U.S. patent number 5,800,378 [Application Number 08/618,583] was granted by the patent office on 1998-09-01 for medical probe device and method.
This patent grant is currently assigned to Vidamed, Inc.. Invention is credited to Stuart D. Edwards, Ronald G. Lax, Ingemar H. Lundquist, Hugh R. Sharkey.
United States Patent |
5,800,378 |
Edwards , et al. |
September 1, 1998 |
Medical probe device and method
Abstract
A medical probe device comprises a catheter having a stylet
guide housing with one or more stylet ports in a side wall thereof
and a stylet guide for directing a flexible stylet outward through
the stylet port and through intervening tissue at a preselected,
adjustable angle to a target tissue. The total catheter assembly
includes a stylet guide lumen communicating with the stylet port
and a stylet positioned in said stylet guide lumen for longitudinal
movement from the port through intervening tissue to a target
tissue. The stylet can be an electrical conductor enclosed within a
non-conductive layer, the electrical conductor being a
radiofrequency electrode. Preferably, the non-conductive layer is a
sleeve which is axially moveable on the electrical conductor to
expose a selected portion of the electrical conductor surface in
the target tissue. The stylet can also be a microwave antenna. The
stylet can also be a hollow tube for delivering treatment fluid to
the target tissue. It can also include a fiber optic cable for
laser treatment. The catheter can include one or more inflatable
balloons located adjacent to the stylet port for anchoring the
catheter or dilation. Ultrasound transponders and temperature
sensors can be attached to the probe end and/or stylet. The stylet
guide can define a stylet path from an axial orientation in the
catheter through a curved portion to a lateral orientation at the
stylet port.
Inventors: |
Edwards; Stuart D. (Los Altos,
CA), Lax; Ronald G. (Grass Valley, CA), Lundquist;
Ingemar H. (Pebble Beach, CA), Sharkey; Hugh R. (Redwood
City, CA) |
Assignee: |
Vidamed, Inc. (Fremont,
CA)
|
Family
ID: |
25458203 |
Appl.
No.: |
08/618,583 |
Filed: |
March 20, 1996 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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313715 |
Sep 27, 1994 |
5531676 |
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12370 |
Feb 2, 1993 |
5370675 |
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929638 |
Aug 12, 1992 |
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Current U.S.
Class: |
604/22; 606/45;
607/99; 607/115; 604/21; 606/39 |
Current CPC
Class: |
A61N
1/40 (20130101); A61N 1/403 (20130101); A61B
18/1485 (20130101); A61N 5/045 (20130101); A61B
18/18 (20130101); A61B 18/1477 (20130101); A61B
18/1815 (20130101); A61B 18/00 (20130101); A61N
5/02 (20130101); A61N 1/06 (20130101); A61B
10/02 (20130101); A61B 2018/00196 (20130101); A61B
2018/00678 (20130101); A61B 2018/00982 (20130101); A61B
10/0241 (20130101); A61B 2018/128 (20130101); A61B
2018/1861 (20130101); A61B 2018/00744 (20130101); A61B
2018/00886 (20130101); A61B 18/1206 (20130101); A61B
2017/2939 (20130101); A61B 2018/00011 (20130101); A61B
2018/00761 (20130101); A61B 2018/00797 (20130101); A61B
2018/00791 (20130101); A61B 2018/0091 (20130101); A61B
2017/3488 (20130101); A61B 2018/00702 (20130101); A61B
18/148 (20130101); A61B 2017/248 (20130101); A61B
2018/00547 (20130101); A61B 2018/00577 (20130101); A61M
25/008 (20130101); A61M 2025/0096 (20130101); A61B
2017/00292 (20130101); A61M 2025/0087 (20130101); A61N
5/04 (20130101); A61M 2025/0086 (20130101); A61B
2017/00106 (20130101); A61B 2018/126 (20130101); A61F
2007/0054 (20130101); A61M 25/0069 (20130101); A61M
2025/0089 (20130101); A61M 2025/018 (20130101); A61B
2018/00005 (20130101); A61B 2018/0022 (20130101); A61B
2018/1425 (20130101); A61B 2018/00726 (20130101); A61B
2090/3614 (20160201); A61B 2018/00095 (20130101); A61B
18/082 (20130101); A61B 2017/00084 (20130101); A61B
2017/00092 (20130101); A61B 2018/0075 (20130101); A61B
2090/3925 (20160201); A61M 25/0068 (20130101); A61B
2018/00083 (20130101); A61B 2018/00869 (20130101); A61B
2018/2238 (20130101); A61B 2090/0814 (20160201); A61B
2017/22077 (20130101); A61B 2017/22082 (20130101); A61B
2018/1273 (20130101); A61B 2018/1412 (20130101); A61B
2090/3782 (20160201); A61B 18/24 (20130101); A61B
2018/00821 (20130101); A61M 25/0082 (20130101); A61B
2017/00274 (20130101); A61B 2017/003 (20130101); A61B
2018/00916 (20130101); A61B 2017/00867 (20130101); A61B
2017/22072 (20130101); A61M 2025/009 (20130101); A61B
2018/1253 (20130101); A61B 2018/00946 (20130101) |
Current International
Class: |
A61N
5/02 (20060101); A61N 1/40 (20060101); A61B
18/18 (20060101); A61B 18/00 (20060101); A61B
18/14 (20060101); A61B 10/00 (20060101); A61N
1/06 (20060101); A61N 5/04 (20060101); A61B
17/22 (20060101); A61B 17/24 (20060101); A61B
17/28 (20060101); A61B 17/34 (20060101); A61B
18/20 (20060101); A61B 18/04 (20060101); A61B
18/08 (20060101); A61B 19/00 (20060101); A61B
18/22 (20060101); A61B 18/24 (20060101); A61M
25/00 (20060101); A61F 7/00 (20060101); A61M
3/00 (20060101); A61M 3/02 (20060101); A61M
1/00 (20060101); A61B 17/00 (20060101); A61B
017/20 () |
Field of
Search: |
;604/19-22,53,164,280
;606/32,33,39,41,45
;607/101,105,96,98,99,102,104,113,115,116,154,156 ;601/2 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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63-275632 |
|
1988 |
|
JP |
|
2121675 |
|
May 1990 |
|
JP |
|
92/10142 |
|
Jun 1992 |
|
WO |
|
93/25136 |
|
Jun 1992 |
|
WO |
|
Other References
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E.F. Nation, M.D., "Evolution of Knife-Punch Resectoscope," (Apr.
1976) Urology, vol. VII, No. 4, pp. 417-427. .
R. Gutierrez, "Transurethral Treatment of Bladder Neck
Obstructions: Endoscopic Prostatic Resection," (Apr. 1933) History
of Urology, vol. II, Chapter V, pp. 137-186. .
C.W. Ogden, Heat and the Prostate from Electrolysis to Microwaves:
Lessons from an Historical Perspective, (Undated) Abstract, 2
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Graversen, et al., "Transurethral incisions of the prostate under
local anaesthesia in high-risk patients; a pilot study," (1987)
Abstract, HealthGate Home Page, p. P000115. .
Miller, et al., "Integrated cystoscope: first rigid multipurpose
operating cystoscope for local anesthetic endoscopy," (1989)
Abstract, HealthGate Home Page, p. P000116. .
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cost-reducing idea," (1984) Abstract, HealthGate Home Page, p.
P000117. .
Orandi, "Transurethral resection versus transurethral incision of
the prostate," (1990) Abstract, HealthGate Home Page, p. P000118.
.
H. LeVeen, "Method for treating benign and malignant tumors
utilizing radio frequency," (Nov. 16, 1976) Abstract, USPTO.GOV,
U.S. Patent No. 3,991,770, pp. P000119-P000120. .
R. Auhll, "The Use of the Resectoscope in Gynecology," (Oct. 1990)
Biomedical Business International, pp. 91-99. .
L. Geddes, "A Short History of the Electrical Stimulation of
Excitable Tissue Including Electrotherapeutic Applications," (1984)
A Supplement to The Physiologist, vol. 27, No. 1, pp.
P000066-P000071. .
W. Moseley, M.D., "The History of Treatment of BPH Including
Current Treatment Alternatives," (Undated) pp. P000187-P000190.
.
D. Paulson, M.D., "Diseases of the Prostate," (1989) Clinical
Symposia, vol. 41, No. 2., pp. P000191-P000195. .
T. Kirwin, "The Treatment of Prostatic Hypertrophy by a New
`Shrinkage` Method," (Aug. 1934) J. Urology, pp. 481-494..
|
Primary Examiner: Bockelman; Mark
Assistant Examiner: Sadula; Jennifer R.
Attorney, Agent or Firm: Flehr Hohbach Test Albritton &
Herbert LLP
Parent Case Text
This application is a continuation of application Ser. No.
08/313,715 filed Sep. 27, 1994, now U.S. Pat. No. 5,531,676 which
is a continuation of application Ser. No. 08/012,370 filed Feb. 2,
1993, now U.S. Pat. No. 5,370,675, which is a continuation-in-part
of application Ser. No. 07/929,638 filed Aug. 12, 1992, abandoned
in favor of file wrapper continuation application Ser. No.
08/172,014 filed Dec. 22, 1993, now U.S. Pat. No. 5,366,490.
