U.S. patent application number 14/954540 was filed with the patent office on 2016-03-24 for systems and methods for prostate treatment.
The applicant listed for this patent is Randall BEYREIS, Michael HOEY, Stephanos PAULOS, Mark SCHROM. Invention is credited to Randall BEYREIS, Michael HOEY, Stephanos PAULOS, Mark SCHROM.
Application Number | 20160081736 14/954540 |
Document ID | / |
Family ID | 44657277 |
Filed Date | 2016-03-24 |
United States Patent
Application |
20160081736 |
Kind Code |
A1 |
HOEY; Michael ; et
al. |
March 24, 2016 |
SYSTEMS AND METHODS FOR PROSTATE TREATMENT
Abstract
A vapor delivery needle is provided that may include any of a
number of features. One feature of the energy delivery probe is
that it can apply condensable vapor energy to tissue, such as a
prostrate, to shrink, damage, denaturate the prostate. In some
embodiments, the needle can ablate a continuous lobe region in the
prostate parallel to the urethral wall. Another feature of the
vapor delivery needle is that it can introduce a cooling fluid into
the urethra during treatment. Methods associated with use of the
energy delivery probe are also covered.
Inventors: |
HOEY; Michael; (Shoreview,
MN) ; SCHROM; Mark; (Forest Lake, MN) ;
PAULOS; Stephanos; (Little Canada, MN) ; BEYREIS;
Randall; (Corcoran, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HOEY; Michael
SCHROM; Mark
PAULOS; Stephanos
BEYREIS; Randall |
Shoreview
Forest Lake
Little Canada
Corcoran |
MN
MN
MN
MN |
US
US
US
US |
|
|
Family ID: |
44657277 |
Appl. No.: |
14/954540 |
Filed: |
November 30, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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14106388 |
Dec 13, 2013 |
9198708 |
|
|
14954540 |
|
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|
|
13072573 |
Mar 25, 2011 |
8632530 |
|
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14106388 |
|
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|
61317358 |
Mar 25, 2010 |
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Current U.S.
Class: |
606/31 ;
606/28 |
Current CPC
Class: |
A61B 2018/00982
20130101; A61B 2018/00035 20130101; A61B 18/04 20130101; A61B
2218/002 20130101; A61B 2218/007 20130101; A61B 2018/00547
20130101; A61B 2018/048 20130101 |
International
Class: |
A61B 18/04 20060101
A61B018/04 |
Claims
1. A method for treating benign prostatic hyperplasia (BPH),
comprising the steps of: positioning an energy-emitting section of
a needle in a plurality of locations in a prostate lobe adjacent
the prostatic urethra; and delivering energy at each location for
less than 30 seconds to thereby confine thermal ablation to lobe
tissue adjacent the prostatic urethra and preventing thermal
diffusion to peripheral lobe tissue.
2. The method of claim 1 wherein the delivering energy step further
comprises delivering a condensable vapor media at each
location.
3. The method of claim 1 further comprising inserting the
energy-emitting section of the needle through a urethral wall into
the prostate lobe.
4. The method of claim 3 wherein the inserting step comprises
inserting a tip of the energy-emitting section of the needle 15 mm
or less through the urethral wall into the prostate lobe.
5. The method of claim 1 wherein the delivering energy step
comprises confining thermal ablation to a continuous lobe region
extending less than 2 cm away from the urethral wall.
6. The method of claim 1 further comprising introducing a cooling
fluid into a urethra during the delivering energy step.
7. The method of claim 6 further comprising inserting a vapor
delivery tool shaft into the urethra, the needle being at least
partially disposed within the shaft, the cooling fluid being
introduced into the urethra through the shaft.
8. The method of claim 6 further comprising introducing the cooling
fluid into the urethra during the entire delivering energy
step.
9. The method of claim 1 further comprising sensing a temperature
and controlling delivery of the energy based on the sensed
temperature.
10. The method of claim 9 wherein the sensing a temperature step
comprises sensing a temperature of the needle.
11. The method of claim 1 further comprising viewing the
positioning step through an endoscope.
12. The method of claim 11 further comprising inserting a vapor
delivery tool shaft into a urethra, the needle and the endoscope
being at least partially disposed within the shaft.
13. The method of claim 12 further comprising introducing a cooling
fluid into the urethra during the delivering energy step, the
cooling fluid being introduced into the urethra through the shaft
around the endoscope.
14. The method of claim 11 further comprising viewing with the
endoscope a mark on the needle that is visible only when the needle
is in one of a retracted position or a deployed position.
15. The method of claim 1 wherein the plurality of locations in the
prostate lobe comprise a first plurality of locations
longitudinally spaced along the urethra, the method further
comprising inserting the needle through the urethral wall in a
second plurality of locations in the prostate, the second plurality
of locations being angularly rotated from the first plurality of
locations.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 14/106,388, filed Dec. 13, 2013, now U.S. Pat. No. 9,198,708,
which is a continuation of U.S. application Ser. No. 13/072,573,
filed Mar. 25, 2011, now U.S. Pat. No. 8,632,530, which application
claims the benefit under 35 U.S.C. 119 of U.S. Provisional
Application No. 61/317,358, filed Mar. 25, 2010, titled "Systems
and Methods for Prostate Treatment", all of which are incorporated
by reference herein.
INCORPORATION BY REFERENCE
[0002] All publications, including patents and patent applications,
mentioned in this specification are herein incorporated by
reference in their entirety to the same extent as if each
individual publication was specifically and individually indicated
to be incorporated by reference.
FIELD OF THE INVENTION
[0003] The present invention relates to devices and related methods
for treatment of benign prostatic hyperplasia using a minimally
invasive approach.
BACKGROUND OF THE INVENTION
[0004] Benign prostatic hyperplasia (BPH) is a common disorder in
middle-aged and older men, with prevalence increasing with age. At
age 70, more than one-half of men have symptomatic BPH, and nearly
90% of men have microscopic evidence of an enlarged prostate. The
severity of symptoms also increase with age with 27% of patients in
the 60-70 age bracket having moderate-to-severe symptoms, and 37%
of patients in their 70's suffering from moderate-to-severe
symptoms.
[0005] The prostate early in life is the size and shape of a walnut
and weighs about 20 grams. Prostate enlargement appears to be a
normal process. With age, the prostate gradually increases in size
to twice or more its normal size. The fibromuscular tissue of the
outer prostatic capsule restricts expansion after the gland reaches
a certain size. Because of such restriction on expansion, the
intracapsular tissue will compress against and constrict the
prostatic urethra thus causing resistance to urine flow.
