U.S. patent application number 15/713591 was filed with the patent office on 2018-01-11 for systems and methods for treating tissue with radiofrequency energy.
This patent application is currently assigned to Mederi Therapeutics, Inc.. The applicant listed for this patent is Mederi Therapeutics, Inc.. Invention is credited to Ronald L. Green, Jeffrey Radziunas, OLEG SHIKHMAN.
Application Number | 20180008336 15/713591 |
Document ID | / |
Family ID | 54868591 |
Filed Date | 2018-01-11 |
United States Patent
Application |
20180008336 |
Kind Code |
A1 |
SHIKHMAN; OLEG ; et
al. |
January 11, 2018 |
SYSTEMS AND METHODS FOR TREATING TISSUE WITH RADIOFREQUENCY
ENERGY
Abstract
A device for applying radiofrequency energy for sphincter
treatment comprising a flexible outer tube, an expandable basket
having a plurality of arms movable from a collapsed position to an
expanded position, and a plurality of electrodes movable with
respect to the arms from a retracted position to an extended
position. An advancer is slidably disposed within the outer tube to
move the plurality of electrodes to the extended position. An
actuator moves the advancer from a first position to a second
position to advance the plurality of electrodes. An aspiration tube
extends within the outer tube. An assembly includes an aspiration
disabler having a first position to enable aspiration from a distal
portion of the aspiration tube to a proximal portion and a second
position to disable aspiration.
Inventors: |
SHIKHMAN; OLEG; (Trumbull,
CT) ; Green; Ronald L.; (Bethel, CT) ;
Radziunas; Jeffrey; (Wallingford, CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mederi Therapeutics, Inc. |
Norwalk |
CT |
US |
|
|
Assignee: |
Mederi Therapeutics, Inc.
Norwalk
CT
|
Family ID: |
54868591 |
Appl. No.: |
15/713591 |
Filed: |
September 22, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14839905 |
Aug 28, 2015 |
9775664 |
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15713591 |
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14708209 |
May 9, 2015 |
9675404 |
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14839905 |
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|
13867042 |
Apr 20, 2013 |
9474565 |
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14708209 |
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12924155 |
Sep 22, 2010 |
|
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|
13867042 |
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62050090 |
Sep 13, 2014 |
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62009222 |
Jun 7, 2014 |
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61664960 |
Jun 27, 2012 |
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61277260 |
Sep 22, 2009 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 2018/00642
20130101; A61B 2018/1475 20130101; A61B 2218/007 20130101; A61B
2034/252 20160201; A61B 18/1815 20130101; A61B 2018/00482 20130101;
A61B 2018/0212 20130101; A61N 7/022 20130101; A61B 2018/044
20130101; A61B 18/14 20130101; A61B 18/1477 20130101; A61B 18/1492
20130101; A61B 2018/00916 20130101; A61B 18/1485 20130101; A61B
2018/00488 20130101; A61B 2034/254 20160201; A61B 2018/00494
20130101; A61B 2018/1467 20130101; A61B 18/02 20130101; A61B
2018/00791 20130101; A61B 2018/143 20130101; A61B 2018/1425
20130101; A61B 18/08 20130101; A61B 2018/1861 20130101; A61B
2018/00702 20130101; A61B 2018/00267 20130101; A61B 2018/00761
20130101; A61B 2018/00678 20130101; A61B 2018/00577 20130101; G06F
3/0481 20130101; A61B 2018/00708 20130101; A61B 2018/00029
20130101; A61B 18/1233 20130101; A61B 2018/005 20130101; A61B 34/25
20160201; A61B 2218/002 20130101; A61B 2018/00553 20130101 |
International
Class: |
A61B 18/14 20060101
A61B018/14; A61B 18/12 20060101 A61B018/12; G06F 3/0481 20130101
G06F003/0481 |
Claims
1-16. (canceled)
17. A method of treating gastrointestinal reflux disease
comprising: providing a treatment device having a plurality of
electrodes and an assembly having a disabler for disabling
aspiration through an aspiration tube extending within the device,
the disabler having a first position to enable aspiration from a
distal portion of the aspiration tube to a proximal portion of the
aspiration tube, the disabler movable to a second position to
disable aspiration to facilitate axial and rotational movement of
the treatment device within tissue and to limit undesired movement
of tissue which can cause overtreatment of tissue and tissue
ablation; applying radiofrequency energy to the plurality of
electrodes to thermally treat tissue below a tissue ablation
threshold and create a plurality of tissue lesions along axially
spaced tissue levels within the upper gastrointestinal tract;
monitoring tissue temperature throughout the applying of
radiofrequency energy; and regulating power ensuring in response to
the monitoring of tissue temperature that the tissue temperature
does not exceed a predetermined value which would cause tissue
ablation and/or tissue necrosis.
18. The method for claim 17, further comprising the step of sliding
a mechanism to selectively cover and uncover an opening in a
sidewall of the aspiration tube.
19. The method of claim 17, further comprising the step of moving a
mechanism radially inwardly to deform a wall of the aspiration
tube.
20. The method of claim 17, wherein the plurality of electrodes
each have a non-penetrating tip substantially conical in
configuration to deform the tissue when advanced into contact with
tissue.
21. The method of claim 17, wherein in the first position an
opening in the aspiration tube is closed to enable aspiration and
in the second position the opening in the aspiration tube is open
to disable aspiration.
22. The method of claim 21, wherein the opening is in a sidewall of
the aspiration tube.
23. The method of claim 17, wherein the plurality of electrodes are
maintained in axial alignment when advanced from the treatment
device.
24. The method of claim 23, wherein tips of the plurality of
electrodes are maintained at equidistant radial spacing when
advanced from the treatment device.
25. The method of claim 17, wherein aspiration is disabled without
having to shut off a vacuum.
26. The method of claim 17, wherein aspiration is disabled at a
handle section of the treatment device.
27. A method of treating gastrointestinal reflux disease in a
patient comprising: providing a treatment device having an
expandable basket assembly, a plurality of electrodes movable from
a retracted position within the basket assembly to an extended
position extending from the basket assembly and an assembly having
a disabler for disabling aspiration through an aspiration tube, the
disabler having a first position to enable aspiration from a distal
portion of the aspiration tube to a proximal portion of the
aspiration tube, the disabler movable to a second position to
disable aspiration to facilitate axial and rotational movement of
the treatment device within tissue and to limit undesired movement
of tissue to prevent overtreatment and tissue ablation; advancing
the plurality of electrodes from the basket assembly; applying
radiofrequency energy to the plurality of electrodes to thermally
treat tissue below a tissue ablation threshold and create a
plurality of tissue lesions at a first tissue level of a plurality
of axially spaced tissue levels within an upper gastrointestinal
tract of the patient; monitoring tissue temperature throughout the
application of radiofrequency energy; regulating power ensuring in
response to the monitoring of tissue temperature that the tissue
temperature does not exceed a predetermined value which would cause
tissue ablation and/or tissue necrosis; disabling aspiration while
the vacuum remains on and subsequently moving the treatment device
axially to a second tissue level of the axially spaced tissue
levels, the disabling of aspiration releasing tissue which could
otherwise be pulled to the second tissue level, advancing the
plurality of electrodes at the second tissue level; and applying
radiofrequency energy to the plurality of electrodes to thermally
treat tissue at the second tissue level below a tissue ablation
threshold and create a plurality of tissue lesions at the second
tissue level within the upper gastrointestinal tract of the
patient.
28. The method of claim 27, wherein the user can disable and enable
aspiration at a handle region of the treatment device.
29. The method of claim 27, wherein disabling suction releases any
tissue hugging the treatment device to avoid unwanted movement of
tissue during axial movement of the device to treat a next axially
spaced tissue level.
30. The method of claim 27, further comprising the step of locking
the disabler in position.
31. The method of claim 27, wherein the plurality of electrodes are
maintained in axial alignment by a spacer within the treatment
device.
32. The method of claim 27, wherein the basket assembly includes a
balloon collapsible for movement of the treatment device.
33. The method of claim 32, wherein aspiration is disabled at a
handle section of the treatment device.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of provisional
application Ser. No. 62/050,090, filed Sep. 13, 2014, and is a
continuation-in-part of application Ser. No. 14/708,209, filed May
9, 2015 which claims the benefit of provisional application Ser.
No. 62/009,222, filed Jun. 7, 2014, and is a continuation-in-part
of application Ser. No. 13/867,042, filed Apr. 20, 2013, which
claims the benefit of provisional application Ser. No. 61/664,960,
filed Jun. 27, 2012, and is a continuation-in-part of application
Ser. No. 12/924,155, filed Sep. 22, 2010, which claims the benefit
of provisional application Ser. No. 61/277,260, filed Sep. 22,
2009. The entire contents of each of these applications are
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] In a general sense, the invention is directed to systems and
methods for treating interior tissue regions of the body. More
specifically, the invention is directed to systems and methods for
treating dysfunction in body sphincters and adjoining tissue by
applying radiofrequency energy to tissue to create tissue lesions
without ablating tissue.
BACKGROUND OF THE INVENTION
[0003] The gastrointestinal (GI) tract, also called the alimentary
canal, is a long tube through which food is taken into the body and
digested. The alimentary canal begins at the mouth, and includes
the pharynx, esophagus, stomach, small and large intestines, and
rectum. In human beings, this passage is about 30 feet (9 meters)
long.
[0004] Small, ring-like muscles, called sphincters, surround
portions of the alimentary canal. In a healthy person, these
muscles contract or tighten in a coordinated fashion during eating
and the ensuing digestive process, to temporarily close off one
region of the alimentary canal from another region of the
alimentary canal.
[0005] For example, a muscular ring called the lower esophageal
sphincter (or LES) surrounds the opening between the esophagus and
the stomach. Normally, the lower esophageal sphincter maintains a
high-pressure zone between fifteen and thirty mm Hg above
intragastric pressures inside the stomach.
[0006] In the rectum, two muscular rings, called the internal and
external sphincter muscles, normally keep fecal material from
leaving the anal canal. The external sphincter muscle is a
voluntary muscle, and the internal sphincter muscle is an
involuntary muscle. Together, by voluntary and involuntary action,
these muscles normally contract to keep fecal material in the anal
canal.
[0007] Dysfunction of a sphincter in the body can lead to internal
damage or disease, discomfort, or otherwise adversely affect the
quality of life. For example, if the lower esophageal sphincter
fails to function properly, stomach acid may rise back into the
esophagus. Heartburn or other disease symptoms, including damage to
the esophagus, can occur. Gastrointestinal reflux disease (GERD) is
a common disorder, characterized by spontaneous relaxation of the
lower esophageal sphincter.
[0008] Damage to the external or internal sphincter muscles in the
rectum can cause these sphincters to dysfunction or otherwise lose
their tone, such that they can no longer sustain the essential
fecal holding action. Fecal incontinence results, as fecal material
can descend through the anal canal without warning, stimulating the
sudden urge to defecate. The physical effects of fecal incontinence
(i.e., the loss of normal control of the bowels and gas, liquid,
and solid stool leakage from the rectum at unexpected times) can
also cause embarrassment, shame, and a loss of confidence, and can
further lead to mental depression.
[0009] In certain surgical systems, radiofrequency energy is
applied to tissue at different tissue levels to create multiple
tissue lesions. Application of such energy requires continuous
monitoring of certain tissue and/or device parameters to ensure
that the tissue is not heated to such extent that damaging burning
of tissue occurs. Thus, these systems monitor tissue temperature
and/or device electrode temperature and provide safety features to
cut off energy flow if the tissue temperature rises too high.
However, with the application of radiofrequency energy, there is a
fine point in which tissue is treated to form lesions and
beneficially alter structure of the tissue, e.g., alter the
structure of the sphincter muscle, while not being ablated.
[0010] Ablation of tissue can be generally defined as a removal of
a part of tissue. Radiofrequency energy to ablate tissue has been
used for various tumor treatments, destroying tissue and creating
tissue necrosis. However, avoiding tissue ablation may be
beneficial in treating the gastrointestinal tract in the foregoing
or other procedures. Therefore, it would be advantageous to provide
a system of applying radiofrequency energy to tissue at a power
setting and time duration which causes thermal effect to tissue to
create tissue lesions along a series of tissue levels but avoids
ablation or burning of tissue.
