U.S. patent application number 09/943646 was filed with the patent office on 2002-08-08 for sphincter treatment apparatus.
This patent application is currently assigned to Curon Medical, Inc.. Invention is credited to Edwards, Stuart D..
Application Number | 20020107512 09/943646 |
Document ID | / |
Family ID | 22095608 |
Filed Date | 2002-08-08 |
United States Patent
Application |
20020107512 |
Kind Code |
A1 |
Edwards, Stuart D. |
August 8, 2002 |
Sphincter treatment apparatus
Abstract
A sphincter treatment apparatus includes an energy delivery
device introduction member including a plurality of arms. Each arm
has distal and proximal sections. The distal sections of the arms
are coupled as are the proximal sections of the arms. The energy
delivery device introduction member is configured to be introduced
in the sphincter in a non-deployed state, expand to a deployed
state to at least partially expand the sphincter. A plurality of
energy delivery devices are coupled to the energy delivery device
introduction member. At least a portion of the plurality of energy
delivery devices are controllably introducible from the energy
delivery device introduction member into the sphincter.
Inventors: |
Edwards, Stuart D.; (Portola
Valley, CA) |
Correspondence
Address: |
RYAN KROMHOLZ & MANION, S.C.
POST OFFICE BOX 26618
MILWAUKEE
WI
53226
US
|
Assignee: |
Curon Medical, Inc.
|
Family ID: |
22095608 |
Appl. No.: |
09/943646 |
Filed: |
August 30, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09943646 |
Aug 30, 2001 |
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09070490 |
Apr 30, 1998 |
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09070490 |
Apr 30, 1998 |
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09026316 |
Feb 19, 1998 |
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6056744 |
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Current U.S.
Class: |
606/41 ; 607/101;
607/133 |
Current CPC
Class: |
A61B 2018/00791
20130101; A61B 2018/124 20130101; A61B 2090/3614 20160201; A61B
2018/1253 20130101; A61B 18/1477 20130101; A61B 2090/3782 20160201;
A61B 2018/00148 20130101; A61B 2018/00494 20130101; A61B 18/14
20130101; A61B 2018/183 20130101; A61B 2018/00744 20130101; A61B
2018/00011 20130101; A61B 18/1492 20130101; A61B 2018/00267
20130101; A61B 17/32 20130101; A61B 2018/126 20130101; A61B
2018/00702 20130101; A61B 2018/00916 20130101; A61B 18/1815
20130101; A61B 2018/00029 20130101; A61B 2018/00214 20130101; A61B
2018/00553 20130101; A61B 2018/00875 20130101; A61B 2018/1472
20130101; A61B 2018/00577 20130101; A61B 2018/00726 20130101; A61B
2018/0022 20130101 |
Class at
Publication: |
606/41 ; 607/101;
607/133 |
International
Class: |
A61B 018/18 |
Claims
What is claimed is:
1. A sphincter treatment apparatus, comprising: an energy delivery
device introduction member; a first energy delivery device coupled
to the energy delivery device introduction member, the first energy
delivery device having a distal portion, wherein the energy
delivery device introduction member is configured to be introduced
in the sphincter in a non-deployed state, and expand to a deployed
state to at least partially expand the sphincter; and a retainer
member coupled to the energy delivery device introduction member
and configured to controllably position the energy delivery device
introduction member in an orifice of a sphincter.
2. The apparatus of claim 1, wherein the retainer member retains
the energy delivery device introduction member along a longitudinal
axis of the sphincter.
3. The apparatus of claim 1, wherein the retainer member reduces a
movement of the energy delivery device introduction member in the
orifice along a longitudinal axis of the sphincter.
4. The apparatus of claim 1, wherein the retainer member reduces a
lateral movement of the energy delivery device introduction member
in the orifice along a longitudinal axis of the sphincter.
5. The apparatus of claim 1, wherein the first energy delivery
device distal portion is introducible into an interior of the
sphincter.
6. The apparatus of claim 5, wherein the first energy delivery
device is an electrode.
7. The apparatus of claim 6, wherein the electrode has a tissue
piercing distal end.
8. The apparatus of claim 1, wherein the energy delivery device
introduction member is expandable.
9. The apparatus of claim 8, wherein the energy delivery device
introduction member is a balloon.
10. The apparatus of claim 8, wherein the energy delivery device
introduction member is a basket device.
11. The apparatus of claim 1, wherein the retainer member is made
of a polymeric material.
12. The apparatus of claim 11, wherein the retainer member is a
catheter
13. The apparatus of claim 11, wherein the retainer member is an
endoscope
14. The apparatus of claim 1, wherein the retainer member reduces a
movement of an esophagus.
15. The apparatus of claim 1, wherein the retainer member has
sufficient rigidity to reduce a movement of the sphincter.
16. The apparatus of claim 15, wherein the retainer member has
sufficient rigidity to reduce a movement of an esophagus.
17. The apparatus of claim 1, wherein the first energy delivery
device is an RF needle electrode.
18. The apparatus of claim 17, wherein the retainer member has
sufficient rigidity to reduce a movement of the sphincter and
reduce an amount of tearing of a sphincter mucosa upon an
introduction of the RF needle electrode into the sphincter.
19. The apparatus of claim 17, wherein the retainer member has
sufficient rigidity to reduce movement of the sphincter and permit
maintenance of a constant angle of penetration of the RF needle
electrode through a sphincter surface.
20. The apparatus of claim 17, wherein the retainer member has
sufficient rigidity to reduce movement of the sphincter and
facilitate introduction of the RF needle electrode into the
sphincter.
21. The apparatus of claim 1, wherein the retainer member at least
partially surrounds the energy delivery device introduction member
to reduce a movement of the energy delivery device introduction
member within the sphincter.
