Note: Descriptions are shown in the official language in which they were submitted.
2129~39
~ 93/1~ PCT/U~93/02077
.. 1
APPARATUS AND r~THOD FOR INTERSTITIAL T.~EATMENT
Related ~pplication
The present application is a continuation-
in-part of U.S. patent application No. 07/625,332,
filed ~e~ember 10, 1990.
Field of the I~vo~tio~
The present invention relates to an
apparatus and method for interstitial treatment or
diagnosis in organs, in particular, by insertion of an
elongated shaft o* the apparatus into a body passage
adjacent the organ to be treated and extension of a
cannula into the organ for delivery of treatment or
diagnosis at a selected site within the organ. More
particularly, the cannula includes an interstitial
locking means for reversibly locking the cannula in
place after positioning and during treatment.
B~kground of the I~ve~tion
Advances in medical technology have provided
many new treatments and diagnostic techniques. For
example, U.S. Patent No. 4,950,267 to Ishihara et al.
discloses a laser beam treatment device for an
endoscope. The endoscope delivers a laser probe to a
position in a body, from which the laser probe is
thrust into the part of the organ to be treated.
However, the disclosure is not too specific as how the
laser probe is inserted into the organ. Also, U.S.
Patent No. 5,047,~2~ to Rydel discloses an
electrosurgical implant for cutting through tissue.
The instrument incl~des two separate terminals at the
distal end that provide an arc discharge when a RF
voltage is applied, thereby allowing the device to cut
tissue. No provision, however, is made for
transporting the distal end to a particular treatment
site with minimal damage to healthy tissue surrounding
the treatment site.
WO93/156~ 2 1 2 9 6 ~ 9 - 2 - PCT/US93/0~077 ~
Other treatment techniques include the
implantation of radioactive seeds for radiation
therapy or interstitially cell-targeted drug
t~erapies. Also, many different types of diagnostic
techniques are known, such as en~oscopic or ultrasound
visualization. However, suita~le apparatus and
methods for applying these techniques interstitially
are lacking in the art
Thus, despite the numerous advances and new
technique~ developed for medical treatment and
diagnosis, there remains in the art a need for a
suitable apparatus and method to interstitially
deliver such treatments to or ~onduct diagnosis at
selected sites within an organ, without excessive and
unnecessary damage to tissue surrounding the treatment
site.
8ummary of the Inve~tio~
It is therefore an object of the present
invention to provide a method and apparatus for
interstitially delivering various treatments or
diagnoses to selected sites within an organ.
It is a further object of the invention to
provide such an apparatus which can be easily and
accurately manipulated by an operator to direct
treatment or diagnosis to the desired interstitial
location with minimal damage to surrounding tissue.
~ nother object of the present invention is
to provide means for securing a cannula interstitially
within an organ to ensure that treatment delivery or
diagnosis occurs at the selected site without the
necessity of constantly monitoring the position the
cannula.
These and other objects are realiæed
according to the invention by an apparatus for
interstitial treatment or diagnosis in an organ which
includes an elongated, and at least partially flexible
2 1 2 9 6 3 9 PCT/US93/01077
_
cannula, means for positioning the cannula in a body
passage adjacent to the organ to be treated, a guide
means mounted on the positioning means to guide the
cannula into the organ, and means for locking the
cannula in place during treatment or diagnosis. The
apparatus further includes a proximal portion that
supports the positioning means for manipulation and
allows the positioning means to be rotated in order to
position the guide means for directing the cannula
into the organ at a predetermined location.
A preferred embodiment of the invention
further includes a support structure with a distally
extending shaft portion that surrounds the positioning ~
means. In this embodiment of the apparatus, a
moveable assembly is mounted into the support
structure to cooperate with the positioning means and
rotate the~positioning means and guide means in
response to its own rotation. The proximal end of the
cannula is also ~ecured to the moveable assembly such
that axial translation of the moveable assembly causes
the cannula to translate with respect to the
positioning means, thus, allowing the cannula to be
inserted into the organ.
According to the further embodiment of the
invention, the cannula comprises an outer member and
an inner member received within the outer mamber. The
locking means includes a locking member secured to the
inner member adjacent to the distal end and disposed
substantially between the inner and outer members.
