U.S. patent number 5,435,805 [Application Number 08/062,364] was granted by the patent office on 1995-07-25 for medical probe device with optical viewing capability.
This patent grant is currently assigned to Vidamed, Inc.. Invention is credited to James A. Baker, Jr., Stuart D. Edwards, Ronald G. Lax, Ingemar H. Lundquist, Hugh R. Sharkey.
United States Patent |
5,435,805 |
Edwards , et al. |
July 25, 1995 |
Medical probe device with optical viewing capability
Abstract
A medical probe device comprising a catheter having a stylet
guide housing with at least one stylet port in a side thereof and
stylet guide means for directing a flexible stylet outward through
at least one stylet port and through intervening tissue to targeted
tissues. The stylet guide housing has an optical viewing means
positioned for viewing the stylet and adjacent structure which
includes a fiber optic channel means for receiving a fiber optic
viewing device. The fiber optic channel means can include a guide
port means for directing longitudinal movement of a fiber optic
device with respect to the stylet guide means in a viewing zone and
a flushing liquid channel in the stylet guide housing having an
exit port positioned to direct flushing liquid issuing therefrom
across the end of a fiber optic device when positioned in the
viewing zone. The optical viewing means can comprise a viewing
window positioned in the stylet guide housing for viewing the
stylet when it is directed outward from its respective stylet port.
The optical viewing means can include a fiber optic channel in the
stylet guide housing for receiving the a fiber optic viewing device
and aligning the viewing end thereof with the viewing window.
Windowed devices can include a flushing liquid channel in the
stylet guide housing having an exit port positioned to direct
flushing liquid issuing therefrom across a surface of the viewing
window.
Inventors: |
Edwards; Stuart D. (Los Altos,
CA), Sharkey; Hugh R. (Redwood City, CA), Lundquist;
Ingemar H. (Pebble Beach, CA), Lax; Ronald G. (Grass
Valley, CA), Baker, Jr.; James A. (Palo Alto, CA) |
Assignee: |
Vidamed, Inc. (Menlo Park,
CA)
|
Family
ID: |
22041995 |
Appl.
No.: |
08/062,364 |
Filed: |
May 13, 1993 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
929638 |
Aug 12, 1992 |
|
|
|
|
12370 |
Feb 2, 1993 |
|
|
|
|
Current U.S.
Class: |
604/22 |
Current CPC
Class: |
A61N
1/06 (20130101); A61B 18/00 (20130101); A61N
1/403 (20130101); A61B 10/0275 (20130101); A61B
10/0233 (20130101); A61B 18/1485 (20130101); A61N
1/40 (20130101); A61B 18/1442 (20130101); A61N
5/045 (20130101); A61B 18/1815 (20130101); A61B
18/1477 (20130101); A61B 18/18 (20130101); A61B
10/06 (20130101); A61B 2018/00083 (20130101); A61B
2018/00821 (20130101); A61B 2017/22082 (20130101); A61B
2090/3782 (20160201); A61B 2018/1425 (20130101); A61B
2017/22072 (20130101); A61B 2018/00982 (20130101); A61B
2217/007 (20130101); A61M 25/0068 (20130101); A61B
10/02 (20130101); A61B 2018/2238 (20130101); A61M
3/0279 (20130101); A61M 2025/0086 (20130101); A61B
2017/00106 (20130101); A61B 2017/00194 (20130101); A61B
2017/00274 (20130101); A61B 2017/00123 (20130101); A61B
2090/3614 (20160201); A61B 2218/003 (20130101); A61B
2018/00005 (20130101); A61B 2017/00867 (20130101); A61B
2018/126 (20130101); A61M 25/0082 (20130101); A61B
10/0241 (20130101); A61B 2017/00181 (20130101); A61B
2018/00946 (20130101); A61B 2017/2939 (20130101); A61B
2018/00011 (20130101); A61B 2018/00678 (20130101); A61B
2017/22077 (20130101); A61B 2018/00023 (20130101); A61B
2018/00797 (20130101); A61B 2018/00291 (20130101); A61B
2018/00875 (20130101); A61M 2025/0087 (20130101); A61B
2018/1253 (20130101); A61B 2017/00296 (20130101); A61B
2018/0091 (20130101); A61B 2090/3786 (20160201); A61N
5/04 (20130101); A61B 18/14 (20130101); A61B
2018/00196 (20130101); A61M 2025/0096 (20130101); A61B
2018/00916 (20130101); A61B 2018/1273 (20130101); A61M
2025/018 (20130101); A61B 2018/00726 (20130101); A61B
2018/00327 (20130101); A61B 18/24 (20130101); A61B
2018/00702 (20130101); A61B 2217/005 (20130101); A61B
2018/00577 (20130101); A61B 2090/0814 (20160201); A61B
