U.S. patent application number 12/582561 was filed with the patent office on 2010-02-18 for systems and methods for creating a lesion using transjugular approach.
This patent application is currently assigned to BOSTON SCIENTIFIC SCIMED, INC.. Invention is credited to Jeffrey M. Cross, Paul DiCarlo.
Application Number | 20100042098 12/582561 |
Document ID | / |
Family ID | 37307394 |
Filed Date | 2010-02-18 |
United States Patent
Application |
20100042098 |
Kind Code |
A1 |
Cross; Jeffrey M. ; et
al. |
February 18, 2010 |
SYSTEMS AND METHODS FOR CREATING A LESION USING TRANSJUGULAR
APPROACH
Abstract
A method of treating a tissue region includes inserting a
flexible sheath within a vessel, the vessel leading to a tissue
region, placing a distal end of the sheath through a wall of the
vessel to thereby position the distal end is at or adjacent the
tissue region, deploying a plurality of electrodes from the distal
end of the sheath such that tips of the deployed electrodes
approximately face towards a proximal end, and delivering energy to
the tissue region using the deployed electrodes.
Inventors: |
Cross; Jeffrey M.;
(Charlestown, MA) ; DiCarlo; Paul; (Middleboro,
MA) |
Correspondence
Address: |
Vista IP Law Group LLP
2040 MAIN STREET, 9TH FLOOR
IRVINE
CA
92614
US
|
Assignee: |
BOSTON SCIENTIFIC SCIMED,
INC.
Maple Grove
MN
|
Family ID: |
37307394 |
Appl. No.: |
12/582561 |
Filed: |
October 20, 2009 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11168234 |
Jun 27, 2005 |
7615050 |
|
|
12582561 |
|
|
|
|
Current U.S.
Class: |
606/41 |
Current CPC
Class: |
A61B 2018/1475 20130101;
A61B 2018/143 20130101; A61B 2018/00404 20130101; A61B 2018/00345
20130101; A61B 18/1492 20130101; A61B 2018/1425 20130101; A61B
2018/0016 20130101; A61B 18/1477 20130101; A61B 18/00 20130101;
A61B 2018/00577 20130101 |
Class at
Publication: |
606/41 |
International
Class: |
A61B 18/14 20060101
A61B018/14 |
Claims
1-21. (canceled)
22. A system for treating tissue within a tissue region surrounding
a vessel or lumen using electrical energy, comprising: a flexible
sheath having a proximal end, a distal end, and a body extending
between the proximal and the distal ends, wherein the body is sized
such that it can be placed within a vessel or lumen, and has a
length such that when placed within the vessel or lumen, the
proximal end is outside a patient's body and the distal end is
adjacent the tissue region; an elastic shaft configured for
slidable movement within the vessel or lumen, the sheath and
elastic shaft having sufficient flexible for allowing the sheath
and shaft to be steered through the vessel or lumen; and an array
of biased electrodes tines disposed at a distal end of the elastic
shaft, the array of biased electrodes having a compressed, low
profile configuration when in the vessel or lumen and a relaxed,
expanded configuration when outside the vessel or lumen such that
tips of the electrode tines face proximally.
23. The system of claim 22, wherein the sheath comprises a sharp
distal tip configured for puncturing the vessel or lumen.
24. The system of claim 22, wherein the sheath has a length that is
between 40 cm and 130 cm.
25. The system of claim 22, wherein the electrode tines have
uniform spacing between adjacent electrode tines.
26. The system of claim 22, wherein the electrode tines have
non-uniform spacing between adjacent electrode tines.
27. The system of claim 22, further comprising a steering device
secured to a proximal end of the flexible sheath and configured to
steer the distal end of the sheath.
28. The system of claim 27, the steering device comprising a
rotatable cam and one or more steering wires extending from the
rotatable cam to the distal end of the sheath.
29. The system of claim 22, wherein the distal end of the flexible
sheath comprises a pre-bent portion.
30. The system of claim 22, further comprising a guidewire disposed
within a lumen of the sheath.
31. The system of claim 22, further comprising a radio opaque
marker located at the distal end of the sheath.
32. The system of claim 22, further comprising a marker disposed on
the proximal end of the flexible shaft.