Claims
We claim:
1. A medical probe device for treating by radio frequency ablation
a target volume in tissue of a prostate of a body of a human male
having a bladder with a base with a urethra formed by a urethral
wall extending into the base of the bladder with the tissue of the
prostate surrounding the urethra near the base of the bladder
comprising an elongate probe member having proximal and distal
extremities and having a passageway extending from the proximal
extremity to the distal extremity along a longitudinal axis, the
elongate probe member having a length so that when the distal
extremity is disposed in the urethra in the vicinity of the
prostate the proximal extremity is outside of the urethra, handle
means coupled to the proximal extremity of the elongate probe
member for introducing the distal extremity of the elongate probe
member into the urethra, a stylet slidably mounted in the
passageway in the elongate probe member and having a distal
extremity, the distal extremity of the stylet being movable between
a retracted position in which the distal extremity of the stylet is
disposed within the passageway and an extended position disposed
outwardly from the distal extremity of the elongate probe member,
the stylet having a length so that the distal extremity of the
stylet extends through the urethral wall into the tissue of the
prostate when in the extended position, means including a radio
frequency generator coupled to the stylet for supplying radio
frequency energy to the stylet and a grounding plate in contact
with the body and electrically coupled to the radio frequency
generator, the stylet including a conductive radio frequency
electrode and a layer of insulating material coaxially disposed on
the conductive electrode so that a distal portion of the conductive
electrode is free of insulation and exposed in the tissue of the
prostate for causing ablation of tissue in the target volume of the
prostate when radio frequency energy is supplied to the conductive
electrode while the layer of insulating material extends through
the urethral wall and protects the urethral wall from radio
frequency energy supplied to the conductive electrode.
2. A device as in claim 1 wherein the layer of insulating material
is slidably mounted on the conductive electrode, the handle means
including means for causing relative movement between the layer of
insulating material and the conductive electrode to expose the
distal portion of the conductive electrode.
3. A device as in claim 1 wherein the conductive electrode is in
the form of a tube having an axial lumen extending
therethrough.
4. A device as in claim 1 together with ultrasound means carried by
the distal extremity of the elongate probe member for providing an
electrical signal for indicating the position of the device in the
human male.
5. A device as in claim 4 wherein said ultrasound means is mounted
on the layer of insulating material.
6. A device as in claim 1 together with temperature sensing means
mounted on the layer of insulating material.
7. A device as in claim 1 together with an additional stylet
slidably mounted in the passageway in the elongated probe member,
the additional stylet being of the same type as the first named
stylet, the distal extremity of the additional stylet being movable
between a retracted position in which the distal extremity of the
additional stylet is disposed within the passageway and an extended
position disposed outwardly from the distal extremity of the
elongate probe member, the additional stylet having a length so
that the distal extremity of the additional stylet extends through
the urethral wall into the tissue of the prostate when in the
extended position.
8. A device as in claim 7 wherein the means for supplying radio
frequency energy includes means for supplying radio frequency
energy to the conductive electrode of the first named for passage
through the tissue of the prostate to the conductive electrode of
the additional stylet so as to cause ablation of the tissue
disposed between the conductive electrodes of the first named and
additional stylets.
9. A device as in claim 1 together with a guide housing carried by
the distal extremity of the elongate probe member, the guide
housing having a lumen for receiving the conductive electrode and a
curved surface in the lumen for directing the conductive electrode
sidewise of the longitudinal axis.
10. A device as in claim 1 wherein the conductive electrode is made
from a shape memory alloy.
11. A medical device for treating by radio frequency ablation a
target volume in tissue of a prostate of a body of a human male
having a bladder with a base with a urethra formed by a urethral
wall extending into the base of the bladder with the tissue of the
prostate surrounding the urethra near the base of the bladder
comprising an elongate probe member having proximal and distal
extremities and a passageway extending from the proximal extremity
to the distal extremity along a longitudinal axis, the elongate
probe member having a length so that when the distal extremity is
disposed in the urethra in the vicinity of the prostate the
proximal extremity is outside of the urethra, first and second
radio frequency conductive electrodes slidably mounted in the
passageway in the elongate probe member and each having a flexible
distal extremity, a layer of insulating material disposed about
each of the first and second conductive electrodes, control means
secured to the first and second conductive electrodes for moving
the distal extremities of the first and second conductive
electrodes between retracted positions in which the distal
extremities of the first and second conductive electrodes are
disposed within the passageway and extended positions disposed
outwardly from the distal extremity of the elongate probe member so
that when the elongate probe member is disposed in the urethra with
the distal extremity in proximity to the prostate the first and
second conductive electrodes extend through the urethral wall when
in the extended positions so as to be disposed in spaced apart
positions in the tissue of the prostate and means including a radio
frequency return coupled to the first and second conductive
electrodes for supplying radio frequency energy to the first
conductive electrode for passage through the tissue of the prostate
to the second conductive electrode so as to cause ablation of
tissue disposed between the first and second conductive electrodes
in the target volume of the prostate.
12. A medical device as in claim 11 together with means carried by
the distal extremity of the elongate probe member and cooperatively
coupled into the passageway for directing the distal extremities of
the first and second conductive electrodes through a curved path as
the distal extremities of the first and second conductive
electrodes are moved to their extended positions.
13. A medical device as in claim 12 wherein said means carried by
the elongate probe member and cooperatively coupled into the
passageway includes a guide housing carried by the distal extremity
of the elongate probe member, the guide housing having first and
second lumens for respectively receiving the first and second
conductive electrodes and a curved surface in each lumen for
directing the first and second conductive electrodes sidewise of
the longitudinal axis.
14. A medical device as in claim 13 wherein the guide housing has
an outer surface provided with first and second spaced-apart ports
in communication with the first and second lumens.
15. A medical device as in claim 11 together with handle means
coupled to the proximal extremity of the elongate probe member for
introducing the distal extremity of the elongate probe member into
the urethra.
16. A medical device as in claim 11 wherein each layer of
insulating material is slidably mounted on the respective
conductive electrode.
17. A medical probe device for treating by radio frequency ablation
a target volume in tissue of a prostate of a body of a human male
having a bladder with a base with a urethra formed by a urethral
wall extending into the base of the bladder with the tissue of the
prostate surrounding the urethra near the base of the bladder
comprising an elongate probe member having proximal and distal
extremities and a passageway extending from the proximal extremity
to the distal extremity along a longitudinal axis, the elongate
probe member having a length so that when the distal extremity is
disposed in the urethra in the vicinity of the prostate the
proximal extremity is outside of the urethra, a stylet slidably
mounted in the passageway in the elongate probe member and having a
distal extremity movable between a retracted position in which the
distal extremity of the stylet is disposed within the passageway
and an extended position disposed outwardly from the distal
extremity of the elongate probe member whereby the stylet can
extend through the urethral wall into the tissue of the prostate,
means including a radio frequency generator coupled to the stylet
for supplying radio frequency energy to the stylet and a grounding
plate in contact with the body and electrically coupled to the
radio frequency generator, the stylet including a conductive radio
frequency needle electrode and a layer of insulating material
coaxially disposed on the conductive electrode so that a distal
portion of the conductive electrode is free of insulation and
exposed in the tissue of the prostate for causing ablation of
tissue in the target volume of the prostate when radio frequency
energy is supplied to the conductive electrode while the layer of
insulating material extends through the urethral wall and protects
the urethral wall from radio frequency energy supplied to the
conductive electrode.
18. A device as in claim 17 together with a means carried by the
elongate probe member and cooperatively coupled into the passageway
for directing the distal extremity of the stylet through a curved
path extending at an angle to the longitudinal axis.
19. A device as in claim 17 wherein the conductive electrode has a
sharpened tip.
20. A device as in claim 17 wherein the conductive electrode is in
the form of a tube having an axial lumen extending
therethrough.
21. A device as in claim 17 wherein the conductive electrode has
proximal and distal extremities and a length so that when the
distal extremity of the conductive electrode is in the tissue of
the prostate the proximal extremity of the conductive electrode is
outside of the urethra.
22. A medical device for treating by radio frequency ablation a
target volume in tissue of a prostate of a body of a human male
having a bladder with a base with a urethra formed by a urethral
wall extending into the base of the bladder with the tissue of the
prostate surrounding the urethra near the base of the bladder
comprising an elongate probe member having proximal and distal
extremities and a passageway extending from the proximal extremity
to the distal extremity along a longitudinal axis, the elongate
probe member having a length so that when the distal extremity is
disposed in the urethra in the vicinity of the prostate the
proximal extremity is outside of the urethra, a radio frequency
needle electrode having a flexible distal extremity and a sharpened
tip slidably mounted in the passageway in the elongate probe
member, a layer of insulating material coaxially disposed about the
needle electrode, control means secured to the needle electrode for
moving the distal extremity of the needle electrode between a
retracted position in which the distal extremity of the needle
electrode is disposed within the passageway and an extended
position disposed outwardly from the distal extremity of the
elongate probe member, means carried by the elongate probe member
and cooperatively coupled into the passageway for directing the
distal extremity of the needle electrode through a curved path
extending at an angle to the longitudinal axis as the needle
electrode is moved to its extended position so that when the
elongate probe member is disposed in the urethra with the distal
extremity in proximity to the prostate the sharpened tip penetrates
the urethral wall and the needle electrode extends through the
urethral wall into the tissue of the prostate and means including a
radio frequency return coupled to the needle electrode for
supplying radio frequency energy to the needle electrode to ablate
tissue in the target volume of the prostate, the distal extremity
of the needle electrode having an axial lumen extending
therethrough for permitting a liquid to be delivered into the
tissue of the prostate.