The locking member is arranged such that it is capable
of movement from a first non-locking position between
the inner and outer members to a second locking
position extending into the tissue surrounding the
cannula. Such movement is in response to relative
movement between the inner and outer members. The
moveable assembly includes a body member secured to
the outer cannula member and a support member secured
',~;
WO93/1~ PCT/US93/01077 ~
2129639 - 4 ~
to the inner cannula member such that relative
movement between the body member and support member
effects the movement of the locking member from the
first to second positions.
In order to allow an operato~ to manipulaté
the apparatus with a single hand, thè apparatus
further includes a handle member mounted on the
support structure cooperating with the body member of
the moveable assembly, whereby squeezing the handle
member causes translation of the moveable assembly
with respect to the support structure in order to
advance the cannula into the organ. The apparatus
further includes a trigger me~ber also mounted on the
support structure and cooperating with the support
member such that depressing the trigger member moves
the support member separately from the body mem~er to
move the locking member from the first position to the
second position. Additionally, a wheel means such as
a-thumb wheel is provided on the body member to allow
ease o~ rotation of the body member for positioning
the guide means.
In a preferred embodiment of the present
invention, the locking cannula includ2s an outer
member that comprises a hollow flexible needle
defining a radial opening adjacent to its distal end.
The inner member comprises an energy delivery means
disposed within ~he needle. The locking m mber
secured to the energy delivery means such that
relative motion between the needle and energy delivery
means causes the locking member to move from the first
non-locking position to the second locking position
extending into surrounding tissue.
In a further preferred embodiment, the inner
member of the locking cannula comprises a hollow inner
sheath with the locking member disposed thereon. The
outer member also comprises a hollow sheath which
defines a radial opening adjacent to its distal end.
212 9 6 3 9 PCT/US93/01077
- 5 -
The locking member and the opening are arranged such
that relative movement between the sheaths moves the
locking member through the opening from the first non-
locking position to the second locked position.
According to further details of the invention, the :
inner sheath may comprise a helically wound
construction and have a separate distal tip portion
which defines a recess that receives the locking
member in the first position. In energy delivery
embodiments of the invention, the distal tip is
preferably a heat resistent and non-conductive
material.
The present inventi~n also includes a kit ~
for interstitial treatment or diagnosis in an organ
including a locking cannula substantially as descri~ed
above and an apparatus generally as described above,
and, further, an endosc~ope configured and dimensioned
to be inserted into the apparatus to allow for
vi~ualizing the insertion of the cannula into the
organ. The kit, according to the invention, may also
include an obturator adapted to be inserted into the
apparatus to facilitate positioning of the app~ratus
in the body passage. The kit may also include a
stylet adapted to be received in the cannula and
extend distally beyond the cannula in order to `~
facilitate insertion of the cannula into the organ. A
further component of the kit is an energy source
having a means for delivering energy configured and
dimensioned to be received within the cannula and
extend beyond the distal end of the cannula for
delivery of energy to the organ. Energy sources
included with the kit, include sources of microwave
energy, ultrasound energy, laser energy,
radiofrequency energy and thermal energy. In order to
deliver these various types of energy, the kit
includes energy delivery means such as an antenna,
.
W093/1~ PCT/US93/01077
2 12963 g ~ 6 -
optical fiber, wire, bipole device or piezoelectric
elem~nt.
The present invention also includes a method
for interstitial treatment or diagnosis within an
organ. According to the ~ethod, a tubular member is
placed within the body passage adjacent to the organ
to be treated. A cannula is guided into the organ hy
the tubular member with the cannula puncturing the
tissue of the organ. The cannul~a is located with its
distal end at a treatment zone within the organ. The
cannula is locked in the organ and treatment or
diagnosis is performed at the zone.
The method according to the invention
includes a multi-step treatment method wherein the
cannula is guided and inserted into the organ by
placing a stylet within ~he cannula and advancing both
the cannula and the stylet together into the organ.
After the cannula is located at the treatment zone and
locked in place, the stylet is withdrawn nd a cell
targeted co~pound ~ensitive to an energy type is
interstitially applied to the organ through the
cannula. The particular type of energy is then
app~ied through the ~annula to the targeted cells.