33. The system of claim 22, further comprising an electrode located
at the distal end of the sheath.
34. The system of claim 22, wherein the electrode tines are
configured to at least partially circumscribe a portion of the
vessel or lumen when deployed from the flexible sheath.
35. The system of claim 22, further comprising a sensor disposed at
the distal end of the flexible sheath.
36. The system of claim 35, wherein the sensor comprises a
temperature sensor.
37. The system of claim 35, wherein the sensor comprises an
impedance sensor.
38. A system for treating tissue within a tissue region surrounding
a vessel or lumen using electrical energy, comprising: a flexible
sheath having a proximal end, a distal end, and a body extending
between the proximal and the distal ends, wherein the body is sized
such that it can be placed within a vessel or lumen, and has a
length such that when placed within the vessel or lumen, the
proximal end is outside a patient's body and the distal end is
adjacent the tissue region, the body including a wall having a
plurality of openings passing through the wall and configured to
increase the flexibility of the sheath; an elastic shaft configured
for slidable movement within the vessel or lumen, the sheath and
elastic shaft having sufficient flexible for allowing the sheath
and shaft to be steered through the vessel or lumen; and an array
of biased electrodes tines disposed at a distal end of the elastic
shaft, the array of biased electrodes having a compressed, low
profile configuration when in the vessel or lumen and a relaxed,
expanded configuration when outside the vessel or lumen.
39. The system of claim 38, further comprising a sharp distal tip
configured for puncturing the vessel or lumen.
40. The system of claim 38, further comprising a steering device
secured to a proximal end of the flexible sheath and configured to
steer the distal end of the sheath.
41. The system of claim 38, wherein the electrode tines are
configured to at least partially circumscribe a portion of the
vessel or lumen when deployed from the flexible sheath.
Description
BACKGROUND
[0001] 1. Field
[0002] The field of the invention relates to medical devices, and
more particularly, to medical devices and methods of their use for
treating tumors or other targeted bodily tissue using electrical
energy.
[0003] 2. Background
[0004] Tissue may be destroyed, ablated, or otherwise treated using
thermal energy during various therapeutic procedures. Many forms of
thermal energy may be imparted to tissue, such as radio frequency
electrical energy, microwave electromagnetic energy, laser energy,
acoustic energy, or thermal conduction.
[0005] In particular, radio frequency ablation (RFA) may be used to
treat patients with tissue anomalies, such as liver anomalies and
many primary cancers, such as cancers of the stomach, bowel,
pancreas, kidney and lung. RFA treatment involves the destroying
undesirable cells by generating heat through agitation caused by
the application of alternating electrical current (radio frequency
energy) through the tissue.
[0006] Various RF ablation devices have been suggested for this
purpose. For example, U.S. Pat. No. 5,855,576 describes an ablation
apparatus that includes a plurality of wire electrodes. Each of the
wires includes a proximal end that is coupled to a generator; and a
distal end that may project from a distal end of a cannula. The
wires are arranged in an array with the distal ends located
generally radially and uniformly spaced apart from the catheter
distal end. The wires may be energized in a monopolar or bipolar
configuration to heat and necrose tissue within a precisely defined
volumetric region of target tissue. The current may flow between
closely spaced wire electrodes (bipolar mode) or between one or
more wire electrodes and a larger, common electrode (monopolar
mode) located remotely from the tissue to be heated. To assure that
the target tissue is adequately treated and/or to limit damaging
adjacent healthy tissues, the array of wires may be arranged
uniformly, e.g., substantially evenly and symmetrically
spaced-apart so that heat is generated uniformly within the desired
target tissue volume. Such devices may be used either in open
surgical settings, in laparoscopic procedures, and/or in
percutaneous interventions.
[0007] Currently, tumor near a vessel may be difficult to ablate.
This is because the vessel continuously provide blood to the tumor
during an ablation procedure, thereby carrying heat away from a
targeted region. As a result, it may be difficult to achieve a
complete burn for the tumor near the vessel.
SUMMARY
[0008] In accordance with some embodiments, a method of treating a
tissue region includes inserting a flexible sheath within a vessel,
the vessel leading to a tissue region, placing a distal end of the
sheath through a wall of the vessel to thereby position the distal
end at or adjacent the tissue region, deploying a plurality of
electrodes from the distal end of the sheath such that tips of the
deployed electrodes approximately face towards a proximal end, and
delivering energy to at least a portion of the tissue region using
the deployed electrodes.
