U.S. patent application number 11/638952 was filed with the patent office on 2007-04-26 for apparatus to treat esophageal sphincters.
This patent application is currently assigned to Curon Medical, Inc.. Invention is credited to Stuart Edwards, David S. Utley.
Application Number | 20070093809 11/638952 |
Document ID | / |
Family ID | 21886570 |
Filed Date | 2007-04-26 |
United States Patent
Application |
20070093809 |
Kind Code |
A1 |
Edwards; Stuart ; et
al. |
April 26, 2007 |
Apparatus to treat esophageal sphincters
Abstract
A sphincter treatment apparatus has an introducer means
including a distal portion means. An expandable device means
includes a plurality of arm means. Each arm means of the plurality
has a distal section means and a proximal section means. Each of
distal sections means of the arm means are coupled and each of the
proximal sections means of the arm means are coupled to the
introducer means distal portion means. The expandable device means
is configured to at least partially dilate a sphincter in a
deployed state. An energy delivery device means is introduceable
from the introducer means into a selected site of the sphincter.
The energy delivery device means is configured to deliver
sufficient energy to reduce a frequency of relaxation of the
sphincter.
Inventors: |
Edwards; Stuart; (Salinas,
CA) ; Utley; David S.; (Redwood City, CA) |
Correspondence
Address: |
RYAN KROMHOLZ & MANION, S.C.
POST OFFICE BOX 26618
MILWAUKEE
WI
53226
US
|
Assignee: |
Curon Medical, Inc.
|
Family ID: |
21886570 |
Appl. No.: |
11/638952 |
Filed: |
December 14, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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|
10838292 |
May 4, 2004 |
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|
11638952 |
Dec 14, 2006 |
|
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|
09971085 |
Oct 4, 2001 |
6749607 |
|
|
10838292 |
May 4, 2004 |
|
|
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09036092 |
Mar 6, 1998 |
|
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09971085 |
Oct 4, 2001 |
|
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Current U.S.
Class: |
606/41 |
Current CPC
Class: |
A61B 2018/1869 20130101;
A61B 2018/00267 20130101; A61B 2018/00827 20130101; A61B 2018/00488
20130101; A61B 2018/00553 20130101; A61B 2018/046 20130101; A61B
2018/00589 20130101; A61B 2018/0293 20130101; A61B 2017/3445
20130101; A61B 2018/00702 20130101; A61B 5/4233 20130101; A61B
18/0218 20130101; A61B 2018/00648 20130101; A61B 2018/0262
20130101; A61B 18/1492 20130101; A61B 2018/00892 20130101; A61B
2018/1861 20130101; A61B 18/1477 20130101; A61B 2018/00821
20130101; A61B 2018/00875 20130101; A61B 2018/00994 20130101; A61B
2017/345 20130101 |
Class at
Publication: |
606/041 |
International
Class: |
A61B 18/14 20060101
A61B018/14 |
Claims
1. A sphincter treatment apparatus comprising: an introducer having
an introducer lumen, an expandable device coupled to the
introducer, the expandable device including a first arm with a
proximal section and a distal section and a second arm with a
proximal section and a distal section, the first and second arm
distal sections being coupled, at least one of the first and second
arms including an arm lumen coupled in fluid communication with the
introducer lumen for delivery of a fluid, the expandable device
being configured to at least partially dilate a sphincter in a
deployed state, and an energy delivery device coupled to the
expandable device.
2. An apparatus as in claim 1 wherein at least a portion of the
energy delivery device is advanceable into the sphincter.
3. An apparatus as in claim 1 wherein the at least one of the first
and second arms includes an aperture coupled to the introducer
lumen and adapted to provide a path for delivery of the fluid from
the introducer.
4. An apparatus as in claim 3 wherein the fluid is cooling
fluid.
5. A method of treating a sphincter comprising: providing an
introducer, the introducer carrying an expandable device, providing
an energy delivery device coupled to the expandable device,
deploying the introducer to a targeted tissue site at or near a
sphincter, expanding the expandable device to at least partially
dilate the sphincter, delivering energy from the energy delivery
device to the targeted tissue site, and delivering a cooling fluid
from the introducer.
6. A method as in claim 5 wherein the expandable device includes a
first arm with a proximal section and a distal section and a second
arm with a proximal section and a distal section, the first and
second arm distal sections being coupled.
7. A method as in claim 6 wherein at least one of the first and
second arms includes a lumen.
8. A method as in claim 5 wherein the introducer includes a
lumen.
9. A method as in claim 5 wherein the cooling fluid is delivered at
a sensed flow rate, further comprising, measuring the temperature
of at least one of the tissue site and the energy delivery device,
and comparing the measured temperature to a pre-set desired
temperature.
10. A method as in claim 9, further comprising maintaining the flow
rate if the measured temperature does not exceed the desired
temperature.
11. A method as in claim 9, further comprising increasing the flow
rate if the measured temperature exceeds the desired temperature.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of application Ser. No.
10/838,292, which is a divisional of application Ser. No.
09/971,085, filed Oct. 4, 2001 (now U.S. Pat. No. 6,749,607), which
is a continuation of application Ser. No. 09/036,092, filed Mar. 6,
1998, now abandoned.
FIELD OF THE INVENTION
[0002] This invention relates generally to an apparatus to treat
sphincters, and more particularly to an apparatus to treat
esophageal sphincters.