Brief De~ription of th~ Dra~i~ -
FIG. l is a view of the median sa~ittal
section of the male pelvis illustrating the use of one
embodiment of the apparatus according to the present
invention for treating the prostate;
FIGS. 2-5 are a sequence of enlarged cross-
sectional views of the prostate, illustrating the
steps of one embodiment the method of the present
invention, utilizing the apparatus shown in FIG. l;
FIG. 6 is a schematic, partial section view
of the apparatus shown in FIG. l, illustrating a
mechanism for positioning, advancing and locking the
cannula according to one embodiment of the invention;
' ~',093/15664 2I29639Pcr/Usl)3/oto77
FI G . 7 is an end view of the guide wheel
shown with the apparatus in FIGS. l and 6;
FIG. 8 is an enlarged, partial section view
of the apparatus shown in FIG. 6;
FIG. 9 is an enlarged section view of the-
distal end of the locking cannula shown in FIG. 1,
with a barb locking means according to the present
invention in the retracted position;
FIG. 10 is a section view of the barb
locking means shown in FIG. 9 in the extended and
locked position;
FIG. 11 is a side view of the distal end of
an alternative embodiment of ~he apparatus of the
invention, similar to the apparatus shown in FIG. 1
with an extended shaft;
FIG. 12 illustrates a further alternative
embodiment of the apparatus according to the
invsntion;
FIGS. 13 and 14 illustrate an obturator and
stylet, respectively, for use with the apparatus shown
in FIG. 12;
FIG. 15 is a section view of the distal end
of the locking cannula of the apparatus of FIG. 12,
with a barb locking in the retracted position and the
stylet in place; `~
FIG. 16 is a section view of the barb
locking means ~hown in FIG. 15 in the extended and
locked posi~ion, with an energy delivery means in
place;
FIG. 17 is a section view of the distal end
of an alternative locking cannula;
FIG. 18 is a section view of the distal end
of the alternative locking cannula shown in FIG. 17,
with an energy delivery means in place; and
FIG. 19 is a section view of a further
alternative embodiment of the locking cannula
according to the present invention.
WO93/1~6~ PCT/US93/01077
2 1~963 9 - 8 -
D~tailea Description of the Prof¢rr~d E~bodi~ents
In order to provide an overall underctanding
of the present invention, the method of the invention
will be discussed with reference to laser ablation
treatment of benign prostatic hyper~rophy (BPH).
However, it will be understood by persons of ordinary
skill in the art that the general method and apparatus
as described herein are equally applicable treatment
of any organ which is accessib~e through a body
passage similar to the accessibility of the prostate
by the urethra. For example, the prostate could be
approached rectally or peritoneally ~y laparoscopic
techniques, as could other organsO Also, numerous
treatments other than laser ablation are possible with
the present invention.
Referring first to FIG. l, an interstitial
treatment delivery apparatus lO according to the
invention is positioned in the prostatic urethra A
with its distal end adjacent to the prostate B.
Locking cannula 12 has been ext~nd~d by squeezing hand
lever 14 and the interstitial locking means 16
deploy~d by depressing trigger 18~ Laser energy has
been or is being delivered to treatment area C by
sharpened tip 20 of laser fiber 22. An Nd:YAG or
diode laser provides a suitable laser energy ~ource.
- A tuneable dye laser also may be used depending on the
particular application. Persons of ordinary skill in
the art could identify other laser sources and select
suitable optical fibers for use therewith. Other
components of apparatus lO shown in FIG. l, whose
function and interrelationship will be explained in
detail below, are fluid ports 24 and 26, endoscope 28,
cannula guide 30, guide wheel 32, hand piece 34 and
shaft 36.
After insertion of endoscope 28 into hand
piece 34, shaft 36 is advanced into the prostatic
urethra A while visualizing the verumontanum, as
2 1 2 9 6 ~ ~ Pcr/US93/0l077
g
ndicated by arrow 37 in FIG. 2. A dilation fluid may
~e introduced through one of ports 24 or 26 which
communicate with distal openings 38 to facilitate
introduction of the shaft. The dilation fluid can be
removed through the other of ports 24 or 26, or be
allowed temporarily to accumulate in the bladder D.