2017/00084 (20130101); A61B 2018/1412 (20130101); A61M
2025/0089 (20130101); A61M 2025/009 (20130101); A61B
2018/00547 (20130101); A61B 2017/00092 (20130101); A61B
2018/00101 (20130101); A61B 2018/0022 (20130101); A61B
2017/3488 (20130101); A61B 2090/3925 (20160201); A61B
2017/00292 (20130101); A61B 2018/00761 (20130101); A61F
2007/0054 (20130101); A61M 25/0069 (20130101); A61B
2017/00101 (20130101); A61B 2017/248 (20130101); A61B
2018/00095 (20130101); A61B 2018/00791 (20130101); A61B
2018/00744 (20130101); A61B 2018/128 (20130101); A61B
18/148 (20130101); A61B 2017/003 (20130101); A61B
2018/00886 (20130101); A61B 2090/378 (20160201) |
Current International
Class: |
A61B
18/18 (20060101); A61B 18/14 (20060101); A61B
18/00 (20060101); A61B 10/00 (20060101); A61N
1/06 (20060101); A61N 5/04 (20060101); A61N
5/02 (20060101); A61N 1/40 (20060101); A61B
17/28 (20060101); A61B 17/24 (20060101); A61B
17/34 (20060101); A61B 17/22 (20060101); A61B
18/20 (20060101); A61B 18/08 (20060101); A61B
18/04 (20060101); A61B 18/22 (20060101); A61B
19/00 (20060101); A61B 18/24 (20060101); A61F
7/00 (20060101); A61M 1/00 (20060101); A61M
25/00 (20060101); A61B 17/00 (20060101); A61M
3/02 (20060101); A61M 3/00 (20060101); A61B
017/39 () |
Field of
Search: |
;128/24AA
;604/19-22,53,164,280 ;606/39,45 ;607/96,98-102,113,115,116,138,156
;601/2 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
10858/92 |
|
Aug 1992 |
|
AU |
|
0370890 |
|
May 1990 |
|
EP |
|
0453071 |
|
Oct 1991 |
|
EP |
|
0495443 |
|
Jul 1992 |
|
EP |
|
521264A2 |
|
Jan 1993 |
|
EP |
|
2848484 |
|
May 1979 |
|
DE |
|
3218314 |
|
Jun 1983 |
|
DE |
|
3844131 |
|
Dec 1988 |
|
DE |
|
3838840 |
|
May 1990 |
|
DE |
|
2121675 |
|
May 1990 |
|
JP |
|
9007303 |
|
Jul 1990 |
|
WO |
|
WO911213 |
|
Aug 1991 |
|
WO |
|
9116859 |
|
Nov 1991 |
|
WO |
|
9207622 |
|
May 1992 |
|
WO |
|
WO92/10142 |
|
Jun 1992 |
|
WO |
|
9210142 |
|
Jun 1992 |
|
WO |
|
9221278 |
|
Dec 1992 |
|
WO |
|
9221285 |
|
Dec 1992 |
|
WO |
|
9304727 |
|
Apr 1993 |
|
WO |
|
9308755 |
|
May 1993 |
|
WO |
|
9308756 |
|
May 1993 |
|
WO |
|
9308757 |
|
Oct 1993 |
|
WO |
|
9320767 |
|
Oct 1993 |
|
WO |
|
9320768 |
|
Oct 1993 |
|
WO |
|
9320886 |
|
Oct 1993 |
|
WO |
|
9320893 |
|
Oct 1993 |
|
WO |
|
WO93/25136 |
|
Dec 1993 |
|
WO |
|
WO93/251136 |
|
Dec 1993 |
|
WO |
|
9403759 |
|
Feb 1994 |
|
WO |
|
9404222 |
|
Mar 1994 |
|
WO |
|
9405226 |
|
Mar 1994 |
|
WO |
|
9406377 |
|
Mar 1994 |
|
WO |
|
9407410 |
|
Apr 1994 |
|
WO |
|
9407411 |
|
Apr 1994 |
|
WO |
|
9407412 |
|
Apr 1994 |
|
WO |
|
9407413 |
|
Apr 1994 |
|
WO |
|
9407441 |
|
Apr 1994 |
|
WO |
|
9407446 |
|
Apr 1994 |
|
WO |
|
9407549 |
|
Apr 1994 |
|
WO |
|
Other References
Diasonics, Brochure DIA 2000 171 CRF May 1988. .
Perinchery, Narayan, "Neoplasms of the Prostate Gland." pp. 378-409
(Date Unknown). .
Urology 5th ed., Storz, Jan. 1992. .
Transuretheral uwave Therotherapy for Prostatism: Early Mayo
Foundation Experience: Blute, Mayo Clinic Proceedings: vol. 67 May
1992 pp. 417-421. .
New Therapies for Benign Prostatic Hyperplasia, Editorial
Bruskewitz, Mayo Clinic Proceedings vol. 67 May 1992 pp. 493-495.
.
Industry Strategies, Urology: "A Multi Billion Dollar Market . . .
" Stephen Scala Nov. 19, 1991, pp. 1-32. .
U.I. Dept. of Health and Human Services, MMWR 41: 401-404 vol. 41,
No. 23 (Jun. 12, 1992). .
Standard Urology Product Catalog, CIRCON ACMI: Stanford (1992).
.
Chang, Raymond J. et al, American Heart Journal, 125: 1276-1283
(May, 1993). .
Cosman, Eric R. et al, Sterostatic and Functional Neurosurgery, pp.
2490-2499 (Date Unknown). .
Blute, Michael L. et al, Mayo Clinic Proceedings, 67:417-421
(1992). .
Bruskewitz, Reginald, Mayo Clinic Proceedings, 67:493-495 (1992).
.
Chang, Raymond J. et al, American Heart Journal, 125: 1276-1283
(May, 1993). .
Scala, Stephen M. et al, Cowen: Industrial Strategies
(1991)..
|
Primary Examiner: Rosenbaum; C. Fred
Assistant Examiner: Mendez; Manuel
Attorney, Agent or Firm: Flehr, Hohbach, Test, Albritton
& Herbert
Parent Case Text
This application is a continuation-in-part of applications Ser. No.
07/929,638 filed Aug. 12, 1992 and Ser. No. 08/012,370 filed Feb.