[0006] FIG. 1 is a sectional schematic view the male urogenital
anatomy, with the walnut-sized prostate gland 100 located below the
bladder 105 and bladder neck indicated at 106. The walls 108 of
bladder 105 can expand and contract to cause urine flow through the
urethra 110, which extends from the bladder 105, through the
prostate 100 and penis 112. The portion of urethra 110 that is
surrounded by the prostate gland 100 is referred to as the
prostatic urethra 120. The prostate 100 also surrounds the
ejaculatory ducts 122 which have an open termination in the
prostatic urethra 120. During sexual arousal, sperm is transported
from the testes 124 by the ductus deferens 126 to the prostate 100
which provides fluids that combine with sperm to form semen during
ejaculation. On each side of the prostate, the ductus deferens 126
and seminal vesicles 128 join to form a single tube called an
ejaculatory duct 122. Thus, each ejaculatory duct 122 carries the
seminal vesicle secretions and sperm into the prostatic urethra
120.
[0007] Referring to FIGS. 2A-2C, the prostate glandular structure
can be classified into three zones: the peripheral zone, transition
zone, and central zone. The peripheral zone PZ, which is the region
forming the postero-inferior aspect of the gland, contains 70% of
the prostate glandular elements in a normal prostate (FIGS. 2A-2C).
A majority of prostate cancers (up to 80%) arise in the peripheral
zone PZ. The central zone CZ surrounds the ejaculatory ducts 122
and contains about 20-25% of the prostate volume. The central zone
is often the site of inflammatory processes. The transition zone TZ
is the site in which benign prostatic hyperplasia develops, and
contains about 5-10% of the volume of glandular elements in a
normal prostate (FIG. 2C), but can constitute up to 80% of such
volume in cases of BPH. The transition zone TZ consists of two
lateral prostate lobes and the periurethral gland region indicated
at 130. As can be understood from FIGS. 2A-2C, there are natural
barriers around the transition zone TZ, i.e., the prostatic urethra
120, the anterior fibromuscular stroma FS, and a fibrous plane FP
between the transition zone TZ and peripheral zone PZ. In FIGS.
2A-2C, the anterior fibromuscular stroma FS or fibromuscular zone
can be seen and is predominantly fibromuscular tissue.
[0008] BPH is typically diagnosed when the patient seeks medical
treatment complaining of bothersome urinary difficulties. The
predominant symptoms of BPH are an increase in frequency and
urgency of urination. BPH can also cause urinary retention in the
bladder which in turn can lead to lower urinary tract infection
(LUTI). In many cases, the LUTI then can ascend into the kidneys
and cause chronic pyelonephritis, and can eventually lead to renal
insufficiency. BPH also may lead to sexual dysfunction related to
sleep disturbance or psychological anxiety caused by severe urinary
difficulties. Thus, BPH can significantly alter the quality of life
with aging of the male population.
[0009] BPH is the result of an imbalance between the continuous
production and natural death (apoptosis) of the glandular cells of
the prostate. The overproduction of such cells leads to increased
prostate size, most significantly in the transitional zone which
traverses the prostatic urethra.
[0010] In early stage cases of BPH, treatments can alleviate the
symptoms. For example, alpha-blockers treat BPH by relaxing smooth
muscle tissue found in the prostate and the bladder neck, which may
allow urine to flow out of the bladder more easily. Such drugs can
prove effective until the glandular elements cause overwhelming
cell growth in the prostate.
[0011] More advanced stages of BPH, however, can only be treated by
surgical interventions. A number of methods have been developed
using electrosurgical or mechanical extraction of tissue, and
thermal ablation or cryoablation of intracapsular prostatic tissue.
In many cases, such interventions provide only transient relief,
and there often is significant peri-operative discomfort and
morbidity.
[0012] In a prior art thermal ablation method, RF energy is
delivered to prostate tissue as schematically depicted in FIGS.
3A-3B. FIG. 3A depicts the elongated prior art RF needle being
penetrated into a plurality of locations in a prostate lobe. In a
first aspect of the prior art method, the elongated RF needle
typically is about 20 mm in length, together with an insulator that
penetrates into the lobe. The resulting RF treatment thus ablates
tissue away from the prostatic urethra 120 and does not target
tissue close to, and parallel to, the prostatic urethra 120. In
another aspect of the prior art RF method, the application of RF
energy typically extends for 1 to 3 minutes or longer which allows
thermal diffusion of the ablation to reach the capsule periphery.
Such prior art RF energy delivery methods may not create a durable
effect, since smooth muscle tissue and alpha adrenergic receptors
are not uniformly ablated around the prostatic urethra. As a
result, tissue in the lobes can continue to grow and impinge on the
urethra thus limiting long term effectiveness of the treatment.
SUMMARY OF THE INVENTION
[0013] In some embodiments, a method for treating benign prostatic
hyperplasia of a prostate of a patient is provided, comprising
inserting a vapor delivery needle through a urethral wall of the
patient in a plurality of locations into a prostate lobe,
delivering condensable water vapor through the needle into the
prostate at each location, and ablating a continuous lobe region
parallel to the urethral wall.
[0014] In some embodiments, the continuous lobe region is between a
bladder neck and a verumontanum of the patient.
[0015] In some embodiments, the inserting step comprises inserting
a tip of the vapor delivery needle 15 mm or less through the
urethral wall into the prostate lobe.
[0016] In other embodiments, the ablating step comprises ablating
the continuous lobe region extending less than 2 cm away from the
urethral wall.
[0017] In some embodiments, the delivering step comprises
delivering the condensable water vapor for less than 30
seconds.
[0018] In one embodiment, the method can further comprise
introducing a cooling fluid into the urethra during the delivering
step. Some embodiments further comprise inserting a vapor delivery
tool shaft into the urethra, the vapor delivery needle being at
least partially disposed within the shaft, the cooling fluid being
introduced into the urethra through the shaft. Another embodiment
is provided, further comprising introducing the cooling fluid into
the urethra during the entire time condensable water vapor is
delivered into the prostate.
[0019] Some embodiments can further comprise sensing a temperature
within the urethra and controlling delivery of the condensable
vapor based on the sensed temperature. In one embodiment, the
sensing a temperature step comprises sensing a temperature of the
vapor delivery needle.
