U.S. patent number RE34,993 [Application Number 07/826,868] was granted by the patent office on 1995-07-04 for method of inserting an lab device into the body.
This patent grant is currently assigned to Kontron, Inc.. Invention is credited to Gerald J. Cicciu, Edward J. Lombardi.
United States Patent |
RE34,993 |
Cicciu , et al. |
July 4, 1995 |
Method of inserting an lab device into the body
Abstract
A method for inserting an intra-aortic balloon device into a
patient without using an insertion sheath is provided.
Additionally, a hemostasis sheath is described for use with the
insertion method. The hemostasis sheath may be incorporated onto
the balloon catheter during manufacture before attachment of the
intra-aortic balloon bladder. The hemostasis sheath is tapered from
a smaller outside diameter at the point closest to the balloon
bladder gradually increasing in diameter towards a large outside
diameter at the end opposite the balloon bladder. The hemostasis
sheath may also have an extended tip of constant outside diameter
at its proximal end to facilitate insertion through the skin. If
bleeding occurs after insertion of the intra-aortic balloon
according to the invention, the hemostasis sheath is slid into the
insertion site to stop the bleeding.
Inventors: |
Cicciu; Gerald J. (Sudbury,
MA), Lombardi; Edward J. (Derry, NH) |
Assignee: |
Kontron, Inc. (Everett,
MA)
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Family
ID: |
44260802 |
Appl.
No.: |
07/826,868 |
Filed: |
January 28, 1992 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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53178 |
May 22, 1987 |
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Reissue of: |
275593 |
Nov 23, 1988 |
04897077 |
Jan 30, 1990 |
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Current U.S.
Class: |
600/18;
606/195 |
Current CPC
Class: |
A61M
25/06 (20130101); A61M 39/0606 (20130101) |
Current International
Class: |
A61M
25/06 (20060101); A61M 25/06 (20060101); A61M
39/06 (20060101); A61M 39/06 (20060101); A61M
39/02 (20060101); A61M 39/02 (20060101); A61B
019/00 () |
Field of
Search: |
;600/18 ;607/122
;128/656-658 ;604/53,158,164,167,169,256,264 ;606/194,195,185 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Seldinger, S. ACTA Radiologica (Stockholm) 39(5) pp. 368-376 May
1983. .
Tegtmeyer et al Technical Notes vol. 139 pp. 231-232 Apr.
1981..
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Primary Examiner: Smith; Ruth S.
Parent Case Text
This application is a .Iadd.reissue application of U.S. Pat. No.
4,897,077 which is a .Iaddend.continuation of application Ser. No.
53,178 filed on May 22, 1987, now abandoned.
Claims
We claim:
1. A method for inserting an intra-aortic balloon apparatus through
a patient's skin and into the femoral artery, wherein said
intra-aortic balloon apparatus includes a balloon catheter having a
proximal end and a distal end, an inflatable and deflatable balloon
bladder means sealidly attached at the distal end of the balloon
catheter and a hollow stylette means passing through the length of
the intra-aortic balloon, said intra-aortic balloon apparatus
further including a hemostasis sheath slidably coupled with the
balloon catheter between the balloon bladder means and the proximal
end of the balloon catheter, said hemostasis sheath having a distal
end adjacent to the balloon bladder means and a proximal end
opposite from the balloon bladder means having a larger outside
diameter than that at the distal end, said intra aortic balloon
apparatus also including sealing means releaseably coupled to said
hemostasis sheath, the method comprising the steps of:
(a) puncturing the patient's skin and femoral artery to create an
opening in the skin and artery;
(b) inserting a guide wire into the opening in the artery and
passing the guide wire up to the patient's aorta;
(c) dilating with dilating means the opening to achieve a diameter
sufficient to permit insertion of the intra-aortic balloon bladder
means in a wrapped configuration into the femoral artery;
(d) removing the dilating means;
(e) without the use of an insertion sheath, directly inserting the
intra-aortic balloon bladder means in a wrapped configuration over
the guide wire and through the opening and passing it up to the
aorta; and
(f) sliding the hemostasis sheath along the balloon catheter,
through the insertion site and into the femoral artery far enough
to control bleeding from the puncture opening in the femoral
artery, yet permit blood flow along the femoral artery.
2. The method of claim 1 further including the step of securing the
sealing means to the hemostasis sheath after the hemostasis sheath
is slid through the insertion site to preclude bleeding between the
hemostasis sheath and the balloon catheter.