22. The apparatus of claim 1, wherein the retainer member at least
partially surrounds the energy delivery device introduction member
and includes a slot to enhance an engagement of the energy delivery
device introduction member with the sphincter.
23. The apparatus of claim 17, wherein the retainer member at least
partially surrounds the energy delivery device introduction member
and includes a slot to enhance an engagement of the energy delivery
device introduction member with the sphincter and facilitate
introduction of the RF needle electrode into the sphincter.
24. The apparatus of claim 17, wherein the retainer member at least
partially surrounds the energy delivery device introduction member
and includes a slot to enhance an engagement of the energy delivery
device introduction member with the sphincter and reduce an amount
of tearing of a sphincter mucosa upon an introduction of the RF
needle electrode into the sphincter.
25. The apparatus of claim 17, wherein the retainer member at least
partially surrounds the energy delivery device introduction member
and includes a slot to enhance an engagement of the energy delivery
device introduction member with the sphincter and permit
maintenance of a constant angle of penetration of the RF needle
electrode through a sphincter surface.
26. The apparatus of claim 9, wherein the balloon has a tapered tip
to facilitate introduction into a sphincter.
27. The apparatus of claim 10, wherein the basket device has a
tapered tip to facilitate introduction into a sphincter.
28. The apparatus of claim 1, wherein the at least a portion of the
energy delivery device introduction member is in a contacting
relationship with a surface of the sphincter in the deployed
configuration.
29. The apparatus of claim 28, wherein the energy delivery device
introduction member has a texturized surface with a sufficient
coefficient of friction to reduce a movement of a sphincter
surface.
30. The apparatus of claim 28, wherein the energy delivery device
introduction member has a texturized surface with a sufficient
coefficient of friction to reduce a movement of an energy delivery
device introduction member.
31. The apparatus of claim 28, wherein the energy delivery device
introduction member has a texturized surface with a sufficient
coefficient of friction to reduce a movement of a sphincter surface
and facilitate introduction of the RF needle electrode into the
sphincter.
32. The apparatus of claim 28, wherein the energy delivery device
introduction member has a texturized surface with a sufficient
coefficient of friction to reduce a movement of a sphincter surface
and reduce an amount of tearing of a sphincter mucosa upon an
introduction of the RF needle electrode into the sphincter.
33. The apparatus of claim 28, wherein the energy delivery device
introduction member has a texturized surface with a sufficient
coefficient of friction to reduce a movement of a sphincter surface
and permit maintenance of a constant angle of penetration of the RF
needle electrode through a sphincter surface.
34. The apparatus of claim 17, wherein the energy delivery device
introduction member is a basket device and the RF electrode is
coupled to an electrode delivery member having proximal and distal
ends.
35. The apparatus of claim 34, further comprising: a guiding tool
coupled to the electrode delivery member, the guiding tool having
at least one aperture with a proximal end and a distal end, wherein
the RF electrode is advanced through the aperture in the guiding
tool and the introduction of the RF needle electrode into the
sphincter is facilitated.
36. The apparatus of 35 wherein the aperture proximal end and the
aperture distal end are located in a different plane.
37. The apparatus of claim 35, wherein the RF electrode is advanced
through an aperture in the energy delivery device introduction
member.
38. The apparatus of claim 17, wherein the energy delivery device
introduction member is a basket device and the RF electrode is
coupled to an electrode delivery member having proximal and distal
ends.
39. The apparatus of claim 38, further comprising: a guiding tool
coupled to the energy delivery device, the guiding tool having at
least one aperture with a proximal end and a distal end, wherein
the RF electrode is advanced through the aperture in the guiding
tool and the introduction of the RF needle electrode into the
sphincter is facilitated.
40. The apparatus of 39, wherein the aperture proximal end and the
aperture distal end are located in a different plane.
41. The apparatus of claim 39, wherein the RF electrode is
advancable through an aperture in the energy delivery device
introduction member.
Description
CROSS-RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 09/026,316 filed Feb. 19, 1998, which is a
continuation-in-part of U.S. patent application Ser. No.
08/731,372, filed Oct. 11, 1996, which is a continuation-in-part of
U.S. patent application Ser. No. 08/319,373, filed Oct. 6, 1994,
which is a continuation-in-part of U.S. application Ser. No.
08/286,862, filed Aug. 4, 1994, which is a continuation-in-part of
U.S. patent application Ser. No. 08/272,162, filed Jul. 7, 1994,
which is a continuation-in-part of U.S. patent application Ser. No.
08/265,459, filed Jun. 24, 1994, and is related to concurrently
filed Application entitled "GERD Treatment Apparatus and Method"
identified as Attorney Docket 14800-748, all with named inventor
Stuart D. Edwards, and all of which are incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to an apparatus for the
treatment of sphincters, and more specifically to an apparatus that
treats esophageal sphincters.
[0004] 2. Description of Related Art
[0005] 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 D O; Johnston B T: Gastroesophageal Reflux Disease:
Current Strategies For Patient Management. Arch Fain Med,
5(4):221-7; (1996 April)).
[0006] 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 J C:
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)).
[0007] One of the possible causes of GERD may be aberrant
electrical signals in the LES or cardia of the stomach. Such
signals may cause a higher than normal frequency of relaxations of
the LES allowing acidic stomach contents to be repeatedly ejected
into the esophagus and cause the complications described above.
Research has shown that unnatural electrical signals in the stomach
and intestine can cause reflux events in those organs (Kelly K A,
et al: Duodenal-gastric Reflux and Slowed Gastric Emptying by
Electrical Pacing of the Canine Duodenal Pacesetter Potential.