[0020] In some embodiments, the method further comprises viewing
the inserting step through an endoscope. In other embodiments, the
method further comprises inserting a vapor delivery tool shaft into
the urethra, the vapor delivery needle and the endoscope being at
least partially disposed within the shaft. The method can further
comprise introducing a cooling fluid into the urethra during the
delivering step, the cooling fluid being introduced into the
urethra through the shaft around the endoscope. In some
embodiments, the method further comprises viewing with the
endoscope a mark on the vapor delivery needle that is visible only
when the needle is in one of a retracted position or a deployed
position.
[0021] In some embodiments, the plurality of locations in the
prostate lobe comprise a first plurality of locations
longitudinally spaced along the urethra, the method further
comprising inserting the vapor delivery needle through the urethral
wall in a second plurality of locations in the prostate, the second
plurality of locations being radially displaced from the first
plurality of locations.
[0022] Another method for treating benign prostatic hyperplasia of
a prostate of a patient is provided, comprising ablating a region
of the prostate less than 2 cm away from urethra without ablating a
peripheral lobe portion of the prostate.
[0023] In some embodiments, the method further comprises inserting
an energy-emitting section of a needle into the prostate, wherein
the ablating step comprises delivering energy to the prostate via
the needle.
[0024] In some embodiments, the inserting step comprises inserting
the needle transurethrally.
[0025] In other embodiments, the inserting step comprises inserting
the needle transurethrally into the prostate in a plurality of
locations, the region of the prostate comprising a continuous lobe
region parallel to the urethral wall.
[0026] In an additional embodiment, the inserting step comprises
inserting the needle transrectally.
[0027] A method for treating benign prostatic hyperplasia (BPH) is
provided comprising positioning an energy-emitting section of
needle in a plurality of locations in a prostate lobe adjacent the
prostatic urethra, and delivering energy at each location for less
than 30 seconds to thereby confine thermal ablation to lobe tissue
adjacent the prostatic urethra and preventing thermal diffusion to
peripheral lobe tissue.
[0028] In some embodiments, energy is delivered from a condensable
vapor media.
[0029] In other embodiments, energy is delivered from a needle
member introduced through a transurethral access path.
[0030] In some embodiments, the method further comprises
introducing a cooling fluid into the urethra during the application
of energy.
[0031] A method for treating benign prostatic hyperplasia of a
prostate of a patient is provided, comprising inserting a vapor
delivery needle through a urethral wall of the patient into the
prostate, viewing the inserting step via an endoscope disposed in
the urethra, delivering condensable water vapor through the needle
into the prostate, and ablating prostate tissue within the
prostate.
[0032] In some embodiments, the method further comprises inserting
a vapor delivery tool shaft into the urethra, the needle and the
endoscope both being at least partially disposed within the
shaft.
[0033] Additionally, the method can further comprise, after the
ablating step, retracting the needle, rotating the shaft and the
needle within the urethra, inserting the vapor delivery needle
through the urethral wall into a different location in the
prostate, delivering condensable water vapor through the needle
into the prostate, and ablating prostate tissue within the
prostate.
[0034] In some embodiments, the method comprises supporting the
shaft with a handle, the rotating step comprising rotating the
handle with the shaft. In other embodiments, the method comprises
supporting the shaft with a handle, the rotating step comprising
rotating the shaft without rotating the handle. In some
embodiments, the rotating step further comprises rotating the shaft
and the needle without rotating the endo scope.
[0035] In one embodiment, the viewing step further comprises
viewing a mark on the needle that is visible only when the needle
is in one of a retracted position or a deployed position.
[0036] A vapor therapy system is provided, comprising a shaft
adapted to be inserted into a male urethra, a vapor delivery needle
in the shaft, the needle comprising a vapor exit port, a scope bore
in the shaft sized to accommodate an endoscope, the bore having an
opening oriented to permit a user to view a distal end of the vapor
delivery needle through the endoscope, a water vapor source, and a
vapor delivery actuator adapted to deliver water vapor from the
water vapor source into the vapor delivery needle and out of the
vapor exit port.
[0037] In some embodiments, the needle is movable between a
retracted position in which a distal needle tip is within the shaft
and a deployed position in which the distal needle tip extends from
the shaft.
[0038] One embodiment of the system further comprises a vapor
needle deployment mechanism adapted to move a tip of the needle
transverse to the shaft. In some embodiments, the deployment
mechanism is adapted to move the needle tip no more than 15 mm from
the shaft.
[0039] In some embodiments, the system further comprises a marking
on a distal tip portion of the vapor delivery needle. In one
embodiment, the marking is visible through the bore when the needle
is in the deployed position but not visible through bore opening
when needle is in the retracted position.
[0040] Some embodiments of the system further comprise a
needle-retraction actuator adapted to retract the needle into the
shaft.
[0041] In some embodiments, the needle is configured to deliver
water vapor over a predetermined length less that 15 mm from shaft.
In other embodiments, the needle comprises a non-energy applicator
portion that does not include a vapor exit port. In some
embodiments, the non-energy applicator portion is approximately the
thickness of the male urethra.
[0042] In some embodiments, the needle is a flexible polymer tube
with sharp tip.
[0043] In other embodiments, the needle is insulated. In one
embodiment, the insulated needle comprises a central bore
surrounded by insulative air gap and an outer sleeve.
[0044] In some embodiments, the system further comprises an
irrigation liquid source and an irrigation passage in the shaft
extending from the irrigation liquid source to an irrigation liquid
outlet. In one embodiment, the irrigation passage is within the
bore. In another embodiment, the system comprises an irrigation
actuator configured to irrigate a cooling fluid from the irrigation
liquid source through the irrigation liquid outlet. In one
embodiment, the irrigation liquid source is connected to the
irrigation passage. In another embodiment, the irrigation actuator
is configured to irrigate the cooling fluid when the vapor delivery
actuator delivers water vapor.
[0045] In some embodiments, the system further comprises an
interlock to prevent water vapor delivery without irrigation of the
cooling fluid.
[0046] In some embodiments, the system further comprises a bridge
element in the opening of the bore configured to prevent tissue
from falling into the opening of the bore.
[0047] In some embodiments, the shaft has blunt distal tip and the
opening of the bore is proximal to a distal end of the shaft.
[0048] In some embodiments, the system further comprises a handle
connected to the shaft through an adjustably rotatable connector
such that shaft can be rotated with respect to the handle. In some
embodiments, the rotatable connector comprises rotational stops at
preset angles.
[0049] In some embodiments, the system further comprises a
temperature sensor operably connected to a controller to control
vapor delivery based on a sensed temperature. In one embodiment,
the temperature sensor is configured to sense needle temperature.
In another embodiment, the temperature sensor is configured to
sense shaft temperature.
