U.S. patent application number 16/019184 was filed with the patent office on 2018-11-01 for expandable mesh platform for large area ablation.
This patent application is currently assigned to Cook Medical Technologies LLC. The applicant listed for this patent is Cook Medical Technologies LLC. Invention is credited to Tyler E. McLawhorn.
Application Number | 20180310981 16/019184 |
Document ID | / |
Family ID | 50137497 |
Filed Date | 2018-11-01 |
United States Patent
Application |
20180310981 |
Kind Code |
A1 |
McLawhorn; Tyler E. |
November 1, 2018 |
Expandable Mesh Platform for Large Area Ablation
Abstract
An ablation device and a method of ablating a tissue are
provided. The ablation device includes a first elongate shaft
having a proximal portion, a distal portion and a lumen extending
at least partially therethrough and a second elongate shaft having
a proximal portion, a distal portion and a lumen extending at least
partially therethrough. The first elongate shaft is coaxially
positioned and longitudinally movable relative to the second
elongate shaft. The ablation device further includes a mesh member
including a proximal portion and a distal portion. The proximal
portion of the mesh member is operably connected to the distal
portion of the second elongate shaft and the distal potion the mesh
member is operably connected to an inner surface of the distal
portion of the first elongate shaft. The mesh member includes a
conductive portion configured to contact a surface for
ablation.
Inventors: |
McLawhorn; Tyler E.;
(Winston-Salem, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cook Medical Technologies LLC |
Bloomington |
IN |
US |
|
|
Assignee: |
Cook Medical Technologies
LLC
Bloomington
IN
|
Family ID: |
50137497 |
Appl. No.: |
16/019184 |
Filed: |
June 26, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14184438 |
Feb 19, 2014 |
10022178 |
|
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16019184 |
|
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61767067 |
Feb 20, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 2018/00488
20130101; A61B 18/14 20130101; A61B 2018/00267 20130101; A61B
18/1492 20130101; A61B 2018/1475 20130101; A61B 2018/00577
20130101 |
International
Class: |
A61B 18/14 20060101
A61B018/14 |
Claims
1. A method of ablating a tissue, the method comprising: inserting
a distal portion of an ablation device into a lumen of a patient,
the ablation device comprising: a first elongate shaft having a
proximal portion, a distal portion and a lumen extending at least
partially therethrough; a elongate shaft having a proximal portion,
a distal portion and a lumen extending at least partially
therethrough, the first elongate shaft coaxially positioned and
movable relative to the second elongate shaft; and a mesh member
comprising a proximal portion and a distal portion, the proximal
portion of the mesh member operably connected to the distal portion
of the second elongate shaft and the distal potion the mesh member
operably connected to an inner surface of the distal portion of the
first elongate shaft, the mesh member having a first diameter and a
second diameter greater than the first diameter and the mesh member
comprising a conductive portion configured to contact a surface for
ablation; positioning at least a portion of the mesh member at a
treatment site; moving the first elongate shaft relative to the
second elongate shaft to move the ablation device to an expanded
configuration having the second diameter; pressing an end face of
the mesh member against the surface; and applying energy to the
tissue from an energy source.
2. The method according to claim 1, comprising longitudinally
moving the first elongate shaft relative to the second elongate
shaft to move the ablation device to an extended configuration
having substantially the first diameter wherein the end face is
configured to be pressed against the surface.
3. The method according to claim 1, comprising longitudinally
moving the first elongate shaft relative to the second elongate
shaft to move the ablation device to retracted configuration where
the distal portion of the mesh member is positioned within the
lumen of the second elongate shaft and the proximal portion of the
mesh member remains operably connected to the outer surface of the
distal end of the second elongate shaft.
4. The method according to claim 1, comprising moving the ablation
device to a second treatment site in the retracted configuration
and expanding the mesh member at the second site by longitudinally
moving the first elongate shaft relative to the second elongate
shaft.
5. The method according to claim 1, comprising delivering the
ablation device to the treatment site using an endoscope.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of U.S. patent application
Ser. No. 14/184,438 filed Feb. 19, 2014, which claims the benefit
under 35 U.S.C. .sctn. 119 of U.S. Patent Application No.
61/767,067 filed Feb. 20, 2013; which are incorporated by reference
in their entirety.
