U.S. patent number 3,889,685 [Application Number 05/412,355] was granted by the patent office on 1975-06-17 for tubular unit with vessel engaging cuff structure.
This patent grant is currently assigned to Cutter Laboratories, Inc.. Invention is credited to William C. Dabney, Paul Kahn, George E. Miller, Jr..
United States Patent |
3,889,685 |
Miller, Jr. , et
al. |
June 17, 1975 |
TUBULAR UNIT WITH VESSEL ENGAGING CUFF STRUCTURE
Abstract
The tubular unit with vessel engaging cuff structure is a
unitary unit including a tube having a compressible cuff
surrounding the outer surface thereof. The cuff includes a
resilient, porous inner material surrounding the tube and an outer
liquid impervious layer which may be bonded to or integrally formed
with the inner material. The tube may include means to evacuate
fluid from the cuff or, alternatively, separate means are directly
connected to the cuff to accomplish such evacuation and contraction
of the cuff. Vessel engaging appendages may be incorporated on the
cuff.
Inventors: |
Miller, Jr.; George E.
(Sacramento, CA), Kahn; Paul (San Francisco, CA), Dabney;
William C. (Oakland, CA) |
Assignee: |
Cutter Laboratories, Inc.
(Berkeley, CA)
|
Family
ID: |
23632673 |
Appl.
No.: |
05/412,355 |
Filed: |
November 2, 1973 |
Current U.S.
Class: |
604/8; 606/192;
604/915; 604/96.01 |
Current CPC
Class: |
A61B
17/00 (20130101); A61B 17/12045 (20130101); A61B
17/12109 (20130101); A61B 17/1219 (20130101); A61M
25/10 (20130101); A61B 17/12136 (20130101); A61M
25/00 (20130101); A61B 17/11 (20130101); A61B
2017/12127 (20130101) |
Current International
Class: |
A61B
17/11 (20060101); A61M 25/00 (20060101); A61M
25/10 (20060101); A61B 17/00 (20060101); A61B
17/03 (20060101); A61B 17/12 (20060101); A61m
025/00 () |
Field of
Search: |
;128/334R,348B,348,344,328,325 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Truluck; Dalton L.
Attorney, Agent or Firm: Gardiver, Sixbey, Bradford &
Carlson
Claims
We claim:
1. A tubular unit with vessel engaging cuff structure for use
within liquid conveying vessels of the body comprising a tube
having an open end and a closed end, a compressible cuff
surrounding said tube and mounted on said tube adjacent the closed
end thereof, the tube being completely closed between said closed
end thereof and a front wall of said cuff to preclude liquid from
passing from said vessel into said tube and fluid from passing from
said tube into said vessel, said cuff including a resilient,
reticulated filler material having a network of fluid receiving
interstices and a vessel engaging, flexible outer surface layer
enclosing said filler material that is formed of a material which
is impervious to liquids and gasses, the cuff also having a front
wall adjacent the closed end of said tube which is inclined
outwardly from said tube away from the closed end thereof, and a
rear wall spaced from said front wall and having a substantially
flat surface extending laterally from said tube, and conducting
means communicating with said filler material to facilitate the
withdrawal of fluid therefrom to contract said cuff inwardly toward
said tube from a normal expanded configuration assumed by said cuff
when said fluid receiving interstices are filled with fluid.
2. The tubular unit of claim 1 wherein said conducting means
includes at least one aperture formed in said tube to connect the
interior of said tube with said filler material.
3. The tubular unit of claim 1 wherein the rear wall of said cuff
is substantially normal to the outer surface of said tube in the
portion thereof surrounded by said cuff.
4. The tubular unit of claim 1 wherein the outer surface layer of
said cuff forming said rear wall is of increased thickness adjacent
said tube and decreases in thickness toward the outer extremities
of said rear wall to impart greater stiffness to said rear wall in
the area adjacent said tube.
5. The tubular unit of claim 1 wherein connector means are mounted
on the open end of said tube to connect the tube to a suction
source, said conducting means including a plurality of apertures
formed in said tube to connect the interior of said tube with the
filler material.
