U.S. patent application number 10/667533 was filed with the patent office on 2004-03-25 for ablation system.
Invention is credited to Fry, Francis J., Phillips, Michael H., Sanghvi, Narendra T..
Application Number | 20040059266 10/667533 |
Document ID | / |
Family ID | 30447849 |
Filed Date | 2004-03-25 |
United States Patent
Application |
20040059266 |
Kind Code |
A1 |
Fry, Francis J. ; et
al. |
March 25, 2004 |
Ablation system
Abstract
An apparatus for ablating tissue within a treatment region
includes an ultrasound treatment transducer (36, 36') for orienting
at a first longitudinal orientation and a first angular orientation
(40, 42) within the treatment region (26), for orienting at the
first longitudinal orientation and a second angular orientation
(40, 42) within the treatment region, and for orienting at a second
longitudinal orientation and the first angular orientation (40, 42)
within the treatment region, and a drive system for exciting (via
conductors 46) the transducer (36, 36') to ablate tissue (60)
oriented adjacent the first longitudinal orientation and the first
angular orientation within the treatment region (26), adjacent the
first longitudinal orientation and the second angular orientation
within the treatment region (26), and adjacent the second
longitudinal orientation and the first angular orientation within
the treatment region (26), respectively.
Inventors: |
Fry, Francis J.; (Port
Charlotte, FL) ; Phillips, Michael H.; (Indianapolis,
IN) ; Sanghvi, Narendra T.; (Indianapolis,
IN) |
Correspondence
Address: |
BARNES & THORNBURG
11 SOUTH MERIDIAN
INDIANAPOLIS
IN
46204
|
Family ID: |
30447849 |
Appl. No.: |
10/667533 |
Filed: |
September 22, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10667533 |
Sep 22, 2003 |
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09647317 |
Sep 28, 2000 |
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6685640 |
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09647317 |
Sep 28, 2000 |
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PCT/US99/06974 |
Mar 30, 1999 |
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60079945 |
Mar 30, 1998 |
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Current U.S.
Class: |
601/2 |
Current CPC
Class: |
A61B 2090/378 20160201;
A61B 2017/00274 20130101; A61B 2018/00547 20130101; A61N 7/022
20130101; A61N 2007/0078 20130101 |
Class at
Publication: |
601/002 |
International
Class: |
A61H 001/00 |
Claims
1. A method of treating tissue comprising orienting an ultrasound
transducer at a first longitudinal orientation and a first angular
orientation adjacent the treatment region, exciting the transducer
to ablate tissue adjacent the first longitudinal orientation and
the first angular orientation within the treatment region,
orienting the transducer at a second longitudinal orientation and
the first angular orientation adjacent the treatment region,
exciting the transducer to ablate tissue adjacent the second
longitudinal orientation and the first angular orientation within
the treatment region, orienting the transducer at the first
longitudinal orientation and a second angular orientation adjacent
the treatment region, and exciting the transducer to ablate tissue
adjacent the first longitudinal orientation and the second angular
orientation within the treatment region.
2. A method of treating tissue comprising orienting an ultrasound
transducer at a first longitudinal orientation and a first angular
orientation adjacent the treatment region, exciting the transducer
to ablate tissue adjacent the first longitudinal orientation and
the first angular orientation within the treatment region,
orienting the transducer at a second longitudinal orientation and a
second angular orientation adjacent the treatment region, and
exciting the transducer to ablate tissue adjacent the second
longitudinal orientation and the second angular orientation within
the treatment region.
3. The method of claim 1 or 2 wherein orienting the transducer at a
first longitudinal orientation and a first angular orientation
includes positioning a catheter including a lumen adjacent the
treatment region, substantially maintaining the position of the
catheter adjacent the treatment region, and passing the transducer
into the lumen so that the transducer is oriented adjacent the
treatment region.
4. The method of claim 3 further includinging providing an
indicator for indicating the longitudinal and angular orientation
of the transducer.
5. The method of claim 1 or 2 further including providing an
indicator for indicating the longitudinal and angular orientation
of the transducer.
6. The method of claim 5 further including providing a drive system
for driving the transducer, providing the transducer and providing
the drive system including providing an ultrasound transducer and
drive system having a variable focal length.
7. The method of claim 4 further including providing a drive system
for driving the transducer, providing the transducer and providing
the drive system including providing a transducer and drive system
having a variable focal length.
8. The method of claim 3 further including providing a drive system
for driving the transducer, providing the transducer and providing
the drive system including providing a transducer and drive system
having a variable focal length.