[0009] In accordance with other embodiments, a system for treating
tissue within a tissue region using electrical energy includes a
flexible sheath having a proximal end, a distal end, and a body
extending between the proximal and the distal ends, wherein the
body is sized such that it can be placed within a blood vessel, and
has a length such that when placed within the blood vessel, the
proximal end is outside a patient's body and the distal end is
adjacent the tissue region, and an array of electrodes slidably
disposed within a lumen of the sheath, wherein the sheath further
has a sharp distal tip for puncturing a vessel.
[0010] In other embodiments, a system for treating tissue within a
tissue region using electrical energy includes a flexible sheath
having a proximal end, a distal end, and a body extending between
the proximal and the distal ends, wherein the body is sized such
that it can be placed within a blood vessel, and has a length such
that when placed within the blood vessel, the proximal end is
outside a patient's body and the distal end is adjacent the tissue
region, a shaft having a body, the body having a wall and a
plurality of openings through the wall, and an array of electrodes
coupled to the shaft, and slidably disposed within a lumen of the
sheath.
[0011] Other aspects and features will be evident from reading the
following detailed description of the embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The drawings illustrate the design and utility of the
illustrated embodiments, in which similar elements are referred to
by common reference numerals. In order to better appreciate how
advantages and objects of the embodiments are obtained, a more
particular description of the embodiments is illustrated in the
accompanying drawings.
[0013] FIG. 1 illustrates a system for delivering electrical energy
to tissue in accordance with some embodiments.
[0014] FIG. 2 is a cross-sectional side view of an embodiment of an
ablation device, showing electrode tines constrained within a
sheath.
[0015] FIG. 3 is a cross-sectional side view of the ablation device
of FIG. 2, showing the electrode tines deployed from the
sheath.
[0016] FIG. 4 illustrates a system for delivering electrical energy
to tissue in accordance with other embodiments.
[0017] FIGS. 5A-5D are cross-sectional views, showing a method for
treating tissue, in accordance with some embodiments.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0018] FIG. 1 shows an ablation system 10, in accordance with some
embodiments. The ablation system 10 includes a source of energy 12,
e.g., a radio frequency (RF) generator, and an ablation device 18
configured to be coupled to the generator 12 via a cable 20 during
use.
[0019] The generator 12 is preferably capable of operating with a
fixed or controlled voltage or current so that power and current
diminish as impedance of the tissue being ablated increases.
Exemplary generators are described in U.S. Pat. No. 6,080,149, the
disclosure of which is expressly incorporated by reference herein.
The preferred generator 12 may operate at relatively low fixed
voltages, typically below one hundred fifty volts (150 V)
peak-to-peak, and preferably between about fifty and one hundred
volts (50-100 V). Such radio frequency generators are available
from Boston Scientific Corporation, assignee of the present
application, as well as from other commercial suppliers. It should
be noted that the generator 12 is not limited to those that operate
at the range of voltages discussed previously, and that generators
capable of operating at other ranges of voltages may also be
used.
[0020] Turning to FIGS. 2 and 3, in the illustrated embodiments,
the ablation device 18 of FIG. 1 is a ablation assembly 50 that
includes a sheath 52 having a lumen 54, a shaft 56 having a
proximal end 58 and a distal end 60, and a plurality of electrode
tines (or wires) 62 secured to the distal end 60 of the shaft 56.
The proximal end 58 of the shaft 56 may include a connector (not
shown) for coupling to the generator 12. Alternatively, the
ablation assembly 50 may itself include a cable (not shown) on the
proximal end 58 of the shaft 56, and a connector may be provided on
the proximal end of the cable (not shown).
[0021] In the illustrated embodiments, the sheath 52 has a length
between about forty and one hundred and thirty centimeters (40-130
cm), and more preferably, between sixty and eighty (60-80 cm).