2, 1993 allowed. A related application Ser. No. 08/061,647 titled
MEDICAL PROBE WITH STYLETS filed concurrently herewith and has been
allowed.. The entire contents of the above applications are hereby
incorporated by reference.
Claims
We claim:
1. A medical probe device for medical treatment of tissue of a
prostate through a urethra defined by a urethral wall comprising a
guide housing having proximal and distal extremities and having a
passageway extending from the proximal extremity to the distal
extremity, a stylet slidably mounted in the guide housings, means
guide carried by the distal extremity of the guide housing and in
communication with said passageway for directing the stylet
sidewise of the guide housing, the stylet including a flexible
radio frequency electrode with a sharpened tip and an insulating
sleeve coaxially mounted on the electrode and movable relative to
the electrode handle means mounted on the proximal extremity of the
guide housing for introducing the distal extremity of the guide
housing into the urethra into the vicinity of the prostate said
handle means including means mounted on the proximal extremity of
the guide housing and secured to the stylet for advancing the
stylet from the passageway of the guide housing to cause the
sharpened tip of the radio frequency electrode and the insulating
sleeve to penetrate the urethral wall and to extend into the tissue
of the prostate with the insulating sleeve extending through the
urethral wall said handle means also including means for causing
relative movement between the insulating sleeve and the radio
frequency electrode to expose a predetermined length of the radio
frequency electrode in the tissue of the prostate; with the
insulating sleeve extending through the urethral wall, means for
supplying radio frequency energy to the radio frequency electrode
to cause the temperature of the tissue of the prostate adjacent the
predetermined length of the radio frequency electrode to be raised
to cause destruction of cells in the tissue of the prostate, and an
optical viewing device positioned in the guide housing having a
viewing field that extends forwardly and sidewardly of the guide
housing to permit viewing of the radio frequency electrode and the
insulating sleeve as they are deployed sidewise from the distal
extremity of the guide housing.
2. A medical probe device as in claim 1 wherein the guide housing
includes a channel receiving said optical viewing device and
permitting longitudinal movement of the optical viewing device with
respect to the guide means to shift the viewing field.
3. A medical probe device as in claim 1 wherein said guide housing
includes a flushing liquid channel for directing a flushing liquid
into the viewing field.
4. A medical probe device as in claim 3 wherein said guide housing
includes at least one flushing liquid return lumen.
5. A medical probe device as in claim 2 wherein the distal
extremity of the guide housing has a tip and wherein the optical
device viewing channel terminates at a position proximal of the
tip.
6. A medical probe device as in claim 5 wherein said guide housing
is provided with a transverse depression proximal of the tip and
within the viewing field of the optical viewing device.
7. A medical probe device as in claim 2 wherein the distal
extremity of the guide housing has a tip and wherein the optical
viewing device channel extends through the tip.
8. A medical probe device as in claim 7 wherein the distal
extremity of the guide housing is provided with a transverse
depression extending through and across the optical device viewing
channel.
9. A medical probe device as in claim 5 wherein the guide housing
includes a window extending through said tip and in the viewing
field.
10. A medical probe device as in claim 1 wherein the optical
viewing device comprises an eyepiece, a fiber optic, a focal lens
and means for adjusting the longitudinal position of the focal lens
with respect to a fiber optic.
11. A device as in claim 1 wherein said guide housing has a
longitudinal axis and wherein said means for directing the stylet
sidewise of the housing includes means for directing the stylet at
an angle ranging from 10 degrees to 90 degrees with respect to the
longitudinal axis of the guide housing.
12. A medical probe device comprising an elongate guide housing
having proximal and distal extremities and having a passageway
therein extending from the proximal extremity to the distal
extremity along a longitudinal axis, a stylet mounted in said guide
housing and having proximal and distal extremities, a handle
mounted on the proximal extremity of the guide housing, means
mounted on the proximal extremity of the guide housing and
connected to the handle and connected to the stylet for causing
advancement of the stylet through said passageway, the distal
extremity of the guide housing being in communication with the
passageway and permitting the distal extremity of the stylet to be
advanced out of the passageway sidewise at an angle with respect to
the longitudinal axis and an optical viewing device mounted in said
guide housing and having a distal extremity positioned in the
distal extremity of the guide housing and having a field of view
which permits viewing the distal extremity of the stylet as it is
advanced from the passageway sidewise of the longitudinal axis.
13. A device as in claim 12 wherein said guide housing is provided
with a rounded tip at its distal extremity and wherein said guide
housing is provided with a transversely extending recess proximal
of the rounded tip, wherein the guide housing causes the distal
extremity of the stylet to pass through the transversely extending
recess and wherein the optical viewing device is disposed so that
the field of view encompasses the transversely extending
recess.
14. A device as in claim 13 wherein the rounded tip has a bore
extending therethrough serving as a window which is disposed in the
field of view to permit viewing distal of the tip.
15. A device as in claim 12 wherein said stylet includes a
conductive radio frequency electrode and an insulating sleeve
coaxially mounted on the conductive radio frequency electrode and
exposing a predetermined length of the conductive radio frequency
electrode.
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
ablation 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 treatment 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
intervention.
In particular, this invention is directed to a medical probe device
provided with an optical viewing capability for precise positioning
of the treatment device.
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 targeted tissues 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 by
the incidence of BPH in 50 percent of men over 50 years of age and
increases in incidence to over 75 percent in men over 80 years of
age. Symptoms of urinary obstruction occur most frequently between
the ages of 65 and 70 when approximately 65 percent of men in this
age group have prostatic enlargement.
