U.S. patent number RE32,348 [Application Number 06/108,932] was granted by the patent office on 1987-02-10 for miniature balloon catheter method and apparatus.
Invention is credited to Paul H. Pevsner.
United States Patent |
RE32,348 |
Pevsner |
February 10, 1987 |
Miniature balloon catheter method and apparatus
Abstract
A miniaturized balloon catheter assembly includes a cannula and
an inflatable tubular balloon constructed of a silastic tubing
detachably mounted on the cannula for performing a surgical
procedure in a human vessel in response to pressure therein. In one
embodiment, the balloon is detachable mounted with the
detachability being responsive to pressure. For example, the
balloon elastically grips the cannula and there is a small metallic
C-shaped spring mounted about the balloon and cannula. In another
embodiment, a valve, such as a pinhole in the silastic material for
example, is included in the balloon which opens only after the
pressure within the balloon exceeds a predetermined amount.
According to a method of the invention, the cannula and the
attached balloon are inserted into a small vessel and the balloon
is pressurized therethrough. The balloon is partially inflated to
allow fluid flow in the vessel to position the balloon at a desired
location. The balloon is further inflated to fix the balloon in
position against the walls of the vessel. Pressure is thereafter
increased in the balloon to activate a desired procedure within the
vessel. In the first embodiment the desired procedure is to
withdraw the cannula from the affixed balloon as the increased
pressure lubricates the connection between the balloon and the
cannula. The C-spring and the silastic balloon cooperate to close
off the opening into the balloon left by the retracted cannula and
thereby leave the balloon in position in the vessel. In the second
embodiment, the desired procedure is for the increased pressure to
open the pin-hole and disperse a fluid into the vessel from the
balloon. There are alternate embodiments for performing the above
methods and the methods can be combined.
Inventors: |
Pevsner; Paul H. (Richmond,
VA) |
Family
ID: |
26806439 |
Appl.
No.: |
06/108,932 |
Filed: |
December 31, 1979 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
681676 |
Apr 29, 1976 |
04085757 |
Apr 25, 1978 |
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Current U.S.
Class: |
606/194; 604/103;
604/907; 604/99.01; 606/195 |
Current CPC
Class: |
A61B
17/12136 (20130101); A61B 17/12109 (20130101) |
Current International
Class: |
A61B
17/12 (20060101); A61M 025/00 () |
Field of
Search: |
;128/325,344,129
;604/96-103 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Luessenhop "Intra-Arterial Instrumentation for
Neurosurgery-Bulletin-Dow Corning-vol. 2, No. 3, 7/60. .
Serbinenko, "Balloon Catherization and Occlusion of Major Cerebral
Vessels-J. Neurosurg. vol. 41, 8-74, pp. 15-145..
|
Primary Examiner: Truluck; Dalton L.
Attorney, Agent or Firm: Griffin, Branigan & Butler
Claims
I claim:
1. A miniaturized balloon catheter assembly for use in small
vessels comprising:
a cannula having proximal and distal ends including an attaching
means at the proximal end thereof for attaching to a source of
pressurized fluid and having a small outer diameter for insertion
into small vessels;
an inflatable balloon including a means forming a mouth at a
proximal end thereof mounted on an external surface of the cannula
at the distal end of the cannula to be in fluid communication
therewith, the cannula and balloon together adapted to be carried
by the fluid in a vessel to desired locations therein, whereupon
attachment of the cannula fluid source of pressurized fluid and
introduction of amounts of pressurized fluid flow inflate the
balloon to fix it in position against the wall of said vessel at a
desired location; and,
a balloon-retaining means responsive to a predetermined further
amount of pressure to initiate a desired procedure within the small
vessels, said balloon-retaining means including a resilient
contracting member surrounding said means forming said mouth for
holding said means forming said mouth on said external surface of
said cannula, said resilient contracting member being constructed
to have a specific predetermined internal size when in a contracted
state for: contracting with a uniform predetermined tension about
said means forming said mouth when said means forming said mouth is
mounted on said cannula to hold said balloon on said cannula upon
said balloon being inflated to fix it in position against the wall
of said vessel at said desired location, expanding in response to
said predetermined further amount of pressure in said balloon to
release said cannula from said mouth, and thereafter contracting
toward said specific predetermined internal size to close said
balloon mouth and thereby retain said inflated balloon fixed in
position against said wall.