23. A device as in claim 22 wherein the means including a radio
frequency return includes a radio frequency generator and a
grounding plate in contact with the body and electrically coupled
to the radio frequency generator.
24. A medical probe device for the treatment of benign prostatic
hypertrophy by radio frequency ablation of a target volume in
tissue of a prostate of a body of a human male having a bladder
with a base and a penis with a urethra therein formed by a urethral
wall extending into the base of the bladder along a longitudinal
axis with the tissue of the prostate surrounding the urethra near
the base of the bladder comprising an elongate probe member having
proximal and distal extremities and having a longitudinal axis and
being sized to be able to enter the urethra and having a length so
that when the distal extremity is disposed in the urethra in the
vicinity of the prostate the proximal extremity is outside of the
urethra, the elongate probe member having a sidewall with a
passageway therein extending along the longitudinal axis to an
opening in the distal extremity, a stylet slidably disposed in the
passageway and including a radio frequency needle electrode having
a distal extremity with a sharpened tip, the stylet movable between
a retracted position in which the distal extremity of the stylet is
disposed within the passageway and an extended position disposed
outwardly of the opening in a direction away from the distal
extremity, the radio frequency needle electrode having a length so
that the distal extremity of the radio frequency needle electrode
penetrates the urethral wall and extends into the tissue of the
prostate when in the extended position, a layer of insulating
material coaxially disposed on the radio frequency needle electrode
so that a distal portion of the radio frequency needle electrode is
free of insulation and exposed in the tissue of the prostate for
causing ablation of tissue in the target volume of the prostate
when radio frequency energy is supplied to the radio frequency
needle electrode while the layer of insulating material extends
through the urethral wall and protects the urethral wall from radio
frequency energy supplied to the radio frequency needle
electrode.
25. A device as in claim 24 further comprising means carried by the
proximal extremity of the elongate probe member for causing
relative movement between the layer of insulating material and the
radio frequency needle electrode to expose the distal portion of
the radio frequency needle electrode.
26. A medical device for treating by radio frequency ablation a
target volume in tissue of a prostate of a body of a human male
having a bladder with a base with a urethra formed by a urethral
wall extending into the base of the bladder with the tissue of the
prostate surrounding the urethra near the base of the bladder
comprising an elongate probe member having proximal and distal
extremities and a passageway extending from the proximal extremity
to the distal extremity along a longitudinal axis, the elongate
probe member having a length so that when the distal extremity is
disposed in the urethra in the vicinity of the prostate the
proximal extremity is outside of the urethra, first and second
radio frequency needle electrodes slidably mounted in the
passageway in the elongate probe member and each having a distal
extremity, a layer of insulating material coaxially disposed about
each of the first and second needle electrodes, control means
secured to the first and second needle electrodes for moving the
distal extremities of the first and second needle electrodes
between retracted positions in which the distal extremities of the
first and second needle electrodes are disposed within the
passageway and extended positions disposed outwardly from the
distal extremity so that when the elongate probe member is disposed
in the urethra with the distal extremity in proximity to the
prostate the first and second needle electrodes extend through the
urethral wall when in the extended position so as to be disposed in
spaced apart positions in the tissue of the prostate and means
including a radio frequency return coupled to the first and second
needle electrodes for supplying radio frequency energy to the first
needle electrode for passage through the tissue of the prostate to
the second needle electrode so as to cause ablation of tissue
disposed between the first and second needle electrodes in the
target volume of the prostate.
Description
FIELD OF THE INVENTION
This invention is directed to a unique device and method for
penetrating body tissues for medical purposes such as tissue
destruction and fluid substance delivery, for example. The device
penetrates tissue to the precise target selected in order to
deliver energy to the tissue and/or deliver substances. It limits
this activity to the precise preselected site, thereby minimizing
trauma to normal surrounding tissue and achieving a greater medical
benefit. This device is a catheter-like device for positioning a
treatment assembly in the area or organ selected for medical
treatment with one or more stylets in the catheter, mounted for
extension from a stylet port in the side of the catheter through
surrounding tissue to the tissue targeted for medical activity.
BACKGROUND OF THE INVENTION
Treatment of cellular tissues usually requires direct contact of
target tissue with a medical instrument, usually by surgical
procedures exposing both the target and intervening tissue to
substantial trauma. Often, precise placement of a treatment probe
is difficult because of the location of a target tissue in the body
or the proximity of the target tissue to easily damaged, critical
body organs, nerves, or other components.
Benign prostatic hypertrophy or hyperplasia (BPH), for example, is
one of the most common medical problems experienced by men over 50
years old. Urinary tract obstruction due to prostatic hyperplasia
has been recognized since the earliest days of medicine.
Hyperplastic enlargement of the prostate gland often leads to
compression of the urethra, resulting in obstruction of the urinary
tract and the subsequent development of symptoms including frequent
urination, decrease in urinary flow, nocturia, pain, discomfort,
and dribbling. The association of BPH with aging has been shown to
exceed 50% in men over 50 years of age and increases in incidence
to over 75% in men over 80 years of age. Symptoms of urinary
obstruction occur most frequently between the ages of 65 and 70
when approximately 65% of men in this age group have prostatic
enlargement.
Currently there is no proven effective nonsurgical method of
treatment of BPH. In addition, the surgical procedures available
are not totally satisfactory. Currently patients suffering from the
obstructive symptoms of this disease are provided with few options:
continue to cope with the symptoms (i.e., conservative management),
submit to drug therapy at early stages, or submit to surgical
intervention. More than 430,000 patients per year undergo surgery
for removal of prostatic tissue in the United States. These
represent less than five percent of men exhibiting clinical
significant symptoms.
Those suffering from BPH are often elderly men, many with
additional health problems which increase the risk of surgical
procedures. Surgical procedures for the removal of prostatic tissue
are associated with a number of hazards including anesthesia
associated morbidity, hemorrhage, coagulopathies, pulmonary emboli
and electrolyte imbalances. These procedures performed currently
can also lead to cardiac complications, bladder perforation,
incontinence, infection, urethral or bladder neck stricture,
retention of prostatic chips, retrograde ejaculation, and
infertility. Due to the extensive invasive nature of the current
treatment options for obstructive uropathy, the majority of
patients delay definitive treatment of their condition. This
circumstance can lead to serious damage to structures secondary to
the obstructive lesion in the prostate (bladder hypertrophy,
hydronephrosis, dilation of the kidney pelves, etc.) which is not
without significant consequences. In addition, a significant number
of patients with symptoms sufficiently severe to warrant surgical
intervention are poor operative risks and are poor candidates for
prostatectomy. In addition, younger men suffering from BPH who do
not desire to risk complications such as infertility are often
forced to avoid surgical intervention. Thus the need, importance
and value of improved surgical and non-surgical methods for
treating BPH is unquestionable.
High-frequency currents are used in electrocautery procedures for
cutting human tissue especially when a bloodless incision is
desired or when the operating site is not accessible with a normal
scalpel but presents an access for a thin instrument through
natural body openings such as the esophagus, intestines or urethra.
Examples include the removal of prostatic adenomas, bladder tumors
or intestinal polyps. In such cases, the high-frequency current is
fed by a surgical probe into the tissue to be cut. The resulting
dissipated heat causes boiling and vaporization of the cell fluid
at this point, whereupon the cell walls rupture and the tissue is
separated.
Destruction of cellular tissues in situ has been used in the
treatment of many diseases and medical conditions alone or as an
adjunct to surgical removal procedures. It is often less traumatic
than surgical procedures and may be the only alternative where
other procedures are unsafe. Ablative treatment devices have the
advantage of using a destructive energy which is rapidly dissipated
and reduced to a non-destructive level by conduction and convection
forces of circulating fluids and other natural body processes.
Microwave, radiofrequency, acoustical (ultrasound) and light energy
(laser) devices, and tissue destructive substances have been used
to destroy malignant, benign and other types of cells and tissues
from a wide variety of anatomic sites and organs. Tissues treated
include isolated carcinoma masses and, more specifically, organs
such as the prostate, glandular and stromal nodules characteristic
of benign prostate hyperplasia. These devices typically include a
catheter or cannula which is used to carry a radiofrequency
electrode or microwave antenna through a duct to the zone of
treatment and apply energy diffusely through the duct wall into the
surrounding tissue in all directions. Severe trauma is often
sustained by the duct wall during this cellular destruction
process, and some devices combine cooling systems with microwave
antennas to reduce trauma to the ductal wall. For treating the
prostate with these devices, for example, heat energy is delivered
through the walls of the urethra into the surrounding prostate
cells in an effort to kill the tissue constricting the urethra.
Light energy, typically from a laser, is delivered to prostate
tissue target sites by "burning through" the wall of the urethra.
Healthy cells of the duct wall and healthy tissue between the
nodules and duct wall are also indiscriminately destroyed in the
process and can cause unnecessary loss of some prostate function.
Furthermore, the added cooling function of some microwave devices
complicates the apparatus and requires that the device be
sufficiently large to accommodate this cooling system.
Application of liquids to specific tissues for medical purposes is
limited by the ability to obtain delivery without traumatizing
intervening tissue and to effect a delivery limited to the specific
target tissue. Localized chemotherapy, drug infusions, collagen
injections, or injections of agents which are then activated by
light, heat or chemicals would be greatly facilitated by a device
which could conveniently and precisely place a fluid supply
catheter opening at the specific target tissue.