By rotating guide wheel 32, cannula guide 30 is
directed toward the wall of the urethra corresponding
to the treatment zone E. Arrow 39 indicates the
movement of cannula guide 3Q. Positioning Qf shaft 36
and cannula guide 30 is viewed through endoscope 28
and endoscope port 40.
Referring to FIGS. 3 and 4, as handle lever
14 is squeezed, locking cannula 12, with sharpened
fiber tip 20, is exposed and directed through the
urethral wall toward txeatment zone E. The sharpened
tip facilitates puncturing the urethral wall and
pushing the cannula through the prostate. However, a
sharpened laser fiber is not required. For example,
as explained below, a stylet may be used for insertion
of the cannula into the organ and subsequently a laser
fiber (or other energy delivery means) with any
desired ti`p may replace the stylet for treatment.
The depth of insertion into the prostate B
can be determined by viewing contrasting markings 42
on the outside of cannula 12. Such contrasting
markings can be on the outer surface of the cannula,
for example as impregnate plastic rings, or located on
an inner surface, visualizable through the cannula
outer surface. Other markings are possible, the
primary requirement being the ability to be readily
visualized on the cannula outer surface.
As the distal end of the locking cannula
approaches the treatment zone E, ultrasound is used to
finely position tip 20 for treatment. The ultrasound
may be applied, for example, with a transrectal
ultrasound probe or by removing endoscope 28 and
. W093/1~ PCT/US93/01077 ~
2~.29639 - 10 -
inserting a transurethral ultrasound probe through
shaft 36. Preferably cannula 12 is provided with an
echogenic construction or surface treatment to improve
contrast and facilitate ultrasound visualization.
Once tip 20 is in the desired position for~
treatment, locking means 16 are deployed as shown in
FIG. 5, to positively lock the cannula in place during
treatment. Locking means 16 are deployed by
depressing trigger 18, which causes a coaxial movement
that extends barbs or other means. The various
alternative configurations of locking means are
described below in greater detail.
Referring again to ~G. l, laser energy is --
shown applied through sharpened tip 20 to treat the
prostate. With a sharpened tip, the area of treatment
is generally spherical, with the tip located
approximately at the c~nter of the sphere.
During application of laser energy, it is
necessary to monitor the temperature of surrounding
tissue in order to prevent unwanted tissue damage.
For this purpose, temperature sensing devices 46, such
as thermocouples or miniaturized thermistors, are
placed in appropriate locations along shaft 36, and
also on cannula 12 as explained below. A person of
ordinary skill in the art would have sufficient
knowledge to provide the necessary connections to
monitoring devices and the exact locations for the
sensing devices.
In high temperature energy delivery systems
it is desirable to cool portions of the anatomy to
prevent damage by overheating. For example, cooling
fluid may be introduced through ports 24 or 26 to cool
shaft 36 in the region of the external sphincter F.
Damage to the externàl sphincter could cause
incontinence. It also may be desirable to extend
shaft 36 ~istally, as shown in FIG. ll, in order to
provide direct cooling to the bladder neck area G.
,
,. ..... .
2129639
~' ~093/1~ PCT/US93/01077
The cooling fluid may be circulated in and out of
ports 24 and 26, or it may exit openings 38 and
temporarily accumulate in the bladder. Accumulation
in the bladder would also allow a degree of cooling of
the bladder neck without a shaft extending -
therebetween.
After treatment, the locking means is
retracted and the ~annula removed. Alternatively, the
cannula may be repositioned and the locking means
redeployed for further treatment.
Turning now to FIGS. 6-l9, wherein like
reference numerals refer to like parts, the details of
the various alternative embodiments of the present
invention may be described in greater detail. FIG. 6
schematically illustrates the operating mechanism of
apparatus lO, shown in FIG. l. Apparatus lO generally
comprises a moveable ~ssembly 4~ and barrel 50
contained within support ~tructure 5~. Support
structure 52 includes shaft portion 36 and hand piece
34. Moveable assembly 48 is ~ounted for both rotation
and axial movement, whereas barrel 50 is constrained
against axial movement but does rotate with moveable
assembly 48. In addition to supporting the moveable
assembly and barrel, support structure 52 provides
passages for flow of fluids between ports 24 and 26, -`~
- and openings 38. The specific arrangement of such
pascaqes is within the skill of an ordinary skilled
worker in the art and therefore they have been omitted
from the drawing for reasons of clarity.