Currently there is no nonsurgical method for treating BPH which has
proven to be effective. 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 in the United States undergo surgery for removal
of prostatic tissue. 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
related 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, chronic infection,
dilation of ureters, etc.), which is not without significant
consequences. Also, a significant number of patients with symptoms
sufficiently severe to warrant surgical intervention are therefore
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.
Ablation 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 an electromagnetic 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 in organs such as the prostate,
and 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 ablation 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 ablate the
tissue causing the constriction of 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.
In addition to ultrasound positioning capabilities, it is desirable
to provide the operator with the ability to optically examine the
location and surfaces of the duct or other passageway in which the
catheter is positioned for treatment, to locate abnormalities and
mope importantly, to precisely position the catheter tip. Retention
of fertility after BPH treatment, for example, requires that the
seminal vesical openings into the urethra remain undamaged. Precise
location of these openings and the positioning of the catheter tip
to avoid damage to them requires simultaneous optical viewing of
the urethra surface and the catheter tip.
OBJECTS AND SUMMARY OF THE INVENTION
It is one object of this invention to provide a device with an
optical viewing capability for penetrating tissue, through
intervening tissues to the precise target tissue selected for a
medical action such as tissue ablation and/or substance delivery,
limiting this activity to the precise preselected site, thereby
minimizing the trauma and achieving a greater medical benefit.
Another object of this invention is to provide a device with
optical viewing capability for precise placement of the device
which delivers the therapeutic energy into targeted tissues while
minimizing effects on its surrounding tissue.
A still further object of this invention is to provide a device and
method for introducing fluid treatment agents such as flowable
liquids or gases, with greater precision and ease to a specific
location in the body.
A further object of this invention is to provide a thermal ablation
device which provides more control over the physical placement of
the stylet and over the parameters of the tissue ablation
process.
In summary, the device of this invention is a medical probe device
comprising a catheter having a stylet guide housing with at least
one stylet port in a side thereof and stylet guide means for
directing a flexible stylet outward through at least one stylet
port and through intervening tissue to targeted tissues. The stylet
guide housing has an optical viewing means positioned for viewing
the stylet which includes a fiber optic channel means for receiving
a fiber optic viewing device. The fiber optic channel means can
include a guide port means for directing axial or longitudinal
movement of a fiber optic device with respect to the stylet guide
means in a viewing zone.
The device preferably includes a flushing liquid channel in the
stylet guide housing having an exit port positioned to direct
flushing liquid issuing therefrom across the end of a fiber optic
device when positioned in the viewing zone.
The optical viewing means can optionally comprise a viewing window
positioned in the stylet guide housing for viewing the stylet when
it is directed outward from its respective stylet port. The optical
viewing means can include a fiber optic channel in the stylet guide
housing for receiving the a fiber optic viewing device and aligning
the viewing end thereof with the viewing window. Windowed devices
can include a flushing liquid channel in the stylet guide housing
having an exit port positioned to direct flushing liquid issuing
therefrom across a surface of the viewing window.
The device preferably includes at least one flushing liquid return
lumen extending to the stylet guide housing.
In the preferred embodiment of this invention, the stylet comprises
an electrical conductor enclosed within a non-conductive sleeve,
the electrical conductor being a radiofrequency electrode.
In one embodiment, the stylet guide housing has a tip portion in
which the stylet guide means is positioned and the fiber optic
channel means terminates at a position behind the tip, whereby
surfaces adjacent the tip portion can be viewed. This can include a
transverse depression positioned between said position behind the
tip and the tip which opens the viewing field of a fiber optic when
positioned in the fiber optic channel. In some embodiments, the tip
defines an fiber optic passageway means for axial or longitudinal
extension of the fiber optic to the end of the style guide housing.
The passageway means can be a longitudinal hole extending to the
end of the housing. Alternatively, the fiber optic passageway means
is an axial or longitudinal depression extending to the terminal
surface of the tip and the transverse depression, to open the axial
viewing field of a fiber optic when positioned in the fiber optic
channel.
Alternatively, the stylet guide housing can include a window
extending to said tip for the viewing field of a fiber optic when
positioned in the fiber optic channel.
The invention includes the medical probe device in combination with
a fiber optic viewing assembly comprising an eyepiece, a fiber
optic, a focal lens, and means for adjusting the axial or
longitudinal position of the focal lens with respect to the fiber
optic.
Some embodiments include a stylet positioned in at least one of
said stylet guide means, the stylet axis forming an angle of from
10.degree. to 90.degree. with the central axis of the stylet guide
housing. In one configuration, the stylet guide housing has an open
end with a curved lip which maintains the stylet axis at said
angle.
The device can have a system to maintain precise positioning of the
stylet tip comprising a catheter having a stylet guide housing at
its distal end and a tension and torque tube assembly at the
proximal end thereof. The stylet guide housing has at least one
stylet port in a side thereof and stylet guide means for directing
a flexible stylet outward through a stylet port and through
intervening tissue to targeted tissues. The tension and torque
assembly can include a twist control knob and torque coupler, an
outer torque tube attached to the torque coupler and extending from
the torque coupler through the twist control knob to the stylet
guide housing. The tension and torque tube assembly includes an
adjusting block means, an non-extendable tension tube having its
proximal end secured to the adjusting block and its distal end
secured to the stylet guide housing, the non-extendable tension
tube being enclosed within the torque tube and enclosing at least
one stylet.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of an RF ablation catheter embodiment
of this invention with an fiber optic viewing accessory.
