipolar channel, the controller 52 samples
temperatures sensed by the sensors 80 carried by each electrode 66.
The controller 52 can average the sensed temperature conditions by
each electrode pair. The controller 52 can include an algorithm to
process the input to achieve a weighted average. Alternatively, the
controller 52 can select the maximum temperature condition sensed
by each electrode pair for control purposes.
[0274] The electrodes 66 used as return electrodes can be larger
than the electrodes 66 used to transmit the energy. In this
arrangement, the return electrodes need not carry temperature
sensors, as the hottest temperature will occur at the smaller
energy transmitting electrode.
[0275] (ii) Partial Ring Electrode Structures
[0276] To prevent overlapping lesions, the operative element 36
can, e.g., carry a number of electrodes 66 sufficient to form, in a
single deployment, a partial arcuate segment of the full
circumferential ring. For example, as FIG. 54 illustrates, when the
desired number of lesions for a given ring is eight, the operative
element 36 carries four electrodes 66 in a closely spaced pattern
spanning 135 degrees on four spines 58.
[0277] In use, the physician deploys the element 36 and creates
four lesions in a partial arcuate segment comprising half of the
full circumferential ring. The physician then rotates the element
36 one-hundred and eighty degrees and creates four lesions in a
partial arcuate segment that comprises the other half of the full
circumferential ring.
[0278] The physician may find that there is less chance of
overlapping lesions by sequentially placing four lesions at 180
intervals, than placing four lesions at 90 degree intervals, as
previously described.
[0279] E. Mechanically Expandable Electrode Structures
[0280] FIGS. 41 and 42 show an operative element 146 suited for
deployment in the lower esophageal sphincter 18, cardia 20, and
other areas of the body.
[0281] In this embodiment, the operative element 146 comprises an
expandable, three-dimensional, mechanical basket 148. As
illustrated, the basket 148 includes eight jointed spines 150,
although the number of spines 158 can, of course, vary. The jointed
spines 150 are pivotally carried between a distal hub 152 and a
proximal base 154.
[0282] Each jointed spine 150 comprises a body made from inert wire
or plastic material. Elastic memory material such as nickel
titanium (commercially available as NITINOL.TM. material) can be
used, as can resilient injection molded plastic or stainless steel.
In the illustrated embodiment, the jointed spines 150 possess a
rectilinear cross sectional shape. However, the cross sectional
shape of the spines 150 can vary.
[0283] Each jointed spine 150 includes a distal portion 158 and a
proximal portion 160 joined by a flexible joint 156. The distal and
proximal portions 158 and 160 flex about the joint 156. In the
illustrated embodiment, the spine portions 158 and 160 and joint
156 are integrally formed by molding. In this arrangement, the
joint 156 comprises a living hinge. Of course, the spine portions
158 and 160 can be separately manufactured and joined by a
mechanical hinge.
[0284] In the illustrated embodiment, a pull wire 162 is attached
to the distal hub 152 of the basket 148. Pulling on the wire 162
(e.g., by means of a suitable push-pull control on a handle at the
proximal end of the catheter tube 30) draws the hub 152 toward the
base 154. Alternatively, a push wire joined to the base 154 can
advance the base 154 toward the hub 152. In either case, movement
of the base 154 and hub 152 toward each other causes the spines 150
to flex outward about the joints 156 (as FIG. 42 shows). The basket
148 opens, and its maximum diameter expands.
[0285] Conversely, movement of the base 154 and hub 152 away from
each other causes the spines 150 to flex inward about the joints
156. The basket 148 closes (as FIG. 41 shows), and its maximum
diameter decreases until it assumes a fully collapsed
condition.
[0286] Each joint 156 carries an electrode 166. The electrode 166
can comprise an integrally molded part of the spine 150, or it can
comprise a separate component that is attached, e,g. by solder or
adhesive, to the spine 150. The electrode material can also be
deposited or coated upon the spine 150.
[0287] When the basket 148 is closed, the electrodes 166 nest
within the joints 156 in a lay flat condition (as FIG. 41 shows),
essentially coplanar with the distal and proximal portions 158 and
160 of the spines 150. As best shown in FIG. 43, as the basket 148
opens, flexure of the spines 150 about the joints 156 progressively
swings the electrodes 166 outward into a position for penetrating
tissue (designated T in FIG. 43).
[0288] As FIG. 43 shows, flexure of a given spine 150 about the
associated joint 156 swings the electrode 166 in a path, in which
the angle of orientation of the electrode 166 relative to the spine
progressively increases. As the basket 148 opens, the electrode 166
and the distal portion 158 of the spine 150 become generally
aligned in the same plane. Further expansion increases the radial
distance between the basket axis 164 and distal tip of the
electrode 166 (thereby causing tissue penetration), without
significantly increasing the swing angle between the basket axis
164 and the electrode 166 (thereby preventing tissue tear). During
the final stages of basket expansion, the electrode 166 moves in
virtually a linear path into tissue. It is thus possible to deploy
the electrode in tissue simultaneously with opening the basket
148.
[0289] FIGS. 44 and 45 show an operative element 168 comprising a
spring biased basket 170. In the illustrated embodiment, the distal
end of the catheter tube 30 carries two electrodes 172. A single
electrode, or more than two electrodes, can be carried in the same
fashion on the distal end of the catheter tube 30.
[0290] The electrodes 172 are formed from a suitable energy
transmitting materials, e.g stainless steel. The electrodes 172
have sufficient distal sharpness and strength to penetrate a
desired depth into the smooth muscle of the esophageal or cardia 20
wall.
[0291] The proximal end of each electrode 172 is coupled to the
leaf spring 174. The leaf spring 174 normally biases the electrodes
172 in an outwardly flexed condition facing the proximal end of the
catheter tube 30 (as FIG. 44 shows).
[0292] An electrode cover 176 is slidably mounted on the distal end
of the catheter tube 30. A stylet 178 is coupled to the electrode
cover 176. The stylet 178 is movable axially along the catheter
tube 30, e.g., by a lever on the handle at the proximal end of the
catheter tube 30.
[0293] Pulling on the stylet 178 moves the electrode cover 176 over
the electrodes 172 into the position shown in FIG. 45. On this
position, the cover 176 encloses the electrodes 172, pulling them
inward against the distal end of the catheter tube 30. Enclosed
within the cover 176, the electrodes 172 are maintained in a low
profile condition for passage through the esophagus, e.g., through
lower esophageal sphincter 18 and into a position slightly beyond
the surface of the cardia 20.
[0294] Pushing on the stylet 178 moves the electrode cover 176
toward a distal-most position beyond the electrodes 172, as shown
in FIG. 44. Progressively unconstrained by the cover 176, the
electrodes 172 spring outward. The outward spring distance of
electrodes 172 depends upon the position of the cover 176. The
electrodes 172 reach their maximum spring distance when the cover
176 reaches its distal-most position, as FIG. 44 shows. The distal
ends of the electrodes 172 are oriented proximally, to point, e.,g.
toward the cardia 20.