Hand piece 34 is constructed of a suitable
rigid material such as stain~ess steel or plastic in
order to support moveable assembly 48 and allow for
manipulation by hand.
Depending on the particular application and
other factors determined by the operator, shaft
portion 36 can take a variety of forms. For example,
it may be rigid, flexible, malleable, articulatable or
2129 - 12 - PCI/USg3/01077 ~'~
expandable. Flexible embodiments may be constructed
similar to known catheters. By providing controllable
joints, articulatable embodiments would be well suited
for manipulation within the peritoneum. Expandable
embodiments include longitudinal expansion by
telescoping shafts and radial ex ansion, for example,
by balloon structures on the shaft. U.S. patent
application No. 07/625,332, filed December 10, l99o,
which is incorporated herein by reference thereto,
discloses a number of shaft balloon configurations
suitable for use in the shaft portion of the present
invention. Balloon expandable shafts provide a
locking feature in addition t~ the locking cannula --
described herein and, thus, provide increased
confidence in the accuracy of treatment application.
Shaft balloon~ can also be inflated using a cooling or
heat transfer medium in order to cool the body passage
and surro~nding tissue during energy delivery.
Moveable assembly 48 is rotated by rotating
guide wheel 54. This also causes barrel 50 to rotate,
which positions cannula guide 30 as described above.
Any suitable means for directing the cannula may serve
as cannula guide 30. A preferred embodiment includes
a member defining a curved passage through which the
cannula slides. The moveable assembly is advanced by
squeezing handle lever 14. When moved in the
direction of arrow 56, the handle lever pivots at
point 58 (mounted on support ~tructure 52) and moves
cam member 60 forward. Cam member 60 engages lever
ring 62 to cause axial movement of the movea~le
assembly. Lever ring 62 is fixed to moveable assembly
48. Notch 64 in cam member 60 allows lever ring 62 to
rotate when the quide wheel is rotated, while at the
same time constantly engaginq ring 62 for axial
adjustment. Guide wheel 54 (FIG. 7) has an internal
key 66 that cooperates with slot 68 in moveable
assembly 48 to allow rotational engagement and free
; ~93/1~ - 13 - PCT/US93/01077
axial movement of the guide wheel with respect to the
moveable assembly.
Trigger 18 is slideably mounted on support
structure 52. Trigger arm 70 includes notch 72 that
cooperates with trigger ring 7~ in the same manner as
notch 64 and lever ring 62. However, trigger ring 76
is not fixed to moveable assembly 48. Trigger ring 76
moves with the moveable assembly ~o long as trigger 18
is not depressed. When the trigger is depressed,
trigger ring 76 moves to the left as shown in FIG. 6,
independent of moveable assembly 48.
As shown in FIG. 8, cannula 12 comprises
inner sheath 80 and outer she~th 82. An energy
delivery nleans, in this case laser fiber 22, is
contained within inner sheath 80. The cannula and
laser fiber are not shown in section~ The cannula is
generally flexible to allow it to be ~uided by cannula
guide 30 and for ease of insertion into the organ.
Also, being flexible, cannula 12 is well suited for
use of a steering fiber as disclosed in co-pending
application No. 07/625,332 in order to provide a
cannula that is steerable within ~he organ. In
certain applications, it may be desirable to provide a
. rigid tip portion to facilitate insertion or increase
insula~ive characteristics as di~cu~ed below, or to - :
provide a rigid proximal shaft portion to enhance
manipulation of the cannula. As understood by a
person skilled in the art, such rigid portions can be
provided without compromising the general flexibility
of the cannula.
Also shown in FIG. 8 is endoscope channel 81
and rotary uniting rod 83. The rotary uniting rod
ensures that barrel 50 rotates with moveable assembly
48, but is received in a hole to allow the moveable
assembly to translate without translation of the
barrel.