DESCRIPTION OF RELATED ART
[0003] Gastroesophageal reflux disease (GERD) is a common
gastroesophageal disorder in which the stomach contents are ejected
into the lower esophagus due to a dysfunction of the lower
esophageal sphincter (LES). These contents are highly acidic and
potentially injurious to the esophagus resulting in a number of
possible complications of varying medical severity. The reported
incidence of GERD in the U.S. is as high as 10% of the population
(Castell DO; Johnston BT: Gastroesophageal Reflux Disease: Current
Strategies For Patient Management. Arch Fam Med, 5(4):221-7; (1996
April)).
[0004] Acute symptoms of GERD include heartburn, pulmonary
disorders and chest pain. On a chronic basis, GERD subjects the
esophagus to ulcer formation, or esophagitis and may result in more
severe complications including esophageal obstruction, significant
blood loss and perforation of the esophagus. Severe esophageal
ulcerations occur in 20-30% of patients over age 65. Moreover, GERD
causes adenocarcinoma, or cancer of the esophagus, which is
increasing in incidence faster than any other cancer (Reynolds JC:
Influence Of Pathophysiology, Severity, And Cost On The Medical
Management Of Gastroesophageal Reflux Disease. Am J Health Syst
Pharm, 53(22 Suppl 3):S5-12 (1996 Nov. 15)).
[0005] Current drug therapy for GERD includes histamine receptor
blockers which reduce stomach acid secretion and other drugs which
may completely block stomach acid. However, while pharmacologic
agents may provide short term relief, they do not address the
underlying cause of LES dysfunction.
[0006] Invasive procedures requiring percutaneous introduction of
instrumentation into the abdomen exist for the surgical correction
of GERD. One such procedure, Nissen fundoplication, involves
constructing a new "valve" to support the LES by wrapping the
gastric fundus around the-lower esophagus. Although the operation
has a high rate of success, it is an open abdominal procedure with
the usual risks of abdominal surgery including: postoperative
infection, herniation at the operative site, internal hemorrhage
and perforation of the esophagus or of the cardia. In fact, a
recent 10 year, 344 patient study reported the morbidity rate for
this procedure to be 17% and mortality 1% (Urschel, JD:
Complications, Of Antireflux Surgery, Am J Surg 166(1): 68-70;
(1993 July)). This rate of complication drives up both the medical
cost and convalescence period for the procedure and may exclude
portions of certain patient populations (e.g., the elderly and
immuno-compromised).
[0007] Efforts to perform Nissen fundoplication by less invasive
techniques have resulted in the development of laparoscopic Nissen
fundoplication. Laparoscopic Nissen fundoplication, reported by
Dallemagne et al. Surgical Laparoscopy and Endoscopy, Vol. 1, No.
3, (1991), pp. 138-43 arid by Hindler et al. Surgical Laparoscopy
and Endoscopy, Vol. 2, No. 3, (1992), pp. 265-272, involves
essentially the same steps as Nissen fundoplication with the
exception that surgical manipulation is performed through a
plurality of surgical cannula introduced using trocars inserted at
various positions in the abdomen.
[0008] Another attempt to perform fundoplication by a less invasive
technique is reported in U.S. Pat. No. 5,088,979. In this
procedure, an invagination device containing a plurality of needles
is inserted transorally into the esophagus with the needles in a
retracted position. The needles are extended to engage the
esophagus and fold the attached esophagus beyond the
gastroesophageal junction. A remotely operated stapling device,
introduced percutaneously through an operating channel in the
stomach wall, is actuated to fasten the invaginated
gastroesophageal junction to the surrounding involuted stomach
wall.
[0009] Yet another attempt to perform fundoplication by a less
invasive technique is reported in U.S. Pat. No. 5,676,674. In this
procedure, invagination is done by a jaw-like device and fastening
of the invaginated gastroesophageal junction to the fundus of the
stomach is done via a transoral approach using a remotely operated
fastening device, eliminating the need for an abdominal incision.
However, this procedure is still traumatic to the LES and presents
the postoperative risks of gastroesophageal leaks, infection and
foreign body reaction, the latter two sequela resulting when
foreign materials such as surgical staples are implanted in the
body.
[0010] While the methods reported above are less invasive than an
open Nissen fundoplication, some still involve making an incision
into the abdomen and hence the increased morbidity and mortality
risks and convalescence period associated with abdominal surgery.
Others incur the increased risk of infection associated with
placing foreign materials into the body. All involve trauma to LES
and the risk of leaks developing at the newly created
gastroesophageal junction.
[0011] Besides the LES, there are other sphincters in the body
which if not functionally properly can cause disease states or
otherwise adversely affect the lifestyle of the patient. Reduced
muscle tone or otherwise aberrant relaxation of sphincters can
result in a laxity of tightness disease states including, but not
limited to, urinary incontinence.
[0012] There is a need to provide an apparatus to treat a sphincter
and reduce a frequency of sphincter relaxation. Another need exists
for an apparatus to create controlled cell necrosis in a sphincter
tissue underlying a sphincter mucosal layer. Yet another need
exists for an apparatus to create controlled cell necrosis in a
sphincter and minimize injury to a mucosal layer of the sphincter.
There is another need for an apparatus to controllably produce a
lesion in a sphincter without creating a permanent impairment of
the sphincter's ability to achieve a physiologically normal state
of closure. Still a further need exists for an apparatus to create
a tightening of a sphincter without permanently damaging anatomical
structures near the sphincter. There is still another need for an
apparatus to create controlled cell necrosis in a lower esophageal
sphincter to reduce a frequency of reflux of stomach contents into
an esophagus.
SUMMARY OF THE INVENTION
[0013] Accordingly, an object of the present invention is to
provide an apparatus that reduces a frequency of sphincter
relaxation.