[0295] With the electrodes 172 sprung outward, the physician pulls
rearward on the catheter tube 30. The electrodes 172 penetrate the
cardia 20. The electrodes apply energy, forming subsurface lesions
in the cardia 20 in the same fashion earlier described. As FIG. 44
shows, the proximal region of each electrode 172 is preferably
enclosed by an electrical insulating material 70, to prevent ohmic
heated of the mucosal surface of the cardia 20.
[0296] Upon formation of the lesions, the physician can move the
catheter tube 30 forward, to advance the electrodes 172 out of
contact with the cardia 20. By rotating the catheter tube 30, the
physician can reorient the electrodes 172. The physician can also
adjust the position of the cover 176 to increase or decrease the
diameter of the outwardly flexed electrodes 172. Pulling rearward
on the catheter tube 30 causes the electrodes to penetrate the
cardia 20 in their reoriented and/or resized position. In this way,
the physician can form desired ring or rings of lesion patterns, as
already described.
[0297] Upon forming the desired lesion pattern, the physician
advances the electrodes 172 out of contact with the cardia 20. The
physician moves the cover 176 back over the electrodes 172 (as FIG.
45 shows). In this condition, the physician can withdraw the
catheter tube 30 and operative element 168 from the cardia 20 and
esophagus 10, completing the procedure.
[0298] F. Extruded Electrode Support Structures
[0299] FIGS. 63 to 65 show another embodiment of an operative
element 216 suited for deployment in the lower esophageal sphincter
18, cardia 20, and other areas of the body. In this embodiment, the
operative element 216 comprises an expandable, extruded basket
structure 218 (as FIG. 65 shows).
[0300] The structure 218 is first extruded (see FIG. 63) as a tube
224 with a co-extruded central interior lumen 220. The tube 224
also includes circumferentially spaced arrays 222 of co-extruded
interior wall lumens. Each array 222 is intended to accommodate an
electrode 66 and the fluid passages associated with the electrode
66.
[0301] In each array 222, one wall lumen accommodates passage of an
electrode 66 and related wires. Another lumen in the array 222 is
capable of passing fluids used, e.g. to cool the mucosal surface.
Another lumen in the array 222 is capable of passing fluids
aspirated from the targeted tissue region, if required.
[0302] Once extruded (see FIG. 64), the tube wall is cut to form
slits 230 between the lumen arrays 222. Proximal and distal ends of
the tube are left without slits 230, forming a proximal base 226
and a distal hub 228. Appropriate ports 232 are cut in the tube
wall between the slits 230 to accommodate passage of the electrodes
66 and fluids through the wall lumens. The base 226 is coupled to
the distal end of a catheter tube 236.
[0303] In the illustrated embodiment (see FIG. 65), a pull wire 234
passing through the interior lumen 220 is attached to the distal
hub 228. Pulling on the wire 234 (e.g., by means of a suitable
push-pull control on a handle at the proximal end of the catheter
tube 236) draws the hub 228 toward the base 226 (as FIG. 65 shows).
Alternatively, a push wire joined to the base 226 can advance the
base 226 toward the hub 228.
[0304] In either case, movement of the base 226 and hub 228 toward
each other causes the tube 224 to flex outward between the slits
230, forming, in effect, a spined basket. The extruded basket
structure 218 opens, and its maximum diameter expands.
[0305] Conversely, movement of the base 226 and hub 228 apart
causes the tube 224 to flex inward between the slits 230. The
extruded basket structure 218 closes and assumes a collapsed
condition.
[0306] The central co-extruded lumen 220 is sized to accommodate
passage of a guide wire or an endoscope, as will be described in
greater detail later.
[0307] G. Cooling and Aspiration
[0308] As previously described with respect to the operative
element 36 shown, e.g., in FIGS. 5, 7, and 11, it is desirable to
cool the mucosal surface while applying energy to ohmically heat
muscle beneath the surface. To accomplish this objective, the
operative element 36 includes a means for applying a cooling liquid
like sterile water to mucosal tissue at the targeted tissue region
and for aspirating or removing the cooling liquid from the targeted
tissue region.
[0309] Various constructions are possible.
[0310] (i) Aspiration Through the Spines
[0311] In the embodiment shown in FIGS. 55 and 56, the spines 58
extend between distal and proximal ends 60 and 62 of the element
36, forming a basket 56. Four spines 58 are shown for purpose of
illustration. An expandable balloon structure 72 is located within
the basket 56, as already described. An inflation tube 204 (see
FIG. 56) conveys a media to expand the structure 72 during use.
[0312] As FIGS. 55 and 56 show, each spine 58 comprises three tubes
186, 188, and 190. Each tube 186, 188, and 190 has an interior
lumen.
[0313] The first tube 186 includes an electrode exit port 192 (see
FIG. 56). The electrode 66 passes through the exit port 192 for
deployment in the manner previously described.
[0314] The second tube 188 includes a cooling port 194. The cooling
liquid passes through the cooling port 194 into contact with
mucosal tissue. The cooling port 194 is preferably situated on the
outside (i.e., tissue facing) surface of the spine 58, adjacent the
electrode exit port 192 (see FIG. 56).
[0315] The third tube 190 includes an aspiration port 196. Cooling
liquid is aspirated through the port 196. The port 196 is
preferably situated on the inside (i.e. facing away from the
tissue) surface of the spine 58.
[0316] Preferable, at least one of the aspiration ports 196 is
located near the distal end 60 of the element 36, and at least one
the aspiration ports 196 is located near the proximal end 62 of the
element 36. In the illustrated embodiment, two aspiration ports are
located near the distal end 60, on opposite spines 58 (see FIG.
55). Likewise, two aspiration ports are located near the proximal
end 62, on opposite spines 58 (see FIG. 56). This arrangement
provides for efficient removal of liquid from the tissue
region.
[0317] The electrodes 66 are commonly coupled to the control lever
198 on the handle 28 (see FIG. 57), to which the catheter tube 30
carrying the element 36 is connected. The lumen of the second tube
188 communicates with a port 200 on the handle 28. In use, the port
200 is coupled to a source of cooling fluid. The lumen of the third
tube 190 communicates with a port 202 on the handle 28. In use, the
port 202 is coupled to a vacuum source. The inflation tube 204
communicates with a port 206 on the handle 28. The port 206
connects to a source of inflation media, e.g., air in a
syringe.
[0318] (ii) Interior Aspiration Through An Inner Member
[0319] In the alternative embodiment shown in FIG. 58A, the spines
58 (eight are shown for purpose of illustration) each comprises at
least two tubes 186 and 188. In FIG. 58A, the inflation tube 204
extends through the expandable balloon structure 72, between the
distal and proximal ends 60 and 62 of the element 36. Inflation
ports 208 communicate with a lumen within the tube 204 to convey
the expansion media into the structure 72.
[0320] The first tube 186 includes the electrode exit port 192,
through which the electrode 66 passes. The second tube 188 includes
the outside facing cooling port 194, for passing cooling liquid
into contact with mucosal tissue.
[0321] At least one aspiration port 196 communicates with a second
lumen in the inflation tube 204. In the illustrated embodiment, two
aspiration ports 196 are provided, one near the distal end 60 of
the element 36, and the other near the proximal end 62 of the
element 36.