Gastroenterology. 1977 Mar; 72(3): 429-433). In particular, medical
research has found that sites of aberrant electrical activity or
electrical foci may be responsible for those signals (Karlstrom L
H, et al.: Ectopic Jejunal Pacemakers and Enterogastric Reflux
after Roux Gastrectomy: Effect Intestinal Pacing. Surgery. 1989
Sep; 106(3): 486-495). Similar aberrant electrical sites in the
heart which cause contractions of the heart muscle to take on life
threatening patterns or dysrhythmias can be identified and treated
using mapping and ablation devices as described in U.S. Pat. No.
5,509,419. However, there is no current device or associated
medical procedure available for the electrical mapping and
treatment of aberrant electrical sites in the LES and stomach as a
means for treating GERD.
[0008] 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.
[0009] 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, J D:
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).
[0010] 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 and 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.
[0011] 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.
[0012] 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 ajaw-like device and fastening
of the invaginated gastroesophageal junction to the findus 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.
[0013] 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 the
LES and the risk of leaks developing at the newly created
gastroesophageal junction.
[0014] 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.
[0015] 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 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 cell necrosis in a lower esophageal sphincter
to reduce a frequency of reflux of stomach contents into an
esophagus.
SUMMARY OF THE INVENTION
[0016] Accordingly, an object of the present invention is to
provide an apparatus to treat a sphincter and reduce a frequency of
sphincter relaxation.
[0017] Another object of the invention is to provide an apparatus
to create controlled cell necrosis in a sphincter tissue underlying
a sphincter mucosal layer.
[0018] Yet another object of the invention is to provide an
apparatus to create cell necrosis in a sphincter and minimize
injury to a mucosal layer of the sphincter.
[0019] 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.
[0020] 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.
[0021] Another object of the invention is to provide an apparatus
to create cell necrosis in a lower esophageal sphincter to reduce a
frequency of reflux of stomach contents into an esophagus.
[0022] Yet another object of the invention is to provide an
apparatus to reduce the frequency and severity of gastroesophageal
reflux events.
[0023] These and other objects of the invention are provided in a
sphincter treatment apparatus. The apparatus includes an energy
delivery device introduction member including a plurality of arms.
Each arm has distal and proximal ends. The distal ends of the arms
are coupled as are the proximal ends of the arms. The energy
delivery device introduction member is configured to be introduced
in the sphincter in a non-deployed state, expand to a deployed
state to at least partially dilate the sphincter. A plurality of
energy delivery devices are coupled to the energy delivery device
introduction member. At least a portion of the plurality of energy
delivery devices are controllably introducible from the energy
delivery device introduction member into the sphincter.
[0024] In another embodiment, the sphincter treatment apparatus has
an expandable basket structure. An expandable basket structure
includes a first arm with a distal and a proximal section, a second
arm with a distal and a proximal section, and a third arm with a
distal and a proximal section. The proximal sections of the first,
second and third arms are coupled to each other. The distal
sections of the first, second and third arms are coupled to each
other. The expanded basket structure has a non-deployed state and a
deployed state where the first, second and third arms distend away
from each other. A first energy delivery device is coupled to the
first arm and includes a distal portion controllably advanceable
from the first arm into the sphincter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is an illustrated lateral view of the upper GI tract
including the esophagus and lower esophageal sphincter and the
positioning of the sphincter treatment apparatus of the present
invention in the lower esophageal sphincter.
[0026] FIG. 2A is a lateral view of the present invention
illustrating the energy delivery device, power supply and expansion
device in an expanded and contracted state.
[0027] FIG. 2B is a lateral view of an embodiment of the invention
illustrating the use of a slotted introducer to facilitate contact
of the expansion device with esophageal wall.
[0028] FIG. 3 depicts a lateral view of the present invention that
illustrates components on the flexible shaft including a proximal
fitting, connections and proximal and distal shaft segments.
[0029] FIG. 4A illustrates a lateral view of the basket assembly
used in an embodiment of the invention.
[0030] FIG. 4B illustrates a lateral view of a basket assembly with
a tapered tip.
[0031] FIG. 5A is a lateral view of the basket assembly that
illustrates the range of camber in the basket assembly.
[0032] FIG. 5B is a perspective view illustrating a balloon coupled
to the basket assembly.
[0033] FIG. 6A is a lateral view of the junction between the basket
arms and the shaft illustrating the pathway used for advancement of
the movable wire or the delivery of fluids.
[0034] 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.
[0035] FIG. 7 is a cross-sectional view of a section of the basket
arm illustrating stepped and tapered sections in basket arm
apertures.
[0036] FIG. 8 is a lateral view of the basket assembly illustrating
the placement of the radial supporting member.
[0037] FIG. 9A is a lateral view of the sphincter treatment
apparatus illustrating the mechanism used in one embodiment of the
invention to increase the camber of the basket assembly.
[0038] FIG. 9B is a similar view to 9A showing the basket assembly
in an increased state of camber.
[0039] FIG. 10 is a lateral view of the sphincter treatment
apparatus illustrating the deflection mechanism.
[0040] FIG. 11 is a lateral view illustrating the use of
electrolytic solution to create an enhanced RF electrode.
[0041] FIG. 12 is a lateral view of the basket assembly
illustrating the use of needle electrodes.
[0042] FIG. 13 is a lateral view illustrating the use of an
insulation segment on the needle electrode to protect an area of
tissue from RF energy.
[0043] FIG. 14 is a lateral view illustrating the placement of
needle electrodes into the sphincter wall by expansion of the
basket assembly.
[0044] FIG. 15 is a lateral view illustrating placement of needle
electrodes into the sphincter wall by advancement of an electrode
delivery member out of apertures in the basket arms.
[0045] FIG. 16 is a cross sectional view illustrating the
configuration of a basket arm aperture used to select and maintain
a penetration angle of the needle electrode into the sphincter
wall.