[0011] However, in avoiding tissue ablation, care needs to be taken
to ensure that tissue is not undertreated. In other words, in
attempts to prevent overheating of tissue which causes ablation,
the system needs to conversely ensure that tissue is not
under-heated and thus not therapeutically treated. Therefore, the
need exists for a system that applies radiofrequency energy to
tissue between these two energy levels.
SUMMARY OF THE INVENTION
[0012] The present invention advantageously provides an
electrosurgical system that applies radiofrequency energy to tissue
to create tissue lesions at different tissue levels and alters the
structure of the tissue, e.g., the sphincter muscle, without
ablating or burning the tissue, while on the other hand reducing
the incidence of tissue undertreatment. That is, the present
invention advantageously provides such electrosurgical system that
avoids such overheating of tissue, while at the same time limiting
under-heating of tissue which does not effectively treat tissue.
Thus, in striking this balance between the overheating and under
heating of tissue, more reliable and consistent tissue treatment is
achieved.
[0013] This prevention of overtreatment and undertreatment are
achieved in various ways. The below described different aspects
utilized to achieve the desired tissue treatment can be implemented
alone or in combination with each other.
[0014] Thus, the system and method of the present invention
advantageously keeps tissue treatment within a target zone to
provide a therapeutic effect to tissue, defined as thermally
heating tissue above a lower parameter wherein tissue is
undertreated and below a tissue ablation threshold wherein tissue
is overheated and ablated.
[0015] The present invention in accordance with one aspect provides
an assembly for disabling suction. In one aspect, a device for
applying radiofrequency energy for sphincter treatment is provided
comprising a flexible outer tube, an expandable basket having a
plurality of arms movable from a collapsed position to an expanded
position, and an opening in the arms. A plurality of electrodes are
movable with respect to the arms from a retracted position to an
extended position to extend through the openings in the arms. An
advancer is slidably disposed within the outer tube, and the
plurality of electrodes are operably coupled to the advancer such
that movement of the advancer advances the plurality of electrodes
through the openings to the extended position. An actuator for
moving the advancer from a first position to a second position to
advance the plurality of electrodes is provided. An aspiration tube
extends within the outer tube and an assembly for disabling
aspiration (suction) through the aspiration tube includes a
disabler having a first position to enable aspiration from a distal
portion of the aspiration tube to a proximal portion, the disabler
movable to a second position to disable aspiration.
[0016] In some embodiments, the disabler includes a sliding
mechanism movable between first and second positions, wherein in
the first position of the sliding mechanism, an opening in the
aspiration tube is closed to enable aspiration and in the second
position of the sliding mechanism the opening is open to disable
aspiration. In some embodiments, the opening is in a sidewall of
the aspiration tube.
[0017] In some embodiments, the sliding mechanism is connected to a
pivotable linkage, wherein movement of the sliding mechanism pivots
the linkage to open and close the opening in the aspiration tube.
In other embodiments, the disabler includes a mechanism movable
transverse to a longitudinal axis of the aspiration tube between
outer an inner positions, wherein in the outer position of the
mechanism an opening in the aspiration tube is closed to enable
aspiration and in the inner position of the mechanism the opening
in the aspiration tube is open to disable aspiration, the inner
position defined as the mechanism positioned further into a
longitudinal lumen of the aspiration tube. In other embodiments,
the disabler includes a mechanism pivotable with respect to the
aspiration tube, wherein in a first position of the mechanism a
longitudinally extending lumen of the aspiration tube is open to
enable aspiration and in a second position of the mechanism the
longitudinally extending lumen of the aspiration tube is closed to
disable aspiration, the mechanism having an engagement surface to
apply a force to and deform a wall of the aspiration tube to close
the longitudinally extending lumen.
[0018] In some embodiments, the disabler includes a mechanism
pivotable between the first and second positions. In other
embodiments, the mechanism is slidable transverse to the
longitudinal axis of the aspiration tube to move between the first
and second position.
[0019] The mechanism can be biased to the first position or the
second position.
[0020] In some embodiments, the mechanism includes a retention
locking feature to lock the mechanism in the inner and/or outer
position.
[0021] In some embodiments, the device further comprises an
elongated spacer positioned within the outer tube, the spacer
having a central lumen to receive the advancer and to maintain a
central position of the advancer. The spacer can have a rib
extending from a wall defining the central lumen to an inner wall
of the spacer. The spacer can have a slit forming a flap which is
elongated and extends longitudinally along at least a portion of
the spacer. The flap can be openable progressively to progressively
lay the wires within the spacer. In some embodiments, the spacer is
more rigid than the outer tube such that the outer tube can be
formed of a more flexible material than if the spacer was not
provided.
[0022] The spacer, if provided, can include an outer wall having at
least one longitudinally extending slit formed therein, the slit
being separable to provide access to an interior of the spacer for
placement of a plurality of wires within the interior of the spacer
and for placement of one or both of an irrigation tube or
aspiration tube within the interior of the spacer. In some
embodiments, the spacer includes a plurality of transverse ribs to
form separate internal regions of the spacer and a plurality of
longitudinally extending slits are formed in the outer wall of the
spacer to provide access to each of the internal regions.
[0023] In some embodiments, the plurality of electrodes include a
location feature engageable with an electrode holder to maintain
radial spacing of the electrodes. In some embodiments, the arms
have an alignment feature engageable with an arm holder to maintain
alignment of the arms. Preferably, the location feature maintains
an equidistant spacing of the distal tips of the electrodes.
[0024] In some embodiments, the electrodes include a substantially
conical non-penetrating tip.
[0025] In accordance with another aspect of the present invention,
a system for controlling operation of a radiofrequency treatment
device to apply radiofrequency energy to tissue to heat tissue to
create tissue lesions without ablating the tissue is provided
comprising a treatment device having a plurality of electrodes for
applying radiofrequency energy to tissue. The treatment device
further includes an assembly having a disabler for disabling
aspiration (suction) through an aspiration tube extending through
the device, the disabler having a first position to enable
aspiration from a distal portion of the aspiration tube to a
proximal portion of the aspiration tube, the disabler movable to a
second position to disable aspiration. A controller includes a
connector to which the treatment device is coupled for use, and a
generator for applying radiofrequency energy to the plurality of
electrodes is provided.
[0026] The system can further include a controller including an
operation system to execute on a display screen a first graphical
interface guiding use of the treatment device, the controller
visually prompting a user in a step-wise fashion to perform a
process using the connected treatment device of forming a pattern
of lesions in a body region in a plurality of axially spaced lesion
levels, each lesion level including a plurality of circumferential
spaced lesions. The controller controls application of energy so
that the tissue is thermally treated to create lesions but
preventing thermal treatment beyond a threshold which would ablate
the tissue.
[0027] In some embodiments, the device further comprises a spacer,
the spacer having a plurality of separable portions for placement
of components within different sections of an interior of the
spacer.
[0028] In some embodiments, the plurality of electrodes include a
location feature engageable with an electrode holder to maintain
radial spacing of the electrodes. The location feature maintains an
equidistant spacing of the distal tips of the electrodes.
[0029] The present invention in accordance with another aspect
provides a method of treating gastrointestinal reflux disease
comprising:
[0030] providing a treatment device having a plurality of
electrodes and an assembly having a disabler for disabling
aspiration (suction) through the aspiration tube, the disabler
having a first position to enable aspiration from a distal portion
of the aspiration tube to a proximal portion of the aspiration
tube, the disabler movable to a second position to disable
aspiration to facilitate axial and rotational movement of the
treatment device within tissue and limit undesired movement of
tissue;
[0031] applying radiofrequency energy to the plurality of
electrodes to thermally treat tissue below a tissue ablation
threshold and create a plurality of tissue lesions along axially
spaced tissue levels within the upper gastrointestinal tract;
[0032] monitoring tissue temperature throughout the procedure;
and
[0033] regulating power ensuring in response to the monitoring step
that the tissue temperature does not exceed a predetermined value
which would cause tissue ablation and/or tissue necrosis.
[0034] In some embodiments, the method further comprises the step
of sliding a mechanism to selectively cover and uncover an opening
in a sidewall of the aspiration tube. In some embodiments, the step
of sliding a mechanism slides the mechanism axially. The method may
further include the step of moving a mechanism radially inwardly to
deform a wall of the aspiration tube.
[0035] Further features and advantages of the inventions are set
forth in the following Description and Drawings, as well as in the
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1A is a schematic view of one embodiment of a system
for use with the device of the present invention;
[0037] FIG. 1B is a perspective view of one embodiment of an
integrated device incorporating features of the system shown in
FIG. 1;
[0038] FIG. 1C is a perspective view of another embodiment of an
integrated device incorporating features of the system shown in
FIG. 1;
[0039] FIG. 2A is an isometric view of a first embodiment of the
device of the present invention shown with the basket in the
non-expanded position;
[0040] FIG. 2B is an isometric view of the device of FIG. 2A shown
with the basket in the expanded position and the electrodes in the
advanced (deployed) position;
[0041] FIG. 3 is an exploded isometric view of the proximal region
of the device of FIG. 1;
[0042] FIG. 4 is an exploded isometric view of the distal region of
the device of FIG. 1;
[0043] FIG. 5 is a side view with a portion of the housing removed
to illustrate the internal components within the handle section and
a proximal portion of the spacer with the clamp;
[0044] FIG. 6 is a side view of a portion of the housing removed to
illustrate the internal components within the handle section and
the proximal portion of the spacer, the clamp removed for
clarity;
[0045] FIG. 7 is an isometric view of the spacer of the present
invention;
[0046] FIG. 8A is front view of the spacer shown with the wires
positioned therein;
[0047] FIG. 8B is a front view of an alternate embodiment of the
spacer;
[0048] FIG. 9 is a side perspective view showing the wires being
inserted into the spacer during a manufacturing step;
[0049] FIGS. 10 and 11 are isometric and side cross-sectional
views, respectively, of the spacer;
[0050] FIG. 12 is a side view of an alternate embodiment of the
spacer of the present invention;
[0051] FIG. 13 is an enlarged isometric cross-sectional view of a
distal portion of the spacer of FIG. 7;
[0052] FIG. 14 is a view similar to FIG. 13 showing the holder and
clamp;
[0053] FIG. 15 is a view similar to FIG. 13 showing the holder,
clamp and irrigation tube;
[0054] FIGS. 16 and 17 are front and back isometric views,
respectively, of the irrigation manifold;
[0055] FIG. 18 is a side view of the irrigation manifold of FIG. 16
with the basket arms inserted;
[0056] FIG. 19 is a side view of the needle electrode of the
present invention;
[0057] FIG. 20 is a top view of the needle electrode of FIG.