[0322] The element 36 shown in FIG. 58A can be coupled to the
handle 28 shown in the FIG. 57 to establish communication between
the tubes 188 and 204 in the manner already described.
[0323] In an alternative embodiment (shown in phantom lines in FIG.
58A), a sponge-like, liquid retaining material 320 can be applied
about each spine 58 over the electrode exit port 192 the cooling
port 194. The electrode 66 passes through the spongy material 320.
Cooling liquid passing through the cooling port 194 is absorbed and
retained by the spongy material 320. The spongy material 320 keeps
the cooling liquid in contact with mucosal tissue at a localized
position surrounding the electrode 66. By absorbing and retaining
the flow of cooling liquid, the spongy material 320 also minimizes
the aspiration requirements. The presence of the spongy material
320 to absorb and retain cooling liquid also reduces the flow rate
and volume of cooling liquid required to cool mucosal tissue, and
could eliminate the need for aspiration altogether.
[0324] In another alternative embodiment, as shown in FIG. 58B, the
spines 58 (eight are shown for purpose of illustration) each
comprises a single tube 186, which includes the electrode exit port
192, through which includes the electrode exit port 192, through
which the electrode 66 passes. As in FIG. 58A, the inflation tube
204 in FIG. 58B extends through the expandable balloon structure
72. Inflation ports 208 communicate with a lumen within the tube
204 to convey the expansion media into the structure 72.
[0325] In this embodiment, the expansion medium comprises the
cooling liquid. A pump conveys the cooling liquid into the
structure 72. Filling the structure 72, the cooling liquid causes
expansion. The structure 72 further includes one or more small pin
holes PH near each electrode 66. The cooling liquid "weeps" through
the pin holes PH, as the pump continuously conveys cooling liquid
into the structure 72. The cooling liquid contacts and cools tissue
in the manner previously described.
[0326] As in FIG. 58A, at least one aspiration port 196
communicates with a second lumen in the inflation tube 204 to
convey the cooling liquid from the treatment site. In FIG. 58B, two
aspiration ports 196 are provided, one near the distal end 60 of
the element 36, and the other near the proximal end 62 of the
element 36.
[0327] (iii) Tip Aspiration/Guide Wire
[0328] In the alternative embodiment shown in FIG. 59, the spines
58 (four are shown for purpose of illustration) each comprises at
least two tubes 186 and 188. Like the embodiment shown in FIG. 58,
the inflation tube 204 in FIG. 59 extends through the expandable
balloon structure 72, between the distal and proximal ends 60 and
62 of the element 36. Inflation ports 208 communicate with a lumen
within the tube 204 to convey the expansion media into the
structure 72.
[0329] The first tube 186 includes the electrode exit port 192,
through which the electrode 66 passes. The second tube 188 includes
the outside facing cooling port 194, for passing cooling liquid
into contact with mucosal tissue.
[0330] In the embodiment shown in FIG. 59, the distal end 60 of the
element 36 includes an aspiration port 196, which communicates with
a second lumen in the inflation tube 204.
[0331] The element 36 shown in FIG. 58 can be coupled to the handle
28 shown in the FIG. 57 to establish communication between the
tubes 188 and 204 in the manner already described.
[0332] In the embodiment shown in FIG. 59, the lumen in the
inflation tube 204 used for aspiration can be alternatively used to
pass a guide wire 210, as FIG. 60 shows. The guide wire 210 is
introduced through the aspiration port 202 on the handle 28 (as
FIG. 61 shows).
[0333] Use of a guide wire 210 can obviate the need for the
introducer 32 previously described and shown in FIG. 9, which may
in certain individuals cause discomfort. In use, the physician
passes the small diameter guide wire 210 through the patient's
mouth and pharynx, and into the esophagus 10 to the targeted site
of the lower esophageal sphincter or cardia. The physician can next
pass the operative element 36 (see FIG. 60) over the guide wire 210
into position. The physician can also deploy an endoscope next to
the guide wire 210 for viewing the targeted site and operative
element 36.
[0334] Use of the guide wire 210 also makes possible quick
exchanges of endoscope and operative element 36 over the same guide
wire 210. In this arrangement, the guide wire 210 can serve to
guide the endoscope and operative element 36 to the targeted site
in quick succession.
[0335] G. Vacuum-Assisted Stabilization of Mucosal Tissue
[0336] As FIG. 66 shows, mucosal tissue MT normally lays in folds
in the area of the lower esophageal sphincter 18 and cardia 20,
presenting a fully or at least partially closed closed path. In the
preceding embodiments, various expandable structures are deployed
to dilate the mucosal tissue MT for treatment. When dilated, the
mucosal tissue folds expand and become smooth, to present a more
uniform surface for submucosal penetration of the electrodes 66.
The dilation mediates against the possibility that an electrode 66,
when deployed, might slide into a mucosal tissue fold and not
penetrate the underlying sphincter muscle.
[0337] (i) Rotational Deployment of Electrodes
[0338] FIGS. 67 to 69 show an alternative treatment device 238
suited for deployment in the lower esophageal sphincter 18, cardia
20, and other regions of the body to direct electrodes 66 into
targeted submucosal tissue regions.
[0339] The device 238 includes a handle 248 (see FIG. 67) that
carries a flexible catheter tube 242. The distal end of the
catheter tube 242 carries an operative element 244.
[0340] The operative element 244 includes a proximal balloon 246
and a distal balloon 248. The balloons 246 and 248 are coupled to
an expansion media by a port 276 on the handle 240.
[0341] An electrode carrier 250 is located between the balloons 246
and 248. As FIGS. 67 and 68 show, the carrier 250 includes a
generally cylindrical housing 252 with an exterior wall 268. The
housing 252 includes a series of circumferentially spaced electrode
pods 256. Each pod 256 extends radially outward of the wall 268 of
housing 252.
[0342] As FIGS. 68 and 69 show, each pod 256 includes an interior
electrode guide bore 258. The guide bore 258 extends in a curved
path through the pod 256 and terminates with an electrode port 262
spaced outward from the wall of the housing.
[0343] The housing 252 also includes a series of suction ports 260
(see FIGS. 68 and 69). Each suction port 260 is located flush with
the housing wall 268 close to an electrode port 262. The suction
ports 260 are coupled to a source of negative pressure through a
port 274 on the handle 240.
[0344] A driver disk 254 is mounted for rotation within the housing
252. Electrodes 264 are pivotally coupled to the driver disk 254 on
pins 266 arranged in an equally circumferentially spaced
pattern.
[0345] The electrodes 264 can be formed from various energy
transmitting materials, e.g., 304 stainless steel. The electrodes
264 are coupled to the generator 38, preferable through the
controller 52.
[0346] The electrodes 264 have sufficient distal sharpness and
strength to penetrate a desired depth into the smooth muscle of the
esophageal or cardia 20 apply energy from the generator 38.
[0347] As previously described with respect to other embodiments,
an electrical insulating material 278 (see FIGS. 68 and 69) is
coated about the proximal end of each electrode 264. When the
distal end of the electrode 264 penetrating the smooth muscle of
the esophageal sphincter 18 or cardia 20 transmits radio frequency
energy, the material 278 insulates the mucosal surface of the
esophagus 10 or cardia 20 from direct exposure to the radio
frequency energy to prevent thermal damage to the mucosal surface.