BACKGROUND
[0002] Endoscopic treatment of gastrointestinal disorders often
requires the need to coagulate tissue for the purpose of hemostasis
and/or marking of the tissue. Areas of diseased tissue within the
gastrointestinal tract may also be treated using an ablation
device. Some ablation devices may be delivered endoscopically.
[0003] Radiofrequency ablation (RFA) is one method that can be used
to deliver energy for treating or marking the tissue. A bipolar
probe is a commonly used RFA device, for example, the Quicksliver
Bipolar Probe (Cook Medical, Inc., Bloomington, Ind.) Typical RFA
probes are 7 to 10 Fr with electrodes mounted on a ceramic tip on
the distal end of the device. One drawback of these probes is that
the size of the ablation zone is dependent on the size of the
catheter and cannot be altered by the user. In addition, the user
must use caution when applying energy when using this type of
bipolar probe. Since all the force is distributed across a small (7
or 10 Fr) surface area, an area of high pressure is created
increasing the risk of perforation of the tissue at the treatment
site.
[0004] What is needed in the art is an ablation treatment device
that is simple to use, reduces the risk of tissue perforation and
is expandable and collapsible to treat larger tissue areas.
BRIEF SUMMARY
[0005] Accordingly, it is an object of the present invention to
provide a device and a method having features that resolve or
improve on one or more of the above-described drawbacks.
[0006] An ablation device is provided. In some embodiments, the
ablation device includes a first elongate shaft having a proximal
portion, a distal portion and a lumen extending at least partially
therethrough and a second elongate shaft having a proximal portion,
a distal portion and a lumen extending at least partially
therethrough. The first elongate shaft is coaxially positioned and
longitudinally movable relative to the second elongate shaft. The
ablation device further includes a mesh member including a proximal
portion and a distal portion. The proximal portion of the mesh
member is operably connected to the distal portion of the second
elongate shaft and the distal potion the mesh member is operably
connected to an inner surface of the distal portion of the first
elongate shaft. The mesh member includes a conductive portion
configured to contact a surface for ablation.
[0007] In some embodiments the ablation device includes a mesh
member including a proximal portion and a distal portion, the mesh
member having a first diameter and a second diameter greater than
the first diameter such that the mesh member is movable to the
second diameter by moving the proximal portion relative to the
distal portion. The mesh member includes a plastic material and a
conductive portion, the conductive portion comprising an ink
covering at least a portion of the plastic material and the
conductive portion is positionable to contact a surface for
ablation.
[0008] In another embodiment, a method of ablating a tissue is
provided. The method includes inserting a distal portion of an
ablation device into a lumen of a patient. The ablation device
includes a first elongate shaft having a proximal portion, a distal
portion and a lumen extending at least partially therethrough and a
second elongate shaft having a proximal portion, a distal portion
and a lumen extending at least partially therethrough. The first
elongate shaft is coaxially positioned and longitudinally movable
relative to the second elongate shaft. The ablation device further
includes a mesh member including a proximal portion and a distal
portion. The proximal portion of the mesh member is operably
connected to the distal portion of the second elongate shaft and
the distal potion the mesh member is operably connected to an inner
surface of the distal portion of the first elongate shaft. The mesh
member includes a conductive portion configured to contact a
surface for ablation. The method further includes positioning a
portion of the mechanically expandable ablation member at a
treatment site, moving the first elongate shaft relative to the
second elongate shaft to move the ablation device to an expanded
configuration having the second diameter, pressing an end face of
the mesh member against the surface and applying energy to the
tissue from an energy source.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a partial view of a distal portion of an ablation
device in an extended configuration accordance with an embodiment
of the present invention;
[0010] FIG. 2 is partial view of the ablation device shown in FIG.