19;
[0058] FIG. 21 is an enlarged view of the location feature of the
electrode needle of FIG. 19;
[0059] FIG. 22 is an isometric view of the needle holder;
[0060] FIG. 23A is an isometric view showing the needle electrode
of FIG. 19 being inserted into the needle holder of FIG. 23;
[0061] FIG. 23B is an isometric view similar to FIG. 23A showing
the needle electrode positioned in the needle holder;
[0062] FIG. 24 is an isometric view illustrating the four needle
electrodes positioned in the needle holder of FIG. 22;
[0063] FIG. 25 is a close up view of the needle holder and
sleeve;
[0064] FIG. 26 is a view similar to FIG. 25 showing the tube clamp
over the needle holder sleeve;
[0065] FIG. 27 is a top view of one of the basket arms
(spines);
[0066] FIG. 28 is an enlarged view of the area of detail identified
in FIG. 27;
[0067] FIG. 29 is a bottom view of the basket arm of FIG. 27;
[0068] FIG. 30A is an isometric view of one of the basket arms
being inserted into the basket holder;
[0069] FIG. 30B illustrates the opposing side of the basket arm and
basket holder of FIG. 30A;
[0070] FIG. 30C is a cross-sectional view illustrating an alternate
embodiment and showing the four arm channels engaged with the
basket holder;
[0071] FIG. 31 is a front view in partial cross-section showing the
basket arm of FIG. 30A engaged within the basket holder;
[0072] FIG. 32 is a side view showing the basket arms positioned in
the basket holder;
[0073] FIG. 33 is a front view showing all four basket arms
positioned in the basket holder;
[0074] FIG. 34A is a front view of the device of FIG. 1 with the
needle electrode in the deployed (advanced) position illustrating
radial alignment of the needle tips;
[0075] FIG. 34B is a side view of the basket and needle electrodes
in the deployed position illustrating radial and longitudinal
alignment of the needle electrode tips;
[0076] FIGS. 35A and 35B illustrate what occurs if the needle
electrode tips are not radially aligned;
[0077] FIG. 35C illustrates what occurs if the needle electrode
tips are not longitudinally aligned;
[0078] FIGS. 36-38 illustrate the method of use of the device of
FIG. 2A wherein FIG. 36 shows the device inserted within a
sphincter in the non-expanded condition; FIG. 37 shows the basket
expanded to dilate the sphincter wall, and FIG. 38 shows the
needles deployed to penetrate tissue;
[0079] FIG. 39 illustrates the desired formation of lesions
utilizing the aligned needle and basket assembly features of the
present invention;
[0080] FIG. 40 is a side view of a proximal portion of the
apparatus showing one embodiment of the aspiration (suction)
disabling assembly of the present invention;
[0081] FIG. 41A is a longitudinal cross-sectional view of a first
embodiment of the suction disabling assembly of the present
invention, the assembly shown in the closed position to enable
suction;
[0082] FIG. 41B is a view similar to FIG. 40 showing the suction
disabling assembly in the open position to disable suction;
[0083] FIG. 41C is a perspective view of the suction disabling
assembly of FIG. 41A;
[0084] FIG. 41D is an exploded view of the suction disabling
assembly of FIG. 41A;
[0085] FIG. 42A is longitudinal cross-sectional view of a second
embodiment of the suction disabling assembly of the present
invention, the assembly shown in the closed position to enable
suction;
[0086] FIG. 42B is a view similar to FIG. 42A showing the suction
disabling assembly in the open position to disable suction;
[0087] FIG. 43A is longitudinal cross-sectional view of a third
embodiment of the suction disabling assembly of the present
invention, the assembly shown in the closed position to enable
suction;
[0088] FIG. 43B is a view similar to FIG. 43A showing the suction
disabling assembly in the open position to disable suction;
[0089] FIG. 44A is longitudinal cross-sectional view of a fourth
embodiment of the suction disabling assembly of the present
invention, the assembly shown in a first position to enable
suction;
[0090] FIG. 44B is a view similar to FIG. 44A showing the suction
disabling assembly in a second position to disable suction;
[0091] FIG. 45A is longitudinal cross-sectional view of a fifth
embodiment of the suction disabling assembly of the present
invention, the assembly shown in the first position to enable
suction;
[0092] FIG. 45B is a view similar to FIG. 45A showing the suction
disabling assembly in the closed position to disable suction;
[0093] FIG. 46A is longitudinal cross-sectional view of a sixth
embodiment of the suction disabling assembly of the present
invention, the assembly shown in the open position to enable
suction;
[0094] FIG. 46B is a view similar to FIG. 46A showing the suction
disabling assembly in the closed position to disable suction;
and
[0095] FIG. 47 is a side view of an alternate embodiment of the
electrode tip; and
[0096] FIG. 48 is a close up view of the electrode tip of FIG. 48
in contact with tissue.
[0097] The invention may be embodied in several forms without
departing from its spirit or essential characteristics. The scope
of the invention is defined in the appended claims, rather than in
the specific description preceding them. All embodiments that fall
within the meaning and range of equivalency of the claims are
therefore intended to be embraced by the claims.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0098] This specification discloses various systems and methods for
treating dysfunction of sphincters and adjoining tissue regions in
the body. The systems and methods are particularly well suited for
treating these dysfunctions in the upper gastrointestinal tract,
e.g., gastro-esophageal reflux disease (GERD) affecting the lower
esophageal sphincter and adjacent cardia of the stomach. For this
reason, the systems and methods will be described in this context.
Still, it should be appreciated that the disclosed systems and
methods are applicable for use in treating other dysfunctions
elsewhere in the body, including dysfunctions that are not
necessarily sphincter-related. For example, the various aspects of
the invention have application in procedures requiring treatment of
hemorrhoids, or fecal incontinence, or urinary incontinence, or
restoring compliance to or otherwise tightening interior tissue or
muscle regions. The systems and methods that embody features of the
invention are also adaptable for use with systems and surgical
techniques that are catheter-based and not necessarily
catheter-based.
[0099] The systems and methods disclosed herein provide application
of radiofrequency energy to tissue via a plurality of electrodes.
The energy is applied via the electrodes to tissue at a series of
axially spaced tissue levels, thereby forming tissue lesions which
alters the tissue structure. Prior application of radiofrequency
energy to tissue in various surgical procedures involved
application of energy at certain levels and for a certain period of
time with the goal to ablate the tissue. That is, the objective was
to cause tissue necrosis and remove tissue. The systems and methods
of the present disclosure, however, treat tissue without ablating
the tissue and without causing tissue necrosis, which
advantageously achieves better clinical results, especially when
treating the sphincter muscles of the GI tract in the specific
surgical procedures disclosed herein. By applying sufficient energy
to cause thermal effect to tissue, but without ablating or burning
the tissue, tissue reconstruction/remodeling occurs which results
in beneficial changes to tissue properties, thus beneficially
treating GERD which is caused by the spontaneous relaxation of the
lower esophageal sphincter and beneficially treating fecal
incontinence caused by loss of tone of the sphincter muscles in the
anal canal. The system of the present disclosure rejuvenates muscle
to improve muscle function. The system of the present invention
also increases the smooth muscle/connective ratio which results in
sphincter reinforcement and remodeling.
[0100] In studies performed, it was found that application of
non-ablative RF energy to sphincter muscle influences the
structural arrangement of smooth muscle and connective tissue
contents. The increase of the smooth muscle fibers area per muscle
bundles as well as the collagen and myofibroblast contents within
the internal anal sphincter were found to be potentially
responsible for sphincter reinforcement and remodeling. More
specifically, in studies, it was found that application of
non-ablative RF energy increased smooth muscle/connective tissue
ratio without changes (increase) in the collagen I/III ratio. There
was an increase in diameter and number of type I fibers in the
external anal sphincter after non-ablative RF and higher cellular
smooth muscle content in the internal anal sphincter, suggesting
that sphincter remodeling by non-ablative RF energy resulted from
activation and repopulation of smooth muscle cells, possibly
related to phenotype switch of fibroblasts into myofibroblasts and
external anal sphincter fibers. In one animal study, quantitative
image analysis showed the cross-section occupied by smooth muscle
within the circular muscle increased by up to 16% after
non-ablative RF, without increase in collagen I/III ratio, and
external anal sphincter muscle fiber type composition showed an
increase in type I/III fiber ratio from 26.2% to 34.6% after
non-ablative RF, as well as a 20% increase in fiber I type diameter
compared to controls.
[0101] For such aforedescribed non-ablation RF treatment, the
system and method of the present disclosure ensure proper radial
and longitudinal (axial) alignment of the tips of the needle
electrodes. This can prevent overheating of tissue since the
equidistantly spaced electrodes ensure there is no undesired
overlap of tissue treatment regions which could occur if the tips
were not equally radially spaced. This is especially the case since
the device in use is rotated to treat lesions at the same axial
lesion level and moved longitudinally to treat tissue at different
axial lesion levels. Such radial spacing and longitudinal alignment
also ensures that tissue is not undertreated which could occur if
spacing between the needle tips is too great and therefore areas of
tissue are not properly treated. Furthermore, the longitudinal
spacing ensures that tissue is not overheated or underheated due to
undesired variations of tissue penetration/depth of energy
application, compounded due to rotation and longitudinal
repositioning of the device. This is discussed in more detail
below.
[0102] Various features of the surgical treatment devices connected
to the controller achieve the foregoing. Preventing overheating of
tissue is achieved by enhanced temperature control of the tissue,
which is accomplished in one way by more accurate needle tip
alignment, more accurate basket alignment, and/or maintaining
centering of the needle advancer during flexing of the catheter to
maintain a desired depth of penetration during bending of the
device.
[0103] FIG. 1A shows a unified system for diagnosing and/or
treating dysfunction of sphincters and adjoining tissue in the
body. The targeted sphincter regions can vary. In the illustrated
embodiment, one region comprises the upper gastro-intestinal tract,
e.g., the lower esophageal sphincter and adjacent cardia of the
stomach. Other regions are also contemplated.
[0104] In the illustrated embodiment, the device 10 of FIGS. 2A and
2B function in the system to apply energy in a selective fashion to
tissue in or adjoining the targeted sphincter region. The applied
energy creates one or more lesions, or a prescribed pattern of
lesions, below the surface of the targeted region without ablating
tissue. The subsurface lesions are desirably formed in a manner
that preserves and protects the surface against thermal damage.
Preferably, the energy is applied to the muscle layer, beyond the
mucosa layer.
[0105] Natural healing of the subsurface lesions leads to a
reconstruction/remodeling of the tissue which leads to beneficial
changes in properties of the targeted tissue. The subsurface
lesions can also result in the interruption of aberrant electrical
pathways that may cause spontaneous sphincter relaxation. In any
event, the treatment can restore normal closure function to the
sphincter region as the non-ablating application of radiofrequency
energy beneficially changes the properties of the sphincter muscle
wall. Such energy rejuvenates the muscle to improve muscle
function.
[0106] With reference to FIG. 1A, the system 2 includes a generator
4 to supply the treatment energy to the device 10. In the
illustrated embodiment, the generator 4 supplies radio frequency
energy, e.g., having a frequency in the range of about 400 kHz to
about 10 mHz, although other ranges are contemplated. Other forms
of energy can be applied, e.g., coherent or incoherent light;
heated or cooled fluid; resistive heating; microwave; ultrasound; a
tissue ablation fluid; or cryogenic fluid. Device 10 is coupled to
the generator 4 via a cable connector 5 to convey the generated
energy to the respective device 10.
[0107] The system preferably also includes certain auxiliary
processing equipment. In the illustrated embodiment, the processing
equipment includes an external fluid delivery apparatus 6 and an
external aspiration apparatus 8.
[0108] Device 10 can be connected via tubing 6a to the fluid
delivery apparatus 6 to convey processing fluid for discharge by or
near the device 10. Device 10 can also be connected via tubing 8a
to the aspirating apparatus 8 to convey aspirated material by or
near the device for removal.
[0109] The system also includes a controller 9. The controller 9,
which preferably includes a central processing unit (CPU), is
linked to the generator 4, and can be linked to the fluid delivery
apparatus 6, and the aspiration apparatus 8. Alternatively, the
aspiration apparatus 8 can comprise a conventional vacuum source
typically present in a physician's suite, which operates
continuously, independent of the controller 9.
[0110] The controller 9 governs the power levels, cycles, and
duration that the radio frequency energy is distributed to the
device 10 to achieve and maintain power levels appropriate to
achieve the desired treatment objectives. In tandem, the controller
9 also desirably governs the delivery of processing fluid and, if
desired, the removal of aspirated material. Thus, the controller
maintains the target tissue temperature to ensure the tissue is not
overheated.
[0111] The controller 9 includes an input/output (I/O) device 7.
The I/O device 7 allows the physician to input control and
processing variables, to enable the controller to generate
appropriate command signals. The I/O device 7 also receives real
time processing feedback information from one or more sensors
associated with the operative element (as will be described later),
for processing by the controller 9 e.g., to govern the application
of energy and the delivery of processing fluid. The I/O device 7
also includes a graphical user interface (GUI), to graphically
present processing information to the physician for viewing or
analysis.
[0112] In an alternate embodiment of FIG. 1B, the radio frequency
generator, the controller with I/O device, and the fluid delivery
apparatus (e.g., for the delivery of cooling liquid) are integrated
within a single housing 200. The I/O device 210 couples the
controller to a display microprocessor 214. The display
microprocessor 214 is coupled to a graphics display monitor 216 in
the housing 200. The controller 212 implements through the display
microprocessor 214 the graphical user interface, or GUI, which is
displayed on the display monitor 216. The graphical user interface
can be realized with conventional graphics software using the MS
WINDOWS.RTM. application. The GUI is implemented by showing on the
monitor 216 basic screen displays.