[0014] Another object of the invention is to provide an apparatus
to create controlled cell necrosis in a sphincter tissue underlying
a sphincter mucosal layer. Yet another object of the invention is
to provide an apparatus to create controlled cell necrosis in a
sphincter and minimize injury to a mucosal layer of the
sphincter.
[0015] A further object of the invention is to provide an apparatus
to controllably produce a lesion in a sphincter without creating a
permanent impairment of the sphincter's ability to achieve a
physiologically normal state of closure.
[0016] Still another object of the invention is to provide an
apparatus to create a tightening of a sphincter without permanently
damaging anatomical structures near the sphincter.
[0017] Another object of the invention is to provide an apparatus
to create controlled cell necrosis in a lower esophageal sphincter
to reduce a frequency of reflux of stomach contents into an
esophagus.
[0018] These and other objects of the invention are provided in a
sphincter treatment apparatus within an introducer means including
a distal portion means. An expandable device means includes a
plurality of arm means. Each arm means has a distal section means
and a proximal section means. Each of the distal section means of
the arm means are coupled and each of the proximal section means of
the arm means are coupled to the introducer means distal portion
means. The expandable device means is configured to at least
partially dilate a sphincter in a deployed state. An energy
delivery device means is introduceable from the introducer means
into a selected site of the sphincter. The energy delivery device
means is configured to deliver sufficient energy to reduce a
frequency of relaxation of the sphincter.
[0019] In another embodiment, an expandable device means is coupled
to an introducer distal portion means. The expandable device means
includes a first arm means with a proximal and distal section means
and a second arm means with proximal and distal section means. The
first and second arm distal portion means are coupled. The
expandable device means is configured to at least partially dilate
a sphincter in a deployed state. An energy delivery device means is
coupled to the expandable device means. The energy delivery device
means is configured to deliver sufficient energy to reduce a
frequency of relaxation of the sphincter while minimizing cell
necrosis of a mucosal layer of the sphincter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is an illustrated lateral view of the upper GI tract
depicting the position of the sphincter treatment apparatus of the
present invention in the lower esophageal sphincter.
[0021] FIG. 2 is a lateral view of the present invention
illustrating the introducer, expansion device and energy delivery
device.
[0022] FIG. 3 depicts a lateral view of an embodiment of the
invention that illustrates the use of a sheath to introduce and
deploy the expansion device.
[0023] FIG. 4 illustrates a lateral view of the basket assembly
used in an embodiment of the invention.
[0024] FIG. 5 is a lateral view of the basket assembly illustrating
the placement of struts on the basket assembly.
[0025] FIG. 6A is a lateral view of the junction between the basket
arms and the introducer illustrating a lumen in the basket arm that
can be used for the advancement of energy delivery devices.
[0026] FIG. 6B is a frontal view of a basket arm in an alternative
embodiment of the invention illustrating a track in the arm used to
advance the movable wire.
[0027] FIG. 7A is a cross-sectional view of a section of a basket
arm and an energy delivery device illustrating stepped and tapered
sections in the basket arm apertures and energy delivery
device.
[0028] FIG. 8A is a lateral view of the basket assembly
illustrating the use of the advancement member and introducer to
position energy delivery devices into the sphincter wall.
[0029] FIG. 8B is a lateral view of the basket assembly
illustrating the use of the advancement member and basket arms to
position energy delivery devices into the sphincter wall.
[0030] FIG. 9 is a cross sectional view illustrating the use of a
needle electrode in combination with an angled aperture segment to
select and maintain a constant penetration angle into the sphincter
wall.
[0031] FIG. 10 is a lateral view illustrating the placement of
needle electrodes into the sphincter wall by expansion of the
basket assembly.
[0032] FIG. 11 is a lateral view illustrating the use of an
insulation layer on the needle electrode to protect an area of
tissue from RF energy.
[0033] FIG. 12 depicts the fluid source and flow path to deliver
fluid to treatment site using the introducer.
[0034] FIG. 13 is a cross sectional view illustrating a
visualization device coupled to an embodiment of the invention.
[0035] FIG. 14 is an enlarged lateral view illustrating the
placement of sensors on/adjacent the energy delivery device and the
coupling of sensors to a feedback control system.
[0036] FIG. 15 is a flow chart illustrating a sphincter treatment
method using the apparatus of the present invention.
[0037] FIG. 16 is a lateral view of sphincter smooth muscle tissue
illustrating electrical foci and electrically conductive pathways
for the origination and conduction of aberrant electrical signals
in the smooth muscle of the lower esophageal sphincter or other
tissue.
[0038] FIG. 17 is a lateral view of a sphincter wall illustrating
the infiltration of tissue healing cells into a lesion in the
smooth tissue of a sphincter following treatment with the sphincter
treatment apparatus of the present invention.
[0039] FIG. 18 is a view similar to that of FIG. 17 illustrating
shrinkage of the lesion site caused by cell infiltration.
[0040] FIG. 19 is a lateral view of the esophageal wall
illustrating the preferred placement of lesions in the smooth
muscle layer of a esophageal sphincter.
[0041] FIGS. 20A-D are lateral views of the sphincter wall
illustrating various patterns of lesions created by the apparatus
of the,present invention.
[0042] FIG. 21 depicts a block diagram of the feed back control
system that can be used with an embodiment of the invention.
[0043] FIG. 22 depicts a block diagram of an analog amplifier,
analog multiplexer and microprocessor used with the feedback
control system of FIG. 21.
[0044] FIG. 23 depicts a block diagram of the operations performed
in the feedback control system depicted in FIG. 21.