1 with a mesh member removed;
[0011] FIG. 3 is a partial view of the ablation device shown in
FIG. 1 in an expanded configuration;
[0012] FIG. 4 is a partial view of the ablation device shown in
FIG. 3 with the mesh member removed;
[0013] FIG. 5 is a partial view of an embodiment the distal portion
of the ablation device;
[0014] FIG. 6 is a partial side view of an embodiment the distal
portion of the ablation device;
[0015] FIG. 7 is a partial side view of an embodiment the distal
portion of the ablation device;
[0016] FIG. 8 is an end view of an end face of an embodiment of the
ablation device in an expanded configuration;
[0017] FIG. 9 is an end view of an end face of an embodiment of the
ablation device in an extended configuration;
[0018] FIGS. 10-13 show a partial view of a distal portion of an
embodiment of the ablation device moving from an extended
configuration to an expanded configuration to a retracted
configuration;
[0019] FIG. 14 is a partial view of a proximal portion of an
embodiment of the ablation device;
[0020] FIG. 15 is a partial sectional view of a distal portion an
embodiment of the ablation device;
[0021] FIG. 16 is an end view of an end face of an embodiment of
the ablation device; and
[0022] FIGS. 17A-17C illustrate operation of the ablation
device.
DETAILED DESCRIPTION
[0023] The invention is described with reference to the drawings in
which like elements are referred to by like numerals. The
relationship and functioning of the various elements of this
invention are better understood by the following detailed
description. However, the embodiments of this invention are not
limited to the embodiments illustrated in the drawings. It should
be understood that the drawings are not to scale, and in certain
instances details have been omitted which are not necessary for an
understanding of the present invention, such as conventional
fabrication and assembly.
[0024] As used in the specification, the terms proximal and distal
should be understood as being in the terms of a physician
delivering the ablation device to a patient. Hence the term
"distal" means the portion of the ablation device that is farthest
from the physician and the term "proximal" means the portion of the
ablation device that is nearest to the physician.
[0025] FIGS. 1 and 2 illustrate an embodiment of an ablation device
10 in accordance with the present invention. The ablation device 10
includes an outer catheter 12, an inner catheter 14, one or more
drive cables 16 and a mesh member 20. The inner catheter 14 and the
drive cable 16 are shown in FIG. 2 without the mesh member 20 so
that the inner catheter 14 and the drive cable 16 can be more
readily viewed. The inner catheter 14 may be coaxially positioned
within the outer catheter 12 and slidably positionable relative to
the outer catheter 12. The outer catheter 12 includes a proximal
end portion 22, a distal end portion 24 and a lumen 26 extending at
least partially therethrough. The inner catheter 14 includes a
proximal end portion 32, a distal end portion 34 and a lumen 36
extending at least partially therethrough. The drive cable 16 is
shown extending through the lumen 36 of the inner catheter 14 in
FIG. 2. In some embodiments, the drive cable 16 may be positioned
external to the inner catheter 14. The drive cable 16 is movable
relative to the outer catheter 12 and in some embodiments the drive
cable 16 is movable together with the inner catheter 14.
[0026] The mesh member 20 is operably connectable to the inner
catheter 14, the outer catheter 12 and the drive cable 16. As the
inner catheter 14 and the outer catheter 12 are moved relative to
each other, the shape of the mesh member 20 changes. In some
embodiments, a distal end portion 38 of the mesh member 20 may be
extended over a distal end 39 of the inner catheter 14, inverted
into the lumen 36 of the inner catheter 14 and operably connected
to an inner surface 41 of the distal end portion 34 of the inner
catheter 14. The drive cable 16 may also be operably connected to
the mesh member 20 to move the mesh member 20 and the inner
catheter 14 relative to the outer catheter 12. The drive cable 16
may also act as the active wire to transmit current from an
electrosurgical unit (ESU) to the mesh member 20 and to the tissue
(described in more detail below). A proximal end portion 40 of the
mesh member 20 may be operably connected to the distal end portion
26 of the outer catheter 12.
[0027] FIG. 1 illustrates an extended configuration 44 of the
device 10 where the distal end portion 36 of the inner catheter 14
is extended distal to the distal end portion 26 of the outer
catheter 12 and the mesh member 20 is fully extended so that the
mesh member 20 has an outer diameter d.sub.1 at a distal portion 46
of an outer surface 48 of the mesh member 20 that is about the same
as an outer diameter d.sub.2 of the outer catheter 12. The mesh
member 20 expands, extends and retracts by longitudinal movement of
the inner catheter 14 relative to the outer catheter 12. The
ablation device 10 may be delivered to the treatment site with the
device 10 in the extended configuration 44. An outer sheath 70 may
be positioned over the ablation device 10 for delivery to a
treatment site. (See FIG. 15 showing an outer sheath.)