[0113] FIGS. 1C illustrates another embodiment where the radio
frequency generator, the controller with I/O device, and the fluid
delivery control apparatus (e.g., for the delivery of cooling
liquid) are integrated within a single housing 200a. Connection
port 209 is for connecting the treatment device.
[0114] Turning now to the treatment device of the present
invention, in general, the device 10 is a catheter-based device for
treating sphincter regions in the upper gastro-intestinal tract,
and more particularly, the lower esophageal sphincter and adjoining
cardia of the stomach to treat GERD. In the embodiment shown, the
device 10 includes a flexible catheter tube 22 that has a handle 16
at its proximal end. The distal end of the catheter tube 22 carries
the operative element. Note that for clarity throughout the
drawings not all identical components are labeled in the specific
drawing.
[0115] With reference to FIGS. 2A-4, wherein like reference
numerals refer to like parts throughout the several views, device
10 has a proximal portion 12, a distal portion 14 and an elongated
flexible outer catheter tube 22. Contained within the outer tube 22
is spacer 40 discussed in more detail below. The basket assembly is
designated generally by reference numeral 18 and is movable between
a collapsed position (configuration) to provide a reduced profile
for delivery and an expanded position (configuration) to dilate the
tissue, e.g., the sphincter wall. The basket assembly 18 includes a
balloon 80 (FIG. 4) which is inflated via inflation portion 30
extending from handle 16 to expand the basket 18.
[0116] Also extending from handle 16 is an aspiration port 26 to
enable aspiration through the device 10 and an irrigation port 28
to enable fluid injection through the device 10.
[0117] The device 10 also includes a plurality of needle electrodes
32 which are movable from a retracted position for delivery to an
advanced position protruding through the basket for penetrating
tissue. Plug 29 extends from handle 16 and electrically
communicates with a generator to apply radiofrequency to the
electrodes 32 for application of such energy to treat tissue as
discussed in more detail below. Slider 24 on handle 16 is one type
of mechanism that can be used to advance the needle electrodes 32.
In this mechanism, slider 24 is movable from an initial position of
FIG. 2A to a second advanced position of FIG. 2B to advance the
electrodes 32. Such advancement is achieved as rod 33 (FIG. 3) is
attached to the slider 24 at one end and the other end is attached
to needle pusher 42. A proximal end of the needle electrodes 32 are
coupled to a distal end of the needle pusher (advancer) 42. Rod 33
can include a calibration nut 33a.
[0118] As used herein, attached or coupled is not limited to direct
attachment as interposing components can be used.
[0119] Spacer 40 is positioned within outer tube 22 and functions
to separate the various internal components and maintain a center
position of needle advancer 42. Needle advancer 42 is slidably
positioned within a central lumen of the spacer 40. Also contained
within the spacer 40, in various quadrants thereof, which will be
discussed in more detail below, are the irrigation tube 44 which
fluidly communicates with the irrigation port 28 and the arms of
the basket assembly 18 and the aspiration tube 46 which
communicates with the aspiration port 26. The aspiration tube 46
opening is positioned proximal of the balloon 80. Inflation tube 48
communicates with inflation port 30 (which receives a syringe) to
inflate the balloon 80 contained within the basket assembly 18 and
is also positioned within spacer 40. A valve is preferably provided
to limit balloon inflation. Wires 50, only a few of which are shown
in FIG. 3 for clarity, although in preferred embodiments twelve
wires would be provided for the reasons described below, are also
positioned within spacer 40. Wire bundle 51 is shown in FIG. 4.
Fastener 52 is attached to internal threads 56 of handle 16, with
spacer clamp 54 clamping fastener 52 to connect spacer 40 to handle
16 (see also FIG. 5). Note FIG. 6 illustrates the spacer 40 mounted
within handle 16 with the clamp 54 removed for clarity.
[0120] In the illustrated embodiment (see FIG. 4), at least one
temperature sensor is associated with each needle electrode 32. One
temperature sensor 108a senses temperature conditions near the
exposed distal end of the electrode 32. A second temperature sensor
108b is located on the corresponding spine 100, which rests against
the mucosal surface when the balloon structure 80 is inflated to
measure temperature of the tissue adjacent the needle electrode
32.
[0121] The irrigation tube 44 communicates with manifold 60. As
shown in FIGS. 16-18, manifold 60 has an inlet opening 62 which is
coupled to the irrigation tube 44 and a plurality of exit openings
64, each communicating with one of the spines 100 of the basket
assembly 18. In this manner, fluid entering the manifold 60 through
the single inlet opening 62 is subdivided for distribution through
each of the four radially spaced spines 100 of the basket assembly
18 for exit through an irrigation opening in each of the spines
100.
[0122] With reference to FIG. 4, the basket structure will now be
discussed. In the illustrated embodiment, the three-dimensional
basket 18 includes one or more spines or arms 100, and typically
includes four spines 100, which are held together at a distal end
by a distal tip 20 and at proximal end by basket holder 84. In the
illustrated embodiment, four spines 100 are shown, spaced
circumferentially at 90-degree intervals.
[0123] An expandable structure comprising a balloon 80 is located
within the basket arms 100. The balloon 80 can be made from various
materials such as by way of example, a Polyethylene Terephthalate
(PET) material, or a polyamide (non-compliant) material, or a
radiation cross-linked polyethylene (semi-compliant) material, or a
latex material, or a silicone material, or a C-Flex (highly
compliant) material.
[0124] The balloon and basket arms are shown in FIG. 2A in a
normally, generally collapsed condition, presenting a low profile
for delivery into the esophagus.
[0125] A balloon tube 82 includes an interior lumen, which
communicates with the interior of the balloon 80. A fitting 30
(FIG. 3), such as a syringe-activated check valve, extends from the
handle 16 and communicates with the lumen in the inflation tube 48
and the lumen within the balloon tube 82. The fitting 30 couples
the lumen to a syringe for injection of fluid under pressure
through the lumen into the balloon structure 80, causing its
expansion.
[0126] Expansion of the balloon 80 urges the basket arms 100 to
open and expand to the expanded position (condition) of FIG. 2B.
The force exerted by the balloon 80 and arms 100, when expanded, is
sufficient to exert an opening or dilating force upon the tissue
surrounding the basket arms 100. The balloon 80 can be expanded to
varying diameters to accommodate for varying patient anatomy.
[0127] As noted above, the basket structure is composed of four
basket arms or spines 100. Each spine 100 has three tube or spine
sections 102, 104 and 106 (see e.g. FIGS. 4 and 27). The spine 100
can be formed by a tri-lumen extrusion or alternately by separate
tubes attached together. Note tube 104 is positioned between tubes
102 and 106 and can have flattened surfaces 104C (FIG. 31), rather
than round surfaces of tubes 102, 106, to facilitate
manufacture.
[0128] Tube 102 has a proximal opening 102a to receive the
irrigation tube 44, tube 104 has a proximal opening 104a to receive
the needle electrode 32, and tube 106 has a proximal opening 106a
to receive the wires for temperature sensors 108a, 108b. As shown,
the proximal openings 102a, 104a and 106a are staggered, with the
opening 102a being the most proximal, the opening 106a being the
most distal and the opening 104a axially intermediate openings 102a
and 106a. Tube 102 of spine 100 has an exit opening 102b (FIG. 28)
to allow for exit of fluid into the tissue, tube 104 has an exit
opening 104b to enable the needle electrode 32 to be angularly
deployed from the spine 100, and tube 106 has an opening 106b for
the sensor 108.
[0129] Balloon 80, positioned within the basket arms 102, 104, 106
has a tube 82 which is mounted within basket holder 84. Basket
holder clamp 86 (FIG. 4) fixedly retains spines 100 within basket
holder 84 and retains basket holder 84 within outer tube 22. Basket
holder clamp 86 is seated within the outer tube 22, and outer clamp
110 is positioned over outer tube 22 and over basket holder clamp
86. Tube extension 88, extending distally from connector tube 81
attached to balloon 80, is connected within the central opening 25
of distal tip 20. The flat ends 101 of basket arms 100 connect
within proximal slots 25a of distal tip 20.
[0130] With reference to FIGS. 27-32, the basket arms (spines) 100
include a location feature or structure to maintain radial
alignment/spacing. In the illustrated embodiment, the location
feature includes a series of grooves on the basket arms 100 which
cooperate with bumps (or projections) on the basket holder 84 so
the arms 100 are maintained in radial alignment with fixed radial
spacing. More specifically, a bottom surface of the tube 104 of
spine 100 includes a set of four grooves 112. The grooves 110 on
the top surface of arms 110 facilitate grasping during manufacture.
The grooves 112 receive projections 89 on basket holder 84. That
is, the configuration and dimension of the grooves correspond to
the configuration and dimensions of the bumps. Thus, this location
feature of the arms 100 ensures the arms are properly seated within
basket holder 84 to ensure the desired alignment of the arms 100
e.g., equidistant radial spacing, is provided during manufacture
and maintained during use. It should be appreciated that this
location feature can alternately be configured so the projections
are on the arms 100 and the grooves are in the basket holder 84.
Other location/alignment engagement features are also contemplated
to maintain radial alignment of the basket arms 100. Also, although
four projections/grooves are provided in the illustrated
embodiment, a different number can be utilized for the engagement
structure. The bump/groove engagement can be a location feature
which requires a clamp such as clamp ring 86 to maintain the
position, or alternatively the location feature can also interlock
to frictionally engage. FIG. 31 illustrates a cross-sectional view
of one of the spines 100 mounted within the basket holder. Only one
of the spines 100 is shown in FIG. 31 for clarity. FIG. 33 is a
front view (looking distally from the proximal end) showing all
four arms 100 attached thereover to the basket holder 34, with the
basket holder clamp ring 86 attached to retain the holder 34 within
outer tube 22.
[0131] Within basket holder 84 is lumen 114 which receives the
aspiration tube 46 and lumen 116 which receives the balloon
inflation tube 48.
[0132] In an alternate embodiment, U-shaped channels 176 can be
provided and circular tubes (not shown) snapped into the channels.
This is illustrated in FIG. 30C wherein three separate tubes (not
shown) would be snapped into channels 176.
[0133] Turning now to the needle electrode assembly, the needle
pusher (advancer) 42, as noted above, is connected to needle
electrodes 32. Pusher 42 is coupled at its distal end to needle
holder 90. Holder ring 94 (FIG. 4) is positioned over needle holder
90 and retained by clamping sleeve 92 positioned over holder ring
94. That is, clamping sleeve 92 is positioned over holder clamp 94
and needle holder 90 to fix the needle electrodes 32 within the
needle holder 90.
[0134] Each spine (basket arm) 100 carries an electrode 32.
Therefore, there are four electrodes circumferentially
equidistantly spaced at 90-degree intervals. Each electrode 32 is
carried within the tubular member or lumen 104 of spine 100 for
sliding movement from a retracted position, withdrawn within the
spine 100, to an extended position, extending outwardly from the
spine 100 (see FIG. 2B) through opening 104a in the lumen 104. A
sliding actuator 24 (FIGS. 3 and 5) on the handle 16 as described
above is coupled to the sliding electrodes 32 so that the actuator
24 controls movement of the electrodes 32 between the retracted
position and the extended position (by sliding the actuator from
the position of FIG. 2A to the position of FIG. 2B).
[0135] The electrodes 32 have sufficient distal sharpness and
strength, when extended, to penetrate a desired depth into the
smooth muscle of the lower esophageal sphincter 18 or the cardia of
the stomach (see FIG. 38). The desired depth can range from about 3
mm to about 10 mm, and more preferably between about 5 mm to about
8 mm, although other depth ranges are also contemplated.
[0136] The electrodes 32 are formed of material that conducts radio
frequency energy, such as by way of example nickel titanium,
stainless steel, e.g., 304 stainless steel, or a combination of
nickel titanium and stainless steel.