FIG. 2 is a cross-sectional view of the optics connecting assembly
of the embodiment of FIG. 1.
FIG. 3 is an exploded, isometric view of the optics connecting
assembly of the embodiment of FIG. 1.
FIG. 4 is an enlarged cross-sectional view of the fiber optic
extension system of the embodiment shown in FIGS. 1-3.
FIG. 5 is a cross-sectional view of the optics system of the
embodiment shown in FIG. 1.
FIG. 6 is a cross-sectional view of the fiber optic viewing
accessory shown in FIG. 1 with the fiber optic viewer
retracted.
FIG. 7 is a cross-sectional view of the fiber optic viewing
accessory shown in FIG. 1 with the fiber optic viewer extended.
FIG. 8 is a fragmented cross-sectional view of a preferred catheter
tip and stylet guide housing of this invention.
FIG. 9 a distal end view of the catheter tip and style guide
housing shown in FIG. 8.
FIG. 10 is a proximal end view of the unassembled catheter tip and
stylet guide housing shown in FIG. 8, showing the lumina for the
components thereof.
FIG. 11 is a cross-sectional view of an alternative catheter tip
and stylet guide housing embodiment with a fiber optic viewing
window permitting a view of the stylet deployment.
FIG. 12 is a isometric view of a further alternative catheter tip
and stylet guide housing embodiment with a fiber optic viewing
window in the end thereof.
FIG. 13 is a isometric view of a still further alternative catheter
tip and stylet guide housing embodiment with two fiber optic
viewing windows, one at the end of the housing and the other
rearward of the stylets.
FIG. 14 is cross-sectional side view of an alternative 90.degree.
stylet guide housing shown in FIG. 8 with the stylet omitted.
FIG. 15 is a cross-sectional side view of an alternative 45.degree.
stylet guide housing of this invention.
FIG. 16 is a cross-sectional side view of an alternative 30.degree.
stylet guide housing of this invention.
FIG. 17 is a cross-sectional side view of an alternative 10.degree.
stylet guide housing of this invention.
FIG. 18 is a schematic view of a stylet deployment into a portion
of a prostate protruding into the urinary bladder.
FIG. 19 is a side view of a 45.degree. shovel nose stylet guide of
this invention.
FIG. 20 is a side view of a 30.degree. shovel nose stylet guide of
this invention.
FIG. 21 is a side view of a 10.degree. shovel nose stylet guide of
this invention.
FIG. 22 is an end view of a shovel nose stylet guide of FIG. 19 for
a single stylet.
FIG. 23 is an end view of a shovel nose stylet guide of FIG. 19 for
two stylets.
FIG. 24 is an exploded view of the RF ablation catheter shown in
FIG. 1.
FIG. 25 is an isometric view of the adjuster block and tension tube
assembly of the RF ablation catheter shown in FIG. 24.
FIG. 26 is a detailed view "A" of the tension tube connections
shown in FIG. 25.
FIG. 27 is an exploded view of the sleeve and electrode slide block
assembly of the embodiment shown in FIG. 24.
FIG. 28 is a schematic view of a deployment of two stylets in a
prostate showing a stylet orientation for overlapping ablation zone
method.
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 ablation or sampling from a catheter positioned in the
vicinity of targeted tissues.
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 targeted tissues. 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
such as a laser fiber optic. 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 microwave antenna, it can be used to ablate or destroy
targeted tissues. As a hollow tube, it can be used to deliver a
treatment fluid such as a liquid to targeted tissues. 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 these procedures 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 utilized 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 ablation with
electrodes positioned within the urethra exposes the urethral wall
to destructive temperatures. To avoid this, 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 prostate 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 targeted tissues is
enclosed within a longitudinally adjustable sleeve shield which
prevents exposure of the tissue adjacent to the sleeve to the RF
current. The sleeve movement is also used to control the amount of
energy per unit surface area which is delivered by controlling the
amount of electrode exposed. Thus the ablation is confined to the
tissues targeted for ablation, namely those causing the mechanical
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 an isometric view of an RF ablation catheter embodiment
of this invention with a fiber optic viewing accessory. The
flexible catheter 2, attached to handle 4, has a terminal stylet
guide 6 with two stylets 8. The handle has stylet electrode tabs 10
and 11 and sleeve tabs 12 and 13 as will be described in greater
detail hereinafter. The handle 4 is also connected to in optical
viewing assembly 14 and RF power connector 16, transponder
connector 18 and thermocouple connectors 20. The portions of the
catheter 2 leading from the handle 4 to the stylet guide tip 6 can
optionally have 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.
The fiber optic viewing assembly in this embodiment includes a lens
focusing assembly 22, a lens viewing assembly support connector 24
assembly attached to a male quick disconnect connector 26 by
flexible tubing 28.
FIG. 2 is a cross-sectional view and FIG. 3 is an exploded,
isometric view of the optics connecting assembly of the embodiment
of FIG. 1. The lens connector assembly 24 comprises receptor
housing 30 having a threaded bore 32. Engagement of the threaded
bore 32 with the threaded tubular housing connector 34 secures the
optical assembly to the handle 4 (FIG. 1). An interior cavity 36 of
the receptor housing 30 receives the distal end of the fiber optic
control housing 38, and the opposed surfaces thereof are sealed by
O-ring 40 and flange 42 to prevent escape of flushing fluid. One
end of the flexible tubing 28 engages cylindrical receptor 44 of
the fiber optic control housing 38, and the other end engages a
cylindrical receptor 46 in the male quick release member 26.