3. The method according to claim 1, including the step of selecting
the hemostasis sheath such that it is gradually tapered to decrease
from its proximal end to its distal end.
4. The method according to claim 1, wherein the dilating step (c)
comprises sliding the dilating means along the guide wire into the
opening so as to dilate the opening.
5. The method according to claim 4, wherein the dilating step (c)
comprises selecting a tapered dilater having an outside diameter
increasing from its distal end closest to the artery to a larger
outside diameter at its proximal end away from the artery.
6. The method according to claim 5, further including the step of
selecting the hemostasis sheath such that it is gradually tapered
to decrease from its proximal end to its distal end.
7. The method according to claim 6, further including the step of
selecting the hemostasis sheath having an inside diameter which is
slightly larger than the outside diameter of the balloon catheter
with the clearance therebetween of about 2 to 3 thousandths of an
inch at least at the distal end of said hemostasis sheath.
8. The method according to claim 6, further including the step of
selecting the dilating means such that it is gradually tapered.
9. A method for inserting an intra-aortic balloon apparatus through
a patient's skin and into the femoral artery, wherein said
intra-aortic balloon apparatus includes a balloon catheter having a
proximal end and a distal end, an inflatable and deflatable balloon
bladder means sealidly attached at the distal end of the balloon
catheter and a hollow support means passing through the length of
the intra-aortic balloon apparatus, said intra-aortic balloon
apparatus further including a hemostasis sheath slidably coupled
with the balloon catheter between the balloon bladder means and the
proximal end of the balloon catheter, said hemostasis sheath having
a distal end portion adjacent to the balloon bladder means and a
proximal end portion opposite from the balloon bladder means having
a larger outside diameter than at the distal end portion, said
intra-aortic balloon apparatus also including sealing means for
precluding blood flow between the hemostasis sheath and the balloon
catheter, the method comprising the steps of:
(a) puncturing the patient's skin and femoral artery to create an
opening in the skin and artery;
(b) inserting a guide wire through the opening and into the femoral
artery;
(c) dilating with dilating means the opening to achieve a diameter
sufficient to permit insertion of the balloon bladder means in a
deflated condition into the femoral artery;
(d) removing the dilating means;
(e) without the use of an insertion sheath, directly inserting the
balloon bladder means in a deflated condition over the guide wire
and through the opening and passing it up the aorta;
(f) sliding the hemostasis sheath along the balloon catheter,
through the opening and into the femoral artery far enough to
control bleeding from the opening; and
(g) engaging the sealing means to the proximal end of the
hemostasis sheath to preclude blood flow between the balloon
catheter and the hemostasis sheath.
10. The method of claim 9 further including the step of selecting
the hemostasis sheath such that it has an inner diameter at least
at its distal end portion just sufficient to permit the hemostasis
sheath to slide along the balloon catheter.
11. The method of claim 9 further including the step of selecting
the hemostasis sheath such that its outside diameter is just larger
than its inner diameter at the distal end portion of the hemostasis
sheath and, at the proximal end portion of the sheath its outside
diameter is predetermined to be at least as large as the opening in
the patient's skin and femoral artery.
12. The method of claim 11, further including the step of selecting
the hemostasis sheath such that its outside diameter is tapered to
increase in a direction from the distal end portion toward the
proximal end portion of the hemostasis sheath.
13. The method of claim 12 further including the step of selecting
the hemostasis sheath such that its outside diameter tapers along
the length of the hemostasis sheath.
14. The method of claim 12 further including the step of selecting
the hemostasis sheath such that it has a conical configuration.
15. The method of claim 11 further including the step of selecting
the sealing means to have a configuration such that the sealing
means is releasably secured to the proximal end of the hemostasis
sheath, and the sealing means has an inner diameter just sufficient
for the sealing means to slide along the balloon catheter yet
preclude blood flow between the inside diameter of the sealing
means and the balloon catheter.
16. A method of claim 15 further including the step of selecting a
cuff as the sealing means.