OBJECTS AND SUMMARY OF THE INVENTION
It is the principal object of this invention to provide a device
and method for penetrating tissue, through intervening tissues to
the precise target tissue selected for a medical action such as
tissue destruction and/or substance delivery, limiting this
activity to the precise preselected site, thereby minimizing the
trauma and achieving a greater medical benefit.
One principal object of this invention is to provide a device and
method for tissue destruction of body tissues which delivers the
therapeutic energy directly into a target tissue while minimizing
effects on its surrounding tissue.
Another principal object of this invention is to provide a device
and method for introducing fluid treatment agents, particularly
flowable liquids, with greater precision and ease to a specific
location in the body.
Another object of this invention is to provide a thermal
destruction device which gives the operator more information about
the temperature and other conditions created in both the tissue
targeted for treatment and the surrounding tissue. In addition, it
will provide more control over the physical placement of the stylet
and over the parameters of the tissue destruction process.
In summary, the medical probe device of this invention comprises a
catheter having a control end and a probe end. The probe end
includes a stylet guide housing having at least one stylet port in
a side wall thereof and guide means for directing a flexible stylet
outward through the stylet port and through intervening tissue at a
preselected angle to a target tissue. The housing can include an
array of such ports. The preselected angle is preferably from
20.degree. to 160.degree. with the central axis of the stylet guide
housing. The total catheter assembly includes one or more stylet
guide lumena communicating with respective stylet ports and a
stylet positioned in each of said stylet guide lumena for
longitudinal movement from the respective port through intervening
tissue to target tissues.
The stylet can be an electrical conductor enclosed within a
non-conductive layer, the electrical conductor being an
radiofrequency electrode. Preferably, the non-conductive layer is a
sleeve which is axially or longitudinally moveable on the
electrical conductor to expose a selected portion of the electrical
conductor surface in the target tissue.
In a still further embodiment, the stylet is a cannula having a
longitudinal, central treatment fluid supply lumen extending
therethrough, and the catheter has a treatment fluid transport
lumen communicating with the treatment fluid supply lumen.
An ultrasound reflector such as a bubble or an ultrasound
transducer can be embedded or otherwise attached to the probe end
or a portion of the stylet to provide a signal for use in
positioning the catheter and stylet.
When the stylet includes a radiofrequency electrode, optimally, at
least one temperature sensor such as a thermistor or fiber optic
cable can be attached to the probe end, stylet guide housing and/or
stylet.
In one preferred embodiment, the stylet guide defines a stylet path
from an axial orientation in the catheter through a curved portion
to a lateral orientation at the stylet port, the curved path
optionally having a radius which is sufficient to deflect the
deployed, extended stylet to the desired angle, that is, a radius
of up to 0.5 cm, depending upon the diameter of the catheter. The
stylet guide means can define a stylet path having a first curved
portion extending in a direction away from the stylet port and a
second curved portion, continuing from the first curved portion and
extending to the stylet port.
For deploying a plurality of stylets, the stylet guide means can
define at least two non-intersecting stylet paths from parallel
axial orientations in the catheter through curved portions to
lateral orientations at stylet ports, the stylet ports having axes
forming an angle of up to 180.degree.. For treating prostate lobes
in one embodiment, the stylet port axes form an angle of less than
90.degree. and preferably from 50.degree. to 70.degree..
The non-conductive sleeve can comprise a leading tip, a rigid
proximal control section, and a flexible portion extending from the
leading tip the rigid proximal control section, whereby the sleeve
can be extended through a curved path from an axial orientation to
an orientation extending outward through a stylet port. The leading
tip can be tapered inward toward its terminal end. The flexible
portion can optionally be a spiral coil. If the spiral coil is made
of conductive material, it can be enclosed in an outer
non-conductive material.
The distal portion of the catheter can be more flexible than the
proximal portion thereof, facilitating its passage through curved
ducts.
In one embodiment, a control handle is attached to the control end
of the catheter and stylet movement means attached to a stylet and
engaging the handle for longitudinal movement of the stylet in the
stylet guide means. The stylet movement means comprises manual
engagement means for translating manual motion into longitudinal
motion of the stylet in the stylet guide means.
In embodiments where the electrical conductor has axial movement in
the non-conductive sleeve, a non-conductive sleeve movement means
is attached to a non-conductive sleeve and an electrical conductor
movement means is attached to the electrical conductor enclosed
therein. The non-conductive sleeve movement means translates manual
motion into longitudinal motion of the non-conductive sleeve in the
stylet guide means. The electrical conductor movement means
translates manual motion into longitudinal motion of the electrical
conductor in the non-conductive sleeve. The non-conductive sleeve
movement means and the electrical conductor movement means engage
the handle for movement thereon. The non-conductive sleeve movement
means and the electrical conductor movement means can include
separate, adjacent manual movement means, mounted on the handle for
both separate and coordinated movement thereon. The housing can
have at least two parallel longitudinal slots through a wall
thereof, the manual movement means each including a finger engaging
surface connected to a slide extending through one of the
longitudinal slots to a connector in the interior of the housing,
the connector being attached to a respective non-conductive sleeve
or electrical conductor.
The method of this invention for applying destructive energy to a
target tissue comprises first introducing a catheter to a zone
adjacent to the tissue to be treated. Then an electrical conductor
is moved from the catheter through surrounding tissue into a target
tissue to be destroyed. The electrical conductor can be a wire or
tube comprising a conductive surface surrounded by a non-conductive
sleeve for preventing significant transfer of energy from the
conductor in tissue surrounding the sleeve. Heat is generated in
the target tissue from an electric current or electromagnetic field
produced by the electrical conductor. The volume of tissue being
treated is controlled by moving the non-conductive sleeve to expose
a selected length of electrode in the body tissue to be treated,
the remaining area of the electrode remaining shielded by the
sleeve to protect the intervening tissues. The amount and duration
of the energy delivery is also varied to control the volume of
tissue being treated.
The electrical conductor can be positioned using a fiber optic
viewing system incorporated within the catheter shaft, positioned
to facilitate positioning of the device. Such a system can also
include separate optics for lumination and viewing, and flushing
fluid supply conduits for flushing the viewing fields.
The electrical conductor can also be positioned in the tissue to be
treated using ultrasound imaging from an ultrasound transducer
positioned at a distance from the target tissue or supported by the
electrical conductor or non-conducting sleeve.
The extent of heating can be monitored and controlled during the
ablative treatment using temperature sensors supported by the
electrical conductor or non-conductive sleeve.
In another embodiment of the method of this invention for treating
a target tissue such as the prostate, two flexible stylets from the
catheter are moved through catheter ports in the sidewall of the
catheter and through the urethra wall and surrounding tissue into
the prostate target tissue to be treated, the catheter ports having
axes forming an angle of less than 180.degree. and for treatment in
some tissue, less than 90.degree..
In a still further embodiment, a grounding plate is placed on the
skin to direct the electrical current passing from one or more
electrodes in a path through the target tissue to be ablated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-sectional drawing of the lower male
anatomy with one embodiment of the device of this invention in
position for treatment.
FIG. 2 is a side view of the terminal housing portion of the
catheter of this invention with a plurality of extended
stylets.
FIG. 3 is an end view of the terminal housing portion shown in FIG.
2.
FIG. 4 is a side elevational view in section of an alternative
embodiment of a catheter or stylet guide of this invention.
FIG. 5 is a cross-sectional representation of an embodiment of a RF
electrode stylet according to this invention.
FIGS. 6 and 7 are cross-sectional representations of an embodiment
of the catheter of this invention with a stylet guide system for
adjusting the stylet guide angle.
FIGS. 8 and 9 are detailed schematic cross-sectional views of a RF
electrode stylet shown in FIG. 4 with a partially retracted sleeve
positioned to treat tissue targeted for destruction while shielding
intervening tissue from treatment according to the method of this
invention.
FIG. 10 is a schematic view of the control console, manual catheter
control device and catheter according to this invention.
FIG. 11 is an isometric representation of an embodiment of a manual
control device of the system of this invention.
FIG. 12 is an isometric representation of an embodiment of a power
and control console of the system of this invention.
FIG. 13 is a plan view of an alternative four-probe embodiment of
the device of this invention.
FIG. 14 is a side elevational of the distal probe end of the device
shown in FIG. 13.
FIG. 15 is a cross-sectional end view of the probe end of the
device shown in FIG. 14, taken along the line 15--15.
FIG. 16 is a partial cross-sectional view of the probe end of the
device of this invention, taken along the 16--16 of FIG. 15.
FIG. 17 is a cross-sectional view of the control end of the device
shown in FIG. 13, taken along its central axis.
FIG. 18 is a cross-sectional view of the control end of the device
shown in FIG. 17, taken along the line 18--18.
FIG. 19 is a cross-sectional view of the control end of the device
shown in FIG. 17, taken along the line 19--19.
FIG. 20 is a side view of the non-conductive sleeve connector of
the embodiment show in FIGS. 17 and 18.
FIG. 21 is a cross-sectional view of the non-conductive sleeve
connector shown in FIG. 20, taken along the line 21--21.
FIG. 22 is a side view of the electrical conductor connector of the
embodiment shown in FIGS. 17 and 19.
FIG. 23 is a cross-sectional view of the electrical conductor
connector shown in FIG. 22, taken along the line 23--23.
FIG. 24 is a cross-sectional view of the distal end of the
non-conductive sleeve shown in FIGS. 14 and 15, taken along its
central axis.