DETAILED DESCRIPTION
[0045] Referring to FIGS. 1 and 2, one embodiment of a sphincter
treatment apparatus 10 delivers energy to a treatment site 12 to
produce lesions 14 in a sphincter 16, such as the lower esophageal
sphincter (LES). In this embodiment, sphincter treatment apparatus
10 comprises a flexible elongate shaft 18, also called introducer
18, coupled to an expansion device 20, in turn coupled with one or
more energy delivery devices 22. Introducer 18 has a distal
extremity also called introducer end 19. Energy delivery devices 22
are configured to be coupled to a power source.
[0046] Expansion device 20 comprises a plurality of arms 24, with
proximal and distal arms ends 25 and 26. Proximal arm ends 25 are
coupled to introducer end 19. Expansion device 20 has a central
longitudinal axis 28 and is moveable between contracted and
expanded/deployed states substantially there along. Expansion
device 20 is configured to be positionable in a sphincter 16 (such
as the LES) or adjacent anatomical structure (such as the cardia of
the stomach) and is further configured to partially dilate
sphincter 16 when in the deployed state. Energy delivery devices 22
are configured to be introduceable from introducer 18 and to
contact and/or penetrate a targeted treatment site 12 in a
sphincter wall 30 or adjoining anatomical structure. They are
further configured to deliver energy to treatment site 12.
[0047] Referring now to FIG. 2, introducer 18 is configured to be
coupled to expansion device 20 and has sufficient length to
position expansion device 20 in the LES and/or stomach using a
transoral approach. Typical lengths for introducer 18 include a
range of 40-180 cm. Introducer 18 may be circular or oval in cross
section. Also, introducer 18 may be flexible, articulated,
coil-reinforced, or steerable, or any combination thereof. Suitable
materials for introducer 18 include polyethylenes, polyurethanes,
silicones and other biocompatible polymers known to those skilled
in the art. Introducer 18 may also be coated with a lubricious
coating as is well known to those skilled in the art.
[0048] Introducer 18 may have one or more lumens 32, that extend
the full length of introducer 18, or only a portion thereof. Lumens
32 may be used as paths for the delivery of fluids and gases, as
well as providing channels for cables, catheters, guide wires, pull
wires, insulated wires, and optical fibers.
[0049] In another embodiment of the invention depicted in FIGS. 3A
and 3B, an introduction member 34, also called a sheath 34, is used
to introduce sphincter treatment apparatus 10 into the LES. Sheath
34 can also function as a sheath for expansion device 20 to keep it
in a nondeployed or contracted state during introduction into the
LES. To facilitate this function, sheath 34 contains a sheath lumen
36 of sufficient inner diameter to allow free movement of sphincter
treatment apparatus 10 within sheath lumen 36. Sheath 34, sheath
lumen 36 and sphincter treatment apparatus 10 are configured to
allow expansion device 20 to go from a contracted state to an
expanded state and vice versa by either i) the retraction or
advancement of sheath 34, or ii) the advancement or withdrawal of
sphincter treatment apparatus 10. Sheath 34 may be flexible,
articulated, coil-reinforced or steerable, or any combination
thereof Suitable materials for sheath 34 include polyethylenes,
polyurethanes, silicones, polytetrafluoroethylenes and other
biocompatible polymers known to those skilled in the art. Typical
diameters for sheath lumen 36 include 0.1 to 2inches, while typical
lengths include 40-180 cms.
[0050] Referring now to FIG. 4, in another embodiment of the
present invention, expansion device 20 comprises one or more
elongated arms 24 that are joined at their proximal ends 25 and
distal ends 2.6 to form a basket assembly 38. Proximal arm end 25
is attached to a supporting structure, which can be distal end 19
of introducer 18 or a proximal cap 40. Likewise, distal arm end 26
is also attached to a supporting structure which can be a distal
basket cap 42 or introducer 18. Arms 24 are of a sufficient number,
two or more, to sufficiently open and efface the folds of sphincter
16 to allow treatment with sphincter treatment apparatus 10, while
preventing herniation of sphincter wall 30 into the spaces 44
between arms 24.
[0051] Arms 24 may form a variety of geometric shapes including,
curved, rectangular, trapezoidal, triangular, or any combination
thereof Also, arms 24 can have an outwardly bowed shaped memory for
expanding basket assembly 38 into engagement with sphincter wall
30. Arms 24 may be preshaped at time of manufacture or shaped by
the physician. Arms 24 can have a variety of cross sectional
geometries including, circular, rectangular and crescent-shaped.
The circumferential spacing of arms 24 can be symmetrical or
asymmetrical with respect to a circumference around longitudinal
axis 28. Suitable materials for arms 24 include spring steel,
stainless steel, superelastic shape memory metals such as nitinol,
or stiff shaft plastic tubing as is well known to those skilled in
the art. Arms 24 may also be color-coded to facilitate their
identification via visual medical imaging methods and equipment,
such as endoscopic methods, which are well known to those skilled
in the art.
[0052] In another embodiment of the invention depicted in FIG. 5, a
supporting member 46 is attached to two or more arms 24. Supporting
member 46, also called strut 46, can be attached to arms 24 along a
circumference of basket assembly 38. Strut 46 may also contain
apertures 50, in one or more places that extend through strut 46 to
arm 24 as will be discussed herein. The cross sectional geometry of
strut 46 can be rectangular, circular or crescent-shaped. Suitable
materials for strut 46 include spring steel, stainless steel,
superelastic shape memory metals such as nitinol, or stiff shaft
plastic tubing as is well known to those skilled in the art.