17. A method for inserting an intra-aortic balloon apparatus
through a patient's skin and into the femoral artery, wherein the
intra-aortic balloon apparatus includes a balloon catheter having a
proximal end and a distal end, an inflatable and deflatable balloon
bladder means sealidly attached at the distal end of the balloon
catheter and a hollow support means passing through the length of
the intra-aortic balloon apparatus, said intra-aortic balloon
apparatus further including hemostasis means slidably disposed on
the balloon catheter between the balloon bladder means and the
proximal end of the balloon catheter for controlling bleeding, the
method comprising the steps of:
(a) puncturing the patient's skin and femoral artery to create an
opening in the skin and artery;
(b) inserting a guide wire through the opening and into the femoral
artery;
(c) dilating with dilating means the opening to achieve a diameter
sufficient to permit insertion of the balloon bladder means in a
deflated condition into the femoral artery;
(d) removing the dilating means;
(e) without the use of an insertion sheath, directly inserting the
balloon bladder means in a deflated condition over the guide wire
and through the opening and passing it up to the aorta; and
(f) sliding the hemostasis means along the balloon catheter,
through the opening and into the femoral artery far enough to
control bleeding from the opening.
18. The method of claim 17 further including the step of selecting
the hemostasis means such that the hemostasis means has a distal
end portion adjacent the balloon bladder means, a proximal end
portion opposed to the balloon bladder means, and an outside
diameter just larger than the outside diameter of the balloon
catheter at the distal end portion, and said outside diameter of
the hemostasis means increasing in a direction toward the proximal
end portion of the hemostasis means to a size which is at least as
large as the opening in the patient's skin and femoral artery.
19. The method of claim 18 further including the step of selecting
the hemostasis means such that it has an inner diameter at least at
the distal end portion of the means just sufficient to permit the
hemostasis means to slide along the balloon catheter, and an outer
diameter which is just larger than the inner diameter at the distal
end portion of the hemostasis means, said outside diameter tapering
in a direction toward the proximal end portion of the hemostasis
means such that it becomes at least as large as the patient's
opening in the skin and femoral artery.
20. The method of claim 18 further including the step of selecting
the hemostasis means such that it has a conical configuration.
21. The method of claim 18 further including the step of selecting
a sealing means for engaging the proximal end of the hemostasis
means to preclude blood flow between the hemostasis means and the
balloon catheter, said sealing means having an inner diameter just
sufficient for the hemostasis means to slide along the balloon
catheter yet permit blood to flow through so as to prevent blood
flow between the balloon catheter and the hemostasis means.
.Iadd.
22. A method for inserting an intra-aortic balloon apparatus
through a patient's skin and into the femoral artery, wherein said
intra-aortic balloon apparatus includes a balloon catheter having a
proximal end and a distal end, an inflatable and deflatable balloon
bladder means sealidly attached at the distal end of the balloon
catheter and a hollow stylette means passing through the length of
the intra-aortic balloon, the method comprising the steps of:
(a) puncturing the patient's skin and femoral artery to create an
opening in the skin and artery;
(b) inserting a guide wire into the opening in the artery and
passing the guide wire up to the patient's aorta;
(c) dilating with dilating means the opening to achieve a diameter
sufficient to permit insertion of the intra-aortic balloon bladder
means in a wrapped configuration into the femoral artery;
(d) removing the dilating means; and
(e) without the use of an insertion sheath, directly inserting the
intra-aortic balloon bladder means in a wrapped configuration over
the guide wire and through the opening and passing it up to the
aorta. .Iaddend. .Iadd.23. The method according to claim 22,
wherein the dilating step (c) comprises sliding the dilating means
along the guide wire into the opening so as to dilate the opening.
.Iaddend. .Iadd.24. The method according to claim 23, wherein the
dilating step (c) comprises selecting a tapered dilater having an
outside diameter increasing from its distal end closest to the
artery to a larger outside diameter at its proximal end away from
the artery. .Iaddend. .Iadd.25. The method according to claim 24,
further including the step of selecting the dilating means such
that it is gradually tapered. .Iaddend. .Iadd.26. A method for
inserting an intra-aortic balloon apparatus through a patient's
skin and into the femoral artery, wherein said intra-aortic balloon
apparatus includes a balloon catheter having a proximal end and a
distal end, an inflatable and deflatable balloon bladder means
sealidly attached at the distal end of the balloon catheter and a
hollow support means passing through the length of the intra-aortic
balloon apparatus, the method comprising the steps of:
(a) puncturing the patient's skin and femoral artery to create an
opening in the skin and artery;
(b) inserting a guide wire through the opening and into the femoral
artery;
(c) dilating with dilating means the opening to achieve a diameter
sufficient to permit insertion of the balloon bladder means in a
deflated condition into the femoral artery;
(d) removing the dilating means; and
(e) without the use of an insertion sheath, directly inserting the
balloon bladder means in a deflated condition over the guide wire
and through the
opening and passing it up to the aorta. .Iaddend. .Iadd.27. The
method according to claim 26, wherein the dilating step (c)
comprises sliding the dilating means along the guide wire into the
opening so as to dilate the opening. .Iaddend. .Iadd.28. The method
according to claim 27, wherein the dilating step (c) comprises
selecting a tapered dilater having an outside diameter increasing
from its distal end closest to the artery to a larger outside
diameter at its proximal end away from the artery. .Iaddend.