FIG. 25 is a top view of a two stylet alternative embodiment of an
RF ablation catheter of this invention.
FIG. 26 is a top view of one embodiment of a stylet tip of this
invention.
FIG. 27 is a side view of the single grind electrode tip shown in
FIG. 26.
FIG. 28 is an end view of the electrode tip shown in FIG. 27.
FIG. 29 is a side view of an alternative double grind electrode
tip.
FIG. 30 is an end view of the electrode tip shown in FIG. 29.
FIG. 31 is a top view of the handle portion of the ablation
catheter of FIG. 25.
FIG. 32 is a side view of the handle portion shown in FIG. 31 taken
along the line 32--32 with the bottom cover plate partially
removed.
FIG. 33 is a bottom view of the handle portion shown in FIG. 31
with the bottom cover plate removed.
FIG. 34 is a cross-sectional view of the handle portion taken along
the line 34--34 in FIG. 33.
FIG. 35 is a cross-section view of the central portion of the
handle portion shown in FIG. 32 in the stylet and sleeve retracted
position.
FIG. 36 is a cross-sectional view of the central portion of the
handle portion shown in FIG. 32 with the stylet and sleeve in an
extended position.
FIG. 37 is a cross-sectional view of the central portion of the
handle portion shown in FIG. 32 with the stylet in an extended
position and the sleeve partially retracted therefrom.
FIG. 38 is a schematic view of a deployment of two stylets in a
prostate showing stylet orientation for the overlapping ablation
zone method of this invention.
DETAILED DESCRIPTION OF THE INVENTION
The device of this invention provides a precise controlled
positioning of a treatment stylet in a tissue targeted for
treatment, destruction or sampling from a catheter positioned in
the vicinity of the target tissue.
The term "stylet" as used hereinafter is defined to include both
solid and hollow probes which are adapted to be passed from a
catheter port through normal tissue to a target tissue. The stylet
is shaped to facilitate easy passage through tissue. It can be a
solid wire, thin rod, or other solid shape or it can be a thin
hollow tube or other shape having a longitudinal lumen for
introducing fluids to or removing materials from a site. The stylet
can also be a thin hollow tube or other hollow shape, the hollow
lumen thereof containing a reinforcing or functional rod or tube.
The stylet preferably has a sharpened end to reduce resistance and
trauma when it is pushed through tissue to a target site.
The stylet can be designed to provide a variety of medically
desired treatments of a selected tissue. As a radiofrequency
electrode or it can be used to ablate or destroy the target tissue.
As a hollow tube, it can be used to deliver a treatment fluid such
as a liquid to a target tissue. The liquid can be a simple solution
or a suspension of solids, for example, colloidal particles, in a
liquid. Since the stylet is very thin, it can be directed from the
catheter through intervening normal tissue with a minimum of trauma
to the normal tissue.
The device and method of this invention provide a more precise,
controlled medical treatment which is suitable for destroying cells
of medically targeted tissues throughout the body, both within and
external to body organs. The device and method are particularly
useful for treating benign prostate hyperplasia (BPH), and the
device and its use are hereinafter described with respect to BPH,
for purposes of simplifying the description thereof. It will be
readily apparent to a person skilled in the art that the device and
method can be used to destroy body tissues in any body cavities or
tissue locations that are accessible by percutaneous or endoscopic
catheters, and is not limited to the prostate. Application of the
device and method in all of these organs and tissues are intended
to be included within the scope of this invention.
BPH is a condition which arises from the benign replication and
growth of cells in the prostate, forming glandular and stromal
nodules which expand the prostate and constrict the opening of the
prostatic urethra. Glandular nodules are primarily concentrated
within the transition zone, and stromal nodules within the
periurethral region. Traditional treatments of this condition have
included surgical removal of the entire prostate gland, digital
removal of the adenoma, as well as transurethral resection of the
urethral canal and prostate to remove tissue and widen the
passageway. One significant and serious complication associated
with the latter method is iatrogenic sterility. More recently,
laser treatment has been employed to remove tissue, limiting
bleeding and loss of body fluids. Balloons have also been expanded
within the urethra to enlarge its diameter, with and without heat,
but have been found to have significant limitations.
Microwave therapy has been provided with some success by
positioning a microwave antenna within the prostatic urethra and
generating heat in the tissue surrounding the urethra with a
microwave field. Coolants are sometimes applied within the catheter
shaft to reduce the temperature of the urethral wall. This
necessitates complicated mechanisms to provide both cooling of the
immediately adjacent tissues while generating heat in the more
distant prostatic tissue. This technique is similar to microwave
hyperthermia. Similarly, radiofrequency tissue destruction with
electrodes positioned within the urethra has limited applicability
since it necessarily exposes the urethral wall to destructive
temperatures. To avoid this, low temperature settings required to
protect the urethra must be so low that the treatment time required
to produce any useful effect is unduly extended, e.g. up to three
hours of energy application.
One embodiment of the device of this invention uses the urethra to
access the prostrate and positions RF electrode stylets directly
into the tissues or nodules to be destroyed. The portion of the
stylet conductor extending from the urethra to the target tissue is
enclosed within a longitudinally adjustable sleeve shield which
prevents exposure of the tissue adjacent to the sleeve to the RF
current. Thus the ablative destruction is confined to the tissues
targeted for destruction, namely those causing the constriction.
Other aspects of the invention will become apparent from the
drawings and accompanying descriptions of the device and method of
this invention. It will be readily apparent to a person skilled in
the art that this procedure can be used in many areas of the body
for percutaneous approaches and approaches through body
orifices.
FIG. 1 is a schematic cross-sectional drawing of the lower male
anatomy during use of the device and method of this invention. The
urethra 2 extends from the urinary bladder 4 through the prostate 6
and urogenital diaphragm 8. BPH is a condition characterized by
constriction of the portion of the prostatic urethra caused
primarily by proliferation of benign glandular and stroma cells in
the prostate. These nodules press the wall of the urethra inwardly,
restricting the urethral diameter, and can press normal tissue
outwardly, possibly enlarging the prostate. Traditional treatments
short of removal of the prostate have included either removal of
tissue from the urethra to enlarge its lumen by resection or laser
tissue destruction, or by expansion and heating of the tissue
surrounding the urethra to a temperature which causes cell death.
The latter method is intended to reduce the swelling or enlargement
of the prostate, and restore the urinary passage to at least a
portion of its former diameter.
In the method of this invention, a catheter 14 with a stylet guide
16 is passed upwardly through the urethra into the prostate. The
position of the guide 16 is precisely controlled, using an
ultrasound image, for example, obtained from signals received from
the conventional ultrasound transducer 18 inserted into the rectum
20 adjacent to the prostate through the anal opening 22. 16
facilitates easy positioning of the stylet 17 into a precise
location under ultrasound imaging. Optionally, fiber optics can be
used to position the stylet guide.
The terminal portion of the catheter 14 can optionally have one or
more dilation balloons 30 and 32. Stylet sleeve 36 can be extended
through the urethra and other tissue to be protected, and an RF
electrode 38, as shown for example in this figure, can be extended
deep into the target tissue 28.
FIG. 2 is a side view and FIG. 3 is an end view of the terminal
portion of one embodiment of a catheter of this invention. One or
more stylet ports 40 are positioned between the unexpanded annular
balloons 30 and 32. An ultrasound transponder 42 can be positioned
at the terminal end 44 for producing signals and images which can
be used for precise positioning of the stylet guide 16 in the
prostate. Alternatively, an echogenic bubble (not shown) can be
incorporated into the distal housing to aid in sonographic location
of the stylet guide. One or more temperature sensors 46, which can
be conventional thermistors, thermocouples or optical fibers, are
positioned along the catheter or stylet guide 16 to provide a
temperature profile of the urethra adjacent to and preferably on
both sides the stylet guide 16. This temperature profile can be
used by the operator to prevent the temperature of the urethral
wall from reaching a level which would cause cell destruction.
FIGS. 2 and 3, show both balloon segments 30 and 32 and six stylets
36 corresponding to the stylet 17 in an extended position.
The catheter or stylet guide 16 can be rotated about its central
axis prior to stylet deployment to orient one or more of the
stylets 36 toward tissues to be treated. After the distal extremity
of the stylet guide catheter 16 is advanced to a treatment position
in the prostatic urethra, the annular balloons 30 and 32 can be
expanded in the urethra to stabilize the catheter or stylet guide
16 and dilate the urethral lumen. The stylets 36 are extended
through the urethral wall and intermediate tissue until they are
positioned in the tissue targeted for treatment. The tissue
targeted for BPH treatment may be nodules, normal tissue or both.
The stylet passageways leading to ports 40 have an orientation such
that their terminal axis forms an angle "a" which can be from about
20.degree. to 160.degree. and preferably from about 30.degree. to
150.degree. with the central axis of the catheter in a plane
therethrough. As will be explained in greater detail hereinafter
with regard to one embodiment of this invention, a non-conducting
sleeve is then moved to expose the target tissue to controlled
heating by an electric current to a destructive temperature above
45.degree. C. and preferably within the range of from 55.degree. to
99.degree. C.