[0050] A vapor therapy system is provided, comprising a shaft
adapted to be inserted into a male urethra, a vapor delivery needle
in the shaft, the needle comprising a vapor exit port, a vapor
needle deployment mechanism adapted to move a tip of the needle
transverse to the shaft no more than 15 mm from the shaft, a water
vapor source; and a vapor delivery actuator adapted to deliver
water vapor from the water vapor source into the vapor delivery
needle and out of the vapor exit port.
[0051] In some embodiments, the vapor needle deployment mechanism
comprises an actuator adapted to deploy an actuation force on the
needle to deploy the needle.
[0052] In other embodiments, the vapor needle deployment mechanism
further comprises a needle deployment spring.
[0053] In some embodiments, the system further comprises a vapor
delivery interlock adapted to prevent delivery of water vapor from
the vapor delivery needle unless the needle is deployed.
[0054] In some embodiments, the needle deployment mechanism further
comprises a limit stop adapted to limit a deployment distance of
the needle.
[0055] In some embodiments, the system further comprises a
needle-retraction actuator adapted to retract the needle into the
shaft.
[0056] In some embodiments, the system further comprises a scope
bore in the shaft sized to accommodate an endoscope, the bore
having an opening oriented to permit a user to view a distal end of
the vapor delivery needle through the endoscope.
[0057] In other embodiments, the system further comprises a marking
on a distal tip portion of the vapor delivery needle. In one
embodiment, the marking is visible through the bore opening when
the needle is in a deployment position but the marking is not
visible through the bore opening when the needle is in a retracted
position.
[0058] In some embodiments, the needle is a flexible polymer tube
with a sharp tip.
[0059] In other embodiments, the needle is insulated. In some
embodiments, the insulated needle comprises a central bore
surrounded by an insulative air gap and an outer sleeve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0060] In order to better understand the invention and to see how
it may be carried out in practice, some preferred embodiments are
next described, by way of non-limiting examples only, with
reference to the accompanying drawings, in which like reference
characters denote corresponding features consistently throughout
similar embodiments in the attached drawings.
[0061] FIG. 1 is a sectional schematic view the male urogenital
anatomy.
[0062] FIG. 2A-2C are views of a patient's prostate showing zones
of prostate tissue.
[0063] FIG. 3A is a sectional view of a normal prostate gland.
[0064] FIG. 3B is a sectional view of a prostate gland with
BPH.
[0065] FIG. 4 is a perspective view of a probe corresponding to the
invention.
[0066] FIG. 5 is a view of components within a handle portion of
the probe of FIG. 4.
[0067] FIG. 6 is another view of components within a handle portion
of the probe of FIG. 4.
[0068] FIG. 7 is a cross sectional view of a probe.
[0069] FIG. 8 is a side view of a microcatheter or needle of a
probe.
[0070] FIG. 9 is a side elevation view of the microcatheter or
needle of the probe of FIG. 4 showing its dimensions and vapor
outlets.
[0071] FIG. 10 is another view of the microcatheter of FIG. 9.
[0072] FIG. 11 is another view of a distal portion of the
microcatheter of FIG. 10.
[0073] FIG. 12 is a sectional view of the microcatheter of FIG. 10
taken along line 11-11 of FIG. 10.
[0074] FIGS. 13A-13B are schematic views of the probe of FIG. 4 in
a head-on view in a prostate indicating the radial angle of the
probe as it is rotated in situ to treat lateral prostate lobes.
[0075] FIGS. 14A-14B are schematic views similar to that of FIGS.
13A-13B showing a method of rotating certain components of the
probe again indicating the radial angles of the penetrating
microcatheter of the probe of FIG. 4, while leaving the probe
handle in a non-rotated position.
[0076] FIGS. 15A-15B are schematic views similar to that of FIGS.
13A-13B showing a method of rotating other components of the probe,
again indicating the radial angles of the penetrating microcatheter
in the lateral lobes of the prostate while leaving the probe handle
in a non-rotated position.
[0077] FIG. 16A is a longitudinal sectional schematic view showing
a method of the invention in treating a prostate for BPH.
[0078] FIG. 16B is a transverse sectional view of the prostate of
FIG. 16A.
[0079] FIG. 17 is another longitudinal sectional view showing
ablation zones in the method of treating a prostate for BPH.
[0080] FIG. 18 is an MRI from a patient 1 week after a treatment as
indicated schematically in FIGS. 16A-17.
[0081] FIG. 19 is a block diagram of a method corresponding to the
invention.
[0082] FIG. 20 is a block diagram of another method corresponding
to the invention.
[0083] FIG. 21 is a block diagram of another method corresponding
to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0084] In general, one method of the invention for treating BPH
comprises introducing a heated vapor interstitially into the
interior of a prostate, wherein the vapor controllably ablates
prostate tissue. This method can utilize vapor for applied energy
of between 50 calories and 200 calories per lobe in an office-based
procedure. The method can cause localized ablation of prostate
tissue, and more particularly the applied energy from vapor can be
localized to ablate tissue adjacent the urethra without damaging
prostate tissue that is not adjacent the urethra.
[0085] The present invention is directed to the treatment of BPH,
and more particularly for ablating transitional zone prostate
tissue without ablating peripheral zone prostate tissue.
[0086] In one embodiment, the present invention is directed to
treating a prostate using convective heating in a region adjacent
the prostatic urethra.
[0087] In one embodiment, the method of ablative treatment is
configured to target smooth muscle tissue, alpha adrenergic
receptors, and sympathetic nerve structures parallel to the
prostatic urethra between the bladder neck region and the
verumontanum region to a depth of less than 2 cm.
[0088] In one embodiment, the system includes a vapor delivery
mechanism that delivers water vapor. The system can utilize a vapor
source configured to provide vapor having a temperature of at least
60.degree. C., 80.degree. C., 100.degree. C., 120.degree. C., or
140.degree. C.
[0089] In another embodiment, the system further comprises a
computer controller configured to deliver vapor for an interval
ranging from 1 second to 30 seconds.
[0090] In another embodiment, the system further comprises a source
of a pharmacologic agent or other chemical agent or compound for
delivery with the vapor. The agent can be an anesthetic, and
antibiotic or a toxin such as Botox.RTM.. The agent can also be a
sealant, an adhesive, a glue, a superglue or the like.
[0091] Another method of the invention provides a treatment for BPH
that can use transrectal approach using a TRUS (ultrasound system
as an imaging means to image the prostate, and navigate a vapor
delivery tool to the treatment sites.
[0092] In another method of the invention, the tool or needle
working end can be advanced manually or at least in part by a
spring mechanism.