As previously described, the mucosal surface can also be actively
cooled during application of radio frequency energy, to further
protect the mucosal surface from thermal damage.
[0348] Each electrode 264 is biased with a bend, to pass from the
pin 266 in an arcuate path through the electrode guide bore 258 in
the associated pod 256. Rotation of the driver disk 254 in one
direction (which is clockwise in FIG. 68) moves the electrodes 264
through the bores 258 outward of the carrier 250 (as FIG. 69
shows). Opposite rotation of the driver disk 254 (which is
counterclockwise in FIG. 68) moves the electrodes 264 through the
bores 258 inward into the carrier 250 (as FIGS. 67 and 68
show).
[0349] A drive shaft 270 is coupled to the driver disk 254 to
affect clockwise and counterclockwise rotation of the disk 254. A
control knob 272 on the handle 240 (see FIG. 67) is coupled to the
drive shaft 254 to extend and retract the electrodes 264.
[0350] In use, the carrier 250 is located at the desired treatment
site, e.g., in the region of the lower esophageal sphincter 18. The
balloons 246 and 248 are expanded to seal the esophagus in the
region between the balloons 246 and 248.
[0351] A vacuum is then applied through the suction ports 260. The
vacuum evacuates air and fluid from the area of the esophageal
lumen surrounding the carrier 250. This will cause the surrounding
mucosal tissue to be drawn inward against the wall 268 of the
housing 252 (see FIG. 69), to conform and be pulled tightly against
the pods 256.
[0352] Applying a vacuum to draw mucosal tissue inward against the
pods 256 causes the tissue to present a surface nearly
perpendicular to the electrode ports 262 (see FIG. 69). Operation
of the driver disk 254 moves the electrodes 264 through the ports
262, in a direct path through mucosal tissue and into the
underlying sphincter muscle. Due to the direct, essentially
perpendicular angle of pentration, the electrode 264 reaches the
desired depth in a short distance (e.g., less than 3 mm),
minimizing the amount of insulating material 278 required.
[0353] The application of vacuum to draw mucosal tissue against the
pods 256 also prevents movement of the esophagus while the
electrodes 264 penetrate tissue. The counter force of the vacuum
resists tissue movement in the direction of electrode penetration.
The vacuum anchors the surrounding tissue and mediates against the
"tenting" of tissue during electrode penetration. Without tenting,
the electrode 264 penetrates mucosal tissue fully, to obtain a
desired depth of penetration.
[0354] (ii) straight Deployment of Electrodes
[0355] FIGS. 70 and 71 show another alternative treatment device
280 suited for deployment in the lower esophageal sphincter 18,
cardia 20, and other regions of the body to direct electrodes 66
into targeted submucosal tissue regions.
[0356] The device 280 includes a handle 282 (see FIG. 70) that
carries a flexible catheter tube 284. The distal end of the
catheter tube 284 carries an operative element 286.
[0357] The operative element 286 includes a proximal balloon 288
and a distal balloon 290. The balloons 288 and 290 are coupled to
an expansion media by a port 292 on the handle 284.
[0358] An electrode carrier 294 is located between the balloons 246
and 248. The carrier 294 includes a generally cylindrical housing
296 with an exterior wall 298 (see FIG. 71). The housing 296
includes a series of circumferentially and axially spaced recesses
300 in the wall 298 (best shown in FIG. 70).
[0359] As FIG. 71 shows, an electrode guide bore 302 extends
through the wall 298 and terminates with an electrode port 304 in
each recess 300. The axis of each guide bore 302 is generally
parallel to the plane of the corresponding recess 300.
[0360] The housing 296 also includes a series of suction ports 306,
one in each recess 300. The suction ports 306 are coupled to a
source of negative pressure through a port 308 on the handle
282.
[0361] An electrode mount 310 (see FIG. 71) is mounted for axial
movement within the housing 296. Electrodes 312 are pivotally
coupled to the mount 310.
[0362] The electrodes 312 can be formed from various energy
transmitting materials, e.g., 304 stainless steel. The electrodes
312 are coupled to the generator 38, preferable through the
controller 52.
[0363] The electrodes 312 have sufficient distal sharpness and
strength to penetrate a desired depth into the smooth muscle of the
esophageal or cardia 20 apply energy from the generator 38. As
previously described with respect to other embodiments, an
electrical insulating material 314 (see FIG. 71) is coated about
the proximal end of each electrode 312.
[0364] Each electrode 312 is generally straight, to pass from the
mount 310 through the electrode guide bore 302. Axial movement of
the mount 310 toward the guide bores 302 extends the electrodes 312
outward into the recesses 300, as FIG. 71 shows. Opposite axial
movement of the mount 310 withdraws the electrodes 312 through the
bores 302 inward from recesses 300 (as FIG. 70 shows).
[0365] A stylet 316 (see FIG. 71) is coupled to the mount 310 to
affect axial movement of the mount 310. A push-pull control knob
318 on the handle 282 is coupled to the stylet 316 to extend and
retract the electrodes 264. Alternatively, a spring loaded
mechanism can be used to "fire" the mount 310 to deploy the
electrodes 312.
[0366] In use, the carrier 294 is located at the desired treatment
site, e.g., in the region of the lower esophageal sphincter. The
balloons 288 and 290 are expanded to seal the esophagus in the
region between the balloons 288 and 290.
[0367] A vacuum is then applied through the suction ports 292. The
vacuum evacuates air and fluid from the area of the esophageal
lumen surrounding the carrier 294. This will cause the surrounding
mucosal tissue to be drawn inward into the recesses, to conform and
be pulled tightly against the recesses 300, as FIG. 71 shows.
[0368] Applying a vacuum to draw mucosal tissue inward into the
recesses 300 causes the tissue to present a surface nearly
perpendicular to the electrode ports 304, as FIG. 71 shows.
Operation of the mount 310 moves the electrodes 312 through the
ports 304, in a path through mucosal tissue and into the underlying
sphincter muscle that is generally parallel to the axis of the
esophageal lumen.
[0369] In the same manner described with regard to the preceding
embodiment, the application of vacuum to draw mucosal tissue into
the recesses 300 also anchors the carrier 294 in the esophagus
while the electrodes 312 penetrate tissue. Ribs and the like can
also be provided in the recesses 300 or along the wall 298 of the
housing 296 to enhance the tissue anchoring effect. The counter
force of the vacuum resists tissue movement in the direction of
electrode penetration. The vacuum anchors the surrounding tissue
and mediates against the "tenting" of tissue during electrode
penetration. The electrodes 312 penetrates mucosal tissue fully, to
obtain a desired depth of penetration.
[0370] H. Visualization
[0371] Visualization of the targeted tissue site before, during,
and after lesion formation is desirable.
[0372] (i) Endoscopy
[0373] As earlier shown in FIGS. 9 and 10, a separately deployed
endoscope 84, carried by a flexible catheter tube 86, is used to
visualize the targeted site. In this embodiment, the operative
element 36 is deployed separately, by means of a separate catheter
tube 30.