9. The method of claim 1 or 2 further including providing a drive
system for driving the transducer, providing the transducer and
providing the drive system including providing a transducer and
drive system having a variable focal length.
10. The method of claim 3 wherein positioning a catheter adjacent
the treatment region includes positioning a catheter including a
balloon region adjacent the treatment region and filling the
balloon region to maintain substantially the position of the
catheter.
11. The method of claim 4 wherein positioning a catheter adjacent
the treatment region includes positioning a catheter including a
balloon region adjacent the treatment region and filling the
balloon region to maintain substantially the position of the
catheter.
12. The method of claim 7 wherein positioning a catheter adjacent
the treatment region includes positioning a catheter including a
balloon region adjacent the treatment region and filling the
balloon region to maintain substantially the position of the
catheter.
13. The method of claim 8 wherein positioning a catheter adjacent
the treatment region includes positioning a catheter including a
balloon region adjacent the treatment region and filling the
balloon region to maintain substantially the position of the
catheter.
14. Apparatus for treating tissue including an ultrasound
transducer for orienting at a first longitudinal orientation and a
first angular orientation adjacent the treatment region, at a
second longitudinal orientation and the first angular orientation
adjacent the treatment region, and at the first longitudinal
orientation and a second angular orientation adjacent the treatment
region, and a drive system for exciting the transducer to ablate
tissue oriented adjacent the first longitudinal orientation and the
first angular orientation within the treatment region, adjacent the
second longitudinal orientation and the first angular orientation
within the treatment region, and adjacent the first longitudinal
orientation and the second angular orientation within the treatment
region, respectively.
15. Apparatus for treating tissue including an ultrasound
transducer for orienting at a first longitudinal orientation and a
first angular orientation adjacent the treatment region, and at a
second longitudinal orientation and a second angular orientation
adjacent the treatment region, and a drive system for exciting the
transducer to ablate tissue oriented adjacent the first
longitudinal orientation and the first angular orientation within
the treatment region, and adjacent the second longitudinal
orientation and the second angular orientation within the treatment
region, respectively.
16. The apparatus of claim 14 or 15 further including a catheter
including a lumen for positioning adjacent the treatment region,
the lumen permitting passage of the transducer into the lumen so
that the transducer can be oriented adjacent the treatment
region.
17. The apparatus of claim 16 further including an indicator for
indicating the longitudinal and angular orientation of the
transducer adjacent the treatment region.
18. The apparatus of claim 14 or 15 further including an indicator
for indicating the longitudinal and angular orientation of the
transducer adjacent the treatment region.
19. The apparatus of claim 18 wherein the transducer and the drive
system together include a transducer and drive system having a
variable focal length.
20. The apparatus of claim 17 wherein the transducer and the drive
system together include a transducer and drive system having a
variable focal length.
21. The apparatus of claim 16 wherein the transducer and the drive
system together include a transducer and drive system having a
variable focal length.
22. The apparatus of claim 14 or 15 wherein the transducer and the
drive system together include a transducer and drive system having
a variable focal length.
23. The apparatus of claim 16 wherein the catheter includes a
balloon region adjacent the treatment region, filling the balloon
region maintaining substantially the position of the catheter.
24. The apparatus of claim 17 wherein the catheter includes a
balloon region adjacent the treatment region, filling the balloon
region maintaining substantially the position of the catheter.
25. The apparatus of claim 20 wherein the catheter includes a
balloon region adjacent the treatment region, filling the balloon
region maintaining substantially the position of the catheter.
26. The apparatus of claim 21 wherein the catheter includes a
balloon region adjacent the treatment region, filling the balloon
region maintaining substantially the position of the catheter.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to techniques and apparatus for
achieving ablation of tissue through the use of focussed
ultrasound. It is disclosed in the context of a system and method
for the ablation of prostate tissue in the treatment of, for
example, benign prostate hyperplasia (BPH), but is believed to be
applicable to the treatment of other conditions as well.
[0002] The use of transrectally applied high intensity focussed
ultrasound in the treatment of diseases of the prostate is well
documented. There are, for example, the disclosures of U.S. Pat.
Nos. 5,117,832 and 5,676,692 and Fry, F. J. et al, "Ultrasound and
Microbubbles: Their Generation, Detection and Potential Utilization
in Tissue and Organ Therapy--Experimental," Ultrasound in Med. and
Biol., vol. 21, no. 9, pp. 1227-1237, 1995 and Sanghvi, N. T., et
al, "Noninvasive Surgery of Prostate Tissue by High-Intensity
Focused Ultrasound," EEE Transactions on Ultrasonics,
Ferroelectrics, and Frequency Control, vol. 43, no. 6, pp.