.Iadd.29. The method according to claim 28, further including the
step of selecting the dilating means such that it is gradually
tapered. .Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improved method of inserting an
intra-aortic balloon (hereinafter "IAB") device into the body by a
sheathless insertion technique. Additionally, the invention relates
to the use of a hemostasis sheath with this technique. When used in
combination with the sheathless insertion technique, the hemostasis
sheath facilitates use of the IAB device by lowering the degree of
the obstruction in the femoral artery while controlling bleeding
back through the insertion site after the IAB has been
inserted.
2. Description
IAB devices are introduced into the body and are used to assist the
pumping action of the heart. See, for example, U.S. Pat. No.
4,362,150. In some instances, they may remain in the body for
extended periods of time, such as several days or more.
One method of installing an IAB device in the body is via a
non-surgical insertion into the femoral common artery through the
skin using the percutaneous insertion (Seldinger) technique.
In the prior art percutaneous insertion technique, the skin is
punctured to form a hole through the skin and in the femoral
artery. A short guide wire is inserted into the femoral artery and
the hole is then expanded by an inserter dilator (for example, an
8-French dilator) which slides over the guide wire through the skin
into the artery. The inserter dilator is removed and a series of
progressively larger dilators are inserted into the hole over the
guide wire to increase the size of the hole. Next an insertion
sheath is passed through the hole and into the femoral artery. This
sheath has an inside diameter generally corresponding to the
outside diameter of the IAB to be inserted. The short guide wire is
removed and is replaced by a long guide wire which is fed up
through the artery to the vicinity of the aorta. The IAB is passed
over the distal end of the guide wire and slides along the guide
wire up through the sheath and along the artery all the way up the
aorta.
Although the foregoing procedure generally is a safe, rapid and
efficacious way of intra-aortic balloon insertion, the prerequisite
insertion and use of the sheath is a step which requires time and
equipment to perform, often under circumstances such that time is a
critical factor to patient survival, as during cardiogenic
shock.
During the foregoing described procedure, arterial bleeding through
the sheath must be carefully controlled during the time interval
between the removal of the short guide wire from the sheath and the
insertion of the wrapped balloon over the long guide wire. Often,
especially in a hypovolemic patient, this loss of blood may be
critical. Also when the balloon bladder is wrapped, spiral
interstices are produced along its length. The interstices of the
wrapped balloon membrane do not provide for the complete occlusion
of the sheath between its inner wall and the wrapped balloon.
Therefore, a certain amount of arterial bleeding takes place during
the time that is required to fully insert the wrapped balloon
membrane portion of the balloon catheter into the blood vessel.
In some cases, the sheath may have to be withdrawn partly from the
percutaneous wound to permit complete introduction of the balloon
membrane into the sheath, especially in those cases of extreme
vascular tortuosity. This creates an additional loss of critical
time and of critical blood.
Another problem experienced with some patients, is that after IAB
insertion is complete, blood flow to the lower extremities is
diminished substantially. The decrease in blood flow is generally
attributable to the obstruction of the femoral artery caused by the
relatively large diameter of the insertion sheath extending into
the artery. By removing the sheath, the obstruction in the femoral
artery can be decreased substantially. Certain prior art techniques
attempts to solve this concern by utilizing splittable insertion
sheaths. Various types of splittable, removable insertion sheaths
which would be suitable for this purpose are disclosed in the prior
art. See for example, U.S. Pat. Nos. 4,166,469, 4,581,019 and
4,581,025. Once the insertion sheath is removed, there would remain
the IAB catheter which connects an inflatable and deflatable
bladder member of the IAB with the external pumping/monitoring
equipment.
U.S. Pat. No. 4,540,404 attempts to address these concerns by using
an IAB with a tapered tip and a sheath which slides over the
balloon bladder to form an assembly. After insertion, the sheath
can be withdrawn to expose the balloon.