[0137] An electrical insulating material can be coated about the
proximal end of each electrode so that when the distal end of the
electrode penetrating the smooth muscle of the esophageal sphincter
or cardia transmits radio frequency energy, the material insulates
the mucosal surface of the esophagus or cardia from direct exposure
to the radio frequency energy. Thermal damage to the mucosal
surface is thereby avoided. The mucosal surface can also be
actively cooled during application of radio frequency energy to
further protect the mucosal surface from thermal damage.
[0138] The controller 9 can condition the electrodes 32 to operate
in a monopolar mode. In this mode, each electrode 32 serves as a
transmitter of energy, and an indifferent patch electrode
(described later) serves as a common return for all electrodes 32.
Alternatively, the controller 9 can condition the electrodes 32 to
operate in a bipolar mode. In this mode, one of the electrodes
comprises the transmitter and another electrode comprises the
return for the transmitted energy. The bipolar electrode pairs can
include electrodes on adjacent spines, or electrodes 32 spaced
apart on different spines.
[0139] With reference to FIGS. 19-26, the needle electrodes are
maintained in axial (longitudinal) and radial alignment. Each
needle electrode 32 includes a location feature or structure in the
form of two ribs or projections (bumps) 165, separated by grooves
166 for cooperation with grooves 97a formed between surfaces 97 of
the needle holder 90. That is, the projections 165 are configured
and dimensioned to fit within grooves 97a. Thus, during
manufacture, the electrodes 32 are placed in alignment by a needle
holder 90. A different number of projections and cooperating
grooves is also contemplated, for the engagement structure. The
bump/groove engagement can be a location feature which requires a
clamp to maintain the position, or alternatively the location
feature can interlock to frictionally engage. Also, alternatively,
the projections could be provided on the needle holder and the
grooves on the electrodes. Other engagement/location structure is
also contemplated.
[0140] More specifically, FIG. 23A illustrates a needle electrode
32 just before engagement with the needle holder 90 and FIG. 23B
illustrates engagement of the needle electrode with the
projections/grooves of the needle holder 90. Each of the four
needle electrodes 32 are interfit to the needle holder 90,
separated at 90 degree intervals. Holder ring 94 is then placed
over the needle holder 90 (FIG. 25) and clamping sleeve 92 (FIG.
25) is then placed over the ring 94 to provide a clamping force to
hold the proximal ends of the needle electrodes 32 engaged with the
needle holder 90, as shown in FIG. 26. The equidistant radial
spacing and longitudinal alignment of the electrodes 32a-32d is
illustrated in FIGS. 34A and 34B with the distal tips of the
electrodes extending the same distance from the basket to terminate
along the same plane. This is achieved by the aforedescribed
location feature
[0141] The advantage of the alignment of the electrodes 32 can be
appreciated with reference to FIGS. 35A-35C showing misalignment
These Figures illustrate what can occur if the needle electrodes 32
are not properly aligned. In FIG. 35a, if the needle electrodes are
not radially equidistantly spaced, then undertreatment and
overtreatment areas will occur. For example, in FIG. 35a, a needle
electrode 32a is shown out of axial alignment, i.e., more than 90
degrees apart from needle electrode 32b, and less than 90 degrees
apart from needle electrode 32d. Optimally, when RF energy is
applied to the tissue via the needle electrode tips, the treatment
areas are space at a minimum of 5 millimeters apart, this occurs
when the electrodes are properly aligned as in the present
invention. After application of RF energy, and the device is
rotated 45 degrees (or 30 degrees) to provide another application
of RF energy, the treatment areas will be equidistantly spaced
between the two treatment areas T1 and T2 provided the electrodes
are properly aligned. However, if an electrode is out of axial
alignment as is electrode 32a in FIG. 35A, space A between
treatment area T3 and T4 is greater than 5 millimeters and space B
between treatment areas T4 and T1 is less than 5 millimeters.
Consequently, in the next application of RF energy after device
rotation (FIG. 35B), treatment region T7 will be too close to
treatment region T4, and can overlap region T4 which can overtreat
the tissue and cause undesired tissue ablation. Conversely,
treatment area T7 will be too far from treatment area T3 which will
lead to undertreatment of tissue. Note new treatment region T5 is
properly spaced from treatment regions T8 and T3.
[0142] The problem of misalignment and undertreatment/overtreatment
is compounded since treatment is in three dimensions. That is,
lesions are formed not only in an axial plane but in spaced
longitudinal planes, and therefore proper spacing needs to be
maintained not only in the axial lesion level, but between axial
lesion levels. Therefore, when the device is moved axially to the
next axial lesion level and the needle electrodes are deployed, the
improper axial spacing will again cause tissue treatment areas too
close or too far from other areas between axial planes.
[0143] A similar problem occurs if the needle electrodes are not
longitudinally aligned i.e., the distal tips of the electrodes do
not terminate the same distance from the spines 100. The locating
feature of the present invention ensures that the needle electrodes
distalmost end terminate at the same distal region. FIG. 35C
illustrates what can occur if the needle electrodes are not
longitudinally aligned in assembly and are deployed during use. As
shown, improperly aligned electrode 32f terminates more proximally
than electrode 32e since its initial position is improperly
rearward of electrode 32f. When the electrodes are deployed,
electrode 32f does not penetrate sufficiently into tissue so that
when RF energy is applied, it will not treat the muscle layer but
rather treat the mucosal layer. Conversely, if one of the needle
electrodes is misaligned and is deployed too far, it can extend
past the desired treatment area. When the device is moved to the
next lesion level, the problem is compounded as the desired spacing
between the treatment areas will not be maintained and RF energy in
some regions will be applied too close to the previously treated
area causing overheating and unwanted ablation and other regions
will be applied too far from the previously treated region causing
undertreatment.
[0144] As noted above, the basket arms 100 include the location
feature to engage the feature on the basket holder 84. If the
basket arms are not properly radially spaced e.g., not spaced
equidistantly, then when the needle electrodes 32 are advanced
through the apertures in the arms 100, they will not be
equidistantly spaced, resulting in the undertreatment/overtreatment
of tissue discussed above. That is, if one of the arms 100 for
example is improperly skewed so it is spaced more than 90 degrees
from an adjacent arm, and closer than 90 degrees from the other
adjacent arm, when the needle electrodes 32 are advanced from these
arms, the tips would likewise be skewed and not spaced 90 degrees
apart, resulting in the aforementioned problems of not maintaining
the desired spacing.
[0145] An alternate embodiment of the electrode tip is shown in
FIG. 41. In this embodiment, rather than a penetrating tip, the
electrodes 162 have a substantially conical tip 162a, tapering in a
distal direction. The substantially conical tip 162a is
non-penetrating and when advanced toward tissue and into contact
with the tissue, upon sufficient force, deforms the tissue. As
shown, the tissue is compressed and forms around the substantially
conical tip 162a as the tip is indented into tissue. Energy applied
to the conical tip 162a heats the tissue for treatment as described
herein.
[0146] Turning now to more details of the spacer 40, spacer 40 has
a proximal end 40a connected to fastener 52 (FIG. 3) as discussed
above. The distal end 40b (FIG. 4) connects to fastener 55, and can
be flared as shown, and is retained within outer tube 22 by distal
clamp 70. With reference to FIGS. 8A and 9-15, spacer 40 has a
central circular rib 142 dimensioned to slidingly receive needle
pusher 42. Emanating from the circular rib 142 are four transverse
ribs 120, 122, 124 and 126 which subdivide the spacer 40 into four
longitudinally extending quadrants 130, 132, 134, and 136. Thus,
quadrant 130 is formed between ribs 120, 122, quadrant 132 is
formed between ribs 122 and 124, quadrant 134 is formed between
ribs 124 and 126 and quadrant 136 is formed between ribs 126 and
120. A pair of wires 50 are received in each of the quadrants, best
shown in FIGS. 8 and 9, forming thermocouples for measuring tissue
temperature of the tissue adjacent the needle electrodes 32. The
spacer 40 is preferably in the form of a plastic tube formed by an
extrusion. The spacer also functions to maintain centering of the
needle advancer during flexing of the catheter. That is, the
slider/actuator 24 movement correlates one to one with movement of
the needle advancer 42 and thus the needle electrodes 32. If not
retained in the channel in the center then the needle electrodes 32
would be at a greater distance if the catheter tube 22 was bent in
one direction and be at a shorter distance if the catheter 22 was
bent in a different direction. This shorter distance can result in
insufficient penetration resulting in undertreatment while on the
other hand, movement a longer distance can result in over
penetration. That is, this varied depth penetration can cause
undertreatment or overtreatment which can lead to ablation of the
tissue, as described in detail herein in conjunction with
non-alignment of the electrodes and/or basket arms.
[0147] The outer wall 138 of spacer 140 is formed with slits to
access each quadrant or area 130, 132, 136, and 138. More
specifically, slit 140a enables access to area 130, slit 140b
enable access to area 142, slit 140c enables access to area 134 and
slit 140c enables access to area 136. The slit is separable during
manufacture so the wires 50, irrigation tube 44 and aspiration tube
46 can be placed in the areas during manufacture. This facilitates
manufacture, as the flap formed by the slit can be progressively
opened and the wires and tube placed inside the area 130-136, with
the flap self closing to retain the components within the
spacer.
[0148] The spacer can in some embodiments be formed of a material
more rigid than the outer tube. This enables a more flexible outer
tube to be utilized as the spacer rather than the outer tube is
utilized to provide a sufficiently rigid structure to retain the
needle advancer.
[0149] Placement of all the wires and tubes are illustrated in FIG.
8A, with the thermocouple wires 50 placed in each of the quadrants
132-138. Irrigation tube 44 is within quadrant 134, balloon
inflation tube 48 is within quadrant 138 and aspiration tube 46 is
within quadrant 136.
[0150] In the alternate embodiment of FIG. 8B, instead of four
separate quadrants, a rib 152 transitions into circular rib 154 to
retain the needle pusher 42 in a centered position within the
spacer. Instead of four separate quadrants, some wires 50,
aspiration tube 44, and balloon inflation tube 48 are placed in one
quadrant and irrigation tube 44 and other wires 50 are placed in a
second quadrant of the spacer 140. A slit 156a and 156b, similar to
slits 140a and 140b of FIG. 8A, are provided to form a flap to
enable access to the interior of the spacer in the same manner as
described above. It should also be appreciated that a different
number of ribs 152 can be provided to provide a different number of
quadrants. For example, three ribs 152 can be provided to create
three quadrants.
[0151] As noted above, the external fluid delivery apparatus 6 is
coupled via tubing 6a (see FIG. 1) to connector 28 (see FIG. 4), to
supply cooling liquid to the targeted tissue, e.g., through holes
in the spines. The external aspirating apparatus 8 is coupled via
tubing 8a (see FIG. 1) to connector or aspiration port 26 (see FIG.
3) to convey liquid from the targeted tissue site, e.g., through
one of the tubes or lumens in the spines 100. The controller 9 can
govern the delivery of processing fluid and, if desired, the
removal of aspirated material.
[0152] FIGS. 40-46B illustrate various embodiments of a mechanism
for disabling suction (aspiration) through the aspiration (suction)
tube of the device. Note the terms suction and aspiration are used
herein interchangeably. In several of the embodiments, a disabler
is movable between two positions: in one position a side opening in
the aspiration tube is covered to enable suction through the
aspiration tube; in another position the side opening is open to
disable aspiration through the aspiration tube. In several other
embodiments, the disabler is movable to pinch the aspiration tube
to close off the lumen in the tube. By disabling aspiration during
the surgical procedure, movement of the device within the patient's
body is facilitated since it avoids tissue being caught in the
instrument during such movement. In other words, when it is desired
to move the instrument to the next axially spaced lesion level as
described herein, the vacuum can be disabled at the handle section
of the device without having to shut off the vacuum, thereby
facilitating movement. By placement at the handpiece, the user does
not have to keep turning the vacuum on and off, but rather can
control aspiration at the handle when desired. Location of the
control for the disabler is shown in FIG. 40 by way of example.