1099-1110, Nov., 1996. U.S. Pat. Nos. 5,409,006 and 5,443,069 also
disclose the application of ultrasound for the treatment of BPH.
Several references disclose the treatment of BPH by electromagnetic
radiation, for example, microwaves, applied transrectally,
transurethrally or otherwise. Illustrative of these references are
U.S. Pat. Nos. 5,330,518 and 5,480,417. Other ultrasound
applications for the treatment of disease are illustrated in, for
example, U.S. Pat. Nos. 5,247,935; 5,219,401; 5,215,680; 5,149,319;
5,054,470; 5,036,855; 4,955,365; 4,951,653; 4,858,613; 4,658,828;
4,586,512; and, 4,620,546. The disclosures of these references are
incorporated herein by reference.
[0003] Although the prostate can effectively be treated
transrectally, urologists are trained in the transurethral
treatment of the prostate. As a result, there has been some
resistance to transrectal treatment of the prostate. The present
invention is disclosed in the context of transurethral treatment of
the prostate.
DISCLOSURE OF THE INVENTION
[0004] According to one aspect of the invention, a method for
treating tissue includes orienting an ultrasound transducer at a
first longitudinal orientation and a first angular orientation
adjacent a treatment region, exciting the transducer to ablate
tissue adjacent the first longitudinal orientation and the first
angular orientation within the treatment region, orienting the
transducer at the first longitudinal orientation and a second
angular orientation adjacent the treatment region, exciting the
transducer to ablate tissue adjacent the first longitudinal
orientation and the second angular orientation within the treatment
region, orienting the transducer at a second longitudinal
orientation and the first angular orientation adjacent the
treatment region, and exciting the transducer to ablate tissue
adjacent the second longitudinal orientation and the first angular
orientation within the treatment region.
[0005] According to another aspect of the invention, a method of
treating tissue comprises orienting an ultrasound transducer at a
first longitudinal orientation and a first angular orientation
adjacent the treatment region, exciting the transducer to ablate
tissue adjacent the first longitudinal orientation and the first
angular orientation within the treatment region, orienting the
transducer at a second longitudinal orientation and a second
angular orientation adjacent the treatment region, and exciting the
transducer to ablate tissue adjacent the second longitudinal
orientation and the second angular orientation within the treatment
region.
[0006] Illustratively according to these aspects of the invention,
orienting the transducer at a first longitudinal orientation and a
first angular orientation includes positioning a catheter including
a lumen adjacent the treatment region, maintaining substantially
the position of the catheter adjacent the treatment region, and
passing the transducer into the lumen so that the transducer is
oriented adjacent the treatment region.
[0007] Further illustratively according to these aspects of the
invention, the method includes providing an indicator for
indicating the longitudinal and angular orientation of the
transducer.
[0008] Further illustratively according to these aspects of the
invention, the method includes providing a drive system for driving
the transducer, providing the transducer and providing the drive
system together including providing an ultrasound transducer and
drive system having a variable focal length.
[0009] Additionally illustratively according to these aspects of
the invention, positioning a catheter adjacent the treatment region
includes positioning a catheter including a balloon region adjacent
the treatment region and filling the balloon region to maintain
substantially the position of the catheter adjacent the treatment
region.
[0010] According to another aspect of the invention, an apparatus
for treating tissue includes an ultrasound transducer for orienting
at a first longitudinal orientation and a first angular orientation
adjacent a treatment region, for orienting at the first
longitudinal orientation and a second angular orientation adjacent
the treatment region, and for orienting at a second longitudinal
orientation and the first angular orientation adjacent the
treatment region, and a drive system for exciting the transducer to
ablate tissue adjacent the first longitudinal orientation and the
first angular orientation within the treatment region, adjacent the
first longitudinal orientation and the second angular orientation
within the treatment region, and adjacent the second longitudinal
orientation and the first angular orientation within the treatment
region, respectively.
[0011] According to another aspect of the invention, an apparatus
for treating tissue includes an ultrasound transducer for orienting
at a first longitudinal orientation and a first angular orientation
adjacent a treatment region, and for orienting at a second
longitudinal orientation and a second angular orientation adjacent
the treatment region, and a drive system for exciting the
transducer to ablate tissue adjacent the first longitudinal
orientation and the first angular orientation within the treatment
region, and adjacent the second longitudinal orientation and the
second angular orientation within the treatment region.