Also, the sheath 52 has an outer diameter or cross sectional
dimension between about one and five millimeters (1-5 mm), and more
preferably, between two and four millimeters (2-4 mm). In one
implementation, the sheath 52 is configured (e.g., sized and
shaped) such that it can be inserted within a vessel (e.g., a
jugular vein), and that a body of the cannula 52 can extend between
a proximal end 72 located outside a patient's body and a distal end
70 located at or adjacent a target region, e.g., a liver, when the
sheath 52 is inserted into a jugular vein. In other embodiments,
the sheath 52 may also have other lengths and outer cross sectional
dimensions, depending upon the application. The sheath 52 may be
formed from a polymer, and the like, as long as it is sufficiently
flexible for allowing the sheath 52 to be steered through a vessel.
The sheath 52 may be electrically active or inactive, depending
upon the manner in which electrical energy is to be applied. The
sheath 52 coaxially surrounds the shaft 56 such that the shaft 56
may be advanced axially from or retracted axially into the lumen 54
of the sheath 52. The shaft 56 can be made from any of a variety of
elastic materials, such as a polymer, or a metal, as long as it is
sufficiently elastic to be steered through a vessel. For example,
the shaft 56 can be a Nitinol tube having a plurality of openings
for providing a desired flexibility for the tube, which is
available at Boston Scientific Corporation, the Precision Vascular
Division. In other cases, instead of being a tube, the shaft 56 can
have a solid cross-section. Optionally, a handle 64 may be provided
on the proximal end 58 of the shaft 56 to facilitate manipulating
the shaft 56. The electrode tines 62 is compressed into a low
profile when disposed within the lumen 54 of the sheath 52, as
shown in FIG. 2. As shown in FIG. 3, the proximal end 58 of the
shaft 56 or the handle 64 (if one is provided) can be advanced to
deploy the wires 62 from the lumen 54 of the sheath 52. When the
electrode tines 62 are unconfined outside the lumen 54 of the
sheath 52, they assume a relaxed expanded configuration. FIG. 3
shows an exemplary two-wire array including electrode tines 62
biased towards a generally "U" shape and substantially uniformly
separated from one another about a longitudinal axis of the shaft
56. Alternatively, each electrode tine 62 may have other shapes,
such as a "J" shape, a flare shape, a bent shape, a parabolic
shape, and/or the array may have one electrode tine 62 or more than
two electrode tines 62. The array may also have non-uniform spacing
to produce an asymmetrical lesion. In some embodiments, the
electrode tines 62 are formed from spring wire, superelastic
material, or other material, such as Nitinol, that may retain a
shape memory. During use of the ablation assembly 50, the electrode
tines 62 are deployed into a target tissue region to deliver energy
to the tissue to create a lesion. Ablation devices having a
spreading array of electrode tines have been described in U.S. Pat.
No. 5,855,576, the disclosure of which is expressly incorporated by
reference herein.
[0022] Optionally, a marker (not shown) may be placed on the handle
64 and/or on the proximal end 58 of the shaft 56 for indicating a
rotational orientation of the shaft 56 during use. In other
embodiments, the ablation assembly 50 may also carry one or more
radio-opaque markers (not shown) to assist positioning the ablation
assembly 50 during a procedure, as is known in the art. For
example, in some embodiments, the ablation assembly 50 may further
include a radio opaque marker located at a distal end 70 of the
sheath 52 or the shaft 56. Alternatively or additionally, one or
more of the electrode tines 62 may each carry a radio opaque
element (e.g., a marker). Optionally, the ablation assembly 50 may
also include a sensor, e.g., a temperature sensor and/or an
impedance sensor (not shown), carried by the distal end of the
shaft 56 and/or one or more of the electrode tines 62. In such
cases, the energy source 12 may be configured to control an amount
of energy delivered to the electrode tines 62 based at least in
part on a signal provided by the sensor.
[0023] In the illustrated embodiments, the ablation assembly 50
further include a steering mechanism 80 secured to the proximal end
72 of the sheath 52 for steering a distal end 70 of the sheath 52.