2. A miniaturized balloon catheter as in claim 1 wherein said
balloon is of an elastomeric silastic material.
3. A miniaturized balloon catheter assembly as in claim 1 wherein
said cannula and said balloon are normally of approximately the
same diamter and attachment of the inflatable portion of the
cannula is achieved by expanding the means forming a mouth, and
extending it over the adjacent end of the cannula.
4. A minaturized balloon catheter as in claim 3 wherein said
resilient contracting member is a C-shaped spring.
5. A miniaturized balloon catheter as in claim 4 wherein the inner
diameter of said balloon is approximately 0.011 inch and its outer
diameter is approximately 0.024 inch while said C-shaped spring has
an inner diameter of approximately 0.018 inch when it is in a
non-expanded condition.
6. A miniaturized balloon catheter as in claim 1 wherein said
resilient contracting member does not wrap about said means forming
said mouth more than once.
7. A diagnostic and therapeutic method for carrying out procedures
in small vessels by utilizing a miniaturized balloon catheter
assembly including a resilient cannula adapted for attachment to a
source of pressurized fluid and having a small outer diameter for
insertion into small vessels and an inflatable balloon having a
mouth at the proximal end thereof mounted on the end of the cannula
in fluid communication therewith comprising the steps of:
inserting the distal end of said cannula into the mouth of said
inflatable balloon;
attaching said inflatable balloon to said resilient cannula with a
resilient contracting member by surrounding a portion of said
inflatable balloon near said mouth with said resilient contracting
member and thereby contracting said balloon onto said resilient
cannula, said resilient contracting member having a predetermined
internal size when in a fully contracted state for: contracting
about said balloon portion to hold said balloon on said cannula
with a uniform tension when said balloon is mounted on said cannula
and for contracting toward said predetermined internal size to
close said balloon mouth when said balloon is not mounted on said
cannula;
inserting the balloon catheter assembly into a small vessel;
attaching the cannula to a source of pressurized fluid and
pressurizing the balloon portion to partially inflate the balloon
portion to permit the balloon portion and attached cannula to be
directed by the fluid flow within the vessel to the desired
location;
further inflating the balloon portion to fix the balloon portion in
position;
increasing the fluid pressure inside the balloon portion to expand
said resilient contracting member; and
withdrawing said cannula from said mouth to allow said resilient
contracting member to contract and thereby close said balloon mouth
to retain said inflated balloon fixed in position.
8. The invention in accordance with claim 7 wherein said resilient
contracting member is a C-shaped spring.
9. A miniaturized balloon catheter as in claim 8 wherein the inner
diameter of said balloon is approximately 0.011 inch and its outer
diameter is approximately 0.024 inch while said C-spring has an
inner diameter of approximately 0.018 inch when it is in a
non-expanded condition.
10. The invention in accordance with claim 7 wherein the balloon
includes an opening in it distal end and expels fluid therethrough
downstream of the balloon portion during and after said cannula is
withdrawn from said mouth. .Iadd.
11. In a miniaturized balloon catheter assembly adapted for use in
diagnostic and therapeutic procedures in connection with small
vessels comprising; a cannula having means at a proximal end for
attachment to a source of pressurized fluid and having a small
outer diameter for insertion into small vessels, an inflatable
tubular balloon having a mouth portion and mounted at the distal
end of the cannula in fluid communication therewith, the cannula
and balloon adapted to be carried by the fluid in the vessel to a
desired location therein, whereupon introduction of an amount of
pressurized fluid flow from the source of pressurized fluid will
inflate the balloon to fix it in position, activation means
responsive to a further amount of pressure to initiate a desired
procedure within the small vessel at the desired location, said
balloon being detachably mounted at the distal end of said
cannula;
the subassembly of a sealing means which, when the cannula and
balloon are positioned at the desired location in the human vessel,
seals the mouth portion of the balloon, said sealing means
including elastomeric self-sealing plug material positioned in the
mouth of the inflatable balloon adjacent to the end of the cannula,
an expandable circumferential band on the outer surface of the
inflatable balloon in concentric position with respect to the plug
material therein, said subassembly further comprising a pin having
a passageway therethrough and one end mounted at the distal end of
the cannula with the passageway therein in communication with the
passageway through the cannula and the other end of the pin
positioned through a small opening in the self-sealing plug
material into fluid communication with the inflatable balloon on
the side of the plug material distal from the cannula and when in
that position expanding the circumferential band, so that when the
balloon is detached from the distal end of the cannula the pin is
removed from the plug material, whereupon the elastomeric
self-sealing plug material and the expandable circumferential band
will close the opening in the plug material and the mouth portion
of the balloon to retain the balloon in inflated condition.