[0046] FIG. 17A is a lateral view illustrating placement of needle
electrodes into the sphincter wall by advancement of an electrode
delivery member directly out of the distal end of the shaft.
[0047] FIG. 17B is a lateral view illustrating the use of a needle
hub to facilitate placement of needle electrodes into the sphincter
wall.
[0048] FIG. 18A is a lateral view illustrating a radial
distribution of electrodes on the expansion device of the
invention.
[0049] FIG. 18B is a lateral view illustrating a longitudinal
distribution of electrodes on the expansion device of the
invention.
[0050] FIG. 18C is a lateral view illustrating a spiral
distribution of electrodes on the expansion device of the
invention.
[0051] FIG. 19 is a flow chart illustrating a sphincter treatment
method using the apparatus of the present invention.
[0052] FIG. 20 is a lateral view of sphincter smooth muscle tissue
illustrating electromagnetic foci and pathways for the origination
and conduction of aberrant electrical signals in the smooth muscle
of the lower esophageal sphincter or other tissue.
[0053] FIG. 21 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.
[0054] FIG. 22 is a view similar to that of FIG. 21 illustrating
shrinkage of the lesion site caused by cell infiltration.
[0055] FIG. 23 is a lateral view of the esophageal wall
illustrating the preferred placement of lesions in the smooth
muscle layer of a esophageal sphincter.
[0056] FIG. 24 is a lateral view illustrating the ultrasound
transducer, ultrasound lens and power source of an embodiment of
the present invention.
[0057] FIGS. 25A-D are lateral views of the sphincter wall
illustrating various patterns of lesions created by the apparatus
of the present invention.
[0058] FIG. 26 is a lateral view of the sphincter wall illustrating
the delivery of cooling fluid to the electrode-tissue interface and
the creation of cooling zones.
[0059] FIG. 27 depicts the flow path, fluid connections and control
unit employed to deliver fluid to the electrode-tissue
interface.
[0060] FIG. 28 depicts the flow path, fluid connections and control
unit employed to deliver fluid to the RF electrodes.
[0061] FIG. 29 is an enlarged lateral view illustrating the
placement of sensors on the expansion device or basket
assembly.
[0062] FIG. 30 depicts a block diagram of the feed back control
system that can be used with the sphincter treatment apparatus.
[0063] FIG. 31 depicts a block diagram of an analog amplifier,
analog multiplexer and microprocessor used with the feedback
control system of FIG. 30.
[0064] FIG. 32 depicts a block diagram of the operations performed
in the feedback control system depicted in FIG. 30.
DETAILED DESCRIPTION
[0065] Referring now to FIGS. 1 and 2, one embodiment of sphincter
treatment apparatus 10 that is used to deliver energy to a
treatment site 12 to produce lesions 14 in a sphincter 16, such as
the lower esophageal sphincter (LES), comprises a flexible elongate
shaft 18, also called shaft 18, coupled to a expansion device 20,
in turn coupled with one or more energy delivery devices 22. Energy
delivery devices 22 are configured to be coupled to a power source
24. The 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. Expansion device 20 is further
configured to facilitate the positioning of energy delivery devices
22 to a selectable depth in a sphincter wall 26 or adjoining
anatomical structure. Expansion device 20 has a central
longitudinal axis 28 and is moveable between contracted and
expanded positions substantially there along. This can be
accomplished by a ratchet mechanism as is known to those skilled in
the art. At least portions of sphincter treatment apparatus 10 may
be sufficiently radiopaque in order to be visible under fluoroscopy
and/or sufficiently echogenic to be visible under ultrasonography.
Also as will be discussed herein, sphincter treatment apparatus 10
can include visualization capability including, but not limited to,
a viewing scope, an expanded eyepiece, fiber optics, video imaging
and the like.
[0066] Referring to FIG. 2A, shaft 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 shaft 18 include, but are not limited
to, a range of 40-180 cms. In various embodiments, shaft 18 is
flexible, articulated and steerable and can contain fiber optics
(including illumination and imaging fibers), fluid and gas paths,
and sensor and electronic cabling. In one embodiment, shaft 18 can
be a multi-lumen catheter, as is well known to those skilled in the
art.
[0067] In another embodiment, an introducing member 21, also called
an introducer, is used to introduce sphincter treatment apparatus
10 into the LES. Introducer 21 can also function as a sheath for
expansion device 20 to keep it in a nondeployed or contracted state
during introduction into the LES. In various embodiments,
introducer 21 is flexible, articulated and steerable and contains a
continuous lumen of sufficient diameter to allow the advancement of
sphincter treatment apparatus 10. Typical diameters for introducer
21 include 0.1 to 2 inches, while typical length include 40-180
cms. Introducer 21 may be of sufficient length and width to extend
into a portion of or past the LES and provide structural support to
and/or immobilize the esophagus. This serves to reduce movement of
the esophagus and/or expansion device 20 so as to facilitate
introduction of a needle electrode (described herein) into
sphincter wall 26. As shown in FIG. 2B, introducer 21 may also
contain slots 25 near introducer distal end 21' or at other points
along its length. Slots 25 are of sufficient length and width to
allow expansion device 20 to engage sphincter wall 26 when it is
put into a deployed state inside introducer 21. Suitable materials
for introducer 21 include coil-reinforced plastic tubing as is well
known to those skilled in the art.