WO93/1~ PCT/US93/01077
- 14 ~
2l29639
Trigger ring 76 has a forward extending,
inner sheath support member 84. The support member is
hollow to define a passage for the laser fiber and is
secured to inner sheath 80 at joint 86. Inner sheath
support member 84 is slideably received in outer
sheath support member 88. The outer sheath support
member extends from body 90 of~ the moveable assembly
and is connected to outer shëath 82 at joint 92.
Therefore, when lever ring 62 is advanced as explained
above, outer sheath 82 moves forward and, as long as
trigger 18 is not depressed, the inner sheath and
laser fiber move with it to extend cannula 12 into t:he
prostate or other organ to be-treated. --
Once the cannula is positioned for
treatment, locking means 16 is deployed. This i5
accomplished by depressing trig~er 18 which, through
the cooperation of the elements as explained, causes
inner sheath 80 to move back or proxi~ally. Trigger
rin~ 76 is shown in a partially depressed position in
FIG. 8.
Deployment of locking means 16 according to
the embodiment shown in FIG. 1 may be explained in
greater detail by reference to FIGS~ 9 and 10. FIG. 1
shows the use of multiple locking members, however, a
single locking member is shown in FIGS. 9 and lO for
clarity. -FIG. 9 illustrates the distal end of the
cannula as it is extended into the organ. Sharpened
laser fiber tip 20 forms the piercing tip of the
cannula. As discussed below, other structures such as
a separate stylet or hollow needle may serve this
purpose. Preferably, the inner and outer sheaths are
tapered at the distal end to form a profile that
facilitates insertion.
Inner sheath 80 in ludes a shaft portion 96
that is constructed from helically wound wire, similar
to known guide wires, in order to combine sufficient
axial stiffness and pushability with bendability. At
~ ~g3/15~ 21 2Y639 P~/US93/01077
- 15 -
the distal end of inner sheath 80, a tip 98 is
provided that carries locking barb 100 in recess 102.
Barb 100 can be made of any biocompatible material
having suf~icient strength, hardness and elasticity to
be inserted and withdrawn from the surrounding tissu`e
a number of times without failure. Such materials
include stainle~s, carbonized or anodized steel,
nitinol and various hard plastics. The end of locking
barb 100 is aligned with opening 104 in outer sheath
82. When inner sheath 80 is moved back as described
above, locking barb 100 exits opening 104 to become
implanted in the organ as shown in FIG. 10. With the
locking barb extended, the distal end of cannula 12 is ~
secured adjacent to the treatment site. The operator
may then release his or her grip on apparatus 10 in
order to concentrate on the treatment, without the
need to manually maintain the laser fiber or other
treatment means in place.
Locking means 16 is retracted or reversed by
moving trigger ring 76 in the opposite direction from
that used to deploy the locking means. This can be
accomplished manually or automatically. One means
(not shown) for automatic retraction is to provide a
spring mechanism which can be locked by the operator
and, when released, biases trigger ring 76 to the
retracted position.
~ or energy delivery treatments that involve
high temperature, such as laser ablation, it is
preferable that tip 98 be made of a non-heat
conductive material in order to prevent heat transfer
to shaft portion 98. In order to monitor energy
delivery and temperature, temperature sensing devices
46 are located along laser fiber 22 and cannula 12.
In addition to thermocouples or thermistors as
explained above, temperature sensing can be
accGmplished by fiber optic temperature sensors or
"
~ infrared measuring along the cannula. Also,
,~ .
WO93/1~ PCT/US93J01077
~ ~2 963~ - 16 -
ultrasound may be used to measure temperature remotelyby tissue characterization through signal processing
of the ultrasound image. The amount of tissue damage
can also be determined by sensing NADPH, a compound
produced by cell death.
Depending on the type of treatment which is
to ~e delivered, the construction and~materials for
outer sheath 82 (also inner sheath 803 will vary. For
high temperature energy delivery systems materials
capable of withstanding the high temperatures must be
used. The outer sheath also must be made of an
insulating or nonconductive material to prevent heat
transfer down its shaft. one advantage of the present --
invention is that by delivering the cannula through a
relatively small puncture wound, the hole heals
quickly and with minimal chance for infection after
treatment. If heat transfer down the outer sheath is
sufficient to cauterize the surrounding tissue, a more
permanent and difficult to heal hole can be created.