6. The tubular unit of claim 1 wherein said flexible outer surface
layer is connected to said filler material to form a unitary
cuff.
7. The tubular unit of claim 1 wherein said flexible outer surface
layer is inelastic to prevent expansion of said cuff beyond a
normal expanded configuration defined by said outer surface layer.
Description
BACKGROUND OF THE INVENTION
The present invention relates to novel devices for effective
operation within a blood vessel or other tubular structure of the
body involved in the conveyance of a liquid which effectively
operates to occlude a space between the inner walls of the vessel
and the outer surface of a catheter or similar substantially
tubular instrument. Such devices are useful in any liquid
conducting vessel of the body such as blood vessels, urinary
tracts, the esophagus or the intestine.
There have been developed a number of catheters for embolectomy or
thrombectomy which include an inflatable balloon section or other
assemblies adapted for positive expansion into engagement with the
inner walls of a blood vessel. Such catheters are disclosed in U.S.
Pat. Nos. 3,435,826, 3,467,101, 3,467,102 and 3,472,230 to T. J.
Fogarty and in U.S. Pat. No. 3,635,223 to C. H. Klieman. These
devices are inserted in a deflated or contracted condition into a
blood vessel and subsequently inflated under the influence of
positive pressure to expand a section thereof into engagement with
the inner walls of the blood vessel. This application of a positive
pressure to the walls of the blood vessel is often injurious to
tissue causing resultant irritation and also can distort the vessel
wall and result in the breaking off of arterial plaque or other
deposits. It is virtually impossible to control with any degree of
accuracy the size of the balloon portion of a balloon catheter
which is inflated by positive pressure once the catheter is
inserted within a blood vessel, and over inflation may result in
serious damage to the vessel. The same may be true of other devices
having sections which are positively expanded such as the Arterial
Bypass disclosed in U.S. Pat. No. 3,516,408 to V. L. Montanti.
In tracheal tubes employing an expanded balloon cuff, attempts have
been made to eliminate irritation or damage to the trachea caused
by balloon cuffs which have been expanded in response to positive
pressure. As an alternative, cuffs for tracheal tubes have been
formed with an elastic cover which is filled with a sponge-like
resilient material. This resilient material may be collapsed in
response to a vacuum, and to prevent wrinkles in the cuff, the
liner or outer surface thereof is formed of elastic material such
as latex rubber. A cuff of this type for a tracheal tube is
disclosed in U.S. Pat. No. 3,640,282 to J. M. Kamen.
The tracheal tube cuffs having a filling of resilient material
which are known to the prior art are intended to provide a
substantially air tight seal in the trachea, but such cuffs would
have inherent disadvantages if they were to be used in blood
vessels. In the sealing of blood vessels, a sealing cuff must
provide a liquid tight seal with the vessel wall, and normally the
seal will be subjected to liquid pressure. Therefore, in many
instances the outside diameter of the cuff member in its normally
expanded form should be slightly larger than the inside diameter of
the surrounding vessel in the area where the cuff is positioned. In
these instances, there should be a slight but untraumatizing
pressure exerted by the cuff against the interior vessel walls.
In cases where positive pressure extended into the cuff might
result in vessel injury if not carefully controlled, it is
preferable to form the outer surface of the cuff integral with or
bonded to the filler material within the cuff so that no space can
be formed between the two. Such spaces present a low resistance to
fluid pressure and result in pockets between the filler material
and the outer surface which might result in excessive pressure
being applied to some portions of the vessel wall. Also, by bonding
the filler material to the outer surface of the cuff, the expansion
of the cuff can be limited by the expansion of the filler material
and thus closely controlled. This unitary constuction is useful but
not essential in devices for removing thrombi.
It is the primary object of the present invention to provide a
novel and improved tubular unit with vessel engaging cuff structure
for the use within liquid conveying vessels of the body. The cuff
structure includes an outer vessel engaging surface which may be
bonded or otherwise integrally formed with an inner filler material
having a number of fluid receiving interstices formed therein. The
withdrawal of fluid from this inner filler material causes the
outer surface of the cuff structure and the filler material to
contract when fluid is withdrawn from the interstices thereof and
to expand when fluid is readmitted.