[0028] FIGS. 3 and 4 illustrate the ablation device 10 in an
expanded configuration 54. Similar to FIG. 2 above, FIG. 4
illustrates the outer catheter 12, the inner catheter 14 and the
drive cable 16 without the mesh member 20 so that the inner
catheter 14 and the drive cable 16 can be more readily viewed. The
inner catheter 14 is shown in FIG. 4 proximally withdrawn relative
to the position of the inner catheter 14 shown in FIG. 2. The
distal end portion 34 of the inner catheter 14 is still distal to
but closer to the distal end portion 24 of the outer catheter 12.
As shown in FIG. 3, with the inner catheter 14 proximally withdrawn
relative to the outer catheter 12 and still having the distal end
portion 34 distal to the distal end portion 24, the mesh member 20
is radially expanded relative to the extended configuration 44 and
has an outer diameter d.sub.3 at the distal portion 46 of the outer
surface 48 of the mesh member 20. The outer diameter d.sub.3 is
greater than the diameters d.sub.1 and d.sub.2. As shown in FIG. 3,
the inner catheter 14 can be withdrawn to the point where an end
face 56 of the mesh member 20 forms a generally flattened surface
that can be advanced into contact with the tissue at the treatment
site.
[0029] FIGS. 5 and 6 illustrate the ablation device 10 in the
expanded configuration 54 with the end face 56 of the mesh member
20 flattened against a surface S for treatment. As shown in FIG. 5,
the ablation device 10 may be used with the inner and outer
catheters 14, 12 generally perpendicular to the treatment surface
S. As shown in FIG. 5, the end face 56 is generally flattened
against the treatment surface S and can form an ablation disc in
the tissue since the end face 56 of the mesh member 20 can directly
contact the tissue across the entire surface of the end face 56.
The end face 56 can be pressed against the tissue and generally
flattened without application of undue force to flatten the end
face 56. The risk of perforation of the tissue is also reduced due
to the decreased pressure and to the spreading of the energy across
the end face 56.
[0030] FIG. 6 illustrates the ablation device 10 in the expanded
configuration 54 with the end face 56 flattened against a surface S
for treatment. In some embodiments, the mesh member 20 is made of a
flexible material that allows the end face 56 of the mesh member 20
to contact the surface S for treatment with the inner catheter 14
and the outer catheter 12 positioned at an oblique angle 60
relative to the surface S. By way of non-limiting example, the mesh
member 20 may be formed of a plastic material coated with a
conductive material (described in more detail below) that is
flexible enough to bend and flatten the end face 56 against the
surface S by moving the mesh member 20. In some embodiments, the
ablation device 10 may include a hinge 64 as shown in FIG. 7 to
facilitate positioning of the end face 56 against the surface S. As
shown in FIG. 7, the outer catheter 12 to be extended generally
perpendicular to the surface S for treatment and the hinge 64
allows the mesh material 20 to bend at the oblique angle 60 so that
the end face 56 of the mesh material 20 is positioned flat against
the surface S for treatment of the tissue. In some embodiments, the
hinge 64 may be on the inner catheter 14 and the outer catheter 12.
The hinge 64 may be used with mesh materials that are formed from
stiffer materials, for example some metal meshes may be too rigid
to deform easily against the surface S and would require too much
pressure against the surface S to flatten the end face 56. The
hinge 64 may be any kind of a hinge that allows the ablation device
10 to be delivered to the site, bent at an angle and then returned
to the generally straight configuration for withdrawal from the
patients. The bending at an angle and return of the ablation device
10 to the straightened position may be by mechanical means such as
a drive cable or by contact with a portion of the body lumen.
[0031] An end view of the end face 56 of the mesh member 20 in the
expanded configuration 54 is shown in FIG. 8. The entire end face
56 may be energized for treatment of tissue or portions of the end
face 56 may be energized as describe in more detail below. The end
face 56 is shown as having a generally circular face, however other
shapes may also be used. By way of non-limiting example, other
shapes for the end face 56 may be formed by changing the weave
pattern of the mesh member 20, for example forming an oval or a
ring. The weave pattern may be varied to also change the overall
size of the end face 56 to create a different size treatment area.