In the embodiment of the catheter or stylet guide shown in FIGS. 4
and 5 the catheter or stylet guide 48 is connected to a stylet
guide housing 50 having a nose 52. A flexible stylet 54 comprises a
solid core needle 56 (see FIG. 5) coaxially positioned within a
tube 58, both of which are preferably constructed of a highly
flexible, conductive metal such as a nickel-titanium alloy,
tempered steel, stainless steel, beryllium-copper alloy and the
like. Nickel-titanium and similar highly flexible, shaped memory
alloys are preferred. The needle 56 is axially or longitudinally
movable within the tube 58. The tube 58 is enclosed within an
non-conductive, sleeve 60 which is longitudinally movable along the
tube 58. The guide housing 50 has a guide channel 61 (see FIG. 4)
which is curved to permit longitudinal advancement of the flexible
stylet.
The sleeve 60 is connected to an annular cylinder 62 connected with
a longitudinal thrust tube 64. Longitudinal movement of the thrust
tube 64 causes a corresponding longitudinal movement of the sleeve
60 along the tube 58. The sleeve movement is used to vary and
control the length of tube 58 and needle 56 exposed to surrounding
tissue and control the amount of energy delivered to the target
tissue. The material, insulating properties, dielectric properties
and thickness of the sleeve 60 are selected to prevent heating
energy delivery to tissue in contact therewith by shielding the
tissue from the conductor. If the tissue is to be heated using
radiofrequency current (300 to 750 kHz), the sleeve 60 must have
sufficient thickness required to prevent both current flow and
capacitance coupling with the tissue.
An alternative embodiment of a catheter or stylet guide 124 is
shown in FIG. 6 and as shown consists of a stylet guide housing 125
having a stylet port 126. A stylet positioning block 128 is
positioned within the housing 125 for axial movement under the
action of a torque and thrust rod 130. The stylet positioning block
128 has a curved stylet lumen 131 containing a stylet 132.
Optionally, a low friction, flexible guide tubing 134 extends from
the positioning block 128 to the port 126. In the position shown in
FIG. 6, the positioning block 128 is in a retracted position,
orienting the stylet to extend at an acute angle "b" of
approximately from about 20.degree. and preferably 30.degree. up to
90.degree. with respect to the central axis of the guide housing.
Advancement of the stylet 132 through the block 128, guide tubing
134 and port 126 directs the stylet into tissue along the dotted
line path 136.
Advancement of the positioning block 128 as shown in FIG. 7 forces
the stylet 132 through a curved path having a smaller diameter
through guide tubing 134 to the port 126. The stylet 132 is then
directed an obtuse angle b which can be as high as about
160.degree. with respect to the guide housing axis. Advancement of
the stylet through the guide block 128, guide tubing 134 and port
126 in this configuration directs the stylet into tissue along the
dotted line path 138 shown in FIG. 8.
As shown in FIGS. 6 and 7, the angular projection of the stylet 132
can be oriented over a wide range of angles in a plane through the
central axis of the stylet guide housing 125. It will be readily
apparent that rotation of the torque and thrust rod 130 about its
central axis will cause a corresponding rotation of the stylet
guide housing 125 and deflection of the stylet in directions
outside of the axial plane. This combined with axial movement of
the catheter or stylet guide 124 to an optimum position in a duct
and rotation of the catheter or stylet guide 124 about its central
axis yields an infinite variety of stylet orientation angles. A
combination of these movements provides greater choices of stylet
angles so that the stylet can be advanced into target tissue at any
angle from the catheter.
After the catheter or stylet guide 48 shown in FIGS. 5 and 6 is
positioned in the urethra, as shown in FIG. 8 the stylet 54 is
advanced from the stylet guide housing 50 through the prostatic
urethra wall 71 to the target tissue 73 to be treated (outlined
with a dotted line). Then, stylet sleeve 60 is retracted to the
position shown in FIG. 8, exposing the portion of the RF electrode
positioned in the target tissue 73. RF current is then directed
from the electrode 56 and 58 through tissue 73 to conventional
grounding plates (not shown) serving as an indifferent electrode.
In selected instances, more directed ablation can be obtained by
using one or more of the stylets as the indifferent electrode and
another of the styles as the active electrode, thereby using only
stylets to complete the dipole and not using a grounding plate. The
RF treatment is continued until the cells in the target tissue 73
have been destroyed.
FIG. 9 is a detailed schematic cross-sectional view corresponding
to FIG. 8 in an optional second step following the procedure
described above in connection with FIG. 8. Following destruction of
the cells in target tissue 73, the RF electrode sleeve 60 can be
retracted along the stylet electrode 58 to the stylet guide housing
50, exposing a length of RF electrode 74 leading from the target
tissue through prostatic urethral wall 71. Sufficient RF current is
then applied to cauterize the surface of the tissue 76 (shown by
dotted lines) immediately in contact with the entire exposed
surface of the electrode 58. For example, this can be achieved with
a higher voltage and shorter duration treatment than is applied to
destroy the cells of the target tissue. The stylet is then fully
withdrawn into the housing 50, leaving a drainage duct leading from
the area of the target tissue 73 to the prostatic urethra. This can
provide drainage of the products of the treated target tissue 73
during the healing process.
The transurethral needle ablation (TUNA) process of this invention
is a process whereby a physician in a unique procedure delivers
radiofrequency to the hyperplastic tissues of the prostate which
develop in men with the condition known as BPH, or Benign Prostatic
Hyperplasia. This procedure is unique in that it is the first
transurethral procedure which selectively provides the ability to
limit the treatment to the constrictive tissue and spare the normal
prostatic tissue. This procedure also minimizes the trauma
sustained by the surrounding prostatic urethra, especially when
compared to previously known procedures for relieving obstructive
uropathy due to BPH. The procedure could possibly be carried out
under local anesthesia only, depending upon the rate of energy
delivery and degree of pain sensation experienced by the patient.
When local anesthetic is adequate, the procedure can be performed
in the physician's office. Local anesthetic could be delivered or
applied in the form of a lubricant containing a topical anesthetic
such as lidocaine mixed with K-Y jelly.
If substantial pain will be experienced by the patient, the patient
must be sedated in addition to application of topical local
anesthetic. This procedure can be provided on an outpatient basis
and would require a short term (2-6 hour) observation. If the
procedure and patient require greater pain control, then spinal
anesthesia or a general anesthesia may be used for patients which
qualify for their use. This would mandate that the procedure be
carried out in the operating room, would require a recovery room,
and could possibly require in-patient care in certain
circumstances. The previously known prostate resection (TURP)
generally requires use of general or spinal anesthesia and
in-patient hospital care following the treatment.
The BPH method of this invention can be carried out in the
following manner, using a RF electrode stylet embodiment of this
invention. A male patient is given the appropriate pre-procedure
preparation which would usually require a fleets enema or bowel
preparation. This would clear the rectal vault of stool in order to
better place a rectal ultrasound probe, if used, and to assure
better visualization. Appropriate anesthetic, would then be
administered. A conventional grounding plate is then placed in
contact with the patient. The rectal probe would then be inserted
to the level of the prostate in order to obtain an ultrasound image
of the prostate. The procedure could be done without the use of
rectal ultrasound, using only direct visualization at the
discretion of the operator. The urethral catheter would then be
inserted in a fashion similar to that used for inserting a Foley
catheter. First the glans and the penile shaft would be bathed in
betadine or other disinfectant. The rest of the groin adjacent
areas are draped with sterile towels in the usual fashion. Then
using aseptic or sterile technique, the shaft of the penis is
grasped in one hand while the catheter is inserted into the
urethral meatus and advanced until it has reached to desired
position in the prostatic urethra. The catheter movement during its
advancement through the urethra can be monitored directly with the
ultrasound image. If direct visualization with fiber optics is
used, the appropriate landmarks are located and identified, i.e.,
verumontanum and bladder neck, etc. If this has not been
accomplished earlier, the various electrical and mechanical
connections between the catheter and the control assembly are
connected at this stage.
The RF electrode stylet is then deployed under direct vision or
ultrasound imaging into a selected target tissue. This requires
that the physician locate the target area to be treated, rotate,
advance and/or retract the catheter as necessary to orient the
stylet guide port toward the target area. The stylet, preferably
completely surrounded in its insulating sleeve or sheath, punctures
and penetrates the epithelial lining of the prostatic urethral,
traveling through prostatic tissue to the target tissue, and
penetrating the tissue to the desired depth. Local anesthetic can
be infiltrated into the target tissue through the central lumen of
the stylet as the stylet is advanced. The insulating sleeve is then
retracted the amount required to expose a precise selected length
of the RF electrode in the target tissue. This amount is selected
to effect the degree and volume of tissue destruction desired, the
volume increasing as the length of the exposed electrode increases.
This volume is selected based on the size of the target tissue to
be ablated and the relative position of the electrode stylet in the
target tissue. The distance the sleeve is withdrawn can be measured
external to the body using a conventional measuring devices such as
a scale.
The electrode stylet is then energized from an RF energy source by
closing a conventional switch. Preferably, the time and/or power
levels are preset by the control unit. The RF energy is delivered
to the target tissue for a preselected time, monitoring the advance
of the destructive lesion by the rectal ultrasound image. Impedance
is also monitored, and when or if it exceeds a preset value, the
power supply can be reduced or terminated. The temperature of the
catheter surface adjacent the urethral lining, the sleeve and even
the exposed electrode can also be monitored using temperature
sensors attached to these components to precisely control the
volume of the lesion and prevent excessive heating of normal
tissue.