However, after removal of the insertion sheath the arterial wall
must constrict to seal around the balloon catheter, which has a
smaller outside diameter than the insertion sheath. Therefore, in
non-elastic or diseased vessels, the required vessel constriction
may not always occur resulting in profuse bleeding from the
insertion site between the IAB catheter and arterial puncture.
One way to stop this bleeding is to exert pressure on the artery
above the insertion site. However, this has the disadvantage that
it may damage the balloon catheter and requires time and an
additional step in the IAB insertion process. If bleeding cannot be
stopped, the IAB must be removed.
SUMMARY OF THE INVENTION
Accordingly, there has been invented an improved method for
inserting an IAB device into the body in a modified percutaneous
insertion technique without the use of an insertion sheath.
Additionally, there is described a hemostasis sheath which is used
in this method to control bleedback through the insertion site
after insertion of the IAB.
In accordance with the invention, an IAB insertion technique is
provided to enable insertion of an IAB device directly into a blood
vessel over a guide wire, without the need first to insert and use
an introducer sheath.
DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference to the following
drawings, which are merely exemplary and are not meant to limit the
scope of the invention in any respects.
FIGS. 1a-d show in succession (a) the puncture of the skin and
artery, (b) insertion of the guide wire, (c) dilation of the
insertion site and (d) insertion of an insertion sheath employing a
prior art (Seldinger) technique.
FIG. 2a is a side elevation view of an IAB device showing the IAB
bladder being directly inserted into the femoral common artery
without an insertion sheath according to the inventive method;
FIG. 2b is a side elevation view partly in cross-section showing
the IAB device of FIG. 1 following insertion of the IAB bladder
into the femoral common artery;
FIG. 3 is a side elevation view of the IAB device of FIGS. 1 and 2
showing the hemostasis sheath of the present invention positioned
within the insertion puncture;
FIG. 4 is a cross-section of the hemostasis sheath according to the
invention showing the hemostasis sheath installed on a balloon
catheter;
FIG. 5 is a cross-section of another embodiment of the hemostasis
sheath according to the invention; and
FIG. 6 is a cross-section of yet another embodiment of the
hemostasis sheath according to the invention showing an inside
diameter which gradually increases from the distal end to the
proximal end.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1a-1d shows various steps employed in the prior art
(Seldinger) technique for inserting an IAB device percutaneously.
There is shown needle 1, guide wire 5, dilator 29, insertion sheath
30, skin 20 and femoral artery 10. FIG. 1a shows puncture of the
skin and the femoral artery using a hypodermic needle 1 (e.g. Potts
cone head). FIG. 1b shows placement of a guide wire 5 into the
artery through the hollow bore of the needle. FIG. 1c shows removal
of the hypodermic needle 1 from the artery leaving the guide wire 5
in place and the dilation of the opening with dilator 29 (e.g.,
Grunzig type). Finally, FIG. 1d shows placement of an insertion
sheath 30 into the artery over the guide wire following dilation of
the insertion site.
With reference to FIGS. 2a, 2b and 3-6 the insertion of an IAB
device into the body via a non-surgical insertion into the femoral
common artery through the skin using a new percutaneous insertion
technique according to the invention will be described. A physician
(not shown) would be positioned in the left-hand margin in relation
to the various elements being described. In FIGS. 1a-1d, FIGS. 2a,
2b, and FIG. 3, the location of the physician is designated by the
symbol "P". The terms "proximal" and "distal" as used herein shall
refer to position relative to that of the physician.
Referring to FIGS. 2a and 2b, the IAB device generally comprises
IAB bladder 40 which is attached to balloon catheter 42. The IAB is
a double lumen device with a central hollow stylette 44 and
preferably of the type described in U.S. Pat. No. 4,362,150, which
patent is incorporated herein by reference. The IAB can have a wrap
handle for rotation as described in the above patent or can have a
fixed type configuration. The hollow stylette preferably is a
hypodermic tubing with a flexible segment within the balloon.
Prior to insertion, the bladder 40 is wrapped about itself to
reduce its diameter either by the manufacturer or by the physician.
The balloon catheter 42 may, for example, as is known in the art be
attached at its proximal end to a rotating or fixed handle (not
shown) and may also be connected in known manner to an intra aortic
balloon pumping/monitoring system (also not shown).
The insertion technique according to the invention will now be
described.