[0053] Referring now to FIG. 6A, arms 24 may be solid or hollow
with a continuous arm lumen 48 that may be coupled with introducer
lumens 32. Also arms 24 may have one or more apertures 50 that may
coupled to arm lumen 48. Coupled lumens 32 and 48, and apertures 50
provide a path for the delivery of a fluid or energy delivery
device 22 from introducer 18 to the surface or interior of
sphincter wall 30. As shown in FIG. 6B, arms 24 may also have a
partially open channel 52, also called a track 52, that functions
as a guide track for the travel of an advancement member (discussed
herein) and/or energy delivery device 22 that permit the controlled
placement of-energy delivery devices 22 at or into sphincter wall
30. Referring now to FIG. 7, apertures 50 may have tapered sections
54 and/or stepped sections 56 in all or part of their length, that
are used to control the penetration depth of energy delivery
devices 22 into sphincter wall 30 as will be discussed herein.
Energy delivery devices 22 may have similar tapered sections 54'
and/or stepped sections 56'.
[0054] Referring now to FIGS. 8A and 8B, in another embodiment of
the invention, energy delivery devices 22 can be coupled to an
energy device delivery member 57, also called an advancement member
57. Advancement member 57 can be an insulated wire, an insulated
guide wire, a plastic-coated stainless steel hypotube with internal
wiring or a plastic catheter with internal wiring as is well known
to those skilled in the art. Advancement member 57 is configured to
be able to introduce energy delivery device 22 into sphincter wall
30 via introducer 18 (see FIG. 8A) or basket assembly 38 as will be
discussed herein (see FIG. 8B). Advancement member 57 is of
sufficient length to position energy delivery device 22 in the LES
and/or stomach using a transoral approach. Typical lengths for
advancement member 57 include a range of 40-180 cms.
[0055] In another embodiment of the invention depicted in FIG. 9,
energy delivery device 22 has a distal portion 58 that is
configured to penetrate sphincter wall 30 with a minimum amount of
tearing of the mucosal and submucosal layers 60 and 62 of sphincter
16. This is facilitated by maintaining a constant angle of
penetration 64, also called penetration angle 64, of distal portion
58 into sphincter wall 30 during the time that energy delivery
device 22 is advanced into sphincter wall 30. The typical range for
penetration angle 64 lies between 1 and 90.degree.. This can be
accomplished through the use of a needle 58' for distal energy
delivery device portion 58, coupled with an angled aperture segment
50' having a preselected penetration angle 64. Needle 58' is of
sufficient sharpness and length to penetrate into the smooth muscle
of sphincter wall 30. In a further embodiment, needle 58' can be a
needle electrode 58. Distal portion 58, including needle 58' and
needle electrode 58 can also be stepped or tapered to enable
control of energy delivery device (see FIG. 7). Suitable materials
for needle 58' and needle electrodes 58'' include 304 stainless
steel and other metals known to those skilled in the art.
[0056] In another embodiment of the invention, energy delivery
device 22 is coupled to arm 24. As shown in FIG. 10, this can be
accomplished by attaching needle 58' to arm 24. When sphincter
treatment apparatus 10 is properly positioned at the treatment site
12, needles 58' are deployed by expansion of basket assembly 38,
resulting in the protrusion of needle 58' into the smooth muscle
tissue of sphincter wall 30 (see FIG. 10). Referring back to FIG.
9, coupling can also be accomplished by employing arm 24 to
introduce energy delivery device 22 into sphincter wall 30 via use
of arm lumen 48.
[0057] Turning now to a discussion of energy delivery, suitable
power sources and energy delivery devices 22 that can be employed
in one or more embodiments of the invention include or more of the
following: (i) a radio-frequency (RF) source coupled to an RF
electrode, (ii) a coherent source of light coupled to an optical
fiber, (iii) an incoherent light source coupled to an optical
fiber, (iv) a heated fluid coupled to a catheter with a closed
channel configured to receive the heated fluid, (v) a heated fluid
coupled to a catheter with an open channel configured to receive
the heated fluid, (vi) a cooled fluid coupled to a catheter with a
closed channel configured to receive the cooled fluid, (vii) a
cooled fluid coupled to a catheter with an open channel configured
to receive the cooled fluid, (viii) a cryogenic fluid, (ix) a
resistive heating source, (x) a microwave source providing energy
from 915 MHz to 2.45 GHz and coupled to a microwave antenna, or
(xi) an ultrasound power source coupled to an ultrasound emitter,
wherein the ultrasound power source produces energy in the range of
300 KHZ to 3 GHz. For ease of discussion for the remainder of this
application, the power source utilized is an RF source and energy
delivery device 22 is one or more RF electrodes 66, also described
as electrodes 66. However, all of the other herein mentioned power
sources and energy delivery devices are equally applicable to
sphincter treatment apparatus 10.
[0058] For the case of RF energy, RF electrode 66 may be operated
in either bipolar or monopolar mode with a ground pad electrode. In
a monopolar mode of delivering RF energy, a single electrode 66 is
used in combination with an indifferent electrode patch that is
applied to the body to form the other electrical contact and
complete an electrical circuit. Bipolar operation is possible when
two or more electrodes 66 are used. Multiple electrodes 66 may be
used. These electrodes may be cooled as described herein.
Electrodes 66 can be attached to advancement member 57 by the use
of soldering methods which are well known to those skilled in the
art.