After the target tissue destruction has proceeded to the desired
stage, the physician has two options. The stylet electrode can be
withdrawn into the catheter to facilitate quick healing and rapid
sealing of the urethral puncture site. Alternatively, the physician
can create a temporary physiological drainage capillary which would
allow any fluid or debris accumulating in the ablated target tissue
to drain into the urethra. This physiological drainage capillary
can be created after target tissue destruction by withdrawing the
insulating sleeve or sheath back into the urethral catheter as
shown in FIG. 9. The conductive stylet is then energized to a level
sufficient to "sear" or cauterize a small hollow channel through
the tissue. This channel will eventually scar and fibrose, or it
will seal and heal. The conductive stylet is then entirely
withdrawn, and the catheter is slowly and carefully withdrawn from
the urethra. The patient is then monitored and treated as
appropriate for the type of anesthesia delivered and the condition
of the patient.
FIG. 10 is a schematic view of the assembly of the power and
control system 150, a manual catheter control unit 152, catheter
154, and power foot control 156. The power foot control functions
can be accomplished by numerous other methods to include manual
digital switches on control box 150 and by a trigger device on the
catheter handle 152. The manual operation of the catheter assembly
is controlled from a manual control unit shown in greater detail in
FIG. 11, with the power control and temperature displays being
provided in the control system 150 shown in greater detail in FIG.
12.
FIG. 12 is an isometric representation of an embodiment of a manual
control system of the system of this invention. The manual control
152 has a pistol grip 158 with a tube 160 leading to the console
shown in FIG. 13. The tube 160 houses RF or power supply cables,
temperature sensors, ultrasound transducer power and signal
delivery leads, balloon inflation fluid and vacuum lumens.
Rocker switches 162 and 164 provide control over the inflation or
deflation of balloons 30 and 32 (FIGS. 1 and 2). Tab 166 sliding in
groove 168 is connected to a stylet 62, advancing it into the a
target tissue as the tab 166 is moved forward. Rotary dial 170 is
attached to the catheter 154 and can be used to rotate the catheter
for orientation of the stylet or stylets. Window 172 has
graduations showing the percentage of balloon expansion.
FIG. 12 is an isometric representation of an embodiment of a power
and control console 150 of the system of this invention. The
housing of this console has a display panel 174 with digital
readout displays 176 showing power to the stylet, antenna
temperatures, tissue temperatures, impedance values, and other
data, for example. The housing can support a sealed membrane switch
panel 178 having system control buttons 179. Power cord 180 leads
to a standard power outlet. Cable 182 leads to the manual catheter
control unit 152 shown in FIG. 11. Cable 184 leads to a optional
power foot control unit. Cable 185 leads to the grounding patch for
use in unipolar systems.
FIG. 13 is a view of an alternative four-probe embodiment of the
device of this invention. The device comprises a handle portion 180
and a catheter portion 182. The catheter portion 182 includes an
elongated catheter 184 having a distal catheter probe end 186. A
plurality of stylets 188 extend outwardly from the probe end 186.
The end 190 of the handle portion 180 is attached to the proximal
end of the catheter 182, and manual control tabs 192 and 194
mounted thereon for sliding engagement with side walls of the
handle portion. Using the handle 180 for control, the catheter is
introduced into a body duct, vascular structure or canal such as
the urethra, for example, and pushed up the duct to the treatment
position, for example a position adjacent the prostate. Stylets 188
are individually and selectively passed outward from the distal end
190 through surrounding tissue to the target tissue to be treated
by movement of respective manual control tab pairs 192 and 194.
When the stylets are electrical conductors surrounded by movable
sleeves, the sleeves can be retracted from the end of the stylets
by movement of manual control tabs 194 as described in greater
detail hereinafter. Preferably, the proximal portion of the
catheter 182 is preferably stiff to facilitate control during
insertion in a body duct, while the distal portion is preferably
flexible to allow the catheter to pass through curved duct
portions.
FIG. 14 is a side partially sectioned view of the distal probe end
of the catheter shown in FIG. 13 with stylets extended from the
side ports, and FIG. 15 is a cross-sectional end view of the probe
end of the device shown in FIG. 14, taken along the line 15--15.
The distal catheter tip 186 is a stylet guide housing having a
lateral surface 196 which merges with a tapered tip portion 198.
The stylets 188 extend outwardly from the lateral surface 196 and
comprise an electrode 200 and movable surrounding sleeve 202. The
proximal portion 204 of the stylet guide is connected to the distal
end 206 of the catheter stem 208. Further stylet ports such as the
port from which stylet 203 extends are positioned at a greater
distance from the tip 198 than ports 216. The embodiment shown in
FIGS. 14 and 15 comprises two sets of stylets, each pair extending
from ports in a common plane perpendicular to the catheter central
axis. It will be readily apparent to a person skilled in the art
that other stylet arrays such as a longitudinal array or a spiral
array can also be used, and these variations are considered to be
fully within the scope of this invention.
The catheter stem 208 includes an outer tubular housing 210 which
encloses a plurality of stylets stems 212 disposed in a parallel
relationship. As can be seen from FIG. 15, the individual stylets
are directed outward in paths which have axes forming angles with
each other. Oppositely disposed stylets can form an angle of up to
180.degree. while in the configuration shown, the axis of adjacent
stylets can form an angle of up to 90.degree. for example.
FIG. 16 is a partial cross-sectional view of the probe end of the
device of this invention, taken along the 16--16 of FIG. 15. The
stylet is directed through a stylet guide means 214 in the distal
catheter end 186 which leads from a path in the proximal end 204 of
the stylet guide means parallel with other stylet guides to a
lateral orientation through stylet port 216. To facilitate
longitudinal movement of the stylet through the guide path, the
guide path preferably has a curved portion 218 extending to the
port 216. The curved path optionally has a radius which is
sufficient to deflect the deployed, extended stylet to the desired
angle, that is, a radius of up to 0.5 cm, depending upon the
diameter of the catheter. Optimally, the guide path also has a
reverse curved portion 220 which extending from the axially
parallel path in the proximal catheter end 214 outwardly away from
the port 216 to the beginning of the curved path 218.
The distal tip 198 of the catheter can have a hollow space or
bubble 222 which reflects ultrasound, permitting its easy
identification with ultrasound generated by a rectal probe as shown
in FIG. 1. Alternatively, a transponder can be mounted in the
distal tip 198.
FIG. 17 is a cross-sectional view of the handle and control end of
the device shown in FIG. 13, taken along its central axis. The
control handle 180 is attached to the control end of the catheter
stem 208. The handle 180 comprises a housing having a distal end
forming an axial sleeve 224 enclosing the proximal end 226 of the
catheter stem 208. The proximal end 226 is held in place by
setscrew 228 extending through the sleeve 224. Manual engagement
means 192 and 194 engage lateral handle housing walls 230 and 232,
and are mounted for sliding engagement with respective slots 234
and 236 in the respective housing walls. They translate the manual
motion into longitudinal motion of the stylet in the stylet guide
means.
FIG. 18 is a cross-sectional view of the control end of the device
shown in FIG. 13, taken along the line 18--18 of FIG. 17.
FIG. 19 is a cross-sectional view of the control end of the device
shown in FIG. 14, taken along the line C--C. Referring to both
FIGS. 17 and 18, finger engaging sleeve movement tabs 192 are
connected to connecting slide portion 238 extending through a
respective longitudinal slot 234 and a inner portion 240 which
forms a sliding engagement with the interior surface of the handle
wall 230. Slot 242 in the connecting slide portion receives a pin
244 extending through a sleeve connector 246. Axial movement of the
tab 192 thus effects an axial movement of corresponding sleeve 248
in the handle. Each side of the handle can have a pair of
longitudinal, parallel slots to accommodate manual tabs for both
sleeve and electric conductor.
FIG. 19 is a cross-sectional view of the control end of the device
shown in FIG. 13, taken along the line 19--19 of FIG. 18. Referring
to FIGS. 17 and 19, finger engaging electrical conductor movement
tab 194 is connected through a connecting slide portion 250
extending through a respective longitudinal slot 236 to a inner
portion 252 which forms a sliding engagement with the interior
surface of the handle wall 232. Slot 254 receives a pin 256
extending through a electrical conductor connector 258. Axial
movement of the tab 194 thus effects an axial movement of the
corresponding electrical conductor 260 in the handle.
Movement of adjacent tabs 192 and 194 advance the corresponding
sleeve and electrical conductor together through the corresponding
stylet guide, out the corresponding stylet port, and through
intervening tissue to the target tissue to be ablated. Reverse
movement of the sleeve tab 192 then retracts the sleeve to expose a
selected area of the electrical conductor surface in the tissue,
preparatory to ablation.
FIG. 20 is a side view of the non-conductive sleeve connector of
the embodiment show in FIGS. 17 and 19, and FIG. 21 is a
cross-sectional view of the non-conductive sleeve connector shown
in FIG. 20, taken along the line 21--21. Connecting pin 244 extends
through a hole in the sleeve connector 246. An axial edge of the
sleeve connector 246 is connected to the proximal end portion 248
of the sleeve.
FIG. 22 is a side view of the electrical conductor connector of the
embodiment show in FIGS. 17 and 19, and FIG. 23 is a
cross-sectional view of the electrical conductor connector shown in
FIG. 22, taken along the line 23--23. Connecting pin 256 extends
through a hole in the electrical conductor connector 258. An axial
edge of the electrical conductor connector 258 is connected to the
proximal end portion 260 of the electrical conductor.