With reference to FIGS. 1a-1d and FIG. 2a, a small hypodermic
needle (not shown in FIG. 2a but shown in FIG. 1a) is inserted
through the skin 20 of a patient to perforate or puncture the
femoral artery 10. When blood spurts from the open external end of
the needle, placement of the hypodermic needle within the artery 10
is confirmed. A long guide wire 5 (e.g. up to about 150-190 cm or
longer) sufficient in length to reach the central aorta is fed into
the artery 10 by passing the guide wire through the center of the
hollow hypodermic needle.
Next, the hypodermic needle leaving the guide wire 5 in place. One
or more progressively larger dilators (preferrably a single
expanding, e.g. Grunzig type dilator) is then placed over the guide
wire and advanced through the perforated skin 20 and into the
artery 10 in order to expand the hole in order to achieve an
opening large enough to permit the passage of the wrapped IAB
bladder 40. For example, when using a 10.5 French IAB the hole
should be dilated to approximately 10 French in diameter. Once the
skin 20 and artery 10 have been fully dilated, the dilator is
removed and the IAB device is inserted directly into the patient
without passing it through the insertion sheath.
Still referring to FIG. 2a, the IAB bladder 40 even in its wrapped
condition has a larger outside diameter than the IAB catheter 42.
As a result the IAB bladder 40 will dilate the insertion site to a
larger diameter than that of the catheter 42.
Reference is now made to FIG. 2b which shows, from left to right,
the hemostasis sheath 50 and IAB catheter 42 of FIG. 2a with the
IAB bladder 40 now inserted into the aorta (not shown).
As can be seen in FIG. 2b, the insertion site 8 after passage of
the IAB, may have an opening which due to some inelasticity in the
skin has not completely closed around the catheter 42. This
condition may result in uncontrollable bleeding from the insertion
site 8.
As a means to diminish this bleeding when it occurs, the present
invention utilizes hemostasis sheath 50 which is slidably coupled
to the catheter 42.
As will be discussed in more detail below, the hemostasis sheath 50
preferrably has a conical configuration and has a distal end 52
which in the preferred embodiment is only slightly larger than the
outside diameter of the catheter 42. Preferably, the inside of the
distal end 52 is sized for a close fit over the outside of catheter
42. The hemostasis sheath 50 also has a proximal end 54 opposite
from the distal end 52. The proximal end 54 has a larger outside
diameter than the distal end 52. Preferably, the proximal end 54
has an outside diameter which is about at least as large or
slightly larger than the outside diameter of the IAB bladder 40 in
its wrapped condition.
FIG. 3 shows from left to right the IAB catheter 42 and hemostasis
sheath 50 of FIGS. 2a and 2b with the hemostasis sheath 50 now
positioned in the insertion site 8.
With reference to FIG. 3, the hemostasis sheath 50 has now been
inserted partially into the opening 14 in the wall of the artery 10
with its distal end 52 extending inside the artery 10. The
hemostasis sheath 50 is inserted into the artery 10 until the point
is reached where its increased diameter at point 56, between the
distal and 52 and proximal end 54, fills the opening 14. As shown
in FIG. 3, the hemostasis sheath 50 is thereby able to stop the
bleeding which might have resulted after insertion of the IAB
device. Additionally, the hemostasis sheath 50 is configured and
dimensioned to pass through the skin 20 and into the artery 10, and
is able to control bleeding without restricting good blood flow
through the artery 10 to any great degree.
In accordance with the inventive method, the hemostasis sheath 50
is advanced along the balloon catheter 42 through the skin and into
the artery by a sufficient distance to control bleeding from the
insertion site 8. In particular, the hemostasis sheath 50 is
advanced to a point where its outside diameter sufficiently fills
the opening made by the passage of the IAB bladder through the skin
and artery to provide an elastic contact between the skin opening
and the outside diameter of the hemostasis sheath 50.
The hemostasis sheath 50 is shown in greater detail in FIGS. 4, 5
and 6. Unless otherwise indicated, FIGS. 4, 5 and 6 show, from left
to right the IAB catheter 42 (FIG. 4 only) a cuff 60 and hemostasis
sheath 50. Additionally, from left to right, the hemostasis sheath
comprises a flange 57, a neck 55, proximal end 54, distal end 52
and an extended portion 59 including a tip 51.
