U.S. patent application number 15/959767 was filed with the patent office on 2018-08-23 for microwave ablation devices including expandable antennas and methods of use.
The applicant listed for this patent is Covidien LP. Invention is credited to Tao D. Nguyen, Darion Peterson, Christopher T. Rusin.
Application Number | 20180235694 15/959767 |
Document ID | / |
Family ID | 41118288 |
Filed Date | 2018-08-23 |
United States Patent
Application |
20180235694 |
Kind Code |
A1 |
Rusin; Christopher T. ; et
al. |
August 23, 2018 |
MICROWAVE ABLATION DEVICES INCLUDING EXPANDABLE ANTENNAS AND
METHODS OF USE
Abstract
A microwave ablation device for treating tissue includes an
inner conductor having a length and a distal end and configured to
deliver energy, a wire extending adjacent the inner conductor and
axially translatable relative thereto, the wire including a length
and a distal end, a distal tip disposed in mechanical cooperation
with the distal end of the inner conductor and the distal end of
the wire, and an outer conductor including a distal end and
defining a longitudinal axis, the outer conductor at least
partially surrounding the inner conductor and the wire at least
partially along their lengths. The distal tip is movable
substantially along the longitudinal axis with respect to the outer
conductor and relative movement of the distal tip towards the
distal end of the outer conductor causes at least a portion of the
inner conductor to move away from the longitudinal axis.
Inventors: |
Rusin; Christopher T.;
(Golden, CO) ; Peterson; Darion; (Longmont,
CO) ; Nguyen; Tao D.; (Redwood City, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Covidien LP |
Boulder |
CO |
US |
|
|
Family ID: |
41118288 |
Appl. No.: |
15/959767 |
Filed: |
April 23, 2018 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
12413011 |
Mar 27, 2009 |
9949794 |
|
|
15959767 |
|
|
|
|
61039851 |
Mar 27, 2008 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 18/18 20130101;
A61B 2018/00214 20130101; A61B 2018/00267 20130101; A61N 5/02
20130101; A61B 18/1815 20130101 |
International
Class: |
A61B 18/18 20060101
A61B018/18; A61N 5/02 20060101 A61N005/02 |
Claims
1-20. (canceled)
21. An electrosurgical device, comprising: a wire defining a
longitudinal axis; an outer conductor at least partially
surrounding the wire; a distal tip portion coupled to the wire, the
wire configured to move the distal tip portion along the
longitudinal axis; and an inner conductor at least partially
surrounded by the outer conductor and having an insulated portion
and an uninsulated portion, the inner conductor configured to move
away from the longitudinal axis upon movement of the distal tip
portion along the longitudinal axis to form a bend at the
uninsulated portion of the inner conductor for treating tissue.
22. The electrosurgical device according to claim 21, wherein the
uninsulated portion is surrounded by the insulated portion.
23. The electrosurgical device according to claim 21, wherein the
inner conductor is configured to be disposed orthogonal to the
longitudinal axis upon movement of the distal tip portion along the
longitudinal axis.
24. The electrosurgical device according to claim 21, further
comprising a plurality of inner conductors radially spaced from
each other about the longitudinal axis.
25. The electrosurgical device according to claim 21, wherein the
electrosurgical device is a microwave antenna configured to deliver
microwave energy to tissue.
26. The electrosurgical device according to claim 21, further
comprising a dielectric material disposed between the inner and
outer conductors and surrounding at least a portion of the
wire.
27. The electrosurgical device according to claim 21, wherein the
distal tip portion is electrically coupled to the wire.
28. The electrosurgical device according to claim 21, wherein the
distal tip portion includes a tapered distal tip configured to
pierce tissue.
29. The electrosurgical device according to claim 21, wherein the
inner conductor is configured to pierce tissue.
30. The electrosurgical device according to claim 21, wherein the
distal tip portion is configured to move along the longitudinal
axis toward a distal end of the outer conductor to move the inner
conductor away from the longitudinal axis.
31. The electrosurgical device according to claim 21, wherein the
wire is configured to move along the longitudinal axis relative to
the outer conductor.
32. The electrosurgical device according to claim 21, wherein the
distal tip portion is mechanically and electrically connected to a
distal end of the inner conductor and a distal end of the wire.
33. The electrosurgical device according to claim 21, wherein the
bend divides the uninsulated portion to include a proximal-facing
surface and an opposing distal-facing surface.