[0068] Referring now to FIG. 3, the flexible elongate shaft 18 is
circular in cross section and has proximal and distal extremities
(also called ends) 30 and 32. Shaft 18 may also be coupled at its
proximal end 32 to a proximal fitting 34, also called a handle,
used by the physician to manipulate sphincter treatment apparatus
10 to reach treatment site 12. Shaft 18 may have one or more lumens
36, that extend the full length of shaft 18, or part way from shaft
proximal end 30 to shaft distal end 32. Lumens 36 may be used as
paths for catheters, guide wires, pull wires, insulated wires and
cabling, fluid and optical fibers. Lumens 36 are connected to
and/or accessed by connections 38 on or adjacent to proximal
fitting 34. Connections 38 can include luer-lock, lemo connector,
swage and other mechanical varieties well known to those skilled in
the art. Connections 38 can also include optical/video connections
which allow optical and electronic coupling of optical fibers
and/or viewing scopes to illuminating sources, eye pieces and video
monitors. In various embodiments, shaft 18 may stop at the proximal
extremity 40 of expansion device 20 or extend to, or past, the
distal extremity 42 of expansion device 20. Suitable materials for
shaft 18 include, but are not limited to, polyethylenes,
polyurethanes and other medical plastics known to those skilled in
the art.
[0069] Referring now to FIG. 4A, in one embodiment of the present
invention expansion device 20 comprises one or more elongated arms
44 that are joined at their proximal ends 46 and distal ends 48 to
form a basket assembly 50. Proximal arm end 46 is attached to a
supporting structure, which can be the distal end 32 of shaft 18 or
a proximal cap 51. Likewise, distal arm end 48 is also attached to
a supporting structure which can be a basket cap 52 or shaft 18. In
one embodiment shown in FIG. 4B, basket cap 52 can be a tapered cap
52' to facilitate insertion through the folds of the LES.
[0070] Attached arms 44 may form a variety of geometric shapes
including, but not limited to, curved, rectangular, trapezoidal and
triangular. Arms 44 can have a variety of cross sectional
geometries including, but not limited to, circular, rectangular and
crescent-shaped. Also, arms 44 are of a sufficient number (two or
more), and have sufficient spring force (0.01 to 0.5 lbs. force )
so as to collectively exert adequate force on sphincter wall 26 to
sufficiently open and efface the folds of sphincter 16 to allow
treatment with sphincter treatment apparatus 10, while preventing
herniation of sphincter wall 26 into the spaces 53 between arms 44.
Suitable materials for arms 44 include, but are not limited to,
spring steel, stainless steel, superelastic shape memory metals
such as nitinol or wire reinforced plastic tubing as is well known
to those skilled in the art. In another embodiment, arms 44 may
have an external layer of texturized material 45 that has
sufficient friction to immobilize the area near and around
sphincter wall 26 contacted by arm 44. Suitable materials for
texturized material 45 include knitted Dacron.RTM. and Dacron
velour.
[0071] Referring to FIG. 5A, arms 44 can have an outwardly bowed
shaped memory for expanding the basket assembly into engagement
with sphincter wall 26 with the amount of bowing, or camber 54
being selectable from a range 0 to 2 inches from longitudinal axis
28 of basket assembly 50. For the case of a curve-shaped arm 44',
expanded arms 44 are circumferentially and symmetrically
spaced-apart. In various other embodiments (not shown), arms 44 may
be asymmetrically spaced and/or distributed on an arc less than
360.degree.. Also, arms 44 may be preshaped at time of manufacture
or shaped by the physician.
[0072] In another embodiment shown in FIG. 5B, an expandable member
55, which can be a balloon, is coupled to an interior or exterior
of basket assembly 50. Balloon 55 is also coupled to and inflated
by lumen 36 using gas or liquid. Balloon 55 may be made of a
textured material, or have a texturized layer 55' that when engaged
with sphincter wall 26, provides sufficient friction to at least
partially immobilize the surface of sphincter wall 26. Suitable
materials for texturized layer 55' include knitted Dacron and
Dacron velour.
[0073] Referring now to FIG. 6A, arms 44 may also be solid or
hollow with a continuous lumen 58 that may be coupled with shaft
lumens 36. These coupled lumens provide a path for the delivery of
a fluid or electrode delivery member 60 (also called an advancement
member) from shaft 18 to any point on basket assembly 50. In
various embodiments electrode delivery member 60 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, all of which are known to those skilled in the
art. As shown in FIG. 6B, arms 44 may also have a partially open
channel 62, also called a track 62, that functions as a guide track
for electrode delivery member 60. Referring back to FIG. 6A, arms
44 may have one or more apertures 64 at any point along their
length that permit the controlled placement of energy delivery
devices 22 at or into sphincter wall 26. Referring now to FIG. 7,
apertures 64 may have tapered sections 66 or stepped sections 68 in
all or part of their length, that are used to control the
penetration depth of energy delivery devices 22 into sphincter wall
26. Referring back to FIG. 6A, apertures 64 in combination with arm
lumens 58 and shaft lumens 36 may be used for the delivery of
cooling solution 70 or electrolytic solution 72 to treatment site
12 as described herein. Additionally, arms 44 can also carry a
plurality of longitudinally spaced apart radiopaque and or
echogenic markers or traces, not shown in the drawings, formed of
suitable materials to permit viewing of basket assembly 50 via
fluoroscopy or ultrasonography. Suitable radiopaque materials
include platinum or gold, while suitable echogenic materials
include gas filled micro-particles as described in U.S. Pat. Nos.
5,688,490 and 5,205,287. Arms 44 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.
[0074] In another embodiment of the present invention, a supporting
member 74 is attached to two or more arms 44. Supporting member 74,
also called a strut, can be attached to arms 44 along a
circumference of basket assembly 50 as shown in FIG. 8. Apertures
64 can extend through radial supporting member 74 in one or more
places. Radial supporting member 74 serves the following functions:
i) facilitates opening and effacement of the folds of sphincter 16,
ii) enhances contact of Apertures 64 with sphincter wall 26; and,
iii) reduces or prevents the tendency of arms 44 to bunch up. The
cross sectional geometry of radial supporting member 74 can be
rectangular or circular, though it will be appreciated that other
geometries are equally suitable.