Another object of the present invention is to provide a novel and
improved tubular unit with vessel engaging cuff structure for use
within liquid conveying vessels of the body wherein the outer cuff
configuration may be formed to a particular shape and a cuff is
constructed to always return to this expanded shape when
unrestrained. The cuff may be formed so as to prevent expansion
under pressure beyond the confines of the preformed cuff shape.
A still further object of the present invention is to provide a
novel and improved tubular unit with vessel engaging cuff structure
for use within liquid conveying vessels of the body wherein
engagement of the outer surface of the cuff structure with a vessel
wall is accomplished by the normal expansion of an internal filler
material to a predetermined shape when fluid previously withdrawn
therefrom is reintroduced. The expansion and contraction of this
filler material is also employed to some extent to control the
contact between the vessel wall and other wall contacting devices
formed integral with the outer layer of the vessel engaging cuff
structure.
These and other objects of the present invention will readily be
apparent upon consideration of the following specification and
claims taken in conjunction with the accompanying drawings in
which:
FIG. 1 is a sectional view of the tubular unit with vessel engaging
cuff structure of the present invention for use in the repair of an
aneurism;
FIG. 2 is a sectional view of a second embodiment of the tubular
unit with vessel engaging cuff structure of the present invention
for the use as an occluder in the resection of an artery;
FIG. 3 is a sectional view of a third embodiment of the tubular
unit with vessel engaging cuff structure of the present invention
for use as a coronary catheter with retaining cuff; and
FIG. 4 is a sectional view of a fourth embodiment of a tubular unit
with vessel engaging cuff structure of the present invention
adapted for use in thromboembolectomy.
Referring now to FIG. 1, it will be noted that a tubular unit with
a vessel engaging cuff structure which is indicated generally at 10
is positioned within the blood vessel 12 for use in the repair of
an aneurism 14 in the wall of the blood vessel. Aneurisms can occur
anywhere in the arterial system of the body and the most dangerous
and difficult to repair are those in the major vessel such as the
aorta or the iliac artery. The unit 10 in FIG. 1 may be used in
those cases where the aneurism is susceptible to repair rather than
replacement. It will be noted that the unit 10 includes an open
ended tube 16 which is preferably formed of flexible material
compatible with blood. For example, the tube 16 may be formed of
silicone rubber, polyethylene, polypropylene, polyurethane,
polyvinyl chloride or the like. Mounted upon the tube 16 are spaced
cuffs 18 which are positioned to engage the walls of the blood
vessel 12 on either side of the aneurism 14. The cuffs 18 are of
identical structure, and each has a generally cylindrical shape,
although other vessel wall engaging shapes may also be achieved
with the cuff structure of the present invention. Each cuff
includes an outer surface layer 20 which is impervious to gases or
liquids and a resilient sponge-like, reticulated filler material 22
which fills the space between the tube 16 and the surface layer 20.
The filler material 22 includes pores or voids which are
interconnected so that any fluid, be it gaseous or liquid, can be
made to flow into or from the pores. Some of the material suitable
for this reticulated structure are polyurethane, silicone
elastomer, rubber and polyvinyl alcohol and other similar foamed
plastic materials. The same materials may be employed to form the
outer surface layer 20, but the outer surface layer will not
contain pores or voids. It is preferred that the outer surface
layer be unitary with the filler material 22, and this may be
achieved by bonding the outer surface layer to the filler material
along the adjoining surface 24 therebetween. The outer surface
layer may be adhered to the filler material by use of adhesive, but
ideally the outer surface is formed by spraying or spreading
surface material over the outer surface of the filler material.
This causes the outer surface material to extend into some of the
pores in the filler material, thereby enhancing the bond. Also, the
outer surface layer 20 may be formed integrally at the time the
spongy filler material is formed so that an impervious skin is
generated over the spongy material. Known molding methods may be
employed to form this outer skin surface during the molding of the
filler material.