FIG. 4 is an enlarged cross-sectional view of the fiber optic
extension system of the embodiment shown in FIGS. 1-3. Axial or
longitudinal adjustment of the fiber optic control housing 38
effects axial or longitudinal movement of the fiber optic in the
stylet guide housing as will be described in greater detail
hereinafter. This axial or longitudinal adjustment is effected by
the relative movement between inner surface 48 of housing 30 and
the outer surface 50 of the distal end of the fiber optic control
housing 38. Advancing movement of the fiber optic control housing
38 (leftward movement in this figure) is limited by the abutment of
surface 52 of flange 42 with the opposing end surface of the
receptor housing 30. The flange 42 has an annular distal sleeve
terminus 54 which is held between respective cylindrical inner
surface 56 of the receptor housing 30 and outer surface 58 of
control housing 38. Its advancing movement is limited by abutment
of surface 60 of the flange 42 and opposed abutment surface 62 of
the control housing 38. Retracting movement of control housing 38
and the fiber optic attached thereto is limited by impingement of
annular stop rim 59 against O-ring 40.
Flushing liquid to clean the viewing tip of the fiber optic is
provided through flushing liquid supply bore 64 from a flushing
liquid supply connector (not shown) and enters the cavity 66.
Escape of the liquid from between the receptor housing 30 and the
control housing 38 is prevented by the sealing engagement of the
O-ring 40 with the surfaces opposed thereto and a seal (not shown)
in opening 41. The liquid flows through channel 72 and opening 74,
and then through a tubing (not shown) surrounding the fiber optic.
Outlet port 70 receives a conventional fiber optic illumination
light source connection.
The distal tip of the housing connector has an expanded diameter or
flange 78 for connection with the handle 4. The receptor housing
has a mounting surface 80 at a sloped angle with the axis thereof
for engaging an opposed upper surface of handle 4 (FIG. 1).
FIG. 5 is a cross-sectional view of the optics system of the
embodiment shown in FIG. 1. The conventional focusing system 22
comprises an eyepiece 82 connected to the end of cylinder 83.
Transparent window 84 is mounted in the proximal end. A quick
disconnect junction 86 is positioned at the distal end of the
cylinder 83. The proximal viewing end of the fiber optic (not
shown) is mounted in the cavity 85.
The lens focusing system comprises a conventional convex lens 88
mounted in a lens support cylinder 90. A manual adjusting sleeve 96
is mounted for sliding movement about the cylinder 83. The
adjusting sleeve 96 is attached to the lens support 90 by pin 94
which extends through slot 92. Slot 92 has the shape of a short
portion of a helix so that rotation of sleeve 96 about the sleeve
in the clockwise direction and counter-clockwise moves the lens
toward or away from the fiber optic viewing end, respectively, to
bring the image into focus for the viewer.
FIG. 6 is a cross-sectional view of the fiber optic viewing
accessory shown in FIG. 1 with the fiber optic viewer retracted,
and FIG. 7 is a cross-sectional view of the fiber optic viewing
accessory shown in FIG. 2 with the fiber optic viewer extended. As
the fiber optic control housing 38 is advanced by the operator into
the receptor housing 30, the viewing tip 102 of fiber optic 104 is
advanced outward through the stylet guide housing 6 toward the tip
thereof from the position shown in FIG. 6 to the position shown in
FIG. 7, enabling the operator to view the duct surfaces surrounding
the housing 6 to determine the condition of these surfaces and
locate the position of ducts such as the seminal ducts which are to
be avoided in the treatment. The stylet housing tip 6 is moved to
position it in the desired location by movement of the handle 4 and
catheter 2 (FIG. 1). By retracting the fiber optic control housing
38 from the housing 30, the fiber optic viewing tip 102 is
withdrawn to the surface of the stylet guide housing 6 as shown in
FIG. 6 for viewing the surface through which the stylets 8 (FIG. 1)
are to be extended.
FIG. 8 is a fragmented cross-sectional view of a preferred catheter
tip and stylet guide housing of this invention. The solid catheter
tip 106 has a lateral depression or saddle 108 therein having a
central axis approximately perpendicular to a plane through the
central axis of the tip. The depression 108 has a proximal wall
110. The depression 108 can extend up to approximately half of the
thickness of the housing, but at least sufficiently to unblock the
viewing surface of the viewing tip 112 of the fiber optic 114. The
fiber optic viewing tip 112, when positioned at the opening in wall
110, provides a field of view with lateral margins 116 and a
terminal margin 118. This includes the path of stylets extended
outward through ports 120.
FIG. 9 is a distal end view of the catheter tip and style guide
housing shown in FIG. 8. The proximal end of depression 108 is
split to form two projections or ears 122 and 124 which define a
longitudinal or axial or longitudinal groove or saddle 126
extending from the depression 108 to the terminal tip 128 of the
catheter 106. Groove 126 opens the field of view for the viewing
tip 112 when in the solid line position shown in FIG. 8 and permits
extension of the fiber optic and its tip (as described with respect
to FIGS. 4, 6 and 7) through the longitudinal groove to the dotted
line positions 114' and 112'. In the latter position, the field of
vision has side margins 130 and a terminal margin 132. This permits
the operator to examine the inner duct surfaces ahead of the
catheter tip. In an alternative embodiment, the grove 126 can be
replaced with a hole in the end of the tip having a size and
position to permit extension of the fiber optic 114
therethrough.