In some embodiments, the density of the weave pattern or the
thickness of the woven portions may also be varied to change the
energy delivered to the treatment area and the flexibility of the
mesh material 20. The size of the inner catheter 12 and the
attachment of the mesh member 20 may also contribute to the size,
density and energy delivery of the end face 56. As shown in FIG. 8,
the mesh member 20 may be folded over the distal end portion 34 of
the inner catheter 14 and extend into the lumen 36 and be connected
to the inside of the catheter 14. The mesh member 20 may extend
across a portion of the lumen 36 so that the end face 56 may be
used to ablate an entire disc of tissue. In some embodiments, the
lumen 36 may be at least partially free from the mesh member 20 if
a ring is desired for the treatment area.
[0032] FIG. 9 illustrates an end view of the end face 56 of the
mesh member 20 in the extended configuration 44. The diameter
d.sub.1 and thus the surface area of the end face 56 in the
extended configuration 44 is smaller than the diameter d.sub.3 of
the end face 56 in the expanded configuration 54. The ablation
device 10 may be used in the extended configuration 44 so that the
end face 56 is energized to treat a smaller tissue area. In some
embodiments, the mesh member 20 may be configured so that the end
face 56 may be energized or a portion of the outer surface 48 of
the mesh member 20 may be energized with the ablation device 10 in
the extended configuration 44 (See also FIG. 1.) The mesh may be
formed from wire such as nickel titanium alloys, for example,
nitinol, stainless steel, cobalt alloys and titanium alloys. In
some embodiments, the mesh may be formed from a polymeric material
such as a polyolefin, a fluoropolymer, a polyester, for example,
polypropylene, polytetrafluoroethylene, polyvinylidene fluoride,
polyethylene terephthalate (PET), and combinations thereof. Other
materials known to one skilled in the art may also be used to form
the mesh member 20.
[0033] FIGS. 10 to 13 illustrate movement of the mesh member 20 of
the ablation device 10. As shown in FIGS. 10 to 13, the mesh member
20 is moved by moving the inner catheter 14 relative to outer
catheter 12 so that distal end portion 34 of the inner catheter 14
is moved closer to the distal end portion 24 of the outer catheter
12. The drive cable 16 may also be used to move the inner catheter
14 relative to the outer catheter 12. The ablation device 10 is in
the extended configuration 44 shown in FIG. 10 with the inner
catheter 14 extended to its distalmost position relative to the
outer catheter 12 so that the mesh member 20 is fully distally
extended. FIGS. 11 and 12 show the inner catheter 14 being
proximally withdrawn relative to the outer catheter 12 and the mesh
member 20 expanding to the expanded configuration 54 and the
diameter of the end face 56 increasing relative to the diameter of
the end face 56 shown in FIG. 10. The drive cable 16 remains
connected to the mesh member 20 in all the configurations so that
the ablation device 10 may be energized in any of the positions
shown in FIGS. 10-12. In FIGS. 10-12, the distal end portion 34 of
the inner catheter 14 is distal to the distal end portion 24 of the
outer catheter 12.
[0034] FIG. 13 illustrates the mesh member 20 in a retracted
configuration 68 where the inner catheter 14 is positioned within
the outer catheter 12 so that the distal end portion 24 of the
inner catheter 14 is positioned proximal to a distal end 25 of the
outer catheter. The mesh member 20 extends over a distal end 29 of
the outer catheter 12. The distal end portion 38 of the mesh member
20 is withdrawn into the lumen 26 of the inner catheter 14 and the
proximal end portion 40 of the mesh member 20 remains connected to
an outer surface 27 of outer catheter 12. The ablation device 10
may be moved to the retracted configuration 68 by proximally
withdrawing the drive cable 16 and/or the inner catheter 14
relative to the outer catheter 12. The retracted configuration 68
may be used to deliver the ablation device 10 to the treatment
site. The ablation device 10 may also be moved to the retracted
configuration 68 from the extended or expanded configurations 44,
54 to facilitate removal of tissue that may be adhered or caught in
the mesh member 20 after the tissue has been ablated. The ablation
device 10 may be returned to the extended or expanded configuration
44, 54 by moving the inner catheter 14 distally relative to the
outer catheter 12 if additional treatments are desired. The
ablation device 10 may be "cleaned" by proximal withdrawal of the
inner catheter 14 relative to the outer catheter 12 and
repositioned by distally moving the inner catheter 14 relative to
the outer catheter 12 as many times as needed for a treatment
procedure.