The filler material 22 may be bonded to the tube 16 along the
extent of the surface 26 therebetween. Thus the portions of the
cuff 18 including the outer surface layer 20 and the filler
material 22 form a unitary unit with the tube 16. By providing such
a unitary unit, there is no space between the tube 16 and the
filler material 22 or between the filler material 22 and the outer
surface 20 in which fluid can collect, and fluid may only flow
through the pores in the filler material.
To facilitate the introduction and withdrawal of fluid from the
interior of the cuff 18, each cuff is provided with a control
conduit 28. The control conduit is a small diameter flexible tube
having an end portion 30 which extends through the outer surface 20
of the cuff into the filler material 22. The outer surface of the
cuff is sealed to the control conduit so that no fluid may escape
from the interior of the cuff at the point of entry of the control
conduit. Preferably, the end 30 of each control conduit within the
cuff is perforated at several points 32 to provide enhanced
communication with the fluid within the pores of the filler
material 22.
The outer end of each control conduit 28 is provided with a
connector 34 which is adapted to connect the control conduit to a
suction system. For example, each connector 34 may be a female Luer
connector into which the Luer tip of a syringe may be placed. In
FIG. 1, the tubular unit with vessel engaging cuff structure 10 is
shown with separate connectors 34 on the ends of two separate
control conduits 28. It is obvious, however, that the two control
conduits might merge at a single outlet having a single connector
34 which would be connected to a suction system for simultaneously
withdrawing fluid from both cuffs of the unit.
In using the tubular unit with vessel engaging cuff structure 10 of
FIG. 1 in the repair of the aneurism 14, clamps are applied
upstream and downstream from the aneurism at points where the
artery appears healthy. A slit is then made in the arterial wall at
the site of the aneurism 14, and sufficient fluid is withdrawn from
cuffs 18 by suction to cause cuff contraction. This may be
accomplished by syringes attached to the connectors 34 which
operate through the control conduits 28 to withdraw fluid from the
interstices of the filler material 22. This withdrawal of fluid
causes the sponge like filler material to contract due to the
exterior atmospheric or liquid pressure which presses against the
outer surface layer 24 of the cuff and is sufficient to overcome
the force of elasticity of the filler material. The resultant
contraction of the cuff permits the unit 10 to be easily inserted
through the slit in aneurism 14 and positioned within the artery
with a cuff on either side of the aneurism. Fluid is now permitted
to flow back through the control conduits 28 into the interstices
of the filler material 22, so that the cuffs return toward normal
size and engage the inner walls of the artery. Since positive fluid
pressure is normally not supplied through the conduits 28, the
normal expansion of the resilient, sponge like filler material 22
causes each cuff to provide a seal which is less injurious to the
tissues of the artery. In fact, in some instances, it is preferable
to form the outer surface layer 20 of flexible but inelastic
material so that the expansion of the cuff 18 will be limited even
if positive pressure is inadvertently applied through the control
conduit 28. With an inelastic surface, the cuff will expand from a
contracted configuration back to a normal expanded configuration,
and at this point, further expansion will be prevented by the
inelastic outer surface 20 even if positive pressure is applied to
the filler material 22.
Once the tubular unit with vessel engaging cuff structure 10 is in
place within the artery 12 and the cuffs 18 are expanded against
the artery wall, the clamps previously placed on the artery are
released so that blood flows freely through the tube 16.
Circulation within the artery now remains uninterrupted while the
surgeon conducts the necessary repair of the weakened wall of the
artery. After the repair is completed, clamps are again applied to
the artery, the cuffs 18 are contracted, and the unit 10 is
withdrawn through the small remaining slit in the arterial wall.
The slit is then sutured and the clamps are released.
FIGS. 2-4 disclose other embodiments of the tubular unit with
vessel engaging cuff structure of the present invention, and in
these embodiments, the cuff structure is generally identical to
that disclosed at 18 in FIG. 1. Therefore, the reference numerals
of FIG. 1 will be applied to corresponding structures found in
FIGS. 2-4.