[0093] In another aspect of the invention, the system may
contemporaneously deliver cooling fluids to the urethra during an
ablation treatment to protect the interior lining of the
urethra.
[0094] FIGS. 4, 5 and 6 depict one embodiment of probe 100 of the
system of the invention that is adapted for trans-urethral access
to the prostrate and which provides viewing means to view the
urethra as the probe in navigated to a site in the interior of the
patient's prostate. The probe 100 further carries an extendable and
retractable microcatheter member 105 (FIGS. 5-6) having a distal
tip portion 108 (FIG. 4) that can be penetrated into precise
targeted locations in prostate lobes to ablate targeted tissue
volumes.
Handle and Introducer Portion
[0095] In FIG. 4, it can be seen that probe 100 has an elongate
introducer portion 110 for insertion into the urethra and a handle
portion 111 for gripping with a human hand. The key structural
component of introducer portion 110 comprises a rigid introducer
sleeve or extension sleeve 112 extending along longitudinal axis
113 with proximal end 114a and distal end 114b. The bore 115 in the
rigid extension sleeve extends along longitudinal axis 116. In one
embodiment, referring to FIGS. 4 and 5, the extension sleeve 112
comprises a thin-wall stainless steel tube with bore 115
dimensioned to receive a commercially available viewing scope or
endoscope 118. The schematic cut-away view of FIG. 5 shows
structural bulkhead 120 coupled to a medial portion 122 of
extension sleeve 112. The structure or bulkhead 120 comprises the
structural member to which the molded handle having pistol grip
124, and more particularly the right- and left-side mating handle
parts, 125a and 125b, are coupled (FIG. 4). The bulkhead can be a
plastic molded part that can be fixed to sleeve 112 or rotationally
coupled to sleeve 112.
[0096] Referring to FIGS. 5-6, in which the molded handle left and
right sides are not shown, it can be seen that bore 115 in sleeve
112 has a proximal open end 130 into which the endoscope 118 can be
inserted. The proximal end portion 114a of extension sleeve 112 is
coupled to an adapter mechanism 132 that releasably engages the
endoscope 118 and rotationally aligns the scope 118 with the
introducer portion 110. The endoscope 118 has a proximal viewing
end 135 and light connector 136 extending outward from the viewing
end 136 for coupling a light source 140 to the endoscope. FIG. 7
illustrates that bore 115 in sleeve 112 has a diameter ranging from
about 2 to 5 mm for accommodating various endoscopes 118, while at
the same time providing an annular space 138 for allowing an
irrigation fluid to flow through bore 115 and outwardly from the
introducer portion.
[0097] In one embodiment of system 100, referring to FIGS. 5-8, the
extendable-retractable microcatheter 105 comprises a thin-wall
flexible polymer tube with a sharp tip that is axially slidable in
a passageway 148 in the introducer portion 110. FIGS. 4, 7 and 9
show that the introducer portion 110 comprises an elongate
introducer body 144 of plastic or another suitable material that
surrounds extension sleeve 112. The introducer body 144 extends to
a distal working end portion 145 having a blunt nose or tip 146 for
advancing through the urethra. The elongate introducer body 144 is
further configured with passageway 148 that accommodates the
microcatheter member 105 as will be described below. Referring to
FIGS. 8-9, the distal end portion 145 of the introducer body 144 is
configured with openings 160 that open to central open region 162
that is distal to the distal lens 164 of endoscope 118 that allows
for viewing of the urethra through the lens 164 of the endoscope
during navigation. The endoscope 118 can have a lens with a
30.degree., 12.5.degree. or other angle for viewing through
openings 160. As can be seen in FIGS. 8-9, the openings 160 have
bridge elements 165 therebetween that function to prevent tissue
from falling into central open region 162 of the introducer body
144. In FIG. 8, it can be seen that the working end portion 105 of
the flexible microcatheter shaft 105 is disposed adjacent to open
region 162 and thus can be viewed through the endoscope lens
164.
Microcatheter and Spring-Actuator
[0098] FIGS. 10-11 show the flexible microcatheter member or needle
105 de-mated from the probe 100 to indicate its repose shape. In
one embodiment, the microcatheter 105 has a first (proximal) larger
cross-section portion 170 that necks down to second (distal)
cross-section portion 175 wherein the smaller cross-section portion
175 has a curved repose shape with the curve configured to conform
without significant resistance to the contour of the curved axis
177 of the path followed by the working end 108 of the
microcatheter 105 as it is moved from its non-extended position to
its extended position as shown in FIGS. 1, 8 and 9. In one
embodiment, referring to FIGS. 10-12, the microcatheter's first
cross section portion 170 comprises a thin wall outer sleeve 180
that is concentrically outward from inner microcatheter tube 185
that extends the length of the microcatheter member 105. As can be
seen in FIG. 12, the outer sleeve 180 provides a thermally
insulative air gap 188 around inner tubular member 185. In one
embodiment shown depicted in FIG. 12, the outer sleeve 180 is
configured with intermittent protrusions 190 that maintain the air
gap 188 between the inner surface 192 of outer sleeve 180 and outer
surface 193 of inner microcatheter tube. FIG. 9 shows that the
outer sleeve 180 has necked down portion 194 that is bonded to
inner microcatheter tube 185 by any suitable means such as
ultrasonic bonding, adhesives or the like. Referring back to FIG.
10, both the outer sleeve 180 and inner tubular member can comprise
a high-temperature resistant polymer such as Ultem.RTM. that is
suited for delivering a high temperature vapor as will be described
below. In one embodiment, the microcatheter tube 185 has an outside
diameter of 0.050'' with an interior lumen 195 of approximately
0.030''. Referring to FIGS. 8-9, one embodiment of working end
portion 108 for delivering vapor media to tissue has a thin wall
198 with a plurality of outlet ports 200 therein that are
configured for emitting a vapor media into tissue as will be
described below. The outlet ports can range in number from about 2
to 100, and in one embodiment consist of 12 outlets each having a
diameter of 0.008'' in six rows of two outlets with the rows
staggered around the working end 108 as shown in FIG. 10. In one
embodiment shown in FIGS. 10-11, the distalmost tip 202 of the
microcatheter tube 185 has a sharpened conical configuration that
can be formed of the plastic material of tube 185. As will be
described below, it has been found that a polymeric needle and
needle tip 202 is useful for its thermal characteristics in that
its heat capacity will not impinge on vapor quality during vapor
delivery.