.Iaddend. .Iadd.12. The subassembly of claim 11 wherein said
expandable circumferential band comprises a single strand element
which does not
extend about said plug material a plurality of times. .Iaddend.
.Iadd.13. A miniaturized balloon catheter assembly adapted for use
in diagnostic and therapeutic procedures in connection with small
vessels comprising; a cannula having means at a proximal end for
attachment to a source of pressurized fluid and having a small
outer diameter for insertion into small vessels, an inflatable
tubular balloon having a mounth means constructed of self-sealing
material for forming an opening into said balloon through which
said balloon can be inflated, but which can be closed to maintain
said balloon in an inflated state, said balloon being mounted at
the distal end of the cannula in fluid communication therewith,
said cannula extending into the mouth means of said balloon so that
said balloon can be inflated and deflated via said cannula, the
cannula and balloon adapted to be carried by the fluid in the
vessel to a desired location therein, whereupon introduction of an
amount of pressurized fluid flow from the source of pressurized
fluid will inflate the balloon to fix it in position and a further
amount of pressure will initiate a desired procedure within the
small vessel at the desired location, said balloon having a sealing
means thereon so that when the cannula and balloon are positioned
in the desired location in the human vessel the cannula can be
detached from the balloon whereupon the sealing means will seal the
mouth portion of the balloon, said sealing means including a
circumferential expandable-band means on the outer surface of the
mouth means of said inflatable balloon tending to hold the balloon
mouth means onto said cannula, said expandable-band means
comprising a single strand element which does not extend about said
mouth means a plurality of times, said expandable-band means and
said mouth means having the joint function of responding to a
sufficient amount of pressurized fluid passing through the cannula
into the inflatable balloon to inflate the balloon to a desired
amount by detaching the cannula from the balloon for removal of the
cannula from the balloon mouth means, and responding to a decreased
pressure in said balloon after said cannula has been removed by
closing the opening in said mouth means of the balloon to retain
the balloon in an inflated condition. .Iaddend. .Iadd.14. A
diagnostic and therapeutic method for carrying out procedures in
small vessels by utilizing a miniaturized balloon catheter assembly
including a resilient cannula adapted for attachment to a source of
pressurized fluid and having a small outer diameter for insertion
into small vessels and an inflatable balloon having a mouth means
constructed of self-sealing material for forming an opening into
said balloon, through which said balloon can be inflated, but which
can be closed to maintain said balloon in an inflated state, said
balloon being mounted on the end of the cannula in fluid
communication therewith, said method comprising the steps of:
inserting the distal end of said cannula into the mouth means of
said inflatable balloon so that said balloon can be inflated and
deflated via said cannula;
attaching said inflatable balloon to said resilient cannula with a
resilient contracting member by surrounding said mouth means with
said resilient contracting member and thereby contracting said
balloon onto said resilient cannula, said resilient contracting
member comprising a single strand element which does not extend
about said mouth means a plurality of times, said contracting
member contracting about said balloon portion to hold said balloon
on said cannula with a uniform tension when said balloon is mounted
on said cannula to close said opening when said balloon is not
mounted on said cannula;
inserting the balloon catheter assembly into a small vessel;
attaching the cannula to a source of pressurized fluid and
pressurizing the balloon portion to partially inflate the balloon
portion to permit the balloon portion and attached cannula to be
directed by the fluid flow within the vessel to the desired
location;
further inflating the balloon portion to fix the balloon portion in
position;
increasing the fluid pressure inside the balloon portion to expand
said resilient contracting member; and
withdrawing said cannula from said mouth means to allow said
resilient contracting member to contract and thereby close said
balloon mouth means to retain said inflated balloon fixed in
position. .Iaddend.