Referring to FIG. 2, there is disclosed an occluder 36 for use
during the resection of an artery and the replacement of a damaged
section with an arterial graft. There are situations where a
damaged artery must be resected and an arterial graft installed to
replace the resected portion. For example, an aneurism usually is
not susceptible to repair so that the damaged artery must be
resected and an arterial graft installed to replace the resected
portion, or a coarctation may occur which requires resection and an
arterial graft replacement. To install a replacement, the surgeon
must have resected ends to work with unencumbered with any device,
and therefore the occluder 36 of FIG. 2 becomes necessary. This
occluder consists of a tube or conduit 38 having a closed end 40
and an open end 42. A suitable connector, such as the connector 34
of FIG. 1, may be attached to the open end 42 so that suction may
be applied to the tube 36.
The closed end 40 of the tube 46 is preferably rounded to provide
an insertion tip and a cuff 18 is bonded to the tube adjacent the
closed end thereof. This cuff is identical in construction to the
cuff of FIG. 1, but in the occluder 36, the tube 38 is provided
with apertures or perforations 44 which communicate with the filler
material 22 within the cuff. Thus contraction of the cuff may be
accomplished by attaching the suction device to the connector 34
and drawing fluid from the filler material 22 through the apertures
44.
To use the occluder 36, the artery is clamped in an area of healthy
tissue upstream of the damaged section. A slit large enough to
accommodate the occluder is made adjacent to and downstream from
the area of the vessel to be resected. The cuff 18 of the occluder
is contracted so that the occluder may be introduced into the
artery downstream from the slit, and the cuff is then allowed to
return toward its original size to engage the arterial wall. The
damaged portion of the artery is then resected. Optionally, a
second occluder may be inserted into the artery at the resected end
near the clamp, and the clamp removed.
Referring again to FIG. 2, the second occluder preferably will
include an umbrella like appendage 46 which is attached at the end
of the cuff 18 adjacent to the closed end 40 thereof. This
appendage is somewhat cup shaped in configuration with the base
portion thereof attached to the outer layer 20 at the curved end of
the cuff 18, and with the open edge portion extending forwardly of
the closed end of the tube 38. The base wall 48 of this appendage
is quite thick with relation to the terminal edge of the side wall
50 thereof which is extremely thin. The appendage 46 is formed of
flexible material, and therefore the side wall 50, particularly in
the area adjacent the outer edge forward of the closed end of the
tube, is extremely flexible. The diameter of the appendage may be
approximately the same as the diameter of the cuff in the expanded
position, and the attachment of the appendage to the outer layer 20
of the cuff insures that the appendage will collapse with the cuff
and not impede the insertion of the occluder into a vessel.
When the second occluder is inserted into the artery, the pressures
against the second occluder in certain procedures may reach as much
as 250 to 350 mm Hg., and at the height of pulsation, the arterial
wall may expand sufficiently to cause blood to creep around the
cuff of the occluder. The elastic appendage 46 is designed to
prevent such blood seepage, for the blood pushes against the
appendage and forces the thin side wall 50 thereof into contact
with the arterial wall. This reduces the blood pressure on the cuff
18 and prevents seepage between the cuff and the arterial wall.
Obviously, the thin sidewall of the appendage facilitates insertion
and withdrawal of the appendage without damage to the arterial
wall, particularly since the terminal edge thereof is extremely
thin and flexible.
The arterial graft is sutured to the resected ends of the vessel
except for about a quarter to one half inch at the point where the
open ends of the tubes 38 of each occluder protrude. At this point,
a loose stitch, such as a purse string stitch is made, and then
each occluder cuff 18 is in turn contracted, the occluder is
withdrawn, and the loose stitch is tightened and tied to complete
the arterial graft.
The use of the occluder 36 is superior to the previously known
techniques of clamping off an artery with a vascular clamp, for the
occluder is less injurious to the arterial tissue. Similar
techniques are also used in the repair of venous blood vessels.
An appendage having a construction similar to that of the appendage
46 may also be used with the tubular unit 10 of FIG. 1 as indicated
at 35. The appendage 35 is identical to the appendage 46 with the
exception that the closed end 40 is not provided on the tube
16.
FIG. 3 discloses a coronary catheter with retaining cuff indicated
generally at 52 for use in open heart surgery. In open heart
surgery there frequently is a need to supply blood to the heart
muscle via the coronaries to prevent the heart muscle from dying. A
coronary catheter for this purpose preferably should have an angled
extremity to fit the coronary vessel and be removed from the
operating site, and thus the coronary catheter 52 includes an
angled, open ended tube 54. This tube is flexible and shaped
adjacent one open end thereof to provide a hook-like configuration.