[0374] In an alternative embodiment (shown in FIGS. 46 to 49), a
treatment device 26 is deployed over the same catheter tube 86 that
carries the endoscope 84. In effect, this arrangement uses the
flexible catheter tube 86 of the endoscope 84 as a guide wire.
[0375] In this embodiment, the treatment device 26 can carry any
suitable operative element (which, for this reason, is generically
designated OE in FIGS. 46 to 49). As FIGS. 47 and 47 show, the
catheter tube 30 passes through and beyond the interior of the
operative element OE. The catheter tube 30 further includes a
central lumen 180, which is sized to accommodate passage of the
flexible catheter tube 86 carrying the endoscope 84.
[0376] As shown in FIG. 48, once the endoscope 84 is deployed in
the manner shown in FIGS. 9 and 10, the operative element OE can be
passed over the catheter tube 86 to the targeted tissue region. In
FIG. 48, the targeted region is shown to be the cardia 20.
[0377] In use, the endoscope 86 extends distally beyond the
operative element OE. By retroflexing the endoscope 86, as FIGS. 48
and 49 show, the physician can continuously monitor the placement
of the operative element OE, the extension of the electrodes 66,
and the other steps of the lesion formation process already
described.
[0378] When the operative element OE includes the expandable
balloon structure 72 (see FIGS. 50 and 51), the structure 72 and
the extent of the catheter tube 30 passing through it, can be
formed of a material that is transparent to visible light. In this
arrangement, the physician can retract the endoscope 84 into
expandable structure 72 (as FIG. 51 shows). The physician can then
monitor the manipulation of the operative element OE and other
steps in the lesion formation process from within the balloon
structure 72. Any portion of the catheter tube 30 can be made from
a transparent material, so the physician can visualize at other
locations along its length.
[0379] As FIG. 52 shows, the mechanically expanded basket 148
(shown earlier in FIGS. 41 and 42) can be likewise be modified for
deployment over the catheter tube 86 that carries the flexible
endoscope 84. In this arrangement, the interior lumen 180 extends
through the catheter tube 30, the basket 148, and beyond the basket
hub 152. The lumen 180 is sized to accommodate passage of the
endoscope 84.
[0380] In another embodiment (see FIG. 62), the endoscope 84 itself
can include an interior lumen 212. A catheter tube 214, like that
previously shown in FIG. 38, can be sized to be passed through the
interior lumen 212 of the endoscope 84, to deploy a mono-polar
electrode 66 (or a bipolar pair of electrodes) into penetrating
contact with a desired tissue region. As FIG. 62 shows, the
electrode 66 can carry a limit collar 121 to resist advancement of
the electrode 66 beyond a desired penetration depth.
[0381] In another embodiment, to locate the site of lower
esophageal sphincter 18 or cardia 20, a rigid endoscope can be
deployed through the esophagus of an anesthetized patient. Any
operative element OE can be deployed at the end of a catheter tube
to the site identified by rigid endoscopy, to perform the treatment
as described. In this arrangement, the catheter tube on which the
operative element is deployed need not be flexible. With an
anesthetized patient, the catheter tube that carries the operative
element OE can be rigid.
[0382] With rigid endoscopy, the catheter tube can be deployed
separately from the endoscope. Alternatively, the catheter tube can
include an interior lumen sized to pass over the rigid
endoscope.
[0383] (ii) Fluoroscopy
[0384] Fluoroscopy can also be used to visual the deployment of the
operative element OE. In this arrangement, the operative element OE
is modified to carry one or more radiopaque markers 182 (as FIG. 24
shows) at one or more identifiable locations, e.g. at the distal
hub 60, or proximal base 62, or both locations.
[0385] With a patient lying on her left side upon a fluoroscopy
table, the physician can track movement of the radiopaque markers
182 to monitor movement and deployment of the operative element OE.
In addition, the physician can use endoscopic visualization, as
previously described.
[0386] (iii) Ultrasound
[0387] The catheter tube can carry an ultrasound transducer 184 (as
FIG. 21 shows) adjacent the proximal or distal end of the operative
element OE. The physician can observe the transesophageal echo as a
real time image, as the operative element OE is advanced toward the
lower esophageal sphincter 18. The real time image reflects the
thickness of the esophageal wall.
[0388] Loss of the transesophageal echo marks the passage of the
ultrasound transducer 184 beyond lower esophageal sphincter 18 into
the stomach 12. The physician pulls back on the catheter tube 30,
until the transesophageal echo is restored, thereby marking the
situs of the lower esophageal sphincter 18.
[0389] With the position of the sphincter localized, the physician
can proceed to expand the structure 72, deploy the electrodes 66,
and perform the steps of procedure as already described. Changes in
the transesophageal echo as the procedure progresses allows the
physician to visualize lesion formation on a real time basis.
[0390] I. The Graphical User Interface (GUI)
[0391] In the illustrated embodiment (see FIGS. 72A and 72B), the
radio frequency generator 38, the controller 52 with I/O device 54,
and the fluid delivery apparatus 44 (for the delivery of cooling
liquid) are integrated within a single housing 400.
[0392] The I/O device 54 includes input connectors 402, 404, and
406. The connector 402 accepts an electrical connector 408 coupled
to a given treatment device TD. The connector 404 accepts an
electrical connector 410 coupled to a patch electrode 412 (for
mono-polar operation). The connector 406 accepts an pneumatic
connector 414 coupled to a conventional foot pedal 416. These
connectors 402, 404, and 406 couple these external devices to the
controller 52. The I/O device 54 also couples the controller 54 to
an array of membrane keypads 422 and other indicator lights on the
housing 400 (see FIG. 73), for entering and indicating parameters
governing the operation of the controller 52.
[0393] The I/O device 54 also couples the controller 52 to a
display microprocessor 474, as FIG. 82 shows. In the illustrated
embodiment, the microprocessor 474 comprises, e.g., a dedicated
Pentium.RTM.-based central processing unit. The controller 52
transmits data to the microprocessor 474, and the microprocessor
474 acknowledges correct receipt of the data and formats the data
for meaningful display to the physician. In the illustrated
embodiment, the dedicated display microprocessor 474 exerts no
control over the controller 52.
[0394] In the illustrated embodiment, the controller 52 comprises
an 68HC11 processor having an imbedded operating system.
Alternatively, the controller 52 can comprise another style of
processor, and the operating system can reside as process software
on a hard drive coupled to the CPU, which is down loaded to the CPU
during system initialization and startup.
[0395] The display microprocessor 474 is coupled to a graphics
display monitor 420. The controller 52 implements through the
display microprocessor 474 a graphical user interface, or GUI 424,
which is displayed on the display monitor 420. The GUI 424 can be
realized, e.g., as a "C" language program implemented by the
microprocessor 474 using the MS WINDOWS.TM. or NT application and
the standard WINDOWS 32 API controls, e.g., as provided by the
WINDOWS.TM. Development Kit, along with conventional graphics
software disclosed in public literature.
[0396] The display microprocessor 474 is also itself coupled to a
data storage module or floppy disk drive 426. The display
microprocessor 474 can also be coupled to a keyboard, printer, and
include one or more parallel port links and one or more
conventional serial RS-232C port links or Ethernet.TM.
communication links.