[0035] A control handle 70 is provided at a proximal portion 72 of
the ablation device 10. An exemplary control handle 70 is shown in
FIG. 14 and one skilled in the art will recognize that other types
of handles suitable for moving the inner catheter 14 relative to
the outer catheter 12 may also be used. By way of non-limiting
example, the handle 70 includes a first portion 73 and a second
portion 75 that move relative to each other. As shown in FIG. 14,
the first portion 73 is operably connected to the inner catheter
14. The second portion 75 is operably connected to the outer
catheter 12. The first portion 73 may be moved proximally and/or
the second portion 75 may be moved distally to move the inner
catheter 14 relative to the outer catheter 12 to move the mesh
member 20.
[0036] The handle 70 may include a lock 76 shown in FIG. 14 to
releasably lock the first portion 73 in position relative to the
second portion 75 and thus lock the mesh member 20 in position. The
lock 76 may releasably lock the first and second portions 73, 75 of
the handle 70 together at any proximal/distal positioning of the
inner and outer catheters 14, 12 so that the mesh member 20 may be
locked at any size and any position that is suitable for the
treatment site. FIG. 7 also illustrates an energy source 84. As
shown in FIG. 14, the handle 70 may include a connector 86 for
operably connecting one or more of the drive cables 16 to the
energy source 84 to operably connect the energy source 84 to the
mesh member 20. A separate wire may also be used to connect to the
energy source 84 so that the mesh member is operably connected to
the energy source 84 to supply energy to the mesh member 20 for
ablation of the tissue. In some embodiments, the energy source 84
may be a radio frequency source. However, other types of energy
sources 84 may also be used to provide energy to the mesh member
20. By way of non-limiting example, additional possible energy
sources may include microwave, ultraviolet, cryogenic and laser
energies.
[0037] In some embodiments, the ablation device 10 may include an
outer sheath 70 that is positionable over the outer catheter 12 and
the mesh member 20 when the ablation device is in the retracted
configuration 68 as shown in FIG. 15 or in the extended
configuration 54 (not shown). The outer sheath 70 may be included
to facilitate delivery of the ablation device 10 to a treatment
site and to withdraw the ablation device 10 after treatment.
[0038] In some embodiments, the ablation device 10 may be provided
as a monopolar device or a bipolar device where the mesh member 20
includes a conductive portion 72. The mesh member 20 itself, when
formed from an electrically conductive material may be the
conductive portion 72 or portions of the mesh member 20 may be
conductive portions 72 with non-conductive portions 73 being coated
with an insulating material. For example, in a bipolar ablation
device 10, an insulating material is used between the active and
return portions. The insulating material can also be used to form
patterns for ablation, where conductive portions 72 of the mesh
member 20 may be activated and non-conductive portions 73 of the
mesh member 20 remain inactive. See for example, FIG. 16
illustrating an embodiment of the ablation device 10 showing the
end face 56 of the mesh member 20 having conductive portions 72
separated by non-conductive portions 73. The non-conductive
portions 73 may be provided between conductive portions 72 of the
mesh member 20 and the space between the conductive portions 72 may
be optimized to control the depth of ablation of the target tissue.
Spacing distances between the conductive portions 72 may be
optimized depending on such factors as the type of target tissue,
the depth of the lesion, the type of energy and the length of
application of the energy to the tissue.
[0039] In some embodiments, the conductive portions 72 of the mesh
member 20 may comprise conductive ink that is applied to the
exterior of the mesh member 20. The conductive ink may be applied
in any pattern and spacing to be used for tissue treatment. In some
embodiments, the conductive ink may be a silver-based ink. An
exemplary silver-based ink may be obtained from Conductive
Compounds (product number AG-510, Hudson, N.H.). However, other
types of conductive ink may also be used, such as platinum-based,
gold-based and copper-based inks. The inks may be epoxy-based inks
or non-epoxy inks, such as urethane inks. In some embodiments, the
active portions of the mesh member 20 may comprise conductive
polymers. The conductive ink may be applied to the mesh member 20
with a variety of printing processes, such as pad printing, ink jet
printing, spraying, marker striping, painting or other like
processes. In some embodiments, the conductive ink may be applied
to the mesh member with by spraying, dipping, painting or an
electrostatic coating process.