[0012] Illustratively according to these aspects of the invention,
the apparatus further includes a catheter including a lumen for
positioning adjacent the treatment region, the lumen permitting
passage of the transducer into the lumen so that the transducer can
be oriented adjacent the treatment region.
[0013] Further illustratively according to these aspects of the
invention, the apparatus includes an indicator for indicating the
longitudinal and angular orientation of the transducer.
[0014] Additionally illustratively according to these aspects of
the invention, the transducer and the drive system together include
a transducer and drive system having a variable focal length.
[0015] Illustratively according to these aspects of the invention,
the catheter includes a balloon region adjacent the treatment
region, filling the balloon region maintaining substantially the
position of the catheter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention may best be understood by referring to the
following detailed description of an illustrative embodiment of the
invention and the accompanying drawings. In the drawings:
[0017] FIG. 1 illustrates a fragmentary sectional side elevational
view of an apparatus constructed according to the invention in
place in the urethra and bladder of a patient being treated for
BPH;
[0018] FIG. 2 illustrates a fragmentary perspective view taken
generally along section lines 2-2 of FIG. 1;
[0019] FIG. 3 illustrates a transducer useful in performing methods
according to the invention;
[0020] FIG. 4 illustrates another treatment method which will
produce a treatment lesion similar to the one illustrated in FIG.
2; and,
[0021] FIG. 5 illustrates a fragmentary sectional side elevational
view of another apparatus constructed according to the
invention.
DETAILED DESCRIPTIONS OF ILLUSTRATIVE EMBODIMENTS
[0022] FIG. 1 illustrates the lower portion of the bladder 20,
bladder neck 22 and the upper portion of the urethra 24 of a
patient suffering from BPH. The prostate 26 which surrounds the
upper portion of the urethra directly beneath the bladder 20 and
around the bladder neck 22 becomes enlarged. The symptoms of the
disease are well known and discomforting. They generally result
from the obstruction of the urethra by the enlarged prostate
tissue. If not treated effectively, the disease can become
complicated with devastating effect. The classical surgical
treatment is resection of some portion of the prostate
transurethrally. While this method of treatment is frequently
effective in the treatment of BPH, it is sometimes contraindicated
by, for example, the patient's condition, reluctance of the patient
based upon potential side effects, and so on.
[0023] According to the invention, a transurethral catheter 30
having a balloon end region 32 to aid in positioning the catheter
30 relative to the prostate 26 includes a lumen 34 in which is
oriented a small ultrasound transducer 36 mounted on a support 38,
such as a stiff wire. Support 38 permits manipulation of the
transducer 36 into the orientations necessary and/or desirable to
treat the prostate 36 in the manner which will be outlined
hereinafter. At the same time however, some mechanism must be
provided for satisfying the treating physician that the transducer
36 is properly oriented in the urethra 24 and prostate 26 prior to
a given step in the treatment. This may mean providing some sort of
index or indicator 40 on the support 38 or on the transducer 36
which may be used in conjunction with some sort of visualization
scheme, such as, for example, a transrectal ultrasound
visualization system, and/or making the support 38 sufficiently
torque-resistant and providing an indicator 42 on the outer end 44
of catheter 30 so that the treating physician can determine the
orientation of the transducer 36. Transducer 36 itself may be
excited in a visualization mode in accordance with known techniques
to aid in the process of orienting transducer 36 appropriately for
the high intensity focussed ultrasound treatment that is to
follow.
[0024] In any event, once the treating physician is satisfied of
the positioning of the transducer 36, the transducer 36 is excited
through appropriate electrical conductors 46 which extend through
the lumen 34 from an ultrasound frequency generator 48. Relatively
high energy density ultrasound, high enough that, once focussed by
the transducer 36, it can either cause cavitation-induced injury
and, ultimately, necrosis or elevate the temperature of the tissue
sufficiently high, for example, 43.degree. C., for a sufficient
time-to cause necrosis, is transmitted by the transducer 36 into
the tissue of the prostate 26, setting in motion the mechanisms of
necrosis in the region of the transducer 36's focal point 52 and in
the near field between the transducer 36 and the focal region in
prostate 26. After necrosis begins, the necrotized tissue is
resorbed into the body, relieving the symptoms of BPH experienced
by the patient. The generator 48 must be capable of exciting the
transducer 36 in the treatment mode with energies high enough to
induce hyperthermia at the focal region when the transducer 36 is
operated in the treatment mode. Energies in the range of hundreds
of volts peak for times in the range of milliseconds ordinarily
will achieve cavitation-induced necrosis in the focal zone. In the
near field between the transducer 36 and the focal zone, lower
exciting energies for longer periods of time, in the range of, for
example, four to twenty seconds or so, provide hyperthermia-induced
necrosis. Thus, different ultrasound-related phenomena can be
employed by the treating physician to achieve tissue necrosis.