[0099] FIGS. 10-11 further illustrate that the distal tip portion
108 of microcatheter tube 185 has at least one marking 204 that
contrasts with the color of the microcatheter tube 185 that is
adapted for viewing through lens 164 of the endoscope 118. In one
embodiment, the distal tip portion has a series of annular marks
204 of a first color that contrasts with second color of tube 185,
wherein the marks are not visible through the endoscope lens 164
when the microcatheter tube 185 is in the non-extended position.
After the microcatheter tube 185 is extended into tissue, the marks
are visible through the lens 164 which indicates the tube 185 has
been extended into tissue.
[0100] Returning now to FIGS. 5 and 6, the cut-away view of the
handle portion 111 shows the microcatheter member 105 and
associated assemblies in the non-extended position. FIG. 5 shows
flanges 208a and 208b of cocking actuator 210 are disposed on
either side of actuator collar 212 that is coupled to proximal end
214 of the slidable microcatheter member 105. As can be understood
from FIG. 5, the downward-extending cocking actuator 210 is adapted
to cock the flanges 208a, 208b and microcatheter 105 to a cocked
position which corresponds to the non-extended position of the
microcatheter 105. In FIG. 5, the actuator 210 is shown in a first
position B (phantom view) and second positions B' following
actuation with an index finger to thus cock the microcatheter
member 105 to the second releasable non-extended position (or
cocked position) B' from its extended position B. The flange 208a
and actuator 210 is further shown in phantom view in the released
position indicated at 208a'. In FIG. 5, the flanges 208a, 208b and
associated assemblies are configured for an axial travel range
indicated at A that can range from about 8 mm to 15 mm which
corresponds to the travel of the microcatheter 105 and generally to
the tissue-penetration depth. In the embodiment of FIG. 5, the
flanges 208a, 208b and microcatheter member 105 are
spring-actuatable to move from the non-extended position to the
extended position by means of helical spring 215 disposed around
sleeve 112. As can be seen in FIG. 5, the spring 215 is disposed
between the slidable flange 208b and trigger block 218 that
comprises a superior portion of the release trigger 220 which is
adapted to release the microcatheter 105 from its cocked
position.
[0101] FIG. 5 further illustrates the release trigger 220
releasably maintaining the flange 205a and microcatheter 105 in its
cocked position wherein tooth portion 222 of the trigger 220
engages the lower edge of flange 205a. It can be understood from
FIG. 5 that the release trigger 220 is configured to flex or pivot
around living hinge portion 224 when trigger 220 is depressed in
the proximal direction by the physician's finger actuation. After
actuation of trigger 220 and release of the microcatheter 105 to
move distally, the axial travel of the assembly is configured to
terminate softly rather than abruptly as flange 208a contacts at
least one bumper element 230 as depicted in FIG. 6. The bumper
elements 230 can comprise any spring or elastomeric element, and in
FIG. 6 are shown as an elastomer element housed in a helical
spring, which serve to cushion and dampen the end of the travel of
the spring-driven microcatheter assembly. The bumper elements 230
are coupled to flange 235 which in turn is configured to be fixed
between right- and left-side handle parts 125a and 125b (FIG.
4).
[0102] Now turning to the energy-delivery aspect of the system, a
vapor source 250 is provided for delivering a vapor media through
the microcatheter member 105 to ablate tissue. The vapor source can
be a vapor generator that can deliver a vapor media, such as water
vapor, that has a precisely controlled quality to provide a precise
amount of thermal energy delivery, for example measured in calories
per second. Descriptions of suitable vapor generators can be found
in the following U.S. patent applications: Application Ser. Nos.
11/329,381; 60/929,632; 61/066,396; 61/068,049; 61/068,130;
61/123,384; 61/123,412; 61/126,651; 61/126,612; 61/126,636;
61/126,620 all of which are incorporated herein by reference in
their entirety. The vapor generation system also can comprise an
inductive heating system similar to that described in Application
Ser. Nos. 61/123,416; 61/123,417; 61/126,647. The system further
includes a controller 255 that can be set to control the various
parameters of vapor delivery, for example, the controller can be
set to delivery vapor media for a selected treatment interval, a
selected pressure, or selected vapor quality.
[0103] Referring to FIG. 5, in one embodiment, the vapor source 250
is remote from the handle 124 and vapor media is carried to the
handle by a flexible conduit 262 that couples handle and check
valve 264 therein. In one embodiment, vapor can be re-circulating
in conduit 262 until a solenoid in the vapor source is actuated to
cause the vapor flow to thus provide an increased fluid pressure
which opens the check valve 265 and allows the vapor media to flow
through flexible tube 268 to valve 270 that can be finger-actuated
by trigger 275. In one embodiment depicted in FIG. 5, the trigger
275 is urged toward a non-depressed position by spring 277 which
corresponds to a closed position of valve 270. The trigger 275 also
can be coupled by an electrical lead (not shown) to controller 255.
Thus, actuating the trigger 275 can cause the controller to actuate
a solenoid valve in the vapor generator to cause vapor flow through
the relief valve. As a safety mechanism, the valve 270 in the
handle is opened only by its actuation to thus permit the flow of
vapor media through flexible tube 278 which communicates with
inflow port portion 280 of collar 212 which in turn communicates
with the lumen 195 in the microcatheter 105. Thus, FIG. 5
illustrates the flow path and actuation mechanisms that provide
vapor flow on demand from the vapor source 250 to the vapor outlets
200 in working end 108 of the microcatheter 105.
[0104] As can be seen in FIG. 5, the handle can also provide an
interlock mechanism that prevents the actuation of vapor flow if
the microcatheter release trigger is in the cocked position,
wherein edge portion 292 coupled to release trigger 220 can engage
notch 294 in trigger 275 to prevent depression of said trigger
275.
[0105] Still referring to FIG. 5, one embodiment of the system
includes a fluid irrigation source 300 that is operatively couple
to the bore 115 in extension member 112 to deliver a fluid outward
from the bore 115 to the open region 162 of the probe working end
145 (see FIG. 8). As can be seen in FIG. 7, the bore 115 is
dimensioned to provide a space 138 for fluid irrigation flow around
the endoscope 118. In FIG. 5, it can be seen that fluid source 300,
which can be a drip bag or controlled pressure source of saline or
another fluid, is detachably coupled to tubing 302 in the handle
which extends to a valve 305 that can be thumb-operated from
actuators 308 on either side of the handle. The thumb actuator 308
can also control the rate of flow of the irrigation fluid by moving
the actuator 308 progressively forward, for example, to open the
valve more widely open. The fluid flows from valve 305 through tube
312 to a port or opening 315 in the extension sleeve 112 to thus
enter the bore 115 of the sleeve.