[0040] The non-conductive portion 73 of the mesh member 20 may be
an insulating portion to separate conductive portions 72 of the
mesh member 20. In some embodiments, a coating may be applied to
the mesh member 20 to form the non-conductive portions 73 in a
quantity that is sufficient to insulate the conductive portions 72
from each other or to coat portions of the mesh member 20 when the
mesh member 20 itself is formed of a conductive material. In some
embodiments, the insulating coating may be made from parylene-N
(poly-p-xylylene). Other xylylene polymers, and particularly
parylene polymers, may also be used as a coating within the scope
of the present invention, including, for example,
2-chloro-p-xylylene (Parylene C), 2,4-dichloro-p-xylylene (Parylene
D), poly(tetraflouro-p-xylylene),
poly(carboxyl-p-xylylene-co-p-xylylene), fluorinated parylene, or
parylene HT.RTM. (a copolymer of per-fluorinated parylene and
non-fluorinated parylene), alone or in any combination. Preferred
coatings will include the following properties: low coefficient of
friction (preferably below about 0.5, more preferably below about
0.4, and most preferably below about 0.35); very low permeability
to moisture and gases; fungal and bacterial resistance; high
tensile and yield strength; high conformality (ready application in
uniform thickness on all surfaces, including irregular surfaces,
without leaving voids); radiation resistance (no adverse reaction
under fluoroscopy); bio-compatible/bio-inert; acid and base
resistant (little or no damage by acidic or caustic fluids);
ability to be applied by chemical vapor deposition
bonding/integrating to wire surface (bonding is intended to
contrast to, for example, fluoroethylenes that form surface films
that are able to be peeled off an underlying wire); and high
dielectric strength.
[0041] Operation of the ablation device 10 will be explained with
reference to FIGS. 17A-17C. FIG. 18A illustrates a patient's
esophagus 90, lower esophageal sphincter (LES) 91 and stomach 92.
Areas of diseased tissue 94 within the esophagus 90 are also shown.
FIG. 17B illustrates the mesh member 20 of the ablation device 10
in the retracted configuration 68 being inserted into the patient's
esophagus 80 for delivery to the proper position. The inner
catheter 14 is positioned within the outer catheter 12 for
advancement to the tissue. In some situations, the ablation device
10 may be delivered using an endoscope 98 that is shown in FIG. 17C
to facilitate placement of the mesh member 20 in the proper
position to ablate the diseased tissue 94. The endoscope 98 may
include a viewing port 99 for visualizing the diseased tissue 94
and positioning the ablation device 10. The ablation device 10 may
be delivered through the working channel or optionally back-loaded
into the working channel of the endoscope before insertion of the
endoscope 98 into the patient. As shown in FIG. 17C, the mesh
member 20 of the ablation device ablation device 10 is delivered
through the endoscope 98 and positioned so that the mesh member 20
is adjacent to the diseased tissue 94 in the expanded configuration
54. The mesh member 20 may be positioned so that the end face 56 of
the mesh member 20 directly contacts the diseased tissue 94 or an
electroconductive fluid may be provided between the end face 56 and
the diseased tissue 94. The power source 84 is activated for a
sufficient time to ablate the diseased tissue 94. The mesh member
20 may then be proximally withdrawn to the retracted configuration
68 by proximally moving the inner catheter 14 relative to the outer
catheter 12. The mesh member 20 may be repositioned at a new tissue
site or removed once the ablation of the diseased tissue is
completed. While the procedure has been described with reference to
the ablation of diseased tissue in the esophagus using the ablation
device 10, the location of the treatment is not limited to the
esophagus. By way of non-limiting example, portions of the stomach,
the gastrointestinal tract, the lungs or the vascular system may
also be treated using the ablation device 10. For example, the
device 10 may be used for treating bleeding varices in the
esophagus or for treatment of prostatic diseases, such as benign
prostatic hyperplasia.
[0042] The above Figures and disclosure are intended to be
illustrative and not exhaustive. This description will suggest many
variations and alternatives to one of ordinary skill in the art.
All such variations and alternatives are intended to be encompassed
within the scope of the attached claims. Those familiar with the
art may recognize other equivalents to the specific embodiments
described herein which equivalents are also intended to be
encompassed by the attached claims.
* * * * *