The fiber optic 114 is positioned in a passageway 134 which is
sufficiently larger than the fiber optic to permit flow of flushing
liquid around the fiber optic to the exit in wall 110. The flushing
liquid flow clears debris from the viewing tip. The inner walls of
the duct (not shown) surrounding the catheter tip 106 during use
confine the liquid flow, so the liquid continues to pass over the
fiber optic tip even when it has been advanced to the dotted line
position. Return flushing liquid lumina 136 and 138 extend through
wall 110 for constant removal of contaminated flushing liquid.
FIG. 10 is a proximal end view of the unassembled catheter tip and
stylet guide housing shown in FIG. 8, showing the lumina for the
components thereof. The stylets are advanced and retracted through
stylet lumina 140 and 142 to the stylet ports 120. The fiber optic
is advanced and retracted through fiber optic lumen 134. The
contaminated flushing fluid is removed through flushing fluid
return lumina 136 and 138. Temperature sensor lumen 144 is used to
house leads of a temperature sensor (not shown).
FIG. 11 is a cross-sectional view of a catheter tip and stylet
guide housing embodiment with a cylindrical fiber optic viewing
window permitting a view of the stylet deployment. In this view,
the catheter end 146 includes a short cylindrical, transparent
window 148 and tip cap 150. Stylet guide tubing 152 extends through
the enclosure defined by the window 148 to ports (not shown). The
catheter end 146 has a lumen 154 in which a fiber optic 155 can be
positioned and a transparent plate 156 for sealing the end of the
lumen 154. The margins 158 of the view through the plate 156
provide a wide 360.degree. view of the inside surface of a
surrounding duct and the extended stylets.
FIG. 12 is an isometric view of a catheter tip and stylet guide
housing embodiment with a fiber optic viewing window in the end
thereof. This stylized view shows a catheter tip 160 with an optic
viewing window 162 in the tip thereof. It has stylets extending
through outlet ports therein, each stylet comprising an antenna 164
surrounded by an insulating sleeve 166. Temperature sensors 168 and
170 monitor the temperature in the duct wall surrounding the
catheter. In this embodiment, the inside wall of the duct can be
examined as the catheter is advanced to the desired position.
FIG. 13 is a isometric view of a catheter tip and stylet guide
housing embodiment with two fiber optic viewing windows, one at the
end of the housing and the other rearward of the stylets. This
stylized view shows a catheter tip 172 with two optic viewing
windows 174 and 176 therein, and stylets extended through outlet
ports therein, each stylet comprising an antenna 178 surrounded by
an insulating sleeve 180. A temperature sensor 182 monitors the
temperature in the duct wall surrounding the catheter. In this
embodiment, two windows are provided, accommodating two fiber
optics or two positions for a single fiber optic. Window 174
provides a view of the surrounding as the catheter is advanced to
the desired position. Window 176 provides a view of the duct wall
in the vicinity of the stylets.
FIG. 14 is a cross-sectional side view of an alternative 90.degree.
stylet guide housing shown in FIG. 8 with the stylet omitted. The
solid catheter tip 106 has a curved guide channel 119 leading to
port 120 through which the stylet is to be guided. Terminal portion
121 of the channel 119 has an orientation of 90.degree. to the
central axis of the housing.
FIG. 15 is a cross-sectional side view of an alternative 45.degree.
stylet guide housing of this invention. In this embodiment, the
solid catheter tip 184 with lateral depression 186 has a curved
channel 188, the terminal portion 190 thereof having an axis which
forms an angle "a" with the central axis of the catheter tip. This
deploys the antenna 192 and insulating sleeve 194 at an angle "a"
in a plane through the central axis of the catheter tip. In this
embodiment, angle "a" is preferably about 45.degree..
FIG. 16 is a cross-sectional side view of an alternative 30.degree.
stylet guide housing of this invention. In this embodiment, the
solid catheter tip 196 with lateral depression 198 has a curved
channel 200, the terminal portion 202 thereof having an axis which
forms an angle "b" with the central axis of the catheter tip. This
deploys the antenna 204 and insulating sleeve 206 at an angle "b"
in a plane through the central axis of the catheter tip. In this
embodiment, angle "b" is preferably about 30.degree. .
FIG. 17 is a cross-sectional side view of an alternative 10.degree.
stylet guide housing of this invention. In this embodiment, the
solid catheter tip 208 with lateral depression 210 has a curved
channel 212, the terminal portion 214 thereof having an axis which
forms an angle "c" with the central axis of the catheter tip. This
deploys the antenna 216 and insulating sleeve 218 at an angle "c"
in a plane through the central axis of the catheter tip. In this
embodiment, angle "c" is preferably about 10.degree..
FIG. 18 is a schematic view of a stylet of FIG. 16 shown deployed
to treat a portion of a prostate protruding into the urinary
bladder. The solid catheter tip 196 is positioned at the end of the
urethra 220. Cell proliferation in the upper end 222 of the
prostate 224 has caused it to protrude into space normally occupied
by the urinary bladder, pushing a portion of the bladder wall 226
into the cavity and forming a restriction 225 beyond the end of the
urethra. The stylet sleeve 206 and electrode 204 are extended at an
angle of about 30.degree. through the urethral wall into a portion
of the protruded prostate, and RF current is applied to form the
lesion 228. This will reduce the protruded prostate, promoting its
retraction from the urethral wall and opening the restriction of
the outlet end of the urethra. The catheter having a desired angle
can be selected from those having angles "a", "b" or "c" shown in
FIGS. 15-17 to precisely orient the stylet and effect precise
penetration of prostate tissue which extends beyond the end of the
urethra, for example.