[0397] The fluid delivery apparatus 44 comprises an integrated,
self priming peristaltic pump rotor 428 with a tube loading
mechanism, which are carried on a side panel of the housing 400.
Other types of non-invasive pumping mechanisms can be used, e.g., a
syringe pump, a shuttle pump, or a diaphragm pump.
[0398] In the illustrated embodiment, the fluid delivery apparatus
44 is coupled to the I/O device 54 via a pump interface 476. The
pump interface 476 includes imbedded control algorithms that
monitor operation of the pump rotor 428.
[0399] For example, the pump interface 476 can monitor the delivery
of electrical current to the pump rotor 428, to assure that the
rotor 428 is operating to achieve a desired flow rate or range of
flow rates during use, or, upon shut down, the rotor 428 has
stopped rotation. An optical encoder or magnetic Halls effect
monitor can be used for the same purpose.
[0400] Alternatively, a flow rate transducer or pressure
transducer, or both, coupled to the pump interface 476, can be
placed in line along the pump tubing, or in the treatment device TD
itself, to monitor flow rate.
[0401] Flow rate information acquired from any one of these
monitoring devices can also be applied in a closed loop control
algorithm executed by the controller 52, to control operation of
the pump rotor 428. The algorithm can apply proportional, integral,
or derivative analysis, or a combination thereof, to control
operation of the pump rotor 428.
[0402] In the illustrated embodiment, it is anticipated that the
physician will rely upon the vacuum source typically present in the
physician's suite as the aspiration apparatus 46. However, it
should be appreciated that the device 400 can readily integrate the
aspiration apparatus 46 by selectively reversing the flow direction
of the pump rotor 428 (thereby creating a negative pressure) or by
including an additional dedicated pump rotor or equivalent pumping
mechanism to perform the aspiration function.
[0403] In the illustrated embodiment, the integrated generator 38
has four independent radio frequency channels. Each channel is
capable of supplying up to 15 watts of radio frequency energy with
a sinusoidal waveform at 460 kHz. As before explained, the four
channels of the generator 38 can operate four electrodes in either
a monopolar or bipolar mode. As also explained earlier, the four
channels can also be configured to operate eight electrodes either
in a monopolar mode or a bipolar mode.
[0404] The integrated controller 52 receives two temperature
measurements through the I/O device 54 for each channel, one from
the tip of each electrode on the treatment device TD, and one from
tissue surrounding the electrode. The controller 52 can regulate
power to the electrodes in a close-loop based upon the sensed tip
temperature, or the sensed tissue temperature, or both, to achieve
and maintain a targeted tip tissue temperature at each electrode.
The controller 52 can also regulate power to the pump rotor 428 in
a closed-loop based upon the sensed tip temperature, or the sensed
tissue temperature, or both, to achieve an maintain a targeted
tissue temperature at each electrode. Alternatively, or in
combination, the physician can manually adjust the power level or
pump speed based upon a visual display of the sensed tip and tissue
temperatures.
[0405] As FIG. 73 best shows, the membrane keypads 422 and other
indicators on the front panel of the device 400 show the various
operational parameters and operating states and allow adjustments
to be made. In the illustrated embodiment, as shown in FIG. 73, the
keypads 422 and indicators include:
[0406] 1. Standby/Ready Button 430, which allows switching from one
mode of operation to another, as will be described later.
[0407] 2. Standby/Ready Indicator 432, which displays a green light
after the device 400 passes a self test upon start up.
[0408] 3. RF On Indicator 434, which displays a blue light when
radio frequency energy is being delivered.
[0409] 4. Fault Indicator 436, which displays a red light when an
internal error has been detected. No radio frequency energy can be
delivered when the Fault Indicator 436 is illuminated.
[0410] 5. Target Duration Keys 438, which allow increases and
decreases in the target power duration at the start or during the
course of a procedure.
[0411] 6. Target Temperature Keys 440, which allow increases and
decreases in the target temperature at the start or during the
course of a procedure.
[0412] 7. Maximum Power Keys 442, which allow increases and
decreases in the maximum power setting at the start or during the
course of a procedure.
[0413] 8. Channel Selection Keys 444, which allow selection of any
or all power channels.
[0414] 9. Coagulation Level Keys 446, which manually increases and
decreases the magnitude of the indicated depth of insertion of the
electrodes within the esophagus. This depth is determined, e.g., by
visually gauging the measured markings along the length of the
catheter tube of the treatment device TD, as previously described.
Alternatively, the coagulation level can be automatically detected
by, e.g., placing optical, mechanical, or magnetic sensors on the
mouth piece 82, which detect and differentiate among the measured
markings along the catheter tube of the treatment device TD to read
the magnitude of the depth of insertion.
[0415] 10. Flow Rate and Priming Keys 448, which allow for
selection of three internally calibrated flow rates, low (e.g., 15
ml/min), medium (e.g., 30 ml/min), and high (e.g., 45 ml/min).
Pressing and holding the "Up" key activates the pump at a high flow
rate for priming, overruling the other flow rates until the "Up"
key is released.
[0416] In the illustrated embodiment, the graphics display monitor
420 comprises an active matrix LCD display screen located between
the membrane keypads 422 and other indicators on the front panel.
The GUI 424 is implemented by showing on the monitor 420 basic
screen displays. In the illustrated embodiment, these displays
signify four different operating modes: Start-Up, Standby, Ready,
RF-On, and Pause.
[0417] (i) Start Up
[0418] Upon boot-up of the CPU, the operating system implements the
GUI 424. The GUI 424 displays an appropriate start-up logo and
title image (not shown), while the controller 52 performs a
self-test. A moving horizontal bar or the like can be displayed
with the title image to indicate the time remaining to complete the
start-up operation.
[0419] (ii) Standby
[0420] Upon completion of the start-up operation, the Standby
screen is displayed, as shown in FIG. 74. No radio frequency energy
can be delivered while the Standby screen is displayed.
[0421] There are various icons common to the Standby, Ready, RF-On,
and Pause screens.
[0422] The Screen Icon 450 is an icon in the left hand corner of
the monitor 420, which indicates the operating condition of the
treatment device TD and its position inside or outside the
esophagus. In FIG. 74, the treatment device TD is shown to be
disconnected and outside the esophagus. Pressing the "Up" priming
key 448, to cause cooling liquid to flow through the treatment
device TD, causes an animated priming stream PS to be displayed
along the treatment device TD in the icon, as FIG. 73 shows. The
animated priming stream PS is displayed in the Screen Icon 450
whenever the pump rotor 428 is operating to indicate the supply of
cooling fluid through the treatment TD.
[0423] There are also parameter icons designating target duration
452, target temperature 454, maximum power 456, channel selection
458, coagulation level 460, and flow rate/priming 462. These icons
are aligned with, respectively, the corresponding Target Duration
Keys 438, Target Temperature Keys 440, Maximum Power Keys 442,
Channel Selection Keys 444, Coagulation Level Keys 446, and Flow
Rate and Priming Keys 448. The icons 452 to 462 indicate current
selected parameter values. The flow rate/priming icon 462 shows the
selected pump speed by highlighting a single droplet image (low
speed), a double droplet image (medium speed), and a triple droplet
image (high speed).