[0075] In one embodiment shown in FIG. 9, arms 44 are attached to
basket cap 52 that in turn, moves freely over shaft 18, but is
stopped distally by shaft cap 78. One or more pull wires 80 are
attached to basket cap 52 and also to a movable fitting 82 in
proximal fitting 34 of sphincter treatment apparatus 10. When pull
wire 80 is pulled back by movable fitting 82, the camber 54 of
basket assembly 50 increases to 54', increasing the force and the
amount of contact applied by basket assembly 50 to sphincter wall
26 or an adjoining structure. Basket assembly 50 can also be
deflected from side to side using deflection mechanism 80. This
allows the physician to remotely point and steer the basket
assembly within the body. In one embodiment shown in FIG. 10,
deflection mechanism 84 includes a second pull wire 80' attached to
shaft cap 78 and also to a movable slide 86 integral to proximal
fitting 34.
[0076] Turning now to a discussion of energy delivery, suitable
power sources 24 and energy delivery devices 22 that can be
employed in one or more embodiments of the invention include: (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, (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, or (xii) a
microwave source. 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 88, also described
as electrodes 88. However, all of the other herein mentioned power
sources and energy delivery devices are equally applicable to
sphincter treatment apparatus 10.
[0077] For the case of RF energy, RF electrode 88 may operated in
either bipolar or monopolar mode with a ground pad electrode. In a
monopolar mode of delivering RF energy, a single electrode 88 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 88 are used. Multiple electrodes 88 may be
used. These electrodes may be cooled as described herein.
Electrodes 88 can be attached to electrode delivery member 60 by
the use of soldering methods which are well known to those skilled
in the art. Suitable solders include Megabond Solder supplied by
the Megatrode Corporation (Milwaukee, Wis.).
[0078] Suitable electrolytic solutions 72 include saline, solutions
of calcium salts, potassium salts, and the like. Electrolytic
solutions 72 enhance the electrical conductivity of the targeted
tissue at the treatment site 12. When a highly conductive fluid
such as electrolytic solution 72 is infused into tissue the
electrical resistance of the infused tissue is reduced, in turn,
increasing the electrical conductivity of the infused tissue. As a
result, there will be little tendency for tissue surrounding
electrode 88 to desiccate (a condition described herein that
increases the electrical resistance of tissue) resulting in a large
increase in the capacity of the tissue to carry RF energy.
Referring to FIG. 11, a zone of tissue which has been heavily
infused with a concentrated electrolytic solution 72 can become so
conductive as to actually act as an enhanced electrode 88'. The
effect of enhanced electrode 88' is to increase the amount of
current that can be conducted to the treatment site 12, making it
possible to heat a much greater volume of tissue in a given time
period.
[0079] Also when the power source is RF, power source 24, which
will now be referred to as RF power source 24, may have multiple
channels, delivering separately modulated power to each electrode
88. This reduces preferential heating that occurs when more energy
is delivered to a zone of greater conductivity and less heating
occurs around electrodes 88 which are placed into less conductive
tissue. If the level of tissue hydration or the blood infusion rate
in the tissue is uniform, a single channel RF power source 24 may
be used to provide power for generation of lesions 14 relatively
uniform in size.
[0080] Electrodes 88 can have a variety of shapes and sizes.
Possible shapes include, but are not limited to, circular,
rectangular, conical and pyramidal. Electrode surfaces can be
smooth or textured and concave or convex. The conductive surface
area of electrode 88 can range from 0.1 mm.sup.2 to 100 cm.sup.2.
It will be appreciated that other geometries and surface areas may
be equally suitable. In one embodiment, electrodes 88 can be in the
shape of needles and of sufficient sharpness and length to
penetrate into the smooth muscle of the esophageal wall, sphincter
16 or other anatomical structure. In this embodiment shown in FIGS.
12 and 13, needle electrodes 90 are attached to arms 44 and have an
insulating layer 92, covering an insulated segment 94 except for an
exposed segment 95. For purposes of this disclosure, an insulator
or insulation layer is a barrier to either thermal, RF or
electrical energy flow. Insulated segment 94 is of sufficient
length to extend into sphincter wall 26 and minimize the
transmission of RF energy to a protected site 97 near or adjacent
to insulated segment 94 (see FIG. 13). Typical lengths for
insulated segment 94 include, but are not limited to, 1-4 mms.
Suitable materials for needle electrodes 90 include, but are not
limited to, 304 stainless steel and other stainless steels known to
those skilled in the art. Suitable materials for insulating layer
92 include, but are not limited to, polyimides and polyamides.
[0081] During introduction of sphincter treatment apparatus 10,
basket assembly 50 is in a contracted state. Once sphincter
treatment apparatus 10 is properly positioned at the treatment site
12, needle electrodes 90 are deployed by expansion of basket
assembly 50, resulting in the protrusion of needle electrodes 90
into the smooth muscle tissue of sphincter wall 26 (refer to FIG.
14). The depth of needle penetration is selectable from a range of
0.5 to 5 mms and is accomplished by indexing movable fitting 82 so
as to change the camber 54 of arm 44 in fixed increments that can
be selectable in a range from 0.1 to 4 mms. Needle electrodes 90
are coupled to power source 24 via insulated wire 60.