[0059] Referring now to FIG. 11, RF electrodes 66 can have an
insulating layer 68, covering an insulated segment 70 except for an
exposed segment 72. For purposes of this disclosure, an insulator
or insulation layer is a barrier to either thermal or
electromagnetic energy flow including RF energy flow. Insulated
segment 70 is of sufficient length to extend into sphincter wall 30
and minimize the transmission of RF energy to a protected site 74
near or adjacent to insulated segment 70. Typical lengths for
insulated segment 70 include, but are not limited to, 1-4 mm.
Suitable materials for insulating layer 68 include electrically
insulating plastics and other materials well known to those skilled
in the art.
[0060] In another embodiment of the invention, the depth of
penetration of energy delivery device 22 into sphincter wall 30 is
controllable. This can be accomplished by the selection and control
of the dimensional relationships (e.g. the amount of clearance
between inner and outer diameters) of energy delivery devices 22
and/or advancement member 57 to one or more of the following
elements: arm lumen 48, apertures 50 and track 52. Control of
penetration depth can also be accomplished through the use of
tapered and/or stepped sections in one or more of the preceding
elements as is discussed herein. In another embodiment, penetration
depth control can be accomplished by the use of one or more of a
variety of positional control means, known to those skilled in the
art, that are coupled to sphincter treatment apparatus 10. Such
positional control means include stepper motor systems, indexing
mechanisms and micromanipulators.
[0061] Referring now to FIG. 12, in another embodiment of the
invention, fluid can be delivered to treatment site 12 via
introducer 18. This is accomplished by the coupling of introducer
18 to a fluid source 76 via introducer lumen 32.
[0062] Referring now to FIG. 13, another embodiment of sphincter
treatment apparatus 10 includes a visualization device 78 coupled
to introducer 18. Visualization device 78 can include a combination
of one or more of the following: a viewing scope, an expanded
eyepiece, fiber optics (both imaging and illuminating fibers),
video imaging devices and the like.
[0063] As shown in FIG. 14, one or more sensors 80 may be
positioned adjacent to or on electrode 66 for sensing the physical
properties of sphincter tissue at treatment site 12. Sensors 80
permit accurate determination of the physical properties of
sphincter wall 30 at an electrode-tissue interface 82. Such
physical properties include temperature, electrical conductivity,
electrical capacitance, thermal conductivity, density, thickness,
strength, elasticity, moisture content, optical reflectance,
optical transmittance, optical absorption acoustical impedance and
acoustical absorption. Sensors 80 can be positioned at any position
on expansion device 20, electrode 66 or basket assembly 38.
Suitable sensors that may be used for sensor 80 include:
thermocouples, fiber optics, photomultipliers, resistive wires,
thermocouple IR detectors, thin film sensors, anemometric sensors
and ultrasound sensors. Sensor 80 can be coupled to a feedback
control system 84, described herein. The coupling of sensor 80 to
feedback control system 84 can be used to regulate the delivery of
energy, fluids and gases to one or more of the following locations:
treatment site 12, sphincter wall 30, and electrode tissue
interface 82.
[0064] FIG. 15 is a flow chart illustrating a method for using
sphincter treatment apparatus 10. First, sphincter treatment
apparatus 10 is introduced into the esophagus under local
anesthesia and positioned at treatment site 12. Sphincter treatment
apparatus 10 can be introduced into the esophagus by itself or
through a lumen in an endoscope (not shown), such as disclosed in
U.S. Pat. Nos. 5,448,990 and 5,275,608, incorporated herein by
reference, or a similar esophageal access device known to those
skilled in the art. Basket assembly 38 is expanded as described
herein. This serves to temporarily dilate the LES sufficiently to
efface all or a portion of the folds of the LES. In an alternative
embodiment, esophageal dilation and subsequent LES fold effacement
can be accomplished by insufflation of the esophagus (a known
technique) using gas introduced into the esophagus through
introducer lumen 32, an endoscope, or others esophageal access
devices known to those skilled in the art. Once treatment is
completed, basket assembly 38 is returned to its predeployed or
contracted state and sphincter treatment apparatus 10 is withdrawn
from the esophagus. This results in the LES returning to
approximately its pretreatment state and diameter. It will be
appreciated that the above procedure is applicable in whole or part
to the treatment of other sphincters in the body.
[0065] The diagnostic phase of the procedure then begins and can be
performed using a variety of diagnostic methods known to those
skilled in the art including the following: (i) visualization of
the interior surface of the esophagus via an endoscope or other
viewing apparatus inserted into the esophagus, (ii) visualization
of the interior morphology of the esophageal wall using
ultrasonography to establish a baseline for the tissue to be
treated, (iii) impedance measurement to determine the electrical
conductivity between esophageal mucosal and submucosal layers 60
and 62 and sphincter treatment apparatus 10, and (iv) measurement
and surface mapping of electropotential signals of the LES and
surrounding anatomical structures during varying time intervals
which may include such events as depolarization, contraction and
repolarization of gastroesophageal smooth muscle tissue. This
latter technique is done to determine target treatment sites 12 in
the LES or adjoining anatomical structures that are acting as
electrical foci 107 or electrically conductive pathways 109 for
abnormal or inappropriate polarization and relaxation of the smooth
muscle of the LES (Refer to FIG. 16).