34. The electrosurgical device according to claim 21, wherein the
insulated portion includes a first insulated surface extending
proximally from a first end of the uninsulated portion and a second
insulated surface extending distally from a second end of the
uninsulated portion to the distal tip portion.
35. An electrosurgical device, comprising: a feedline defining a
longitudinal axis, the feedline including: an inner conductor
configured to treat tissue and having an insulated portion and an
uninsulated portion; an outer conductor at least partially
surrounding the inner conductor; and a dielectric material disposed
between the inner and outer conductors; and a distal tip portion
connected to the inner conductor and configured to move along the
longitudinal axis to move the inner conductor away from the
longitudinal axis such that the inner conductor forms a bend at the
uninsulated portion for treating tissue.
36. The electrosurgical device according to claim 35, further
comprising a wire extending along the longitudinal axis and having
a distal end connected to the distal tip portion, the wire
configured to move the distal tip portion along the longitudinal
axis.
37. The electrosurgical device according to claim 35, wherein the
distal tip portion is mechanically and electrically connected to a
distal end of the inner conductor.
38. The electrosurgical device according to claim 35, wherein the
bend divides the uninsulated portion to include a proximal-facing
surface and an opposing distal-facing surface.
39. The electrosurgical device according to claim 35, wherein the
insulated portion includes a first insulated surface extending
proximally from a first end of the uninsulated portion and a second
insulated surface extending distally from a second end of the
uninsulated portion to the distal tip portion.
40. The electrosurgical device according to claim 35, wherein the
uninsulated portion is surrounded by the insulated portion.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/413,011 filed on Mar. 27, 2009, which
claims priority to U.S. Provisional Application No. 61/039,851
filed on Mar. 27, 2008, the contents of each of which is
incorporated herein by reference.
BACKGROUND
Technical Field
[0002] The present disclosure relates to microwave ablation devices
and methods. More particularly, the disclosure relates to microwave
antennas that are insertable into tissue and capable of being
expanded.
Background of Related Art
[0003] In the treatment of diseases such as cancer, certain types
of cancer cells have been found to denature at elevated
temperatures that are slightly lower than temperatures normally
injurious to healthy cells. These types of treatments, known
generally as hyperthermia therapy, typically utilize
electromagnetic radiation to heat diseased cells to temperatures
above 41.degree. C. while maintaining adjacent healthy cells at
lower temperatures where irreversible cell destruction will not
occur. Other procedures utilizing electromagnetic radiation to heat
tissue also include ablation and coagulation of the tissue. Such
microwave ablation procedures, e.g., such as those performed for
menorrhagia, are typically done to ablate and coagulate the
targeted tissue to denature or kill it. Many procedures and types
of devices utilizing electromagnetic radiation therapy are known in
the art. Such microwave therapy is typically used in the treatment
of tissue and organs such as the prostate, heart, and liver.
[0004] One non-invasive procedure generally involves the treatment
of tissue (e.g., a tumor) underlying the skin via the use of
microwave energy. The microwave energy is able to non-invasively
penetrate the skin to reach the underlying tissue. However, this
non-invasive procedure may result in the unwanted heating of
healthy tissue. Thus, the non-invasive use of microwave energy
requires a great amount of control. This is partly why a more
direct and precise method of applying microwave radiation has been
sought.
[0005] Presently, there are several types of microwave probes in
use, e.g., monopole, dipole, and helical. One type is a monopole
antenna probe consisting of a single, elongated microwave conductor
exposed at the end of the probe. The probe is sometimes surrounded
by a dielectric sleeve. The second type of microwave probe commonly
used is a dipole antenna consisting of a coaxial construction
having an inner conductor and an outer conductor with a dielectric
separating a portion of the inner conductor and a portion of the
outer conductor. In the monopole and dipole antenna probe,
microwave energy generally radiates perpendicularly from the axis
of the conductor.
[0006] Because of the perpendicular pattern of microwave energy
radiation, conventional antenna probes are typically designed to be
inserted directly into the tissue, e.g., a tumor, to be radiated.
However, such typical antenna probes commonly fail to provide
uniform heating axially and/or radially about the effective length
of the probe.
[0007] It is often difficult to assess the extent to which the
microwave energy will radiate into the surrounding tissue, i.e., it
is difficult to determine the area or volume of surrounding tissue
that will be ablated. Furthermore, when conventional microwave
antennas are inserted directly into the tissue, e.g., cancerous
tissue, there is a danger of dragging or pulling cancerous cells
along the antenna body into other parts of the body during
insertion, placement, or removal of the antenna probe.