Description
BACKGROUND OF THE INVENTION
This invention relates broadly to the art of balloon catheters, and
more particularly to the art of miniaturized balloon catheters
generally for use in blood vessels and the like.
A significant publication disclosing prior art developments in the
area of this invention is Serbinenko, Balloon Catheterization and
Occlusion of Major Cerebral Vessels, Journal of Neurosurgery,
Volume 41, August 1974, pages 125-145. This article describes the
work of Dr. Serbinenko with miniaturized balloon catheters. Dr.
Serbinenko has employed balloon catheters to occlude vessels in
cardiovascular surgery as well as for other purposes, and his
article is incorporated by reference here.
Dr. Serbinenko employs a latex balloon that is held onto a cannula
by means of an elastic string for achieving permanent occlusion of
vessels. The balloon is inserted into a vessel and allowed to move
to a proper position by fluid circulation within the vessel. The
balloon is then inflated by means of a solidifying filler until it
is fixed against the walls of the vessel. After the solidifying
filler has solidified the cannula is pulled from the balloon and
the balloon is left in the vessel.
A difficulty with Dr. Serbinenko's arrangement is that the balloon
sometimes comes off of the cannula prematurely because the elastic
string does not tightly hold the balloon to the cannula. Still
another difficulty with Dr. Serbinenko's arrangement is that the
solidifying filler is somewhat difficult and awkward to work with.
Thus, it is an object of this invention to provide a miniaturized
balloon catheter which can be used for permanent occlusion of a
vessel but which is not prematurely detached from the cannula and
which can be inflated by a nonsolidifying fluid.
Dr. Serbinenko has also employed a miniaturized balloon catheter to
achieve profusion. That is, Dr. Serbinenko has made a small
pin-hole in his latex balloon from which a dye or the like is
discharged from the balloon into the vessel. However, in Dr.
Serbinenko's arrangement, the fluid to be profused passes through
the pin-hole as soon as the fluid enters the balloon. It is
sometimes desirable that the fluid not pass through the hole until
the balloon has accomplished occlusion of the vessel. Thus, it is
another object of this invention to provide a miniaturized balloon
catheter which does not initiate profusion of fluid until the
balloon has achieved occlusion of the vessel.
It is a further object of this invention to provide a miniaturized
ballon catheter, and a method for using the miniaturized balloon
catheter which is efficient in operation, and relatively easy and
inexpensive to manufacture.
SUMMARY
According to principles of one aspect of this invention, a
miniaturized balloon catheter is inflated within a vessel until it
is fixed against the walls of the vessels, and thereafter released
from its attached cannula and sealed off against deflation. In this
respect, the mechanism for attaching the balloon catheter to the
cannula responds to increased pressure within the balloon once the
balloon is fixed to release the balloon from the cannula so that
the cannula can be pulled from the balloon and thereafter closes
the opening in the balloon left by the extracted cannula. In one
embodiment, the balloon is of a self-sealing silastic material and
its diameter is approximately the same as the cannula. The balloon
is fitted onto the cannula and a C-spring is mounted over the
balloon and cannula to hold the balloon to the cannula. Pressure
within the balloon beyond a predetermined degree opens the C-spring
to allow the cannula to be removed.
Also in accordance with principles of another aspect of this
invention, additional pressure within the balloon after the balloon
is fixed against the walls of the vessel opens a valve in the
balloon to disperse fluid from the balloon into the vessel for
perfusion. This valve, in one embodiment, comprises a pin-hole in
the self-sealing silastic balloon.
Additional arrangements for performing the above functions are also
described herein.