Also, similar to the i~ner sheath, the outer sheath
must be axially stiff but bendable, al~hough the
stiffness may be provided by a guide wire-like
construction of the inner sheath. As an alternative,
the outer and inner sheaths can be two or more parts,
with the tapered distal portion being a relatively :-
stiff and highly nonconductive material such as
ceramic. Persons skilled in the art can identify
suitable materials, surh as teflon, silicon,
polyurethane, polymers and copolymers, which will meet
the requirements for the particular application.
To assist in ultrasound positioning, the
cannula can be provided with an echogenic
construction. This may result as a function of the
different materials chosen for the inner and outer
sheaths, or can be intentionally created, for example,
by forming the cannula with two different materials
having different acoustical impedances and interfacin~
~``p93/1~ 2 1 2 9 ~ 3 9 pCT/~S93/010~7
non-uniformly to crea~.e multiple angles of
reflectance.
In certain applications it may be desirable
to create a more permanent hole, for example for
drainage, or to otherwise cauterize the surrounding
tissue. In such instances the sheaths may be
constructed of highly conductive material such that
energy delivery at the tip is transferred down along
the outer sheaths. Alternatively, and in particular
in non-energy delivery applications, it may be
desirable to provide the cannula itself with a heat
source for cauterization. For example, electric
resistance heating could be used for this purpose. --
Turning now to FIG. 11, there is shown an
alternative embodiment of apparatus lo having an
extended shaft portion 106. An opening 108 is
provided in the snaft to allow cannula guide 30 and
endoscope port 40 to access the urethral wall.
Otherwise the construction and operation of the
apparatus is substantially the same as described
above. Extended shaft portion 106 is especially well
suited for use of a tip balloon as disolosed in co-
pending V.S. application No. 07/625~332. The extended
shaft can also be of sufficie~t length to be disposed
within the bladder neck G during energy delivery in
order to provide a direct coolinq source thereto.
~ IG~ 12 illustrates a further alternative
embodimen~ of the present invention. In FI~. 12,
apparatus 110 is shown substantially as it would
appear in place for energy delivery treatment to an
organ. An introducer assembly 112 includes shaft 114,
which generally corresponds to shaft 36 in apparatus
10. A preferred configuration of shaft 114 is a 21-22
french stainless steel cannula, although alternatives
such as those explained above in connection with
apparatus 10 are also possible. Endoscope 116 is
shown inserted into the introducer assembly.
WOg3/15~ PCT/US93/01077 ~
2129639 - 18 -
Irrigation and light source connections 118 and 120,
respectively, are also provided. The distal end of
shaft 114 provides an endoscope port and fo~ms a
cannula guide 122. The direction of insertion of
cannula 12 thus may be controlled by turning the
introducer assembly.
Locking cannula 12 enters introducer
assembly 112 through port 126 and extends out of
cannula guide 122. Locking actuator i30 provides
coaxial movement between outer shea~h ~2 and inner
sheath 80 (shown in detail in FIGS. 15 and 16). An
energy delivery means 136 is inserted into the cannula
through port 138 in locking actuator 130. --
In use, the introducer assembly would first
be fitted with obturator 140, shown in FIG. 13. At
this point neither the endoscope nor the cannula would
be placed in the introducer assembly. The operator
would then insert introducer assembly 112, with
obturator 140, into the urethra in a similar manner to
the insertion of a cystoscope. Again, as with
apparatus 10, the uret~ra and prostate are used as a
reference for descriptive purposes only and not as a
limitation of the invention.
After the distal end of shaf~ 114 is in the
vicinity of the prostate or other tar~eted organ,
obturator 140 is removed and endosc~pe 116 is inserted
with appropriate connections to the light source and
irrigation. Stylet 142 is insPrted into c~nnula 12,
through port 138. Stylet 142 is shown in FIGS. 14 and
15. Cannula 12 is then inserted into the introducer
assembly through port 126 until it extends from
cannula guide 122 and is visible through the
endoscope. The introducer assembly is rotated to
position the cannula in the direction of the treatment
zone. Cannula 12 is then extended into the prostate
by gripping its proximal end and pushing or by pushing
on actuator 130 to force stylet 142 into the prostate.