[0008] One conventional method for inserting and/or localizing
wires or guides includes a wire guide that is delivered into breast
tissue, for example, through a tubular introducer needle. When
deployed, the wire guide cuts into and scribes a circular path
about the tissue distal to a lesion while the remainder of the
distal portion of the wire guide follows the path scribed by the
distal tip and locks about the tissue.
[0009] In certain circumstances, it is advantageous to create a
relatively large ablation region, which often requires multiple
ablation instruments to be inserted into a patient. It would
therefore be desirable to provide a single instrument that can be
used to create a relatively large ablation region.
SUMMARY
[0010] A microwave ablation device for treating tissue includes an
inner conductor having a length and a distal end and configured to
deliver energy, a wire extending adjacent the inner conductor and
axially translatable relative thereto, the wire including a length
and a distal end, a distal tip disposed in mechanical cooperation
with the distal end of the inner conductor and the distal end of
the wire, and an outer conductor including a distal end and
defining a longitudinal axis, the outer conductor at least
partially surrounding the inner conductor and the wire at least
partially along their lengths. The distal tip is movable
substantially along the longitudinal axis with respect to the outer
conductor and relative movement of the distal tip towards the
distal end of the outer conductor causes at least a portion of the
inner conductor to move away from the longitudinal axis.
[0011] The inner conductor may arc away from the longitudinal axis
in response to the relative movement of the distal tip with respect
to the distal end of the outer conductor, and at least a portion of
the inner conductor may be flexible. Also, at least a portion of
the inner conductor may be configured to pierce tissue.
[0012] A corner may be formed on the inner conductor in response to
movement of the distal tip with respect to the distal end of the
outer conductor, and this corner may be uninsulated.
[0013] In some embodiments, the microwave ablation device may
further include at least a second inner conductor, the second inner
conductor including a length and a distal end and connected to the
distal tip adjacent the distal end thereof.
[0014] In some embodiments, the distal tip is configured to pierce
tissue and is electrically coupled to the distal tip.
[0015] In some embodiments, relative movement of the distal tip
away from the distal end of the outer conductor causes at least a
portion of the inner conductor to move towards the longitudinal
axis.
[0016] In some embodiments, a dielectric material may be disposed
between the outer conductor and the inner conductor.
[0017] In some embodiments, the inner conductor is an expandable
mesh.
DESCRIPTION OF THE DRAWINGS
[0018] Embodiments of the presently disclosed microwave ablation
devices are disclosed herein with reference to the drawings,
wherein:
[0019] FIG. 1 is a perspective view of a microwave ablation device
in accordance with an embodiment of the present disclosure;
[0020] FIG. 2 is a schematic view of the microwave ablation device
of FIG. 1 connected to a generator;
[0021] FIG. 3 is a cross-sectional view of a portion of a feedline
of the microwave ablation device of FIGS. 1 and 2, as taken through
3-3 of FIG. 2;
[0022] FIG. 4 is a side view of a distal portion of the microwave
ablation device of FIG. 1-3;
[0023] FIG. 5 is a perspective view of the distal portion of the
microwave ablation device of FIGS. 1-4;
[0024] FIG. 6 is a side view of a distal portion of the microwave
ablation device of FIG. 1 in a first stage of deployment, in
accordance with an embodiment of the present disclosure;
[0025] FIG. 7 is a distal end view of the distal portion of the
microwave ablation device of FIGS. 1 and 6;
[0026] FIG. 8 is a perspective view of the distal portion of the
microwave ablation device of FIGS. 1, 6 and 7 in a second stage of
deployment;
[0027] FIGS. 9 and 10 are sides views of a distal portion of a
microwave ablation device in accordance with another embodiment of
the present disclosure illustrating various stages of deployment
thereof; and
[0028] FIGS. 11 and 12 are side views of a distal portion of a
microwave ablation device in accordance with another embodiment of
the present disclosure illustrating various stages of deployment
thereof.
DETAILED DESCRIPTION OF EMBODIMENTS
[0029] Embodiments of the presently disclosed microwave ablation
devices are described in detail with reference to the drawings, in
which like reference numerals designate identical or corresponding
elements in each of the several views. As used herein the term
"distal" refers to that portion of the microwave ablation device,
or component thereof, farther from the user while the term
"proximal" refers to that portion of the microwave ablation device
or component thereof, closer to the user.