A cuff 18 is secured to the tube near the angled portion thereof.
This cuff is formed identically to the cuffs of FIGS. 1 and 2 with
the exception that the cuff is preferably spherical or ovate and is
shorter in length. Also, the cuff 18 of the coronary catheter
should be somewhat softer and more resilient than the cuff 18 in
FIGS. 1 and 2, but basically, the coronary catheter 52 constitutes
one half of the unit 10 of FIG. 1. The open end of the coronary
catheter opposite to the cuff is provided with a connection 56
connectable to a blood supply which is to be pumped into the
coronary artery into which the catheter has been secured.
A catheter 58 for use in thromboembolectomy is disclosed in FIG. 4.
This catheter is similar to the occluder of FIG. 2 and includes
tube 38 having a connector 34 at the open end thereof and
perforations 44 for communication with the interior of the cuff 18.
The closed end of the catheter 58 includes a forward tip 60 which
is somewhat firmer than the closed forward end 40 of the catheter
36, for the tip 60 assists in the penetration of a thrombus. Also,
it will be noted that the outer layer 20 of the cuff 18 is
thickened at 62 to provide a stiffened rear wall 64 on the cuff.
This rear wall does not have a round surface similar to that of the
front wall of the cuff which is inclined with respect to the
surface of the tube 38, but instead has a relatively flat surface
which extends outwardly from the surface of the cuff. This rear
wall 64 is stiff enough due to the thickened portion 62 of the
outer layer 20 to act as a retaining wall for the thrombus as the
catheter and cuff are drawn backward through the vessel after
penetration of the trombus. Thus the thrombus will be prevented
from slipping around the cuff as it is withdrawn. Since only the
rear wall of the cuff is thickened for added stiffness, the
remainder of the outer layer 20 which contacts the vessel wall is
yielding and flexible so that the cuff will not scrape against
plaque adhering to the vessel wall. To insure that plaque will not
be engaged and torn from the vessel wall during withdrawal of the
cuff, the rear wall 64 is thick adjacent the tube 38 and tapers
upwardly so that the outer extremities of the rear wall are thinner
and much more flexible than the portions adjacent the tube.
In the use of the device 58 of FIG. 4, an artery or vein is entered
above or below a thrombus by means of an incision. Suction is
applied to the connector 34 to remove fluid through the
perforations 44, thereby constricting the filler material 22 and
the outer surface 20 bonded thereto. The catheter 58 with the
constricted cuff 18 is then introduced through the slit into the
blood vessel. Once the cuff section has passed through the
thrombus, the cuff is then allowed to return to normal size. Device
58 is withdrawn, and the cuff retains the thrombus and carries it
forward to the exit slit. After the removal of the thrombus and the
device 58, the slit is sutured. It should be noted that the cuff
section exerts little or no pressure on the vessel wall, only that
which results from the natural return of these structures from a
contracted state.
For use in blood vessels, it is generally more advantageous to fill
the interstices of the filler material 22 of the cuff 18 with
liquid, such as water, since the liquid is less compressible than
gas and the volume of the cuff will be less subject to change.
However, air or other gas can be used to fill the interstices,
particularly when the outer surface 20 of the cuff is formed of
flexible but nonelastic material to positively limit cuff
expansion.
It will be readily apparent to those skilled in the art that the
present invention provides a novel tubular unit with vessel
engaging cuff structure which is particularly well adapted for use
in the liquid conveying vessels of the body. This device is readily
adaptable for uses other than those specifically described, and for
example may be employed as a sail to carry a pressure sensor to a
desired position in the cardiovascular system. For this use, the
device of FIG. 2, without the appendage 46, may be attached to a
pressure sensor. The cuff 18 can then be expanded as a sail to
carry the sensor into the cardiovascular system, and the size of
the cuff in the expanded position would be less than the diameter
of the walls of the blood vessel through which it is traveling.
* * * * *