~`'pD93~15~ g _ 2 1 2 9 6 3 9 PCT/US93/0l0,7
Contrasting markings 42 on cannula 12 can be viewed
through the endoscope and also with the nakPd eye at
port 126. Final positioning for treatment is again
accomplished by ultrasound.
~ fter the treatment zone is reached, inner
sheath 80 is retracted using finger grips 146 and 148
of anchor actuator 130. Locking means 16 is thereby
deployed as previously described. As shown in FIG.
16, once the distal end of cannula 12 is locked in
place, stylet 142 is removed and energy delivery means
136 is inserted to extend a predetermined distance
distally out of the cannula. The amount of extension
can be determined visually by ~arkin~s or by a ~-
mechanical stop.
FIGS. 17 and 18 illustrate another
alternative embodiment of the present invention. In
this embodiment, the coaxial movement of inner sheath
80 and outer sheath 82 is reverse~ from that shown in
FIGS. 15 and 16. As the treatment zone is approached,
inner sheath 80 is extended forward to the final
position. This a~tion causes barb 150 to extend ou~
of ope~ing 152 and lock the distal end of the cannula
in place. In order to assume its hook-like shape, it
is preferred that barb 150 be made of a material with
a good elastic memory, such as nitinol. After the -"
barb is extended, stylet 142 may be withdrawn and
energy delivery means 136 inserted in its place.
Energy delivery means 136 need not be a
laser fiber. Other energy delivery systems which will
produce the desired effect on the tissue may be used.
For example, for ablation, means 136 could comprise a
microwave antenna, an ultrasound probe (either a wire
leading to a remote source or a piezoelectric
apparatus at the distal locatîon~, a radio frequency
source such as a bipole located at the tip, or other
thermal energy systems such as electrical resistance.
WOg3/1~ 2 129639 - ~0 - PCT/US93~01077
Due to the capabili~y of removing the energy
delivery means with~ut removing the apparatus as
whole, the present invention is particularly well
suited for multiple step therapies. For example, a
pbotodynamic therapy may be applied using a compound
which is specifically targeted to particular cells and
sensitive to selected light frequencies. Such
targeting can be achieved ~y linking the compound to
monoclonal antibodies having an;~àffinity for the
target cells. The compound would be applied through
cannula 12 and allowed sufficient time to reach the
target cells. An optical fiber would then be inserted
into cannula 12 to apply laser-or other appropriate
light for treatment. The interstitial locking means
16 ensures that the light energy is applied at the
same location as was the compound.
It is also not required that an energy
delivery system be used at all. After cannula 12 is
locked in place by locXing means 16, and stylet 142 is
removed, the cannula provides an ideal conduit for
other treatments such as interstitially targeted drug
therapy, radiation treatment by implantation of s
radioactive "seeds", or implantation of microwave
"se~ds" (essentially small metal strips) for
subsequent application of microwave energy. Cannula
12 also may be used for aspiration or irrigation
direct~y at a treatment site.
Additionally, cannula 12 can be used for
- diagnostic purposes as well as therapeutic. For
example, the probe of an endoscope or ultrasound
imager may be directed to a specific location in an
organ. Contrast agents could be delivered to improve
external radiographic, magnetic resonance or
ultrasound imaging.
It is not re~uired that cannula 12 have
coaxial sheaths. FIG. l9 shows a further embodiment
of the invention utilizing flexible needle 154 as an
; :~93/1~ 2 1 2 9 6 3 9 pCT/US93/01077
- 21 -
outer member and energy delivery means 136 to deploy
locking barb 15~. Locking barb 156 is secured to
delivery means 136 by collar 158 and received in
recess 160 in needle 154 when retracted. In use,
needle 154 is inserted into the organ, to the
treat~ent location, by suitable means as described
herein. The needle is then slîghtly backed off and
means 136 separately advanced into the treatment
position, simultaneously deploying barb 156 through
curved guide hole 16~. Means 136 ma~ have a tapered
or sharpened end to facilitate its advancement into
the passage created by the needle. This embodiment is
particularly well suited for application with the -
flexible and steerable needles and apparatus disclosed
in U.S. application No. 07/625,332, which has been
incorporated by reference.