[0082] In another embodiment of sphincter treatment apparatus 10
shown in FIG. 15, needle electrodes 90 are advanced out of
apertures 64 in basket arms 44 into the smooth muscle of the
esophageal wall or other sphincter 16. In this case, needle
electrodes 90 are coupled to RF power source 24 by electrode
delivery member 60. In this embodiment, the depth of needle
penetration is selectable via means of stepped sections 66 or
tapered sections 68 located in apertures 64. Referring to FIG. 16,
apertures 64 and needle electrodes 90 are configured such that the
penetration angle 96 (also called an emergence angle 96) of needle
electrode 90 into sphincter wall 26 remains sufficiently constant
during the time needle electrode 90 is being inserted into
sphincter wall 26, such that there is no tearing or unnecessary
trauma to sphincter wall tissue. This is facilitated by the
selection of the following parameters and criteria: i) the
emergence angle 96 of apertures 64 which can vary from 1 to
90.degree., ii) the arc radius 98 of the curved section 100 of
aperture 64 which can vary from 0.001 to 2 inch, iii) the amount of
clearance between the aperture inner diameter 102 and the needle
electrode outside diameter 104 which can very between 0.001" and
0.1"; and, iv) use of a lubricous coating on electrode delivery
member 60 such as a Teflon.RTM. or other coatings well known to
those skilled in the art. Also in this embodiment, insulated
segment 94 can be in the form of an sleeve that may be adjustably
positioned at the exterior of electrode 90.
[0083] In another alternative embodiment shown in FIG. 17A ,
electrode delivery member 60 with attached needle electrodes 90,
can exit from lumen 36 at distal shaft end 32 and be positioned
into contact with sphincter wall 26. This process may be
facilitated by use of a hollow guiding member 101, known to those
skilled in the art as a guiding catheter, through which electrode
delivery member 60 is advanced. Guiding catheter 101 may also
include stepped sections 66 or tapered sections 68 at it distal end
to control the depth of penetration of needle electrode 90 into
sphincter wall 26.
[0084] In an alternative embodiment shown in FIG. 17B, needle
electrodes 90 can be advanced through an aperture 64' in needle hub
103 (located inside basket assembly 50) and subsequently advanced
through aperture 64 in arm 44 and into sphincter wall 26. Aperture
64' has proximal and distal ends 64" and 64'". Also needle hub 103
is configured to be coupled to delivery member 60 or basket
assembly 50 and serves as a guiding tool to facilitate penetration
of needle electrode 90 into sphincter wall 26. In one embodiment,
proximal and distal ends 64" and 64'" of apertures 64' are located
in different planes.
[0085] RF energy flowing through tissue causes heating of the
tissue due to absorption of the RF energy by the tissue and ohmic
heating due to electrical resistance of the tissue. This heating
can cause injury to the affected cells and can be substantial
enough to cause cell death, a phenomenon also known as cell
necrosis. For ease of discussion for the remainder of this
application, cell injury will include all cellular effects
resulting from the delivery of energy from electrode 88 up to, and
including, cell necrosis. Cell injury can be accomplished as a
relatively simple medical procedure with local anesthesia. In one
embodiment, cell injury proceeds to a depth of approximately 1-4
mms from the surface of the mucosal layer of sphincter 16 or that
of an adjoining anatomical structure.
[0086] Referring now to FIGS. 18A, 18B and 18C, electrodes 88
and/or apertures 64 may be distributed in a variety of patterns
along expansion device 20 or basket assembly 50 in order to produce
a desired placement and pattern of lesions 14. Typical electrode
and aperture distribution patterns include, but are not limited to,
a radial distribution 105 (refer to FIG. 18A) or a longitudinal
distribution 106 (refer to FIG. 18B). It will be appreciated that
other patterns and geometries for electrode and aperture placement,
such as a spiral distribution 108 (refer to FIG. 18C) may also be
suitable. These electrodes may be cooled as described
hereafter.
[0087] FIG. 19 is a flow chart illustrating one embodiment of the
procedure for using sphincter treatment apparatus 10. In this
embodiment, sphincter treatment apparatus 10 is first introduced
into the esophagus under local anesthesia. 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 similar esophageal access device known to those
skilled in the art. Basket assembly 50 is expanded and can be done
through slots 25 in introducer 21 as described herein. This serves
to temporarily dilate the LES or sufficiently to efface a portion
of or all 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 shaft lumen 36, or
an endoscope or similar esophageal access device as described
above. Once treatment is completed, basket assembly 50 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.
[0088] The diagnostic phase of the procedure can be performed using
a variety of diagnostic methods, including, but not limited to, 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 the esophageal mucosal layers
and sphincter treatment apparatus 10 and (iv) measurement and
surface mapping of the electropotential of the LES during varying
time periods which may include such events as depolarization,
contraction and repolarization of LES 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 foci
107 or pathways 109 for abnormal or inappropriate polarization and
relaxation of the smooth muscle of the LES (Refer to FIG. 20).
[0089] In the treatment 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 88 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) sphincter contractile force
measurement via manometry. The feedback mechanism permits the
selected on-off switching of different electrodes 88 in a desired
pattern, which can be sequential from one electrode 88 to an
adjacent electrode 88, or can jump around between non-adjacent
electrodes 88. Individual electrodes 88 are multiplexed and
volumetrically controlled by a controller.
[0090] 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 26. Typical energies delivered
to the esophageal wall include, but are not limited to, a range
between 100 and 50,000 joules per electrode 88. It is also
desirable to deliver sufficient energy such that the 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. 21). As shown in FIG. 22,
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 LES or sphincter
16. These changes are reflected in transformed lesion 14' shown in
FIG. 19B. The diameter of lesions 14 can vary between 0.1 to 4 mms.
It is preferable that lesions 14 are less than 4 mms in diameter in
order to reduce the risk of thermal damage to the mucosal layer. In
one embodiment, a 2 mm diameter lesion 14 centered in the wall of
the smooth muscle provides a 1 mm buffer zone to prevent damage to
the mucosa, submucosa and adventitia, 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. 23).