[0106] FIG. 5 further depicts an aspiration source 320 operatively
coupled to tubing 322 in the handle 124 which also can be actuated
by valve 305 wherein the thumb actuator 308 can be rocked
backwardly to allow suction forces to be applied through the valve
305 to tubing 312 that extends to port 315 in the extension
member--which is the same pathway of irrigation flows. Thus,
suction or aspiration forces can withdraw fluid from the working
end of the device during a treatment.
[0107] Another aspect of one embodiment of probe 100 corresponding
to the invention, referring to FIGS. 4, 5, 6 and 8, is the
orientation of the microcatheter or needle 105 as it exits the
working end 145 relative to the orientation of the pistol grip 124
of the handle portion 111. In a method use further described below,
the introducer will typically be introduced through the urethra
with the pistol grip in a "grip-downward" orientation GD (FIG. 13A)
with the pistol grip 126 oriented downwardly which comfortable for
the physician. The treatment will typically include rotationally
re-orienting the probe as indicated in FIG. 13A so that the
microcatheter or needle 105 can be penetrated into prostate lobes
at 90.degree. to about 135.degree. relative to a grip-downward
position. FIGS. 13A and 13B are schematic head-on views of the
probe 100 in a prostate with the microcatheter 105 deployed showing
the orientation of the handle pistol grip 124, the deployed
microcatheter 105 and the connector endoscope 136 which indicate
the rotational orientation of the endoscope 118 and thus the
orientation of the camera image on the monitor. As can be seen in
FIGS. 4-6, the assembly of the introducer 110, microcatheter 105
and endoscope 118 is rotatable within the handle within flanges
235A and 235B. In one embodiment, the system has click-stops at
various angles, such as every 15.degree. between 75.degree. and
135.degree. relative to the grip-downward orientation GD of FIG.
13A. Thus FIGS. 13A-13A and 14A-14B depict optional methods that
the surgeon may use.
[0108] FIGS. 13A and 13B depict the physician locking all
components of the probe 100 in a single rotational orientation, and
simply using his rotating his hand and pistol grip 124 to a
selected orientation of greater that 90.degree. from the grip-down
position GD, then releasing the microcatheter 105 to penetrate into
the prostate lobe. After actuating the vapor delivery trigger, the
vapor ablates are region indicted at 400. It can be appreciated
that the endoscope 118 is rotated so that the image on the monitor
is also rotated. Thereafter, the physician rotates the probe as
depicted in FIG. 13B to treat the other prostate lobe. This method
may be preferred by physicians that are familiar with anatomical
landmarks, opt for simplicity and are accustomed to viewing an
image on the monitor which is rotated relative a true vertical axis
of the patient anatomy.
[0109] FIGS. 14A and 14B depict the physician utilizing the
rotational feature of the probe and maintaining the handle pistol
grip 124 in the grip-down orientation GD and rotating the
introducer 110 and microcatheter 105 to the appropriate angles to
treat the first and second lobes of the prostate. This method again
is suited for physicians that are familiar with anatomical
landmarks and are accustomed to viewing a rotated image on the
monitor in the OR.
[0110] FIGS. 15A and 15B depict the physician utilizing another
embodiment of a probe to treat the two prostate lobes. In the
embodiment of FIGS. 5-6, it can be seen that the endoscope 118 is
locked in rotational orientation with introducer 110 and the
microcatheter 105--but not with the handle pistol grip. It can
easily be understood a probe can be made that allows rotational
adjustment between the introducer 110 and microcatheter 105
relative to the handle pistol grip 124--but that provided a bracket
that rotationally locks the endoscope 118 to the handle pistol grip
124. FIGS. 15A-15B depict the use of such an embodiment, wherein
the physician can maintain the handle pistol grip 124 in the
grip-down orientation GD and then rotates only the introducer 110
and microcatheter 105. In this embodiment, the image on the monitor
will remain vertical instead of rotated, which may be preferred by
physicians accustomed to laparoscopy in which images are not
rotated on the monitor when instruments are manipulated.
[0111] In another aspect of the invention, referring to FIGS.
10-11, the microcatheter 105 carries a temperature sensor or
thermocouple 405 at a distal location therein, for example as
indicated in FIG. 10. The thermocouple is operatively connected to
controller 255 to control vapor delivery. In one embodiment, an
algorithm reads an output signal from the thermocouple 405 after
initiation of vapor delivery by actuation of trigger 275, and in
normal operation the thermocouple will indicate an instant rise in
temperature due to the flow of vapor. In the event, the algorithm
and thermocouple 405 do not indicate a typical rise in temperature
upon actuation of trigger 275, then the algorithm can terminate
energy delivery as it reflects a system fault that has prevented
energy delivery.
[0112] In another embodiment, referring again to FIGS. 10-11, the
microcatheter 105 can carry another temperature sensor or
thermocouple 410 in a portion of microcatheter 105 that resides in
passageway 148 of the introducer body 144. This thermocouple 410 is
also operatively connected to controller 255 and vapor source 250.
In one embodiment, an algorithm reads an output signal from
thermocouple 410 after initiation of vapor delivery and actuation
of actuator 308 that delivers an irrigation fluid from source 300
to the working end 145 of the probe. The delivery of irrigation
fluid will maintain the temperature in the region of the
thermocouple at a predetermined peak level which will not ablate
tissue over a treatment interval, for example below 55.degree. C.,
below 50.degree. C. or below 45.degree. C. If the temperature
exceeds the predetermined peak level, the algorithm and controller
can terminate vapor energy delivery. In another embodiment, a
controller algorithm and modulate the rate of cooling fluid inflows
based on the sensed temperature, and/or modulate the vapor flow in
response to the sensed temperature. In an alternative embodiment,
the thermocouple 410 can be in carried in a portion of introducer
body 144 exposed to passageway 148 in which the microcatheter
resides.
Method of Use
[0113] Referring to FIGS. 16A and 16B, the device and method of
this invention provide a precise, controlled thermal ablative
treatment o tissue in first and second lateral prostate lobes (or
right- and left-side lobes), and additionally an affected median
lobe in patients with an enlarged median lobe. In particular, the
ablative treatment is configured to ablate stromal or smooth muscle
tissue, to ablate alpha adrenergic (muscle constriction) receptors,
and to ablate sympathetic nerve structures. More in particular, the
method of ablative treatment is configures to target smooth muscle
tissue, alpha adrenergic receptors, and sympathetic nerve
structures parallel to the prostatic urethra between the bladder
neck region 420 and the verumontanum region 422 as depicted in
FIGS. 16A-16B. The targeted ablation regions 425 have a depth
indicated at D in FIGS. 16A-16B that is less than 2 cm from the
prostatic urethra 120, or less than 1.5 cm. Depending on the length
of the patient's prostatic urethra 120, the number of ablative
energy deliveries can range from 2 to 4 and typically is 2 or
3.