[0153] The suction disabler also helps obtain treatment without
ablating tissue by ensuring the tissue (and not just the device) is
properly positioned for application of energy. For example, if
tissue is retained against the device due to the suction, e.g.,
around the basket or balloon, and the device is moved axially, the
tissue can be pulled from its "normal" position along with the
device. If this occurs, when the electrodes are redeployed and
energy is applied, the energy could undesirably be applied to the
same region of tissue as previously applied rather than a new
region of tissue which can cause overtreatment of tissue and
ablation. Also, by not treating the new region under treatment can
occur. In other words, the undesired movement of tissue can
adversely result in improper spacing of tissue regions receiving
energy, causing the undesired consequences described herein.
Therefore, the suction disabler, by cutting off suction, releases
any tissue "hugging" the device to avoid unwanted movement of
tissue during axial movement of the device to treat the next level
of tissue.
[0154] Turning first to the embodiments which disable aspiration
(suction) by controlling the covering of a side opening in the
aspiration tube, a first embodiment of a aspiration (suction)
disabler, designated generally by reference numeral 210, is shown
in FIGS. 40-41D. The aspiration (suction) tube 200 has an opening
202 in its side wall. Suction is applied via external aspiration
source such as aspiration source 8 of FIG. 1A which is coupled to
aspiration port 26 in the device handle. Suction disabler 210 is
slidable from a first position of FIG. 41A wherein the opening 202
in aspiration tube 200 is closed off to enable suction through tube
200 to a second position wherein the opening 202 is open so that
suction is disabled. More specifically, suction disabler 210
includes a slidable control or lever 212, a post 214 extending
inwardly from the lever 212 (toward the tube 200) and a cover 216
at the opposing end of the post 214. A gripping surface 213 can be
provided on an external surface of lever 212 for ease of sliding.
Lever 212 extends through a slot 223 in the handle housing 228.
Preferably, the disabler 210 is formed of a monolithic or unitary
piece, although it is also contemplated that one or more of the
lever, post or cover can be a separate component and attached
together.
[0155] A support block 218 is attached to the aspiration tube 200
such as by gluing or other methods. A cylindrical portion 220
extending from the inner surface of support block 218 extends into
opening 202 of aspiration tube 200 and the outer wall portion 203
of the aspiration tube 200 is seated on shoulder 222 as shown in
FIGS. 41A and 41B. The support block 218 includes a slot 225
dimensioned to receive post 214 to enable sliding movement of the
post 214 and slot portion 226 receives cover 216. The cover 216 is
movable between two positions: to cover and thereby close off the
opening 202 in the sidewall 203 of the aspiration tube 200 to
enable aspiration or uncover the opening 202 to disable
aspiration.
[0156] In use, when suction is desired, the lever 212 is moved by
the user to the positon of FIG. 41A. In this position, the cover
216 covers the outer opening in the cylindrical portion 220 to seal
the opening. Thus, blood or other particles can be suctioned
through the tube 200 in the direction of the arrows of FIG. 41A,
exiting a proximal end of the tube. When it is desired to disable
suction, the lever 212 is moved to the position of FIG. 41B wherein
the opening 202 in the side wall 203 of tube 200 is uncovered as
cover 216 provides a gap so that a vacuum is not created through
tube 200. Note that the post 214 slides within the slot 225 in the
support block 218 to enable back and forth movement of the cover
216. In this manner, the user can selectively enable and disable
suction as desired. Note the lever's normal (or original) position
can be either that of FIG. 41A or FIG. 41B, and a locking mechanism
can be provided to retain the lever in either or both the positions
of FIGS. 41A and 41B. A spring could be provided to bias the lever
to one of the positions.
[0157] In the alternate embodiment of FIGS. 42A and 42B, suction
disabler 230 includes a slidable control or lever 232, a two bar
linkage having outer bar 234 and inner bar 236. Outer bar 234 is
pivotably attached to support post 238 via pivot pin 240 and
pivotably attached to inner bar 236 via pivot pin 242. A support
block 235 is attached to an outer surface of the aspiration tube
200 such as by gluing or other known methods, with stem 237
extending into the opening 202. A shoulder 239 of support block 235
supports the wall of the aspiration tube 200. Inner bar 236 is
L-shaped as shown so that horizontal cover portion 244 is
substantially parallel to a longitudinal axis of the aspiration
tube 200 in the first position of the disabler 230. Cover portion
244 in this first position, covers the opening 202 in the
aspiration tube 200 which allows aspiration through tube 200. In
the second position, cover portion 244 is pivoted towards and into
the lumen 203, thereby uncovering and opening side opening 202 in
the aspiration tube 200 for escape through the side opening 202 of
tube 200 and support block 235 so a vacuum is not created. This is
achieved by sliding the lever 238 distally from the position of
FIG. 42A to the position of FIG. 42B to cause pivoting of the
linkage as shown.
[0158] In use, when suction is desired, the lever 232 is moved by
the user to the positon of FIG. 42A. In this position, the cover
244 covers the opening 202. Thus, blood or other particles can be
suctioned through the tube 200 in the direction of the arrows of
FIG. 42A. When it is desired to disable suction, the lever 232 is
moved to the position of FIG. 42B wherein the opening 202 in the
side wall is uncovered as cover 244 is pivoted into the lumen of
the aspiration tube 200 so that a vacuum is not created. In this
manner, the user can selectively enable and disable suction as
desired. Note the lever's normal (or original) position can be
either that of FIG. 42A or FIG. 42B, and a locking mechanism can be
provided to retain the lever in either or both the positions of
FIGS. 42A and 42B. A spring could be provided to bias the lever to
one of the positions.
[0159] In the embodiment of FIGS. 43A and 43B, suction disabler 250
includes a spring biased elongated cover 252 movable transverse to
a longitudinal axis of the aspiration tube 200. Cover 252 with
elongated stem 253 is shown biased by spring 254 to an outer
position, i.e., further from the longitudinal axis of the
aspiration tube 200. Stem 253 moves within support housing 256,
which also contains the spring 254 therein. Support housing 256 is
attached to the aspiration tube 200 by gluing or by other known
methods. Spring 254 rests on ledge 258 of stem 253 and is
compressed as shown in FIG. 43B when the cover 252 is moved from
its outer to its inner position. Housing 256 includes inner portion
260 which extends into the opening 202 in the aspiration tube 200,
and an outer wall of the aspiration tube 200 rests on shoulder 264
of housing 256. When cover 252 is in the outer position of FIG.
43A, aspiration opening 202 is closed and suction can occur through
the aspiration tube 200 in the direction of the arrows of FIG. 43A.
When the cover 252 is moved inwardly toward the lumen 201 of the
aspiration tube 200 as stem 253, which extends through the an
opening in handle housing 251, is moved toward the tube 200, a gap
is created between cover 252 and opening 202 so a vacuum is not
created.
[0160] In use, when suction is desired, the cover 252 is maintained
in the positon of FIG. 43A. In this position, the cover 252 covers
the opening 202 in the aspiration tube 200 to seal the opening.
Thus, blood or other particles can be suctioned through the tube
200 in the direction of the arrows of FIG. 43A. When it is desired
to disable suction, the exposed end 253 of cover 252 is pressed
inwardly toward the tube 200 by the user to the position of FIG.
43B wherein the opening 202 in the side wall is uncovered as cover
252 enables formation of a gap so that a vacuum is not created. In
this manner, the user can selectively enable and disable suction as
desired. Note that as the cover 252 is pressed inwardly, the spring
254 is compressed. Therefore, once the user releases cover 252, it
returns to the position of FIG. 43A under the force of spring 254.
Note the cover's normal (or original) position can be either that
of FIG. 43A or FIG. 43B, and a locking mechanism can be provided to
retain the cover in either or both the positions of FIGS. 43A and
43B.
[0161] In the embodiments of FIGS. 41-43, the suction disabling is
achieved by uncovering a side opening 202 in the wall of the
aspiration tube 200. Several examples of mechanisms to close or
cover the side opening are disclosed by way of example, it being
understood that alternative mechanisms to cover and uncover the
opening can be provided to obtain such disabling. In the alternate
embodiments of FIGS. 44A-46B, aspiration disabling is achieved by
deforming the wall of the aspiration tube to block flow. Some
examples of this structure for disabling suction are discussed
below, it being understood that alternative mechanisms can be
provided to close off the tube to obtain such disabling. It both
versions, preferably the control to disable suction is positioned
on the handle housing to facilitate access and manipulation by the
user.
[0162] Turning first to the embodiment of FIGS. 44A and 44B,
suction disabler 260 includes a pivotal lever 262, substantially
L-shaped in configuration, and attached to housing 270 by pivot pin
272. One leg 264 of the lever extends transverse to a longitudinal
axis of the aspiration tube 300 and has an irregular surface 266 to
facilitate manipulation by the user. Leg 264 extends through
opening 261 in the handle housing 263, and the irregular surface
266 is exposed for manipulation by the user. The other leg 268 of
lever 262 is substantially perpendicular to leg 264 and extends
substantially along the longitudinal axis of the aspiration tube
300. The initial position of suction disabler 260 is shown in FIG.
44B.
[0163] Leg 268 terminates in bent tip 267 with tube contacting
surface 269. Tip 267 is shown at an angle of about 90 degrees but
other angles are also contemplated. Tip 267 applies a force to tube
300 to pinch tube 300 and close lumen 301 extending through tube
300.
[0164] In use, to allow suction, pivotal lever 262 is in the
position of FIG. 44A with suction enabled in the direction of the
arrows. To disable suction, pivotal lever 262 is pivoted about
pivot pin 272 to the position of FIG. 44B, therefore moving tip 267
toward tube 300 and applying a radial force to the tube 300 to move
the wall into apposition to seal off the vacuum. Note a locking
mechanism can be provided to retain the pivotal lever 262 in the
suction enabling position of FIG. 44A and/or the suction disabling
position of FIG. 44B. A spring can be provided to bias the lever
262 to either the position of FIG. 44A or 44b.
[0165] The pinching/clamping of the aspiration tube 300 can also be
achieved by sliding movement instead of pivoting member as in FIG.
44A. In FIG. 45A, suction disabler 280 includes a spring biased
pinching member or button 282 movable transverse to a longitudinal
axis of the aspiration tube 300. Member 282 is shown biased by
spring 284 to an outer position, i.e., further from the
longitudinal axis of the aspiration tube 300. Member 282 slidably
moves within support housing 286, which also contains the spring
284 therein. Support housing 286 is positioned circumferentially
about the aspiration tube 300 and can be attached by gluing or by
other known methods. Spring 284 rests on ledge 288 of member 282
and is compressed as shown in FIG. 45B when the pinching member 282
is moved from its outer to its inner position. When member 282 is
in the outer position of FIG. 45A, aspiration lumen 301 of
aspiration tube 302 is open and suction can occur through the
aspiration tube 300 in the direction of the arrows of FIG. 45A.
When the pinching member 282 is moved inwardly toward the
aspiration tube 301, it pinches the wall of the tube so that it
closes off lumen 301 to disable suction through lumen 301.
[0166] In use, when suction is desired, the pinching member is
maintained in the positon of FIG. 45A. In this position, the
pinching member 282 does not deform the wall of the aspiration tube
300 so that vacuum can be applied and blood or other particles can
be suctioned through the tube 300 in the direction of the arrows of
FIG. 45A. When it is desired to disable suction, the exposed end
283 of pinching member 282 (extending through an opening 287 in
housing 281) is pressed inwardly by the user to the position of
FIG. 45B wherein the wall of the aspiration tube 300 is pinched or
deformed to close off flow through the lumen 301. In this manner,
the user can selectively enable and disable suction as desired.
Note that as the member 282 is pressed inwardly, the spring 284 is
compressed. Therefore, once the user releases member 284, it
returns to the position of FIG. 45A under the force of spring 284.
Note the pinching member's normal (or original) position can be
either that of FIG. 45A or FIG. 45B, and a locking mechanism can be
provided to retain the pinching member in either or both the
positions of FIGS. 45A and 45B.
[0167] The suction disabler 280 can be provided with an interlock
to maintain the pinching member in the clamping position. An
example of such interlock is shown in FIGS. 46A-46B. The suction
disabler of FIGS. 46A and 46B is identical to the suction disabler
of FIGS. 45A and 45B except for the interlock. Therefore, for
brevity, a discussion of each of the same features are not repeated
herein and the same features/components are labeled with "prime"
designations corresponding to the labeling of FIGS. 45A and 45B.