The outside diameter (D) of the hemostasis sheath 50 gradually
increases from its distal end 52 towards its proximal end 54. The
inside diameter (I) of the hemostasis sheath 50 may be about the
same throughout its entire length (as shown in FIGS. 4 and 5) or
may gradually increase from the distal end 52 towards the proximal
end 54 (as shown in FIG. 6, for example). Preferably, the inside
diameter (I) is sized at the distal end 52 to provide a close
clearance 58 between the inside of the hemostasis sheath 50 and the
outside of the balloon catheter 42. Preferably the inside diameter
(I) of the hemostasis sheath 50 at its distal end 52 is between
about 2 to 3 thousandths of an inch larger than the outside
diameter of the balloon catheter 42 to allow for manufacturing
tolerance. More preferably, in view of the resilience of the
materials utilized, one can maintain an interference fit such that
the distal end 52 the inside diamter (I) of the hemostasis sheath
50 is the same as the outside diameter of the balloon catheter 42.
This close fit clearance 58 permits the outside diameter of the
hemostasis sheath 50 to be as small as possible at the distal end
52 with the balloon catheter 42 providing structural support for
the hemostasis sheath 50 during insertion to prevent an accordian
effect from occurring at the distal end 52. This close fit
clearance also reduces the risk of bleedblock between the bladder
catheter 42 and the hemostasis sheath 50.
For example, in a preferred embodiment wherein the outside diameter
of the balloon catheter is about 10.5 french (i.e., about 0.138
inches), the outside diameter (D) of the hemostasis sheath 50 at
its distal end 52 is about 0.146 inches, the outside diameter (D)
at its proximal end 54 is about 0.185 inches and the inside
diameter (I) of the hemostasis sheath 50 at the distal end 52 is
about 0.140 inches to provide a clearance 58 of about 0.002 inches
at the distal end 52.
Preferably, the outside diameter (D) of the hemostasis sheath 50
tapers gradually from its distal end 52 to its proximal end 54 and
the distance (T) between the distal end 52 and proximal end 54 is
preferably about 2.0 to 2.5 inches. Of course, the outside diameter
may also increase in a step-wise manner (not shown). By "gradual"
is meant any shape which increases in outside diameter in a
continuous, as opposed to step-wise, manner. Such gradual shapes
include cones having straight sides along their length or curved
sides.
As shown in FIGS. 5 and 6, in another preferred embodiment, the
distal end 52 of the hemostasis sheath 50 may further include
constant diameter portion 59.
The constant diameter portion 59 would preferably have a length of
at least about 1/4 inch and an inside diameter which is about 2 to
3 thousandths of an inch larger than the outside diameter of the
balloon catheter 42.
The constant diameter portion 59 is configured to generate less
initial resistance during insertion through the skin so that the
tip 51 of the hemostasis sheath 50 can be more easily inserted.
Once the constant diameter portion 59 has been inserted through the
skin, the overall resistance to further insertion will increase as
the outside diameter of the hemostasis sheath 50 increases.
However, with the tip 51 safely passed through the skin, the danger
of collapsing or buckling as an accordian at the tip 51 can be
avoided.
The hemostasis sheath 50 is provided at its proximal end with a
neck 55 and flange 57. The neck 55 and flange 57 are held within
the cuff 60. As shown in FIGS. 4 and 5, the cuff 60 is sized to
provide a close clearance 64 between the cuff 60 and the neck 55 of
the hemostasis sheath 50. Additionally, the cuff 60 is sized to
provide a close clearance 62 between the cuff 60 and the balloon
catheter 42. In this manner, the cuff 60 is able to seal the
proximal end of the hemostasis sheath 50 against bleeding when the
distal end 52 is positioned within the femoral artery 10. Closed
clearance 62 also precludes slippage of cuff 60 and, in turn,
hemostasis sheath 50 along catheter 42 due to arterial pressure and
the like.
In a preferred embodiment, the hemostasis sheath 50 is manufactured
from a resilient, for example plastic, material, which is
preferably polytetrafluoroethylene (Teflon .RTM.)or polyethylene.
Also in the preferred embodiment, the cuff 60 is manufactured from
an elastomeric material, for example silicone. However, no
particular elastomeric material is preferred.
The various features and advantages of the invention are thought to
be clear from the foregoing description. Various other features and
advantages not specifically enumerated will undoubtedly occur to
those versed in the art as likewise will many variations and
modifications of the preferred embodiment illustrated, all of which
may be achieved without departing from the spirit and scope of the
invention as defined by the following claims.
* * * * *