The steering mechanism 80 includes a rotatable cam and one or more
steering wires (not shown) connected between the cam and the distal
end 70 of the sheath 52. During use, the cam can be rotated to
apply tension to a steering wire, thereby causing the distal end 70
of the sheath 52 to bend. Further details regarding the steering
mechanism 80 are described in U.S. Pat. No. 5,273,535, the entire
disclosure of which is herein incorporated by reference. Steering
devices that can be used with the ablation assembly 50 have also
been described in U.S. Pat. Nos. 5,254,088, 5,336,182, 5,358,478,
5,364,351, 5,395,327, 5,456,664, 5,531,686, 6,033,378, and
6,485,455, the entire disclosures of which are expressly
incorporated by reference herein.
[0024] In other embodiments, the ablation assembly 50 does not
include the steering mechanism 80. In such cases, a separate
introducer sheath or introducer catheter may be used to gain access
through a vessel. The introducer sheath may have a pre-bent distal
end for assisting steering through a vessel. Alternatively, the
introducer sheath may be steered using a guidewire in a
conventional manner, or may include a steering mechanism, such as
the steering mechanism 80 discussed previously, for steering its
distal end. In some embodiments, the introducer sheath/catheter can
have a sharp distal tip for piercing tissue.
[0025] In other embodiments, the ablation assembly 50 can include a
guidewire (not shown) to assist placement of the distal end 70 of
the sheath 52 in a conventional manner. The guidewire may be
located within the lumen 54 of the sheath 52, or alternatively,
located within another lumen (not shown) in the sheath 52 that is
parallel to the lumen 54.
[0026] It should be noted that the ablation device 18 is not
necessarily limited to the ablation assembly 50 shown in FIGS. 2
and 3, and that the ablation device 18 may be selected from a
variety of devices that are capable of delivering ablation or
therapeutic energy. For example, medical devices may also be used
that are configured for delivering ultrasound energy, microwave
energy, and/or other forms of energy for the purpose of ablation,
which are well known in the art. In the illustrated embodiments,
the ablation assembly 50 also includes an electrode 90 secured to
the sheath 52. A wire (not shown) may be disposed within the wall
of the sheath 52 to electrically couple the electrode 90 to the
generator 12 during use. The electrode 90 and the array of
electrodes 62 are connected to opposite terminals of the generator
12 for delivering energy to target tissue in a bipolar mode. In
other embodiments, the ablation assembly 50 does not include the
electrode 90 (FIG. 4). In such cases, the system 10 further
includes an electrode pad 92 electrically coupled to the generator
12. The electrode pad 92 functions as a return electrode, and
operates in conjunction with the ablation assembly 50 to deliver
energy to target tissue in a monopolar mode.
[0027] Referring now to FIGS. 5A-5D, the ablation system 10 may be
used to treat at least a portion, e.g., a target tissue TS, within
a treatment region TR within tissue T located beneath skin or an
organ surface S of a patient. First, if an introducer
sheath/catheter 100 is provided, the introducer sheath 100 can be
inserted through a patient's skin and into a vessel V. The
introducer sheath 100 is then steered through the vessel V in a
conventional manner (e.g., using a guidewire or a steering
mechanism) until its distal end 102 is at or adjacent to the
treatment region TR. As shown in FIG. 5A, the sharp distal tip of
the introducer sheath 100 can then be used to puncture the vessel V
to gain access to the treatment region TR. Next, the ablation
assembly 50 is inserted into the introducer sheath 100, and is
advanced until the distal end 70 of the sheath 52 of the ablation
assembly 50 reaches the treatment region TR (FIG. 5B). In other
embodiments, instead of using an introducer sheath/catheter 100, if
the ablation assembly 50 includes the steering mechanism 80, the
ablation assembly 50 can be inserted through a patient's skin and
into the vessel V, and be steered to a desired location at or
adjacent to the target region TR. In one implementation, a
transjugular approach may be used, in which the distal end 70 is
inserted through a jugular vein in the patient's neck. After the
distal end 70 of the sheath 52 has been inserted through the
patient's skin, the distal end 70 is then steered to the tissue T,
such as a liver tissue, through the vessel V. The sheath 52 may be
steered by using the guidewire in a conventional manner, or by
applying tension to steering wire(s) (if the steering mechanism 80
is provided). If the sheath 52 has a sharp distal tip, it can be
used to puncture the vessel V to allow the distal end 70 of the
sheath 52 to gain access to the target region TR. In other
embodiments, a separate puncturing device, such as a wire or a
needle, can be inserted through the sheath 52 to puncture the
vessel V.