[0030] An ablation device (e.g., a microwave ablation device) in
accordance with the present disclosure is referred to in the
figures as reference numeral 10. Referring initially to FIG. 1,
microwave ablation device 10 includes a microwave antenna 12 and a
handle portion 13. Microwave antenna 12 includes a shaft or
feedline 14 having at least one inner conductor 16, a wire 18 and
an outer structure 20, which defines a longitudinal axis X-X. A
power transmission cord 21 is shown to connect microwave ablation
device 10 to a suitable electrosurgical generator 22 (see FIG. 2).
Additionally, an actuation element 7 is illustrated in FIG. 1 in
accordance with various embodiments of the present disclosure.
[0031] As seen in FIG. 2, each inner conductor 16 extends from
feedline 14 and a penetrating tip 30 is disposed adjacent to or
coupled to a distal end of each inner conductor 16. In the
illustrated embodiment, the proximal end of feedline 14 includes a
coupler 19 that electrically couples antenna 12 to generator 22 via
power transmission cord 21.
[0032] It is envisioned that microwave ablation device 10 may be
introduced to the treatment site via a straight, arcuate,
non-deployable and/or deployable applicator or introducer. It is
further envisioned that tip 30 is configured to pierce tissue to
facilitate introduction of microwave ablation device 10 to the
treatment site.
[0033] As described above and as shown in FIG. 3, feedline 14 may
be in the form of a coaxial cable. Portions of feedline 14 may be
formed of an outer structure 20 (e.g., an outer conductor)
surrounding at least one inner conductor 16. Each inner conductor
16 and/or outer structure 20 may be made of a suitable conductive
metal that may be semi-rigid or flexible, such as, for example,
copper, gold, or other conductive metals with similar conductivity
values. Alternatively, portions of each inner conductor 16 and
outer structure 20 may also be made from stainless steel that may
additionally be plated with other materials, e.g., other conductive
materials, to improve their properties, e.g., to improve
conductivity or decrease energy loss, etc.
[0034] For example, inner conductors 16 may be made of stainless
steel having an impedance of about 50.OMEGA.. In order to improve a
conductivity of a stainless steel inner conductor 16, inner
conductor 16 may be coated with a layer of a conductive material
such as copper or gold. Although stainless steel may not offer the
same conductivity as other metals, it does offer increased strength
required to puncture tissue and/or skin.
[0035] With continued reference to FIG. 3, feedline 14 of antenna
12 is shown including a dielectric material 28 surrounding at least
a portion of a length of each inner conductor 16 and outer
structure 20 surrounding at least a portion of a length of
dielectric material 28 and/or each inner conductor 16. That is, a
dielectric material 28 is interposed between inner conductor 16 and
outer structure 20, to provide insulation therebetween and may be
comprised of any suitable dielectric material.
[0036] Various embodiments of a distal portion 22 of microwave
ablation device 10 are shown in FIGS. 4-12. With specific reference
to FIGS. 4 and 5, distal portion 22 of microwave ablation device 10
includes at least one inner conductor 16 (e.g., three inner
conductors 16a, 16b and 16c being shown in FIG. 5), a wire 18, an
outer structure or conductor 20 and a distal tip 30. Distal tip 30
is in mechanical cooperation with each inner conductor 16 and wire
18 and is movable with respect to outer structure or conductor 20.
In some embodiments, distal tip 30 is also in electrical
communication with each inner conductor 16 and wire 18.
[0037] It is envisioned that translation of actuation element 7
(see FIG. 1) causes movement of distal tip 30 (substantially along
longitudinal axis X-X) with respect to outer structure or conductor
20. Moreover, distal translation of actuation element 7 causes
distal tip 30 to move distally in the direction of arrow "A" and
proximal translation of actuation element 7 causes distal tip 30 to
move proximally in the direction of arrow "B." It is also
contemplated that distal translation of actuation element 7 may
cause outer structure 20 to move distally in the direction of arrow
B and proximal translation of actuation element 7 may cause outer
structure 20 to move proximally in the direction of arrow A.