To summarize, in general, the method and device of this invention
deals with a miniaturized balloon catheter assembly adapted for use
in diagnosis in therapy procedures in connection with small human
vessels. The device includes a cannula having a small outer
diameter for insertion into small human vessels. An inflatable
tubular balloon is mounted on the end of the cannula that is
inserted into the vessel. The cannula and balloon are adapted to be
carried by fluid in the vessel to a desired location therein. The
force of pressure operates at the other end of the cannula to
inflate the balloon. The balloon includes elements for responding
to increased pressure therein once the balloon is fixed to the
walls of the vessel to initiate desired diagnostic and/or therapy
procedures within the vessel at the desired location.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the
invention will be apparent from the following more particular
description of preferred embodiments of the invention, as
illustrated in the accompanying drawings in which reference
characters refer to the same parts throughout the different views.
The drawings are not necessarily to scale, emphasis instead being
placed upon illustrating the principles of the invention in a clear
manner.
FIG. 1 is a plan view of a balloon catheter assembly of the
invention;
FIG. 2 is a sectional view taken on line 2--2 of FIG. 1;
FIG. 3 is an enlarged fragmentary plan view thereof showing the
inflatable balloon portion attached to the end of a cannula;
FIG. 4 is an enlarged fragmentary view thereof showing a form of
inflatable balloon portion attached to the end of the cannula;
FIG. 5 is a partial sectional view of an alternate form of the
balloon catheter assembly of the invention showing only the end
portion of the cannula which is attached to the balloon
portion;
FIG. 6 is a partial sectional view of the alternate arrangement of
the balloon catheter with a wire by which detachment at any balloon
size may be achieved;
FIG. 7 is a sectional view of a further alternative form of the
balloon catheter of the invention;
FIGS. 8-12 are sequential schematic representations of the use of
the types of devices depicted .Iadd.in .Iaddend.FIGS. 1-4;
FIG. 13 is a schematic representation of the use of a balloon
catheter of this invention for achieving profusion.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1 and 2 show a catheter assembly 20 which includes a hollow
cannula 22, open at both ends, with a connector 24 at one end which
is adapted for connection to a conventional source of pressurized
fluid. Mounted on the other open end of the cannula 22 is an
inflatable balloon portion or inflatable tube 26 as a self-sealing
material described further below. The distal end 28 of the balloon
portion is closed by knotting the end. The proximal end 30 is
expanded to cover and frictionally engage the adjacent end of the
cannula 22. In this respect, in a preferred embodiment the interior
diamters of both the balloon or tube portion 26 and the hollow
cannula 22 are approximately 0.011 inch and the outer diameters
thereof are 0.024 inch. Thus, the balloon or tube portion 26
contracts onto the hollow cannula 22. This brings the passageway in
the cannula 22 in communication with the interior passage of the
inflatable balloon portion or tube 26. As shown in FIG. 2, the
inflatable .Iadd.tube .Iaddend.26 has a pin-hole 32 adajcent to the
distal end 28 which is normally closed when the balloon portion 26
is in the relaxed, uninflated condition since the material of the
balloon is self-sealing. This hole could also be in the distal end
28. Again this is accomplished by forming the balloon portion 26 of
an elastomeric self-sealing material such as silastic tubing.
FIG. 4 shows an alternative means for forming the distal end of the
balloon portion 26. In place of the knot at the end 28, a plug 34
attached by an adhesive is employed. It is also contemplated that
in place of a pin-hole 32, an opening can be positioned through the
knot or the plug 34. The pin-hole 32 forms a passageway for fluid
to pass from the distal end of the balloon portion 26 once the
pressure within the balloon portion exceeds a predetermined
amount.
Materials which can be used for the components of catheter 20 are,
for cannula 22, a plastic such as polyethylene or any conventional
substitute therefor; and, for the expandable balloon portion 26,
silastic tubing.
In addition to balloon portion 26 contracting onto the hollow
cannula 22, a C-shaped spring 33 is mounted on the outside of the
balloon portion to positively hold the balloon portion 26 and the
hollow cannula 22 together. The C-shaped spring is constructed of a
watch-spring metal and, in a preferred embodiment, this spring has
a contracted internal diameter of 0.018 inch and an outside
diameter of 0.020 inch. When the spring has expanded, it has an
inside diameter of 0.028 inch and an outside diameter of 0.033
inch. These dimensions of the C-spring cooperate with those of the
balloon portion 26 such that when the cannula 22 is not positioned
within the C-spring 33 then the opening to the balloon portion 26,
which the cannula 22 held open, is closed by the C-spring.