[0066] After diagnosis, the treatment phase of the procedure
begins. In this phase of the procedure, the delivery of energy to
treatment site 12 can be conducted under feedback control, manually
or by a combination of both. Feedback control (described herein)
enables sphincter treatment apparatus 10 to be positioned and
retained in the esophagus during treatment with minimal attention
by the physician. Electrodes 66 can be multiplexed in order to
treat the entire targeted treatment site 12 or only a portion
thereof. Feedback can be included and is achieved by the use of one
or more of the following methods: (i) visualization, (ii) impedance
measurement, (iii) ultrasonography, (iv) temperature measurement;
and, (v) contractile force measurement via manometry. The feedback
mechanism permits the selected on-off switching of different
electrodes 66 in a desired pattern, which can be sequential from
one electrode 66 to an adjacent electrode 66, or can jump around
between non-adjacent electrodes 66. Individual electrodes 66 are
multiplexed and volumetrically controlled by a controller.
[0067] The area and magnitude of cell injury in the LES or
sphincter 16 can vary. However, it is desirable to deliver
sufficient energy to the targeted treatment site 12 to be able to
achieve tissue temperatures in the range of 55-95.degree. C. and
produce lesions 14 at depths ranging from 1-4 mms from the interior
surface of the LES or sphincter wall 30. Typical energies delivered
to the esophageal or stomach wall include, but are not limited to,
a range between 100 and 50,000 joules per electrode 66. It is also
desirable to deliver sufficient energy such that resulting lesions
14 have a sufficient magnitude and area of cell injury to cause an
infiltration of lesion 14 by fibroblasts 110, myofibroblasts 112,
macrophages 114 and other cells involved in the tissue healing
process (refer to FIG. 17). As shown in FIG. 18, these cells cause
a contraction of tissue around lesion 14, decreasing its volume
and/or altering the biomechanical properties at lesion 14 so as to
result in a tightening of the LES or sphincter 16. These changes
are reflected in transformed lesion 14'. The diameter of lesions 14
can vary between 0.1 to 4 mm. It is preferable that lesions 14 are
less than 4 mmns in less than 4 mms in diameter in order to reduce
the risk of thermal damage to mucosal and submucosal layers 60 and
62. In one embodiment, a 2 mm diameter lesion 14 centered in the
wall of the smooth muscle provides a 1 mm buffer zone on either
side of lesion 14 to prevent damage to mucosal and submucosal
layers 60 and 62 and the adventitia (not shown), while still
allowing for cell infiltration and subsequent sphincter tightening
on approximately 50% of the thickness of the wall of the smooth
muscle (refer to FIG. 19).
[0068] It is desirable that lesions 14 are predominantly located in
the smooth muscle layer of selected sphincter 16 at the depths
ranging from 1 to 4 mm from the interior surface of sphincter wall
30. However, lesions 14 can vary both in number and position within
sphincter wall 30. It may be desirable to produce a pattern of
multiple lesions 14 within the sphincter smooth muscle tissue in
order to obtain a selected degree of tightening of the LES or other
sphincter 16. Typical lesion patterns shown in FIGS. 20 A-D
include, but are not limited to, (i) a concentric circle of lesions
14 all at fixed depth in the smooth muscle layer evenly spaced
along the radial axis of sphincter 16, (ii) a wavy or folded circle
of lesions 14 at varying depths in the smooth muscle layer evenly
spaced along the radial axis of sphincter 16, (iii) lesions 14
randomly distributed at varying depths in the smooth muscle, but
evenly spaced in a radial direction and, (iv) an eccentric pattern
of lesions 14 in one or more radial locations in the smooth muscle
wall. Accordingly, the depth of RF and thermal energy penetration
into sphincter 16 is controlled and selectable. The selective
application of energy to sphincter 16 may be the even delivery of
RF energy to the entire targeted treatment site 12, a portion of
it, or applying different amounts of RF energy to different sites
depending on the condition of sphincter 16. If desired, the area of
cell injury can be substantially the same for every treatment
event.
[0069] A second diagnostic phase may be included after the
treatment is completed. This provides an indication of LES
tightening treatment success, and whether or not a second phase of
treatment, to all or only a portion of the esophagus, now or at
some later time, should be conducted. The second diagnostic phase
is accomplished through one or more of the following methods: (i)
visualization, (ii) measuring impedance, (iii) ultrasonography,
(iv) temperature measurement, or (v) measurement of LES tension and
contractile force via manometry.
[0070] In one embodiment of the invention, sensor 80 is coupled to
an open or closed loop feedback control system 84. Referring now to
FIG. 21, an open or closed loop feedback system 84 couples sensor
80, now described as sensor 346, to an energy source 392. In this
embodiment, an energy delivery device 314 is one or more RF
electrodes 314; however, in various other embodiments, energy
delivery device 314 may include others described herein. Similarly,
in this embodiment, sensor 346 senses temperature, but in various
other embodiments, sensor 346 may sense other physical properties
described herein.
[0071] The temperature of the tissue, or of RF electrode 314, is
monitored, and the output power of energy source 392 adjusted
accordingly. The physician can, if desired, override the closed or
open loop system 84. A microprocessor 394 can be included and
incorporated in the closed or open loop system to switch power on
and off, as well as modulate the power. The closed loop system 84
utilizes microprocessor 394 to serve as a controller, monitor the
temperature, adjust the RF power, analyze the result, refeed the
result, and then modulate the power.
[0072] With the use of sensor 346 and feedback control system 84,
tissue adjacent to RF electrode 314 can be maintained at a desired
temperature for a selected period of time without causing a shut
down of the power circuit to electrode 314 due to the development
of excessive electrical impedance at electrode 314 or adjacent
tissue. Each RF electrode 314 is connected to resources which
generate an independent output. The output maintains a selected
energy at RF electrode 314 for a selected length of time.
[0073] Current delivered through RF electrode 314 is measured by
current sensor 396. Voltage is measured by voltage sensor 398.