Resorption will typically follow in due course.
[0025] Using a transducer 36 which has a relatively short focal
length increases the likelihood that all of the treated tissue can
be constrained to the prostate. A transducer 36' (FIG. 3) with a
variable focal depth, such as one of the general type illustrated
in U.S. Pat. No. 4,586,512, and supplied with ultrasound exciting
signals related to each other as outlined in that patent, can be
used to advantage to vary the focus of such a transducer 36' in
such a treatment scheme. For example, the proper focal depth to
treat any given depth of the prostate from the transducer's
location in the urethra can be selected and the transducer 36'
excited accordingly. Alternatively, or perhaps additionally, an
appropriate frequency of excitation to provide the desired depth of
ultrasound penetration and tissue treatment can be selected for any
given treatment depth. The treatment time can be established in
accordance with known principles and guidelines. Guidelines can
also be established for target, or desired, treatment lesion size
and shape. One example of the flexibility of this method in the
treatment of BPH can be appreciated by referring to FIG. 2.
[0026] In FIG. 2, the diseased prostate 26 is illustrated in
perspective, and is sectioned at about the level at which the
transducer 36 resides in the urethra 24. After treatment of the
prostate 26 with the transducer 36 oriented at a specific angle of,
for example, 0.degree., corresponding to vertically upward in FIG.
2, a radially extending, or ray, lesion 60-1 is formed. The tissue
in this lesion begins to necrose. The transducer support 38 is
manipulated to turn transducer 36 so that its focal point now lies
on a ray or radius extending at an angle of, for example, 5.degree.
clockwise from vertical in FIG. 2. Another treatment step just like
the first is conducted, resulting in a second ray lesion 60-2. The
tissue in this lesion begins to necrose. This process continues
until a somewhat star- or bicycle wheel spokes-shaped composite
lesion 60 is formed. The support is then manipulated to move the
transducer's focal point into a plane adjacent, but spaced slightly
from, the plane of lesion 60. The entire process is repeated,
forming an adjacent and desirably overlapping star- or bicycle
wheel spokes-shaped lesion 62. The treating physician proceeds
along the urethra in this manner, forming a number of adjacent and
desirably overlapping lesions 60, 62, 64, 66, . . . . Necrosis of
BPH tissue adjacent the urethra 24 results, eventually relieving
the patient's symptoms.
[0027] Of course, the treating physician can also proceed along the
length of the urethra 24 in the treatment zone first, and then
reorient the transducer 36 angularly and move the transducer 36
along a path adjacent to the path followed during formation of the
first lesion, repeating this process until a desired number of
adjacent spoke-like lesions extending along the length of the
desired treatment zone are formed. Such a path is illustrated in
FIG. 4. Other procedures can also be followed to produce a
composite lesion such as the one illustrated in FIG. 2, or any
other desired configuration of lesion.
[0028] The transducer 36 can be a composite type, as illustrated by
transducer 36' in FIG. 3. Other multi-element transducer types,
such as two or more single element transducers side by side in
lumen 34, can be employed with one element operated in a
visualization mode and one in a treatment mode. One such composite
transducer is illustrated in FIG. 5. This composite transducer puts
a treatment transducer 64 and a visualization transducer 66 side by
side in the lumen 68 of a catheter 70. Additionally, this composite
transducer adds another treatment transducer 72 which can be
excited separately from treatment transducer 64 and/or
visualization transducer 66. While the treatment transducers 36, 64
will effectively treat the main lobes of the prostate 74, a median
lobe 76 of the prostate 74 of a BPH sufferer can grow inside the
bladder neck 78. This median lobe can be difficult to treat using
transducers oriented as transducers 36, 64 are. The transducer 72
oriented to face toward the remote end 74 of catheter 70 and at an
angle .alpha., 0.degree.<.alpha.<90.degree. to the
longitudinal extent of catheter 70, permits treatment of the median
lobe 76 of the prostate 74 to relieve the symptoms of BPH caused by
enlargement of the median lobe 76 into the bladder neck 78.
* * * * *