FIG. 5 depicts an alternate device which is used as a detachable
implant device for permanent vessel occlusion, for example. The
materials used for .Iadd.cannula .Iaddend.22a and inflatable
balloon portion 26a are the same as in the previously discussed
embodiments and the difference in structure resides in the
interconnection between portion 26a and cannula 22a. In place of
the expanded frictional interengagement, a combination type
structure is employed. In this regard, a proximal end 36 of
inflatable portion 26a is expanded in the same manner and coupled
with the outer surface of cannula 22a. Spaced from end 36 on
portion 26a is an expandable ring 38 which is concentrically
aligned with an inner plug 40. The plug is of an expandable
elastomeric self-sealing material and is provided with a small
pin-hole that may be formed by a wire or it may be pierced by a
hollow pin 42 located within inflatable portion 26a. Pin 42 has a
through passageway 44 which communicates at one end with the
through passageway 46 of cannula 22a and at the other communicates
with the chamber 48 in the main body portion of inflatable balloon
26a. This communication is accomplished by passing the pointed tip
50 of pin 42 through plug 40 so that its open tip is in
communication from cannula 22 to the chamber 48 in balloon 26a.
An additional element of structure on pin 42 is a side opening 52
located between lug 40 and the end of cannula 22a. This side
opening is utilized for activating the detachment between
inflatable portion 26a and cannula 22a as will be described in
detail below in connection with FIGS. 8-12. The through passageway
is provided so that the fluid from the pressure source can pass
into the inflatable portion and inflate balloon 26a. The FIG. 5
embodiment is perhaps cheaper to manufacture than the FIGS. 1-4
embodiments.
The embodiment of FIG. 6 is the same as the FIG. 5 embodiment with
the exception of an additional wire 41 which passes through the
through-passageway and terminates in a stop at the end in the form
of a sphere 43. Naturally other configurations for the stop can be
readily contemplated. The wire is of smaller character than the
passageway so that fluid can bypass the wire and inflation can
occur to the desired degree. Then the wire can be withdrawn to
block the open end of tip 50 by engagement with stop 43 which
closes the opening. Thereafter, further pressure will only be able
to exit through the side opening 52 to accomplish detachment. In
this manner, no further expansion of the balloon occurs during the
detachment procedure. All fluid passes through the side
opening.
The embodiments of FIGS. 5 and 6 do not have the pin-hole at the
distal end of portion 26a for perfusion of material contained
therein. However, it is contemplated that a passageway can be
provided as is present in the embodiments of FIGS. 1-4 so that the
combination of detachable means and perfusion means is present in
the same device.
Turning to operation of the embodiments of FIGS. 1-6, reference is
made to FIGS. 8-12. It should be noted at the outset that it is
possible for the device to be initially introduced into a human
vessel 54 by first passing a catheter of larger diameter into the
vessel and then passing the cannula 20 or 20a through the larger
catheter into the vessel 54. The larger catheter can then be
removed or retained in position during the remainder of the
operable procedures. It is contemplated that the larger catheter
through which the device can be passed can be used with all of the
discussed embodiments.
Naturally the dimensions of the balloon catheter assembly are a
matter of choice depending upon the particular human vessel to
which it is to be applied, keeping in mind, that the device is to
be used in very small human vessels. In any event, the length and
lateral dimensions are determined by use. In addition to expanding
the balloon portion to engage the outer surface of the end of the
cannula, it is also possible to shrink the end of the balloon
portion on the end of the cannula to produce the same result.
Turning to operation of cannula 20, FIG. 8 shows the cannula 20 in
position in the small human vessel 54 prior to introduction of
pressured fluid to expand portion 26. A first amount of pressurized
fluid is then introduced as shown in FIG. 9 so as to partially
expand balloon portion 26. This increases the lateral dimension of
the assembly and gains the assistance of blood flowing through the
vessel to push the assembly along through the vessel until it
reaches the desired operable location. At that point, as shown in
FIG. 10, further pressurized fluid is passed into the assembly so
as to expand balloon 26 until it engages with the inner wall 56 of
the vessel 54 and becomes fixed in position.