[0028] Turning to FIG. 5C, after the sheath 52 is properly placed,
the shaft 56 of the ablation assembly 50 is then advanced distally,
thereby deploying the array of electrode tines 62 from the distal
end 70 of the sheath 52 into the target tissue TS at the target
region TR. As illustrated, delivering the electrode tines 62 via
the vessel V that leads to the target region TR is advantageous in
that, if any bleeding occurs at the target region TR, it will do so
back into the vessel V. In the illustrated embodiments, the
electrode tines 62 are deployed such the electrode tines 62 are
located in close proximity (e.g., within 0.1 millimeter (mm) to 10
mm) to the vessel V. In such arrangement, the distal ends of the
electrode tines 62 are positioned among or around sub-branches (not
shown) of the vessel V, thereby allowing ablation energy to be
effectively delivered to the target tissue TS while minimizing, or
at least reducing, the effect of the heat sink due to blood
delivered to or from the target region TR. As shown in the figure,
the distal ends 63 of the deployed electrode tines 62 are distal to
the distal end of the vessel V. Alternatively, the distal ends 63
of the deployed electrode tines 62 may be proximal to the distal
end of the vessel V such that the deployed electrode tines 62 at
least partially circumscribe a portion of the vessel V. Preferably,
the electrode tines 62 are biased to curve radially outwardly as
they are deployed from the sheath 52. The shaft 56 of the ablation
device 18 may be advanced sufficiently such that the electrode
tines 62 fully deploy to circumscribe substantially tissue within
the target tissue TS of treatment region TR, as shown in FIG. 5D.
Alternatively, the electrode tines 62 may be only partially
deployed or deployed incrementally in stages during a
procedure.
[0029] Next, energy, preferably RF electrical energy, may be
delivered from the generator 12 to the wires 62 of the ablation
device 18, thereby substantially creating a lesion at the target
tissue TS of the treatment region TR. If the system of FIG. 1 is
used, the electrode 90 and the electrodes 62 will operate to
deliver ablation energy in a bipolar mode. In such cases, ablation
energy will flow between the electrode 90 and the array of
electrodes 62. Alternatively, if the system of FIG. 4 is used, the
electrode pad 92 may be coupled to the opposite terminal (not
shown) of the generator 12, and is placed on the patient's skin in
a conventional manner. In such cases, ablation energy will flow
between the electrode pad 92 and the electrodes 62, thereby
delivering ablation energy in a monopolar manner. As shown in the
figure, the deployed electrodes 62 have distal ends 63 that point
at least partially towards a proximal end (e.g., a component of the
vector representing the direction in which the distal ends 63 point
is towards a proximal end--e.g., towards the vessel V). Such
configuration allows the ablation energy to be effectively
delivered to the target tissue TS while minimizing, or at least
reducing, the heat sink effect resulted from blood flowing to or
from the vessel V.
[0030] When a desired lesion at the target tissue TS of the
treatment region TR has been created, the electrode tines 62 of the
ablation device 18 may be retracted into the lumen 54 of the sheath
52, and the ablation device 18 may be removed from the treatment
region TR. In some cases, the entire treatment region TR may be
ablated in a single pass. In other cases, if it is desired to
perform further ablation to increase the lesion size or to create
lesions at different site(s), e.g., at other target tissue TS,
within the treatment region TR or elsewhere, the electrode tines 62
of the ablation device 18 may be introduced and deployed at
different target site(s), and the same steps discussed previously
may be repeated.
[0031] Although particular embodiments have been shown and
described, it will be understood that it is not intended to limit
the present inventions to the preferred embodiments, and it will be
obvious to those skilled in the art that various changes and
modifications may be made without departing from the spirit and
scope of the present inventions. For example, the electrode tines
62 may be a single electrode made from a plurality of conductive
components, or a plurality of electrodes. As such, the term, "a
plurality of electrodes" should not be limited to more than one
electrode, and may include a single electrode having a plurality of
conductive components/parts. The specification and drawings are,
accordingly, to be regarded in an illustrative rather than
restrictive sense. The present inventions are intended to cover
alternatives, modifications, and equivalents, which may be included
within the spirit and scope of the present inventions as defined by
the claims.
* * * * *