[0091] From a diagnostic standpoint, it is desirable to image the
interior surface and wall of the LES or other sphincter 16,
including the size and position of created lesions 14. It is
desirable to create a map of these structures which can input to a
controller and used to direct the delivery of energy to the
treatment site. Referring to FIG. 24, this can be accomplished
through the use of ultrasonography (a known procedure) which
involves the use of an ultrasound power source 116 coupled to one
or more ultrasound transducers 118 that are positioned on expansion
device 20 or basket assembly 50. An output is associated with
ultrasound power source 116.
[0092] Each ultrasound transducer 118 can include a piezoelectric
crystal 120 mounted on a backing material 122 that is in turn,
attached to expansion device 20 or basket assembly 50. An
ultrasound lens 124, fabricated on an electrically insulating
material 126, is mounted over piezoelectric crystal 120.
Piezoelectric crystal 120 is connected by electrical leads 128 to
ultrasound power source 116 Each ultrasound transducer 118
transmits ultrasound energy into adjacent tissue. Ultrasound
transducers 118 can be in the form of an imaging probe such as
Model 21362, manufactured and sold by Hewlett Packard Company, Palo
Alto, Calif. In one embodiment, two ultrasound transducers 118 are
positioned on opposite sides of expansion device 20 or basket
assembly 50 to create an image depicting the size and position of
lesion 14 in selected sphincter 16.
[0093] 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 mms from the interior surface of sphincter wall
26. However, lesions 14 can vary both in number and position within
sphincter wall 26. 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. 25A-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
sphincter 16 is controlled and selectable. The selective
application of energy to sphincter 16 may be the even penetration
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.
[0094] Referring to FIG. 26, it may be desirable to cool all or a
portion of the area near the electrode-tissue interface 130 before,
during or after the delivery of energy in order to reduce the
degree and area of cell injury. Specifically, the use of cooling
preserves the mucosal layers of sphincter wall 26 and protects, or
otherwise reduces the degree of cell damage to cooled zone 132 in
the vicinity of lesion 14. Referring now to FIG. 27, this can be
accomplished through the use of cooling solution 70 that is
delivered by apertures 64 which is in fluid communication with
shaft lumen 36 that is, in turn, in fluid communication with fluid
reservoir 134 and a control unit 136, whose operation is described
herein, that controls the delivery of the fluid.
[0095] Similarly, it may also be desirable to cool all or a portion
of the electrode 88. The rapid delivery of heat through electrode
88, may result in the build up of charred biological matter on
electrode 88 (from contact with tissue and fluids e.g., blood) that
impedes the flow of both thermal and electrical energy from
electrode 88 to adjacent tissue and causes an electrical impedance
rise beyond a cutoff value set on RF power source 24. A similar
situation may result from the desiccation of tissue adjacent to
electrode 88. Cooling of the electrode 88 can be accomplished by
cooling solution 70 that is delivered by apertures 64 as described
previously. Referring now to FIG. 28, electrode 88 may also be
cooled via a fluid channel 138 in electrode 88 that is in fluid
communication with fluid reservoir 134 and control unit 136 .
[0096] As shown in FIG. 29, one or more sensors 140 may be
positioned adjacent to or on electrode 88 for sensing the
temperature of sphincter tissue at treatment site 12. More
specifically, sensors 140 permit accurate determination of the
surface temperature of sphincter wall 26 at electrode-tissue
interface 130. This information can be used to regulate both the
delivery of energy and cooling solution 70 to the interior surface
of sphincter wall 26. In various embodiments, sensors 140 can be
positioned at any position on expansion device 20 or basket
assembly 50. Suitable sensors that may be used for sensor 140
include: thermocouples, fiber optics, resistive wires, thermocouple
IR detectors, and the like. Suitable thermocouples for sensor 140
include: T type with copper constantene, J type, E type and K types
as are well known those skilled in the art.
[0097] Temperature data from sensors 140 are fed back to control
unit 136 and through an algorithm which is stored within a
microprocessor memory of control unit 136. Instructions are sent to
an electronically controlled micropump (not shown) to deliver fluid
through the fluid lines at the appropriate flow rate and duration
to provide control temperature at the electrode-tissue interface
130 (refer to FIG. 27).
[0098] The reservoir of control unit 136 may have the ability to
control the temperature of the cooling solution 70 by either
cooling the fluid or heating the fluid. Alternatively, a fluid
reservoir 134 of sufficient size may be used in which the cooling
solution 70 is introduced at a temperature at or near that of the
normal body temperature. Using a thermally insulated reservoir 142,
adequate control of the tissue temperature may be accomplished
without need of refrigeration or heating of the cooling solution
70. Cooling solution 70 flow is controlled by control unit 136 or
another feedback control system (described herein) to provide
temperature control at the electrode-tissue interface 130.
[0099] 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.
[0100] In one embodiment, sphincter treatment apparatus 10 is
coupled to an open or closed loop feedback system. Referring now to
FIG. 30, an open or closed loop feedback system couples sensor 346
to energy source 392. In this embodiment, electrode 314 is one or
more RF electrodes 314.
[0101] 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. 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
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.
[0102] With the use of sensor 346 and the feedback control system a
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 as is discussed herein. 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.
[0103] 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.
[0104] 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 in an appropriate amount in order to
maintain the desired power delivered at respective RF electrodes
314.
[0105] 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
energy 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 in 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.
[0106] 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.
[0107] 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.
[0108] 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.
[0109] 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.
[0110] Referring now to FIG. 31, 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 AID 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.
[0111] 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.
[0112] 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.
[0113] FIG. 32 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 cooling solution 70 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 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. If measured impedance is within
acceptable limits, energy continues to be applied to the
tissue.
[0114] The control of cooling solution 70 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 preset signal
representative of the desired temperature. 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. 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.
[0115] 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.
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