Thereafter, as shown in FIG. 11, a third stage of further
pressurized fluid is passed through cannula 22. Since further
expansion of balloon 26 is retarded the further fluid tries to pass
between the balloon portion 26 and the cannula 22 under the
C-spring 33. The passage of this fluid lubricates the connection
between balloon 26 and the cannula 22 so that the cannula 22 can be
relatively easily withdrawn from the balloon 26.
A similar procedure is followed for the embodiment of FIGS. 5 and 6
wherein once the balloon is fixed within the vessel so that further
expansion of the balloon 26 is retarded, fluid passes through side
opening 52 in the pin 42 and expands the proximal end portion of
balloon 26a which is between band 38a and the proximal tip
including portion 36. This expansion of portion 36 frees it from
engagement with cannula 22a and permits cannula 22a and pin 42 to
be withdrawn from inflatable portion 26a. There is minimal
resistance between tip 50 and plug 40 due to the nature of the
material of plug 40 or the prepositioned hole therein and the
tapered tip 50 of the pin 42. The cannula 22a and pin 42 can thus
be removed from the assembly and from the vessel 54 leaving the
inflatable portion 26a in position as an implant.
Once pin 42 has been removed from plug 40 the self-sealing nature
of plug 40 or the resilience of outer band 38 or both cause the
plug 40 to close the open therethrough thereby forming a valve
means to seal the inflated balloon portion 26a and retain it in
expanded position in proper location in the vessel.
Operation of the perfusion embodiment is depicted in FIG. 13.
Introduction and positioning of assembly 20 is accomplished in the
same manner depicted in FIGS. 8-10. Thereafter the third stage is
reached at which additional fluid is introduced through cannula 22
from the fluid source and, since inflatable portion 26 is retarded
from further expansion, the fluid forces a medicament or radiopaque
dye, contained within the balloon portion 26, out through opening
32 in the end of body 26. Since body 26 seals the vessel at the
point of its location the dye is not diluted by blood at the
upstream end of the vessel and accordingly is fully effective in
use at the point of perfusion.
As discussed above, the device can be a combination of the one
depicted in use in FIGS. 8-12 and the one depicted in use in FIG.
13 so that perfusion can be produced and detachment achieved with
perfusion continuing after the implant is made for a length of
time.
FIG. 7 of the drawings shows a further embodiment of the present
invention wherein a balloon catheter 60 is designed for
non-detachable use and, in particular, for perfusion. The balloon
portion 62 is friction fit over the open end of the cannula 64 for
introduction of fluid. The friction fit can be accomplished as in
previous embodiments by a shrink fit between the parts or expanding
the elastomeric balloon portion until it frictionally engages with
the outer surface of catheter 64. The opposite end of the balloon
portion has a plug 66 of self-sealing elastomeric material such as
silastic with a passageway 68 therethrough normally closed in view
of the nature of the material of plug 66. Sufficient introduction
of fluid into balloon portion 62 will expand the balloon portion
and eventually provide sufficient pressure to cause the elastomeric
plug 66 to open passageway 68 and permit perfusion of the material
contained within the balloon portion to be expelled downstream. It
is possible to put the opening in the balloon portion at the end as
shown in FIG. 5 or in the side as shown in FIGS. 1-3 or even in the
rear end portion for introduction of material from the balloon
portion upstream of its location.
It is also contemplated that the introduction catheter for the
embodiment shown can be of the double lumen type. That is, one
lumen is directed into the balloon portion of the catheter assembly
for introduction of fluid and expansion of the balloon portion;
and, the other lumen is for introduction of fluid into the area of
attachment between the balloon portion of the catheter. In this
manner the connection portion is expanded and detachment of the
components is accomplished so that the balloon portion remain as an
implant. With the double lumen design, it is possible to retain a
predetermined expansion level of the balloon portion since further
expansion will not occur when fluid is passed only through the
second lumen which opens into the area for detachment only and not
into the balloon portion.
Thus the several aforenoted objects and advantages are most
effectively attained. Although several somewhat preferred
embodiments have been disclosed and described in detail herein, it
should be understood that this invention is in no sense limited
thereby and its scope is to be determined by that of the appended
claims.
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