[0424] There is also a floppy disk icon 464 that is normally
dimmed, along with the coagulation level icon 460, until a floppy
disk is inserted in the drive 426. When a floppy disk is inserted
in the drive 426, the icons 460 and 464 are illuminated (see FIG.
73), and data is saved automatically after each application of
radio frequency energy (as will be described later).
[0425] There is also an Electrode Icon 466. The Electrode-Icon 466
comprises an idealized graphical image, which spatially models the
particular multiple electrode geometry of the treatment device TD
selected to be deployed in the esophagus. As FIG. 74 shows, four
electrodes are shown in the graphic image of the Icon 466, which
are also spaced apart by 90 degrees. This graphic image is intended
to indicate that the selected treatment device TD has the geometry
of the four-electrode configuration shown, e.g., in FIG. 5.
[0426] For each electrode, the Icon 466 presents in a spatial
display the magnitude of tip temperature as actually sensed (in
outside box B1) and the magnitude of tissue temperatures as
actually sensed (in inside box B2). Until a treatment device TD is
connected, two dashes appear in the boxes B1 and B2. The existence
of a faulty electrode in the treatment device will also lead to the
same display.
[0427] The controller 52 prohibits advancement to the Ready screen
until numeric values register in the boxes B1 and B2, as FIG. 75
shows. The display of numeric values indicate a functional
treatment device TD.
[0428] No boxes B1 or B2 will appear in the Icon 466 for a given
electrode if the corresponding electrode/channel has been disabled
using the Channel Selection Keys 444, as FIG. 76 shows. In the
illustrated embodiment, the physician is able to manually select or
deselect individual electrodes using the Selection Keys 444 in the
Standby or Ready Modes, but not in the RF-On Mode. However, the
controller 52 can be configured to allow electrode selection while
in the RF-On Mode, if desired.
[0429] While in the Standby Mode, the physician connects the
treatment device TD to the device 400. The physician couples the
source of cooling liquid to the appropriate port on the handle of
the device TD (as previously described) and loads the tubing
leading from the source of cooling liquid (e.g., a bag containing
sterile water) in the pump rotor 428. The physician also couples
the aspiration source to the appropriate port on the handle of the
treatment device TD (as also already described). The physician also
couples the patch electrode 412 and foot pedal 416. The physician
can now deploy the treatment device TD to the targeted tissue
region in the esophagus, in the manners previously described. The
physician extends the electrodes through mucosal tissue and into
underlying smooth muscle.
[0430] Once the treatment device TD is located at the desired
location and the electrodes are deployed, the physician presses the
Standby/Ready Button 430 to advance the device 400 from Standby to
Ready Mode.
[0431] (iii) Ready
[0432] In the Ready Mode, the controller 52 commands the generator
38 to apply bursts of low level radio frequency energy through each
electrode selected for operation. Based upon the transmission of
these low level bursts of energy by each electrode, the controller
52 derives a local impedance value for each electrode. The
impedance value indicates whether or nor the given electrode is in
desired contact with submucosal, smooth muscle tissue. The use of
impedance measurements for this purpose has been previously
explained.
[0433] As FIG. 77 shows, the Ready screen updates the Screen Icon
450 to indicate that the treatment device TD is connected and
deployed in the patient's esophagus. The Ready screen also
intermittently blinks the RF On Indicator 434 to indicate that
bursts of radio frequency energy are being applied by the
electrodes. The Ready screen also updates the Electrode Icon 466 to
spatially display in the inside and outside boxes B1 and B2 the
actual sensed temperature conditions. The Ready screen also adds a
further outside box B3 to spatially display the derived impedance
value for each electrode.
[0434] On the Ready screen, instantaneous, sensed temperature
readings from the tip electrode and tissue surface, as well as
impedance values, are continuously displayed in spatial relation to
the electrodes the boxes B1, B2, and B3 in the Electrode Icon 466.
An "acceptable" color indicator (e.g., green) is also displayed in
the background of box B1 as long as the tip temperature reading is
within the desired pre-established temperature range (e.g., 15 to
120 C.). However, if the tip temperature reading is outside the
desired range, the color indicator changes to an "undesirable"
color indicator (e.g., to white), and two dashes appear in box B1
instead of numeric values.
[0435] The controller 52 prevents the application of radio
frequency energy if any temperature reading is outside a selected
range (e.g., 15 to 120 degrees C.).
[0436] The physician selects the "Up" key of the Flow Rate and
Priming Keys 448 to operate the pump rotor 428 to prime the
treatment device TD with cooling fluid. An animated droplet stream
PS is displayed along the treatment device TD in the Icon 450, in
the manner shown in FIG. 75, to indicate the delivery of cooling
liquid by the pump rotor 428.
[0437] By touching the Target Duration Keys 438, the Target
Temperature Keys 440, the Maximum Power Keys 442, the Channel
Selection Keys 444, the Coagulation Level Keys 446, and the Flow
Rate and Priming Keys 448, the physician can affect changes to the
parameter values for the intended procedure. The controller 52
automatically adjusts to take these values into account in its
control algorithms. The corresponding target duration icon 452,
target temperature icon 454, maximum power icon 456, channel
selection icon 458, coagulation level icon 460, and flow
rate/priming icon 462 change accordingly to indicate the current
selected parameter values.
[0438] When the physician is ready to apply energy to the targeted
tissue region, the physician presses the foot pedal 416. In
response, the device 400 advances from Ready to RF-On Mode,
provided that all sensed temperatures are within the selected
range.
[0439] (iv) RF-On
[0440] When the foot pedal 416 is pressed, the controller 52
activates the pump rotor 428. Cooling liquid is conveyed through
the treatment device TD into contact with mucosal tissue at the
targeted site. At the same time, cooling liquid is aspirated from
the treatment device TD in an open loop. During a predetermined,
preliminary time period (e.g. 2 to 5 seconds) while the flow of
cooling liquid is established at the site, the controller 52
prevents the application of radio frequency energy.
[0441] After the preliminary time period, the controller 52 applies
radio frequency energy through the electrodes. The RF-On screen,
shown in FIG. 79, is displayed.
[0442] The RF-On screen displays the Screen Icon 450, indicate that
the treatment device TD is connected and deployed in the patient's
esophagus. The flow drop animation PS appears, indicating that
cooling is taking place. A flashing radio wave animation RW also
appears, indicating that radio frequency energy is being applied.
The RF On Indicator 434 is also continuously illuminated to
indicate that radio frequency energy is being applied by the
electrodes.
[0443] The RF-On screen also updates the Electrode Icon 466 to
display in the box B1 the actual sensed tip temperature conditions.
The RF-On screen also displays the derived impedance value for each
electrode in the boxes B3.
[0444] Unlike the Ready or Standby screens, the surface temperature
is no longer displayed in a numerical format in a box B2. Instead,
a circle C1 is displayed, which is color coded to indicate whether
the surface temperature is less than the prescribed maximum (e.g.,
45 degrees C.). If the surface temperature is below the prescribed
maximum, the circle is colored an "acceptable" color, e.g., green.