Impedance and power are then calculated at power and impedance
calculation device 400. These values can then be displayed at user
interface and display 402. Signals representative of power and
impedance values are received by a controller 404.
[0074] A control signal is generated by controller 404 that is
proportional to the difference between an actual measured value,
and a desired value. The control signal is used by power circuits
406 to adjust the power output an appropriate amount in order to
maintain the desired power delivered at respective RF electrodes
314.
[0075] In a similar manner, temperatures detected at sensor 346
provide feedback for maintaining a selected power. Temperature at
sensor 346 is used as a safety means to interrupt the delivery of
power when maximum pre-set temperatures are exceeded. The actual
temperatures are measured at temperature measurement device 408,
and the temperatures are displayed at user interface and display
402. A control signal is generated by controller 404 that is
proportional to the difference between an actual measured
temperature and a desired temperature. The control signal is used
by power circuits 406 to adjust the power output an appropriate
amount in order to maintain the desired temperature delivered at
the sensor 346. A multiplexer can be included to measure current,
voltage and temperature, at the sensor 346, and energy can be
delivered to RF electrode 314 in monopolar or bipolar fashion.
[0076] Controller 404 can be a digital or analog controller, or a
computer with software. When controller 404 is a computer it can
include a CPU coupled through a system bus. This system can include
a keyboard, a disk drive, or other non-volatile memory systems, a
display, and other peripherals, as are known in the art. Also
coupled to the bus is a program memory and a data memory.
[0077] User interface and display 402 includes operator controls
and a display. Controller 404 can be coupled to imaging systems
including, but not limited to, ultrasound, CT scanners, X-ray, MRI,
mammographic X-ray and the like. Further, direct visualization and
tactile imaging can be utilized.
[0078] The output of current sensor 396 and voltage sensor 398 are
used by controller 404 to maintain a selected power level at RF
electrode 314. The amount of RF energy delivered controls the
amount of power. A profile of the power delivered to electrode 314
can be incorporated in controller 404 and a preset amount of energy
to be delivered may also be profiled.
[0079] Circuitry, software and feedback to controller 404 result in
process control, the maintenance of the selected power setting
which is independent of changes in voltage or current, and is used
to change the following process variables: (i) the selected power
setting, (ii) the duty cycle (e.g., on-off time), (iii) bipolar or
monopolar energy delivery; and, (iv) fluid delivery, including flow
rate and pressure. These process variables are controlled and
varied, while maintaining the desired delivery of power independent
of changes in voltage or current, based on temperatures monitored
at sensor 346.
[0080] Referring now to FIG. 22, current sensor 396 and voltage
sensor 398 are connected to the input of an analog amplifier 410.
Analog amplifier 410 can be a conventional differential amplifier
circuit for use with sensor 346. The output of analog amplifier 410
is sequentially connected by an analog multiplexer 412 to the input
of A/D converter 414. The output of analog amplifier 410 is a
voltage which represents the respective sensed temperatures.
Digitized amplifier output voltages are supplied by A/D converter
414 to microprocessor 394. Microprocessor 394 may be a type 68HCII
available from Motorola. However, it will be appreciated that any
suitable microprocessor or general purpose digital or analog
computer can be used to calculate impedance or temperature.
[0081] Microprocessor 394 sequentially receives and stores digital
representations of impedance and temperature. Each digital value
received by microprocessor 394 corresponds to different
temperatures and impedances.
[0082] Calculated power and impedance values can be indicated on
user interface and display 402. Alternatively, or in addition to
the numerical indication of power or impedance, calculated
impedance and power values can be compared by microprocessor 394 to
power and impedance limits. When the values exceed predetermined
power or impedance values, a warning can be given on user interface
and display 402, and additionally, the delivery of RF energy can be
reduced, modified or interrupted. A control signal from
microprocessor 394 can modify the power level supplied by energy
source 392.
[0083] FIG. 23 illustrates a block diagram of a temperature and
impedance feedback system that can be used to control the delivery
of energy to tissue site 416 by energy source 392 and the delivery
of a cooling medium to electrode 314 and/or tissue site 416 by flow
regulator 418. Energy is delivered to RF electrode 314 by energy
source 392, and applied to tissue site 416. A monitor 420
ascertains tissue impedance, based on the energy delivered to
tissue, and compares the measured impedance value to a set value.
If measured impedance is within acceptable limits, energy continues
to be applied to the tissue. However if the measured impedance
exceeds the set value, a disabling signal 422 is transmitted to
energy source 392, ceasing further delivery of energy to RF
electrode 314.
[0084] The control of the delivery of cooling medium to electrode
314 and/or tissue site 416 is done in the following manner. During
the application of energy, temperature measurement device 408
measures the temperature of tissue site 416 and/or RF electrode
314. A comparator 424 receives a signal representative of the
measured temperature and compares this value to a pre-set signal
representative of the desired temperature. If the measured
temperature has not exceeded the desired temperature, comparator
424 sends a signal to flow regulator 418 to maintain the cooling
solution flow rate at its existing level. However if the tissue
temperature is too high, comparator 424 sends a signal to a flow
regulator 418 (connected to an electronically controlled micropump,
not shown) representing a need for an increased cooling solution
flow rate.
[0085] The foregoing description of a preferred embodiment of the
invention has been presented for purposes of illustration and
description. It is not intended to be exhaustive or to limit the
invention to the precise forms disclosed. Obviously, many
modifications and variations will be apparent to practitioners
skilled in this art. It is intended that the scope of the invention
be defined by the following claims and their equivalents.
* * * * *