FIG. 24 is a cross-sectional view of the distal end of the
non-conductive sleeve shown in FIGS. 15-17, taken along its central
axis. The non-conductive sleeve 202 comprises a tapered leading tip
262 and a rigid proximal portion 264. A flexible portion 266
extends between the leading tip 262 to the rigid proximal portion
264. The flexible portion 266 can be any flexible configuration
such as a spiral coil, wire braid, stainless steel tube, or any
other flexible construction which yields a catheter which has the
required flexibility and torque strength. If the flexible portion
266 and the rigid proximal portion 264 are made of a conductive
materials such as metal, they can be covered with an insulating
sleeve 268. The annular ridges 270 in the rigid proximal portion
and the flange 272 in the tip engage the sleeve 268, securing the
sleeve in place. The inner lumen 274 of the non-conductive sleeve
202 receives the electrical connector 200. A temperature sensor
such a thermistor 271 can be mounted on the tip to provide local
temperature information. An ultrasound transponder 273 can also be
mounted on the tip to provide a signal useful for precise
positioning of the stylet tip in a tissue to be ablated.
FIG. 25 is a top view of a two stylet preferred embodiment of an RF
ablation catheter of this invention. The flexible catheter 300,
attached to handle 302, has a terminal stylet guide 304 with two
stylets 306 and 308. The handle has stylet sleeve tabs 356 and
electrode tabs 358 as will be described in greater detail
hereinafter. The handle is also connected to a visual monitor 301
and RF power connector 303, transponder connector 305 and
thermocouple connector 307. The portion of the catheter 300 leading
from the handle 302 to the stylet guide tip 304 can optionally has
a graduated stiffness. For example, the catheter can be designed to
be more stiff near the handle and more flexible near the tip, or
any other stiffness profiles. The catheter can be constructed of an
inner slotted stainless steel tube with outer flexible sleeve such
as is described in U.S. Pat. No. 5,322,064, the entire contents of
which are incorporated herein by reference. It can also be made of
coiled or braided wire to which an outer sleeve is bonded.
FIG. 26 is a top view of the stylet tip of the embodiment shown in
FIG. 25, FIG. 27 is a side view of the single grind electrode tip
shown in FIG. 26, and FIG. 28 is an end view of the electrode tip
shown in FIG. 27. In this embodiment, the sharpened tip 337 and
leading cutting edges 328 and 330 are formed by grinding one
surface of the tip, the cutting edges forming an angle, "d", of
from 15.degree. to 45.degree. and preferably from 25.degree. to
35.degree. with a line parallel with the central axis of the tip.
The proximal surface of the tip forms a shoulder 332 which the
leading or distal edge 334 of the sleeve 336 abuts, preventing
movement of the sleeve 336 over the sharpened tip. The sleeve 336
can also support temperature sensors such as a thermistor 338 and a
ultrasound transponder 340.
FIG. 29 is a side view of an alternative double grind electrode
tip, and FIG. 30 is an end view of the electrode tip shown in FIG.
29. In this embodiment, the sharpened tip 342 and leading cutting
edges 344 and 341 are formed by grinding both surfaces of the tip.
The proximal surface of the tip forms a shoulder 348 which the
leading or distal edge of a sleeve (not shown) abuts, preventing
movement of the sleeve over the sharpened tip. The forward cutting
edges of this embodiment make little if any contact with the inner
surface of the stylet guide in the catheter tip, preventing dulling
of the cutting edge.
FIG. 31 is a top view of the handle portion of the ablation
catheter of FIG. 25. The handle 302 has an upper housing plate 350
upon which stylet sleeve positioning slides 352 and electrode
positioning slides 354 with manual tabs 356 and 358 are mounted for
sliding movement in the direction of the central axis of the
housing. The position of the leading edges 360 of the slides
relative to the graduated markings 362 on the housing plate surface
are used to determine the distance the sleeve and stylet have been
advanced from the stylet guide toward tissue to be treated.
FIG. 32 is a side elevational view of the handle portion shown in
FIG. 31 taken along the line 32--32 with the bottom housing cover
plate partially removed. The proximal end of the catheter 300
passes through a cylindrical hole 364 in the cylindrical knurled
knob 366 and cylindrical receptor 368 formed by the opposed
hemicylindrical surfaces in the distal ends of the upper housing
plate 350 and lower housing plate 370. The proximal end of the
knurled knob 366 has a cylindrical receptor 372 which forms a
sliding fit with a cylindrical projection 374 formed by the distal
ends of the housing plates 350 and 370. Setscrew 376 secures the
knob 366 to the catheter 300 so they rotate together as a unit. Pin
378 extends through the knob 366 into an annular groove 380,
allowing rotation but preventing axial movement of the knob 366
relative to the cylinder 374. The angular position of the knob 366
relative to the housing plate 350 is shown by the position of the
arrow 382 relative to the graduations 384 on the knob (FIG. 31).
Knurled knob 386 treadingly engages hole 388 in the housing plate
350. When the catheter knob 366 has been turned to rotate the
catheter 300 (and the stylet guide on its end) to a desired stylet
orientation, advancement of the knob 386 against the catheter
surface 390 secures its angular position. The stylets are then
advanced through surrounding tissue to the depth desired, as
indicated by graduations 362.
FIG. 33 is a bottom view of the handle portion shown in FIG. 31
with the catheter, distal knob and bottom cover plate removed, and
FIG. 34 is a cross-sectional view of the handle portion taken along
the line 34--34 in FIG. 33. Stylet movement guide plates 392 and
394 are securely mounted in terminal end receptors 396 in the inner
surfaces of upper housing plate 350. Each of the guide plates 392
and 394 has a sleeve guide slot 398 and a electrode guide slot 400
therein. Screws 402 extend through sleeve guide slots 400 and
threadingly engage the sleeve guide blocks 404. Axial movement of
the screws 402 and guide blocks 404 attached thereto is limited by
the length of the slots 398. Sleeve connector 406 attached to
stylet sleeve 408 is secured to the guide block 404 by screw 410.
Slide plate 412 mounted for sliding movement in a slot 414 in the
housing plate 350 is secured to guide block 404. Screws 416 extend
through sleeve guide slots 400 and threadingly engage the electrode
guide blocks 418. Axial movement of the screws 416 and guide blocks
418 attached thereto is limited by the length of the slots 400.
Electrode connector 420 attached to stylet electrode 422 is secured
to the guide block 418 by screw 424. Slide plate 354 mounted for
sliding movement in a slot 426 in the housing plate 350 is secured
to guide block 418.
FIG. 35 is a cross-sectional view of the central portion of the
handle portion shown in FIG. 32 in the stylet and sleeve retracted
position (corresponding to the positions in FIG. 31). FIG. 36 is a
cross-sectional view with the stylet and sleeve in an extended
position, and FIG. 37 is a cross-sectional with the stylet in an
extended position and the sleeve partially retracted therefrom. The
stylets are extended after the catheter is inserted to place the
stylet guides in a position laterally adjacent the target tissue to
be treated and the catheter has been rotated to orient the stylet
guide outlets in the direction of the target tissue. The stylets
are extended through intervening tissue to the target tissue by
moving the manual tabs 356 and 358 toward the distal end of the
handle as shown in FIG. 37. This effects simultaneous movement of
the stylet sleeve 408 and electrode 422. After the extension has
proceeded to the extent required to place the tip of the electrode
422 in the target tissue, the sleeve 408 is retracted to the
position shown in FIG. 37 by moving the manual tab 356 in the
proximal direction to the extent required to expose the desired
portion of the electrode as indicated by graduations 362 (FIG. 31).
The RF current is then applied to the electrodes until the desired
ablation has been achieved. With this embodiment, two stylets can
be extended, sleeves retracted, and the ablation achieved either
concurrently or sequentially.
FIG. 38 is a schematic view of a deployment of two stylets in a
prostate showing stylet orientation for overlapping ablation zone
method of this invention. For purposes of illustration but not by
way of limitation, the prostate has been selected for this
explanation, and application of this method and assembly to other
areas of the body are intended to be included.
The tissues to be treated for the treatment of BPH are located in
the transition zone 428 of the prostate. A catheter of this
invention 430 has been inserted up the urethra 432 to a position
adjacent the prostate. Two stylets 434 and 436 have been passed
through the urethral wall 432 and surrounding tissue into the
target tissue, and the non-conducting sleeves 438 and 440 have been
retracted to expose a portion of the respective electrical
conductors 442 and 444 at the end of each stylet. The angle between
the axes of the stylets in this embodiment, "e", is less than
180.degree., preferably less than 110.degree.. For most overlapping
ablations, angles of 15.degree. to 90.degree., and more usually
from 20.degree. to 70.degree. are most practical. A grounding plate
(not shown) is placed on the body exterior.
When electrodes 442 and 444 are supplied with RF current, the
circuit from the electrodes to a grounding plate is closed. The
current density flowing through the tissue passes through the
target tissue to be treated, creating lesions having the
approximate cross-sectional shape of overlapping zones 446 and 448.
The current density rapidly decreases as a function of distance,
limiting the size of the lesions. In this manner, lesions can be
caused to overlap to form a larger lesion, increasing the
efficiency of the treatment. It will be readily apparent that these
processes can be carried out concurrently, as described, or
sequentially, and these variations are intended to be included in
this invention.
Although preferred embodiments of the subject invention have been
described in some detail, it is understood that obvious variations
can be made without departing from the spirit and the scope of the
invention as defined by the appended claims.
* * * * *