Thus, suction disabler 280' has a spring biased pinching member or
button 282' extending through housing 281' and movable transverse
to a longitudinal axis of the aspiration tube 300. Member 282' is
shown biased by spring 284' to an outer position, i.e., further
from the longitudinal axis of the aspiration tube 300. Member 282'
slidably moves within support housing 286', which also contains the
spring 284' therein. Support housing 286' is positioned
circumferentially about the aspiration tube 300 and can be attached
by gluing or by other known methods. Spring 284' rests on ledge 288
of member 282' and is compressed as shown in FIG. 46B when the
pinching member 282' is moved from its outer to its inner
position.
[0168] The interlock includes a retention feature 290 in the form
of a screw thread engagement. When the pinching member 282' reaches
its furthest inward travel, it is rotated so that its threaded
inner surface 291 engages the outer threads 289 on support housing
286'. To unlock, the pinching member 282' is rotated in the reverse
direction to release the retention feature 290.
[0169] Turning now to the use of the device for applying energy to
form lesions and with reference to device 10, the device 10 is
manipulated to create a preferred pattern of multiple lesions
comprising circumferential rings of lesions at several axially
spaced-apart levels (about 5 mm apart), each level comprising from
8 to 12 lesions. A representative embodiment of the lesion pattern
is shown in FIG. 39. The rings are preferably formed in the
esophagus in regions above the stomach, at or near the lower
esophageal sphincter, and/or in the cardia of the stomach. The
rings in the cardia are concentrically spaced about the opening
funnel of the cardia. At or near the lower esophageal sphincter,
the rings are axially spaced along the esophagus. As shown, the
device is inserted in the collapsed position of FIG. 36, expanded
to the position of FIG. 37 by inflation of the balloon to dilate
the sphincter and then the needle electrodes 32 are advanced into
tissue as shown in FIG. 38 for application of energy.
[0170] Multiple lesion patterns can be created by successive
extension and retraction of the electrodes 32, accompanied by
rotation and/or axial movement of the catheter tube to reposition
the basket assembly 18. The physician can create a given ring
pattern by expanding the balloon structure 80 and extending the
electrodes 32 at the targeted treatment site, to form a first set
of four lesions. The physician can then withdraw the electrodes 32,
collapse the balloon structure 80, and rotate the catheter tube 22
by a desired amount, e.g., 30-degrees or 45-degrees, depending upon
the number of total lesions desired within 360-degrees. The
physician can then again expand the structure 18 and again extend
the electrodes 32, to achieve a second set of four lesions. The
physician repeats this sequence until a desired number of lesions
within the 360-degree extent of the ring is formed. Additional
lesions can be created at different levels by advancing the
operative element axially, gauging the ring separation by external
markings on the catheter tube.
[0171] As shown in FIG. 39, a desirable pattern comprises an
axially spaced pattern of six circumferential lesions numbered
Level 1 to Level 6 in an inferior direction, with some layers in
the cardia of the stomach, and others in the esophagus above the
stomach at or near the lower esophageal sphincter. In the
embodiment shown in instant FIG. 5, in the Levels 1, 2, 3, and 4,
there are eight lesions circumferentially spaced 45-degrees apart
(i.e., a first application of energy, followed by a 45-degree
rotation of the basket 56, followed by a second application of
energy). In the Levels 5 and 6, there are twelve lesions
circumferentially spaced 30-degrees apart (i.e., a first
application of energy, followed by a 30-degree rotation of the
basket 56, followed by a second application of energy, followed by
a 30-degree rotation of the basket assembly 18, followed by a third
application of energy). In Level 5, the balloon 80 is only
partially expanded, whereas in Level 6, the balloon 80 is more
fully expanded, to provide lesion patterns that increase in
circumference according to the funnel-shaped space available in the
funnel of the cardia.
[0172] Note that to secure against overinflation of the balloon,
especially in tissue Levels 1-4 where the device is positioned in
the esophagus, a pressure relief valve is attached to the air
syringe, upstream of the balloon inflation port of the device, to
allow air to escape if pressure levels are exceeded. That is, in
Levels 1-4, the air syringe is filled with air, and the balloon is
inflated to a target pressure so there is enough contact to
slightly tension the tissue but not enough to stretch the tissue,
with the pressure relief ensuring the pressure is not exceeded.
Preferably, the balloon would be inflated to no more than about 2.5
psi. In the stomach, at Levels 5 and 6, there is more room for the
balloon inflation, so the balloon can be further inflated and the
pressure relief valve can be removed. The balloon is preferably
inflated by volume to about 25 ml for treatment at Level 5, and
after treatment at Level 5, deflated at Level 6 to about 22 ml.
Note at Levels 5 and/or 6, the inflated balloon can also be used as
an anchor. In an alternate embodiment, after treatment of Level 4
the balloon is deflated and the instrument is advanced, then
retracted, wherein Level 6 is treated, then the instrument is
pulled further proximally to subsequently treat Level 5. Stated
another way, Level 5 can be considered distal of Level 6 and
therefore being more distal, treated before Level 6. Note the
balloon would still be inflated to about 25 ml in the more distal
level and to about 22 ml in this embodiment. The balloon can also
serve as an anchor.
[0173] In an alternate embodiment of the device 10, one or more
digital cameras can be mounted along the catheter tube, e.g., with
the camera lens directed to the basket assembly 18, to provide
visualization of the site. In another alternate embodiment, the
catheter tube can be designed to fit within a lumen of an
endoscope, relying on the endoscope for visualization of the
site.
[0174] A. Set-Up
[0175] In use, the GUI displays an appropriate start-up logo and
title image (not shown), while the controller 52 performs a
self-test. An array of SETUP prompts 502 leads the operator in a
step-wise fashion through the tasks required to enable use of the
generator and device. The GUI is described in detail in Publication
No. 2011/0112529, the entire contents of which are incorporated
herein by reference and therefore for brevity is not repeated
herein.
[0176] The physician can couple the source of cooling liquid to the
appropriate port on the handle of the device 10 and load the tubing
leading from the source of cooling liquid (e.g., a bag containing
sterile water) into the pump. The physician can also couple the
aspiration source 8 to the appropriate port on the handle of the
treatment device 10. In the SET-UP prompt array, a graphic field of
the GUI displays one or more icons and/or alpha-numeric indicia
that prompt the operator to connect the return patch electrode,
connect the foot pedal or switch 41, connect the selected treatment
device 10 (designed by its trademark STRETTA.RTM.) and to prime the
irrigation pump.
[0177] Note in some embodiments, the user controls the pump speed
to increase fluid flow if the temperature is rising. In alternate
embodiments, the system is designed with an automatic cooling
feature, thus enabling quicker application of cooling fluid to
address rising tissue temperatures to faster cool the tissue
surface which in turn cools the underlying tissue which helps to
maintain the tissue temperature below the "tissue ablation
threshold."
[0178] More specifically, at certain tissue temperatures, the speed
of the pump is changed automatically to reduce the temperature.
That is, if the tissue surface temperature, e.g., at the mucosa
layer as measured by the tissue temperature sensor, reaches a
certain threshold (a "first value"), the pump speed will increase
to pump more cooling fluid to the tissue. In some embodiments, for
certain tissue temperature values, the system can enable the user
to override the automatic pump to reduce the fluid flow. In other
embodiments, a user override feature is not provided. In either
case, the system is preferably designed so that if a second
predetermined higher temperature value ("second value") is reached,
the pump is automatically moved to its maximum pump speed, which
preferably cannot be overridden by the user. When a third
predetermined still higher tissue temperature value is reached (a
"third cutoff value"), the electrode channel is disabled as
discussed herein to shut off energy flow to that electrode.
Consequently, before the third cut off value is reached, as the
temperature is rising, the system provides for a quicker response
to the rising temperature by automatically increasing fluid flow,
rather than relying on the slower response time of the user to
implement the pump speed change, thereby helping to keep
temperature below the tissue ablation threshold temperature.
[0179] Exemplary tissue values are provided solely by way of
example, it being understood that other tissue values can also be
utilized to achieve quick application of cooling fluid and ensure
the non-ablation, and non-burning, of tissue. For example, in the
upper GI tract treatment device described herein (see FIG. 3), the
first value could be about 38 degrees, the second predetermined
value could be about 40 degrees and the third value where the
energy is shut down could be about 43 degrees. For a lower GI tract
treatment device described herein (see FIG. 6), the first value
could be about 45 degrees, the second predetermined value could be
about 46 degrees and the third value where the energy is shut down
could be about 54 degrees.
[0180] If the identification code for the device is registered, the
GUI displays an appropriate start-up logo and title image for the
device.
[0181] In some embodiments, the coded identification device is part
of a printed circuit board (PCB) positioned in the handle of the
treatment device. The PCB processes the calculated parameters. The
PCB in conjunction with thermocouples provides a temperature
measurement mechanism. The PCB measures the voltage generated by
the thermocouples, converts it from an analog to a digital value
and stores it in the internal memory. Upon request by the
generator, the PCB communicates the digital data to the generator.
This step is performed during the 100 millisecond break between
radiofrequency pulses discussed below. By placement of the
temperature measurement mechanism in the treatment device, i.e., in
the disposable handpiece, rather than in the housing 400, data
collection is closer to the source which translates into less noise
susceptibility and improved accuracy. That is, since processing of
temperature values occurs closer to the tissue and electrode tip,
measurements can be more accurate. More accurate readings translate
into tighter power controls and better clinical results and it
better ensures the tissue is not ablated during treatment as it is
maintained below a tissue ablation threshold.
[0182] In a preferred embodiment, the PCB, which is asymmetrically
positioned within the handle, is shielded to reduce interference
which could otherwise disrupt communication between the disposable
treatment device and the generator. Such interference (noise) could
corrupt the data and unnecessarily result in system errors which
can unnecessarily shut down energy flow to the electrode(s) during
the procedure. In a preferred embodiment, the shield is a copper
foil, although other ways to shield the PCB are also contemplated.
In other words, the disruption of communication could adversely
affect processing and evaluation of the data collected by the
treatment device. By eliminating such disruptions, and thereby
disabling fewer electrodes, improved consistency of treatment is
achieved. Also, as can be appreciated, if too many electrodes are
disabled in a procedure, the tissue may not be sufficiently
thermally treated to achieve the desired clinical result.
[0183] In an alternate embodiment, the identification code is
positioned in the handle of the treatment device 10, but the other
hardware, e.g., the printed circuit board for temperature
calculation, etc. is outside the handle. Thus, the temperature data
collection is performed outside the disposable treatment device
which reduces costs since it need not be disposed of with the
disposable treatment device. Note these embodiments still have the
advantage of data collection closer to the source than if in the
housing 400.
[0184] Upon completion of the SET-UP operation, the controller 52
proceeds to condition the generator and ancillary equipment to
proceed step-wise through a sequence of operational modes. The
operational modes have been preprogrammed to achieve the treatment
protocol and objective of the selected device 10.
[0185] In the GUI, there is a parameter icon designating cooling
fluid flow rate/priming. The Flow Rate/Priming Icon shows the
selected pump speed by the number of bars, one bar highlighting a
low speed, two bars highlighting a medium speed, and three bars
highlighting a high speed.
[0186] Each GUI includes an Electrode Icon comprising an idealized
graphical image, which spatially models the particular multiple
electrode geometry of the device that has been coupled to the
controller 42. This is illustrated and described in detail in
Patent Publication No. 2011/0112529.
[0187] In some embodiments, temperature of the needle tips is
measured when the needles are deployed at the lesion level, but
prior to application of RF energy. If the measured temperature
exceeds an expected value, the temperature reading alerts the user
that the needle position might need to be readjusted. If the
temperature value is too high, this can mean that the electrode
position is too close to the previous tissue level treated, and
thereby the user can readjust the electrode position by increasing
the spacing, thereby reducing the chances of overtreating the
tissue which can cause undesired tissue ablation or burning of
tissue. Consequently, continuous treatment of tissue can be
achieved with reduced overlapping of treatment.