If the surface temperature is exceeds the prescribed maximum, the
color of the circle changes to an "not acceptable" color, e.g., to
red.
[0445] Likewise, in addition to displaying numeric values, the
boxes B1 and B3 are also color coded to indicate compliance with
prescribed limits. If the tip temperature is below the prescribed
maximum (e.g., 100 degrees C.), the box B1 is colored, e.g., green.
If the tip temperature is exceeds the prescribed maximum, the box
border thickens and the color of the box B1 changes, e.g., to red.
If the impedance is within prescribed bounds (e.g., between 25 ohms
and 1000 ohms), the box B3 is colored, e.g., grey. If the impedance
is outside the prescribed bounds, the box border thickens and the
color of the box B3 changes, e.g., to red.
[0446] If desired, the Electrode Icon 466 can also display in a box
or circle the power being applied to each electrode in spatial
relation to the idealized image.
[0447] The RF-On screen displays the target duration icon 452,
target temperature icon 454, maximum power icon 456, channel
selection icon 458, coagulation level icon 460, and flow
rate/priming icon 462, indicating the current selected parameter
values. The physician can alter the target duration or target
temperature or maximum power and pump flow rate through the
corresponding selection keys 438, 440, 442, and 448 on the fly, and
the controller 52 and GUI instantaneously adjust to the new
parameter settings. As before mentioned, in the illustrated
embodiment, the controller 52 does not permit change of the
channel/electrode while radio frequency energy is being applied,
and, for this reason, the channel selection icon 458 is dimmed.
[0448] Unlike the Standby and Ready screens, the RF-On screen also
displays a real time line graph 468 to show changes to the
temperature profile (Y-axis) over time (X-axis). The RF-On screen
also shows a running clock icon 470, which changes appearance to
count toward the target duration. In the illustrated embodiment, a
digital clock display CD is also shown, indicating elapsed
time.
[0449] The line graph 468 displays four trending lines to show the
minimum and maximum surface and tip temperature readings from all
active electrodes. In the illustrated embodiment, the time axis
(X-axis) is scaled to one of five pre-set maximum durations,
depending upon the set target duration. For example, if the target
duration is 0 to 3 minutes, the maximum time scale is 3:30 minutes.
If the target duration is 3 to 6 minutes, the maximum time scale is
6:30 seconds, and so on.
[0450] The line graph 468 displays two background horizontal bars
HB1 and HB2 of different colors. The upper bar HB1 is colored,
e.g., green, and is centered to the target coagulation temperature
with a spread of plus and minus 10 degrees C. The lower bar HB2 is
colored, e.g., red, and is fixed at a prescribed maximum (e.g., 40
degrees C.) to alert potential surface overheating.
[0451] The line graph 468 also displays a triangle marker TM of a
selected color (e.g., red)(see FIG. 80) with a number corresponding
to the channel/electrode that is automatically turned off by the
controller 52 due to operation outside the selected parameters. As
before described, the circle C1 and boxes B1 and B3 for this
electrode/channel are also modified in the electrode icon 466 when
this situation occurs.
[0452] The Electrode Icon 466 can graphically display other types
of status or configuration information pertinent to the treatment
device TD. For example, the Electrode Icon 466 can display a
flashing animation in spatial relation to the idealized electrodes
to constantly remind the physician that the electrode is extended
into tissue. The flashing animation ceases to be shown when the
electrode is retracted. The flashing animation reminds the
physician to retract the electrodes before removing the treatment
device TD. As another example, the Electrode Icon 466 can display
another flashing animation when the expandable structure of the
treatment device TD is expanded. The flashing animation reminds the
physician to collapse the electrodes before removing the treatment
device TD.
[0453] (v) Pause
[0454] The controller 52 terminates the conveyance of radio
frequency ablation energy to the electrodes and the RF-On screen
changes into the Pause screen (see FIG. 81), due to any of the
following conditions (i) target duration is reached, (ii) all
channels/electrodes have an erroneous coagulation condition
(electrode or surface temperature or impedance out of range), or
(iii) manual termination of radio frequency energy application by
pressing the foot pedal 416 or the Standby/Ready Button 430.
[0455] Upon termination of radio frequency ablation energy, the
running clock icon 470 stops to indicate total elapsed time. The
controller 52 commands the continued supply of cooling liquid
through the treatment device TD into contact with mucosal tissue at
the targeted site. At the same time, cooling liquid is aspirated
from the treatment device TD in an open loop. This flow of cooling
liquid continues for a predetermined time period (e.g. 2 to 5
seconds) after the supply of radio frequency ablation energy is
terminated, after which the controller 52 stops the pump rotor
428.
[0456] During Pause, the controller 52 continues to supply
intermittent bursts of low power radio frequency energy to acquire
impedance information.
[0457] The Pause screen is in most respects similar to the RF-On
screen. The Pause screen displays the Screen Icon 450, to indicate
that the treatment device TD is connected and deployed in the
patient's esophagus. The flashing radio wave animation is not
present, indicating that radio frequency energy is no longer being
applied. The RF On Indicator 434 is, however, intermittently
illuminated to indicate that bursts of radio frequency energy are
being applied by the electrodes to acquire impedance
information.
[0458] The RF-On screen also updates the Electrode Icon 466 to
display in the boxes B1 and B3 the actual sensed tip temperature
and impedance conditions. However, no background color changes are
registered on the Pause screen, regardless of whether the sensed
conditions are without or outside the prescribed ranges.
[0459] The Pause screen continues to display the target duration
icon 452, target temperature icon 454, maximum power icon 456,
channel selection icon 458, coagulation level icon 460, and flow
rate/priming icon 462, indicating the current selected parameter
values.
[0460] The real time temperature line graph 468 continues to
display the four trending lines, until the target duration is
reached and five additional seconds elapse, to show the drop off of
electrode temperature.
[0461] If further treatment is desired, pressing the standby/Ready
button 430 returns the device 400 from the Pause back to the Ready
mode.
[0462] (vi) Procedure Log
[0463] As previously described, the floppy disk icon 464 and
coagulation level icon 460 are normally dimmed on the various
screens, until a floppy disk is inserted in the drive 426. When a
floppy disk is inserted in the drive 426, the icons 460 and 464 are
illuminated, and data is saved automatically after each application
of radio frequency energy.
[0464] When the floppy disk is inserted, the controller 52
downloads data to the disk each time it leaves the RF-On screen,
either by default or manual termination of the procedure. The
downloaded data creates a procedure log. The log documents, by date
of treatment and number of treatments, the coagulation level, the
coagulation duration, energy delivered by each electrode, and the
coolant flow rate. The procedure log also records at
pre-established intervals (e.g., every 5 seconds) the temperatures
of the electrode tips and surrounding tissue, impedance, and power
delivered by each electrode. The procedure log preferably records
these values in a spreadsheet format.
[0465] The housing 400 can carry an integrated printer, or can be
coupled through the I/O device 54 to an external printer. The
printer prints a procedure log in real time, as the procedure takes
place.
[0466] Various features of the invention are set forth in the
following claims.
* * * * *