[0038] In response to the relative movement between outer structure
or conductor 20 and distal tip 30, at least a portion of each inner
conductor 16 is forced radially away from longitudinal axis X-X, in
the direction of arrows "C" and/or "D" (see FIG. 5). Thus, an
ablation region 40, as defined by the boundaries of inner
conductors 16a, 16b, 16c (including the area between inner
conductors 16a, 16b, 16c and adjacent wire 18), is expanded (e.g.,
widened) as a distance between outer structure or conductor 20 and
distal tip 30 becomes smaller. In the embodiment illustrated in
FIGS. 4 and 5, inner conductors 16a, 16b, 16c arc away from
longitudinal axis X-X. In such an embodiment, it is envisioned that
at least a portion of each inner conductor 16 is flexible.
[0039] Each inner conductor 16 may be configured to pierce or slice
through tissue, either mechanically and/or with the aid of energy,
e.g., radiofrequency energy. In the embodiment where inner
conductor(s) 16 can mechanically pierce or slice through tissue,
inner conductor(s) 16 may be thin enough to pierce or slice through
tissue upon the exertion of a predetermined amount of force (e.g.,
the amount of force created when outer structure or conductor 20
and distal tip 30 are approximated). Additionally or alternatively,
inner conductor(s) 16 may be configured to receive energy, e.g.,
from a generator, to piece or slice through tissue or assist in
piercing or slicing through tissue.
[0040] Another embodiment of microwave ablation device 10 is
illustrated in FIGS. 6-8. Here, upon decreasing the distance
between outer structure 20 and distal tip 30, inner conductors 16d,
16e, 16f move away from longitudinal axis X-X, such that each inner
conductor 16d, 16e, 16f forms a corner, point or bend 17d, 17e,
17f, respectively (as opposed to forming an arc-like shape as shown
in FIGS. 4 and 5).
[0041] It is envisioned that insulation 50 may be disposed on at
least a portion of inner conductors 16 of the various embodiments
disclosed herein. For example, as seen in FIGS. 6-8, inner
conductors 16d, 16e, 16f include insulation 50 along at least a
portion of their lengths and define a respective uninsulated or
exposed portion 52d, 52e, 52f (e.g., adjacent and/or including
bends 17d, 17e, 17f).
[0042] In the embodiment illustrated in FIGS. 9 and 10, inner
conductor 16 is in the form of an expandable mesh 60. Here,
expandable mesh 60 extends between outer structure or conductor 20
and distal tip 30 and defines ablation region 40 therebetween. Upon
relative movement of distal tip 30 and outer structure or conductor
20, at least a portion of expandable mesh 60 moves or deflects away
from wire 18 (as shown by arrows "E" and "F" in FIG. 10).
Expandable mesh 60 may be configured to deliver energy, e.g.,
radiofrequency, ultrasound, cryotherapy energy, laser energy and/or
microwave energy to the target tissue.
[0043] In the embodiment illustrated in FIGS. 11 and 12, inner
conductor 16 is in the form of an expandable sheath 70. In this
embodiment, expandable sheath 70 (e.g., including a polymeric
material) is used to create or define ablation region 40.
Expandable sheath 70 may be filled or inflated with a conductive
material, a dielectric material or a combination thereof. Upon
relative movement between distal tip 30 and outer structure 20, at
least a portion of expandable sheath 70 moves away from wire 18 (as
shown by arrows "G" and "H" in FIG. 12). Expandable sheath 70 may
be configured to deliver energy, e.g., radiofrequency, ultrasound,
cryotherapy energy, laser energy and/or microwave energy.
[0044] A method of treating tissue using ablation device 10 is also
included by the present disclosure. The method may include at least
providing an microwave ablation device, such as ablation device 10
described above, inserting at least a portion of the ablation
device into a target surgical site while in a collapsed condition,
moving a distal tip of the ablation device to cause at least a
portion of an inner conductor to move away from a longitudinal axis
thereof, and delivering energy to the target surgical site via at
least a portion of the inner conductor. The method may further
include moving a distal tip of the ablation device to cause at
least a portion of an inner conductor to move towards the
longitudinal axis thereof, and withdrawing the ablation device from
the target surgical site. The method may further include energizing
at least a portion of the ablation device during insertion of the
portion of the ablation device into the target surgical site.
[0045] It will be understood that various modifications may be made
to the embodiments disclosed herein. Therefore, the above
description should not be construed as limiting, but merely as
exemplifications of various embodiments. Those skilled in the art
will envision other modifications within the scope and spirit of
the claims appended hereto.
* * * * *