[0114] In a method of use, the physician would first prepare the
patient for trans-urethral insertion of the extension portion 110
of the probe 100. In one example, the patient can be administered
orally or sublingually a mild sedative orally or sublingually such
as Valium, Lorazepam or the like from 15-60 minutes before the
procedure. Of particular interest, it has been found that prostate
blocks (injections) or other forms of anesthesia are not required
due to lack of pain associated with an injection of a condensable
vapor. The physician then actuates the needle-retraction actuator
210, for example with an index finger, to retract and cock the
microcatheter 105 by axial movement of the actuator (see FIGS.
4-6). By viewing the handle 124, the physician can observe that the
microcatheter 105 is cocked by the axial location of trigger 210. A
safety lock mechanism (not shown) can be provided to lock the
microcatheter 105 in the cocked position.
[0115] Next, the physician advances the extension portion 110 of
the probe 100 transurethrally while viewing the probe insertion on
a viewing monitor coupled to endoscope 118. After navigating beyond
the verumontanum 422 to the bladder neck 420, the physician will be
oriented to the anatomical landmarks. The landmarks and length of
the prostatic urethra can be considered relative to a pre-operative
plan based on earlier diagnostic ultrasound images or other images,
such as MRI images.
[0116] The physician can rotate the microcatheter-carrying probe
about its axis to orient the microcatheter at an angle depicted in
FIG. 13A to treat a first lobe. Thereafter, the treatment included
cocking and releasing the microcatheter followed by vapor delivery,
the moving and repeating the vapor injection for a total of three
vapor injections in each lobe. FIG. 17 is a schematic view of a
method the invention wherein three penetrations of the
microcatheter 105 are made sequentially in a prostate lobe and
wherein energy delivery is provided by vapor energy to produce
slightly overlapping ablations or lesions to ablate the smooth
muscle tissue, alpha adrenergic receptors, and sympathetic nerve
structures in a region parallel to the prostatic urethra. The
method of the invention, when compared to prior art, reduces the
burden of ablated tissue and thus lessens the overall inflammatory
response leading to more rapid tissue resorption and more rapid
clinical improvement.
[0117] FIG. 18 is a sagittal MRI image of an exemplary BPH
treatment of a patient 1 week following the procedure, in which the
treatment included the following steps and energy delivery
parameters. The patient's prostate weighed 44.3 gms based on
ultrasound diagnosis. Amparax (Lorazepam) was administered to the
patient 30 minutes before the procedure. In the treatment of the
patient in FIG. 18, each treatment interval consisted of 10 seconds
of vapor delivery at each of six locations (3 injections in each
lobe). Thus, the total duration of actual energy delivery was 60
seconds in the right and left prostate lobes. The energy delivered
was 6 cal/sec, or 60 cal. per treatment location 425 (FIG. 16A) and
a total of 360 calories in total to create the ablation parallel to
the prostatic urethra, which can be seen in the MRI of FIG. 18. In
the patient relating to the MRI image of FIG. 18, the median lobe
was also treated with a single 10 second injection of vapor, or 50
calories of energy. The vapor can be configured to delivery energy
in the range of 5 to 10 cal/sec.
[0118] By comparing the method of the present invention (FIG. 17)
with the prior art (FIGS. 3A-3B), it can be understood the method
and apparatus of the present invention is substantially different
than the prior art. FIG. 3A schematically depicts the prior art RF
needle that is elongated, typically at about 20 mm in length, which
ablates tissue away from the prostatic urethra and does not target
tissue close to and parallel to the prostatic urethra. Second, the
prior art RF energy delivery methods apply RF energy for 1 to 3
minutes or longer which allows thermal diffusion of effect to reach
the capsule periphery, unlike the very short treatment intervals of
the method of the present invention which greatly limit thermal
diffusion. Third, the prior art RF energy delivery methods do not
create a uniform ablation of tissue adjacent and parallel to the
prostatic urethra to ablate smooth muscle tissue, alpha adrenergic
receptors, and sympathetic nerve structures in a region parallel to
the prostatic urethra.
[0119] One method corresponding to the invention is shown in the
block diagram of FIG. 19, which includes the steps of advancing a
probe trans-urethrally to the patient's prostate, extending a
energy applicator or microcatheter into prostate lobes in a
plurality of locations to a depth of less than 2 cm, and then
applying energy at each location to create an ablation zone in a
continuous region parallel to at least a portion of the prostatic
urethra.
[0120] Another method of the invention is shown in the block
diagram of FIG. 20, which includes the steps of advancing a probe
trans-urethrally to the patient's prostate, extending a energy
applicator or microcatheter into prostate lobes in a plurality of
locations, and applying energy at each location for less than 30
seconds to thereby prevent thermal diffusion to peripheral portions
of the lobes.
[0121] Another method of the invention is shown in FIG. 21, which
includes the steps of advancing a probe trans-urethrally to the
patient's prostate, extending a energy applicator or microcatheter
into prostate lobes in a plurality of locations, and applying
energy at each location for a selected interval and irrigating the
urethra with a cooling fluid throughout the selected interval of
energy delivery. It has been found that such a flow of cooling
fluid may be useful, and most important the flow of cooling fluid
can be continuous for the duration of the treatment interval since
such times are short, for example 10 to 15 seconds. Such a
continuous flow method can be used in prior art methods, such as RF
ablation methods of FIGS. 3A-3B, since the cooling fluid volume
accumulates in the patient's bladder and the long treatment
intervals would result in the bladder being filled rapidly. This
would lead to additional steps to withdraw the probe, remove the
excess fluid and then re-start the treatment.
[0122] Although particular embodiments of the present invention
have been described above in detail, it will be understood that
this description is merely for purposes of illustration and the
above description of the invention is not exhaustive. Specific
features of the invention are shown in some drawings and not in
others, and this is for convenience only and any feature may be
combined with another in accordance with the invention. A number of
variations and alternatives will be apparent to one having ordinary
skills in the art. Such alternatives and variations are intended to
be included within the scope of the claims. Particular features
that are presented in dependent claims can be combined and fall
within the scope of the invention. The invention also encompasses
embodiments as if dependent claims were alternatively written in a
multiple dependent claim format with reference to other independent
claims.
* * * * *