FIG. 19 is a side view of a 45.degree. shovel nose stylet guide of
this invention. In this embodiment, the catheter tip 230 has the
shape of a shovel or scoop, the extended lip 232 of which guides
the stylet 234 in a desired angle "d". This configuration opens the
upper viewing field 236 of the fiber optic 238 in the unextended
position and permits an unobstructed viewing field 240 in the fully
extended position. In this embodiment, the angle "d" is about
45.degree..
FIG. 20 is a side view of a 30.degree. shovel nose stylet guide of
this invention. In this embodiment, the catheter tip 242 has the
shape of a shovel or scoop, the extended lip 244 of which guides
the stylet 246 in a desired angle "e". This configuration opens the
upper viewing field 248 of the fiber optic 250 in the unextended
position and permits an unobstructed viewing field 252 in the fully
extended position. In this embodiment, the angle "e" is about
30.degree..
FIG. 21 is a side view of a 10.degree. shovel nose stylet guide of
this invention. In this embodiment, the catheter tip 254 has the
shape of a shovel or scoop, the extended lip 256 of which guides
the stylet 258 in a desired angle "f". This configuration opens the
upper viewing field 260 of the fiber optic 262 in the unextended
position and permits an unobstructed viewing field 264 in the fully
extended position. In this embodiment, the angle "f" is about
10.degree..
FIG. 22 is an end view of a shovel nose stylet guide of FIG. 19 for
a single stylet 234.
FIG. 23 is an end view of an alternative embodiment of a shovel
nose stylet guide for two stylets 266 and 268, the stylet guide tip
270 having a shovel lip 272 and fiber optic 274.
FIG. 24 is an exploded view of the RF ablation catheter assembly
shown in FIG. 1. The upper handle plate 276 has two central slots
278 and 280 through which the electrode control slides 10 and 11
are attached to respective left electrode slide block 282 and right
electrode slide block 284. Sleeve control slides 12 and 13 are
attached through outer slots 286 and 288 to respective left sleeve
slide block 290 and right sleeve slide block 292. Fiber optic
receptor housing 30 is mounted on the proximal surface of the upper
handle plate 276. The electrical receptor 294 is received in
respective cavities 296 and 298 in the respective upper handle
plate 276 and lower handle plate 300 attached thereto. The lower
handle plate 300 has a central cavity 302 which accommodates the
electrode and sleeve slide blocks and associated elements.
Microswitch activator blocks 304 (only left sleeve block shown) are
connected to the sleeve slide blocks 290 and 292. They are
positioned to actuate the microswitches 306 when the respective
sleeve block (and sleeve attached thereto) have been advanced. The
microswitches 306 hold the respective RF power circuits open until
the respective sleeves are advanced to a position beyond the
urethra wall and into the prostate to prevent direct exposure of
the urethra to the energized RF electrodes. Extension of the sleeve
5 mm beyond the guide is usually sufficient to protect the
urethra.
The tension-torque tube assembly 308 is mounted in the distal end
of the housing in the receptor 310.
FIG. 25 is an isometric view of the adjuster block and tension tube
assembly 308 of the RF ablation catheter shown in FIG. 24. The
torque tube 312 extends from the torque coupler 314 through the
twist control knob 316 to the stylet guide 6. Bending flexure of
the torque tube 312 during use lengthens the path from the handle
to the guide tip 6. To prevent a resulting retraction of the stylet
sleeve and electrode components when the torque tube 312 is flexed,
a tension tube 318 having a fixed length and diameter smaller than
the inner diameter of the torque tube 312 is provided. The distal
end of the tension tube 318 is securely attached to the stylet
guide 6, and the proximal end 320 is secured to the adjuster block
322, for example by an adhesive. The axial or longitudinal position
of the adjuster block 322 can be adjusted to insure the stylets are
initially positioned just inside the outlet ports in the stylet
guide 6. Torque coupler 314 is mounted on the coupler block 324.
Twist control knob stop pin 326 extends into a grove (not shown)
and limits rotation of the control knob 316.
FIG. 26 is a detailed view "A" of the distal end tension tube
connections of the tension tube shown in FIG. 25. The tension tube
18 is securely connected to the proximal end 328 of the stylet
guide 6, for example by a length of shrink tubing 330.
FIG. 27 is an exploded view of the sleeve and electrode slide block
assembly of the embodiment shown in FIG. 24. The right sleeve slide
block 292 has a projection 332 which extends inward under the right
electrode slide block 284. Right sleeve connector 334 is mounted to
the inner end of the projection 332, secured to the end of the
proximal end of the sleeve 336. Right electrode connector 338 is
attached to an inner surface of the electrode slide block 284 and
is secured to the proximal end of electrode 340. The right sleeve
and electrode slide blocks 292 and 284 are slidingly attached to
the right friction adjustment rail 342 by screws (not shown)
through slots 344 and 346, the screws being adjustable to provide
sufficient friction between the blocks and the rail 342 to provide
secure control over the stylet movement. The left sleeve slide
block 290 and left electrode slide block 282 are mirror replicas of
the right blocks and are similarly mounted on the left friction
rail 348. The left sleeve and electrodes are not shown.
FIG. 28 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 urethra wall 432 through forward movement of tabs 12
and 13 (FIG. 1) and through surrounding tissue into targeted
tissues. The non-conducting sleeves 438 and 440 have been retracted
by rearward movement of sleeve tabs 12 and 13 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, "f", 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 targeted
tissues 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.
* * * * *