[0188] Also, as can be appreciated, the temperature of the
electrode tip, the tissue temperature and the impedance, along with
other safety parameters, such as adequate connections, are
monitored during the procedure to ensure energy flow is correct.
This includes proper flow through the cable, electrodes, ground
pad, etc. The electrode needle is then disabled if a safety
condition is suspected and indicated. Each needle can be controlled
separately.
[0189] In use of the system, impedance is intermittently checked
throughout the procedure. Impedance is measured by measuring the
current at the channel of the electrode tip. The impedance
monitoring provides an indication of how well the treatment device
is connected and communicating with the tissue, which includes the
needle penetration and the path with the return pad. If there is
not good contact between the electrode and tissue, impedance is
high and a patient can get burned. Therefore, if a patient moves,
needle penetration could be affected. However, oftentimes a minor
adjustment can be made which does not require shutting down energy
flow. To avoid premature shutting down of the system a multiple
error check is conducted by the system which is described in more
detail below. This multiple error check reduces the incidence of
needle disabling which in turn reduces the incidence of
undertreatment.
[0190] Note the impedance is measured by applying a voltage,
measuring the current and calculating the impedance. The RF energy
is applied in 0.9 second intervals, with a 0.1 second break in
between where an artificial pulse is sent for 0.1 second, in which
impedance is measured. The temperature of the electrode tip and
tissue temperature is also measured during this 0.1 second
interval, for calculating such measurement. Preferably, the RF
energy is repeatedly applied for 0.9 seconds, with 0.1 second
"measurement intervals" for a time period of 60 seconds.
[0191] There is also a Lesion Level Icon in each display adjacent
to the respective Electrode Icon. The Lesion Level Icon comprises
an idealized graphical image, which spatially models the desired
lesion levels and the number of lesions in each level, described in
detail in Patent Publication 2011/0112529. As described in this
publication, the Lesion Level Icons change in real time, to
step-wise guide the physician through the procedure and to record
the progress of the procedure from start to finish.
[0192] The GUI graphically changes the display of the Lesion
Levels, depending upon the status of lesion formation within the
respective levels.
[0193] The open segments remaining in the segmented circle prompt
the physician to rotate the basket by 45-degrees, and actuate the
electrodes for second time. After the pre-set period (tracked by
the Timer Icon), more treatment indicia (the dots) appear in the
remaining segments of the circle. This indicates that all the
lesions prescribed for Lesion Level 1 have been formed, and to
deflate the basket and move to the next treatment level. The Marker
that is displayed directs the physician to Lesion Level 2, which is
5 mm below Lesion Level 1. The Balloon Icon can reappear to prompt
the physician to deflate the balloon.
[0194] The physician is thereby prompted to deflate the basket,
move to Lesion Level 2, and expand the basket. Upon sensing
electrode impedance, indicating contact with tissue at Lesion Level
2, the GUI changes the graphical form of Lesion Level 1 back to an
edgewise cylinder. The edgewise cylinder for Lesion Level 1
includes an indicator, e.g., checkmark, to indicate that Lesion
Level 1 has been treated. The insertion of the treatment completed
indicator is yet another graphical form the GUI displays to
communicate status information to the physician.
[0195] With the device positioned at Lesion Level 2, the physician
actuates the electrodes for a first pre-set period, then rotates
the device 26a 45-degrees, and actuates the electrodes for the
second pre-set period. The Timer Icon reflects the application of
radio frequency energy for the pre-set periods, and the treatment
indicia (e.g., dots) are added to the segments of the graphical
segmented circle, indicating the formation of the first four
lesions and the next four lesions, as well as their spatial
orientation.
[0196] The physician is thereby prompted to deflate the basket,
move to Lesion Level 3, and expand the basket upon sensing
electrode impedance, indicating contact with tissue at Lesion Level
3.
[0197] The physician proceeds to form eight lesions in Lesion Level
3 then moving on to Lesion Level 4. All the while, the GUI visually
records and confirms progress. On Lesion Levels 5 and 6, twelve
lesions are to be formed. In the Levels 5 and 6, there are twelve
lesions circumferentially spaced 30-degrees apart (i.e., a first
application of energy, followed by a 30-degree rotation of the
basket 56, followed by a second application of energy, followed by
a 30-degree rotation of the basket 56, followed by a third
application of energy). In Level 5, the balloon structure is only
partially expanded, whereas in Level 6, the balloon structure 72 is
more fully expanded, to provide lesion patterns that increase in
circumference according to the funnel-shaped space available in the
funnel of the cardia.
[0198] Thus, the GUI, by purposeful manipulation of different
stylized graphical images, visually prompts the physician step wise
to perform a process of forming a pattern of lesions comprising a
plurality of axially spaced lesion levels, each lesion level
comprising a plurality of circumferential spaced lesions. The GUI
registers the formation of lesions as they are generated in real
time, both within and between each circumferentially spaced level.
The GUI therefore displays for the physician a visual record of the
progress of the process from start to finish. The GUI assures that
individual lesions desired within a given level are not skipped, or
that a given level of lesions is not skipped.
[0199] In the GUI, each Lesion Level 1 to 6 is initially depicted
by a first stylized graphical image comprising an edgewise cylinder
with a number identification of its level. When the formation of
lesions at a given level is indicated, the GUI changes the first
stylized graphical image into a second stylized graphical image,
different than the first image, comprising an axial view of the
cylinder, presented as a segmented circle, with the numbers of
segments corresponding to the number of lesions to be formed. There
also appears juxtaposed with the next lesion level to be treated
(still displayed as an edgewise cylinder), a marker along with a
number indicating its distance from the present legion level. As
the physician manipulates the device to form lesions on the
indicated levels, the second graphical image further changes to a
third graphical image, different than the first or second images,
by adding indicia within the segmented circle to reflect the
formation of lesions, to guide the physician to successively rotate
and operate the device at the lesion level. Upon forming the
desired lesion pattern on a given level, the UGUI 504 again changes
the third graphical image to a fourth graphical image, different
than the first, second, and third graphical images, comprising an
edgewise cylinder with a number identification of its level, and
further an indicator (e.g. a check mark) that indicates all desired
lesions have been formed at the respective level. A Marker is
successively updated to direct the physician to the next Lesion
Level. In this way, the GUI prompts the formation of eight lesions
circumferentially spaced 45-degrees apart in the Levels 1, 2, 3,
and 4, and the formation of twelve lesions circumferentially spaced
30-degrees apart at Lesion Levels 5 and 6. Thus, a total of 56
lesions can be formed in this procedure.
[0200] During the procedure utilizing the radiofrequency treatment
device 10, certain error messages are graphically indicated on the
GUI. Certain of these error messages relate to user errors which
could be in the user's control, and therefore could potentially be
correctable by the user. For example, if there is an error in the
treatment device connection, the generator returns to the set up
screen and the icon representing the treatment device displayed by
the GUI begins flashing. Another example is if the error relates to
the return pad, e.g., improper placement or contact of the pad, the
generator likewise returns to the set up screen and the return pad
icon displayed by the GUI begins flashing. Another example is if
the needles are not treated properly. With these errors indicated,
the user can attempt to make the proper adjustments, e.g., check
the connection of the treatment device, adjust the position of the
return pad, etc. By easily identifying these correctible errors,
the system will shut down fewer times thereby enabling the creation
of more lesions. Stated another way, the instrument continuously
measures temperature which is transmitted back to the generator.
The generator expects the temperature to be in a certain range. If
the temperature does not appear right, e.g., is outside an expected
range, if the RF channel was immediately shut down, then it could
result in premature/unnecessary termination of RF energy which
could undertreat tissue. Therefore, the present invention provides
steps to ensure a shut down result is truly necessary, thus
advantageously limiting undertreatment of the tissue. Similarly, if
calculated impedance from current measurement does not appear
correct, i.e., is outside a desired range, e.g. 50-500 ohms for the
instrument of FIGS. 6 and 50-100 ohms for the instrument of FIG. 2,
the system of the present invention ensures that a channel shut
down is warranted before shut down, again avoiding
premature/unnecessary termination of RF energy which can result in
undertreatment of tissue.
[0201] The system, due to its faster processing speed which enables
faster processing of data and faster adjustment of parameters,
enables rechecking of detected errors to reduce the instances of
prematurely shutting down energy flow to an electrode. As discussed
above, premature termination of energy flow can result in
insufficient application of thermal energy which in turn can result
in undertreatment of tissue. In other words, the system
advantageously is designed to reduce the number of events that
would lead to energy cutoff to an electrode. More specifically,
during the treatment cycles, oftentimes an error is detected which
can be readily addressed by the user, such as by a small adjustment
of the treatment device position if the error is caused for example
by patient movement which affects the impedance reading, or even
self-adjusts. If the system was designed to immediately shut down
upon such error detection, then the electrode would be disabled and
the lesion might not be created in that tissue region. Therefore,
to reduce these occurrences, the system has been designed to
recheck certain errors.
[0202] More specifically, for certain detected errors, the system
does not permanently interrupt energy flow on the first error
reading, but suspends energy flow until a second check of the
system is performed. If on the second check the error is no longer
detected, energy flow is resumed. However, if on the second check,
e.g., re-measurement/calculation, an error still exists, the system
runs yet a third check. If the error no longer exists, the energy
flow resumes; if the error still exists, energy flow is cut off to
that electrode at that treatment position. Consequently, only after
the system runs a triple check is a final determination made to
either transition back to energy flow or record the error and
disable the electrode channel, i.e., shut down RF energy flow to
that electrode. Thus, the error can be checked multiple times to
ensure it actually requires interruption of energy flow, thus
avoiding premature disabling of an electrode to thereby enhance
tissue treatment by not skipping tissue levels, or regions
(quadrants) within each tissue level which could otherwise have
been treated. As a result, a more comprehensive and uniform tissue
treatment is achieved.
[0203] This triple error checking feature exemplifies the speed of
the processor which enables quicker processing of temperature
calculations and quicker response to address rising temperatures so
the tissue is not treated above the tissue ablation threshold. As
noted above, this tissue ablation threshold can be exceeded if the
energy is applied for too long a duration and/or too high a setting
such that the tissue temperature rises or applied for too long a
duration once the tissue temperature has reached the tissue
ablation threshold before the flow of energy is terminated.
[0204] Also contributing to preventing overtreatment is to ensure
the spacing between the electrodes in manufacture is precise so
during application of energy, the amount of overlapping in a
circumferential orientation is reduced. Such accurate and
consistent spacing can also prevent undertreatment such as if the
two of the circumferential array of electrodes are undesirably
angled or curved too much toward each other, that would mean they
are angled further away from the electrode on the opposite side,
possibly creating a gap in the treatment in a circumferential
orientation. The axial distance of the electrodes can also affect
treatment. Therefore, maintaining the proper axial distance of the
electrodes, preferably with the tips terminating at the same distal
distance from the respective spine, and maintaining the proper
radial distance of the tips, preferably evenly spaced along a
circumference, will aid in maintaining the treatment between the
lower threshold and maximum value threshold, i.e., between
undertreatment and overtreatment.
[0205] The system, as noted above, also avoids ablating tissue due
to careful and more accurate calibration of the tissue temperature
measurement mechanism. This is basically achieved by precisely
calibrating the PCB so it can read the voltage generated by the
thermocouples more accurately, reducing the likelihood of heating
tissue beyond the tissue ablation threshold. Thus, the PCB enables
more accurate temperature measurements which in turn allows the
system to disable or make the appropriate adjustment, e.g.,
increasing cooling fluid application, when the temperature limits
are reached.
[0206] As discussed above, the centering of the needle pusher and
attached electrodes, the alignment of the electrodes and the
alignment of the basket arms provide maintain proper treatment
zones to ensure the tissue is treated between the range of
undertreatment and overtreatment. The suction disabling features
discussed above also help to prevent overtreatment, i.e., ablation,
of tissue.
[0207] While the above description contains many specifics, those
specifics should not be construed as limitations on the scope of
the disclosure, but merely as exemplifications of preferred
embodiments thereof. Those skilled in the art will envision many
other possible variations that are within the scope and spirit of
the disclosure as defined by the claims appended hereto.
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