U.S. patent application number 09/975377 was filed with the patent office on 2002-02-28 for perfusion procedure and apparatus for preventing necrosis following failed balloon angioplasty.
Invention is credited to Wallace, Richard K..
Application Number | 20020026174 09/975377 |
Document ID | / |
Family ID | 23277416 |
Filed Date | 2002-02-28 |
United States Patent
Application |
20020026174 |
Kind Code |
A1 |
Wallace, Richard K. |
February 28, 2002 |
Perfusion procedure and apparatus for preventing necrosis following
failed balloon angioplasty
Abstract
A perfusion catheter is used to avoid ischemia in case of
failure of a conventional balloon angioplasty procedure on a
stenotic blood vessel and a resulting partial or complete occlusion
of the vessel. The balloon catheter is first removed from the
vessel while the guide wire and the guide catheter are left in
place. The perfusion catheter is immediately inserted into the
guide catheter and run past the stenosis using the guide wire
already in place. Blood is drawn from a side port in the sheath
introduced at the point of entry into the vascular system of the
patient under normal arterial pressure or after passing through an
exterior pump for pressurization and re-injection in the perfusion
catheter. Thus, blood flow to the part of the vessel past the
occlusion can be reestablished within minutes of angioplasty
failure and the patient can be stabilized in preparation for heart
surgery.
Inventors: |
Wallace, Richard K.;
(Bellevue, NE) |
Correspondence
Address: |
Antonio R. Durando
Durando Birdwell & Janke, P.L.C.
2929 E. Broadway Blvd.
Tucson
AZ
85716
US
|
Family ID: |
23277416 |
Appl. No.: |
09/975377 |
Filed: |
October 10, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09975377 |
Oct 10, 2001 |
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09327645 |
Jun 8, 1999 |
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6315768 |
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Current U.S.
Class: |
604/508 ;
604/264; 604/96.01 |
Current CPC
Class: |
A61M 2025/1095 20130101;
A61M 25/007 20130101 |
Class at
Publication: |
604/508 ;
604/96.01; 604/264 |
International
Class: |
A61M 031/00 |
Claims
I claim:
1. A method for maintaining a blood supply past a stenotic site
after failure of a procedure wherein an angioplasty catheter is
introduced into a blood vessel of a patient through a guide
catheter and a sheath placed in the vessel and on a guide wire
extended through the stenotic site, and wherein a vessel occlusion
along the guide wire occurs following retraction of the angioplasty
catheter from the site, said method comprising the following steps:
(a) completely removing the angioplasty catheter from the vessel;
(b) introducing a perfusion catheter into the vessel of the patient
through said guide catheter and extending a distal end of the
perfusion catheter past the vessel occlusion using the guide wire,
wherein the sheath placed in the vessel has an extraction port
connecting through a proximal segment into the interior of said
sheath; (c) providing means for extracting the patient's blood from
said extraction port; and (d) injecting blood into an exterior end
of the perfusion catheter such as to maintain a perfusion rate
sufficient to prevent ischemia.
2. The method of claim 1, wherein said perfusion rate is 40-60
cc/min.
3. The method of claim 1, wherein the step of injecting blood is
carried out by withdrawing the patient's blood and passing it
through a pump having an output connected to said exterior end of
the perfusion catheter.
4. The method of claim 3, wherein said perfusion rate is 40-60
cc/min.
5. The method of claim 1, wherein the step of injecting blood is
carried out by connecting an input of a pump to said extraction
port and an output of the pump to said exterior end of the
perfusion catheter.
6. The method of claim 5, wherein said perfusion rate is 40-60
cc/min.
7. The method of claim 1, wherein said patient's blood is arterial
blood.
8. The method of claim 2, wherein said patient's blood is arterial
blood.
9. The method of claim 3, wherein said patient's blood is arterial
blood.
10. The method of claim 6, wherein said patient's blood is arterial
blood.
11. The method of claim 1, wherein said procedure is an
angioplasty.
12. The method of claim 2, wherein said procedure is an
angioplasty.
13. The method of claim 1, wherein said procedure is a stent
placement.
14. The method of claim 2, wherein said procedure is a stent
placement.
Description
RELATED APPLICATIONS
[0001] This application is a continuation application of U.S. Ser.
No. 09/327,645, filed on Jun. 8, 1999.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention is related in general to the field of
angioplasty treatment of atherosclerotic vessels in mammalian
bodies. In particular, the invention pertains to a procedure for
providing immediate blood flow through a blocked vessel following
its collapse as a result of a failed angioplasty or stent
placement.
[0004] 2. Description of the Related Art
[0005] Angioplasty treatments of body vessels are invasive
procedures whereby a catheter is inserted into the vascular system
to reach and treat a partial or total occlusion causing reduced
blood flow. Most notable is balloon angioplasty, where the distal
end of the catheter includes an inflatable balloon that is used to
expand the vessel and restore sufficient lumen size to ensure
adequate blood flow after removal of the catheter.
[0006] This procedure has become very common in treating
cardiovascular disease and is normally performed, when possible, as
a preferable alternative to coronary bypass surgery. Similarly, the
placement of a stent, a cylindrical wire mesh that is expanded in
the area of stenosis to open and support a coronary artery, is
always preceded by an angioplasty. As well understood in the art,
the procedure involves placement of a balloon catheter through the
locus of a stenosis, typically in a coronary artery, and inflation
of the balloon to press against the material creating the
occlusion. Because of the pressure exerted by the balloon, the
vessel remains completely obstructed during the procedure, which
normally lasts one to two minutes. During this time, blood flow
through the vessel is essentially precluded and the heart tissue
downstream of the blockage is dangerously deprived of oxygen.
Therefore, cardiologists try and limit angioplasty procedures to
the minimum time required to restore the stenotic passage to an
acceptable size.
[0007] Various perfusion angioplasty catheters have been developed
to enable the continued supply of blood during angioplasty and
avoid the occurrence of ischemia. For example, U.S. Pat. Nos.
4,857,054, 5,746,709, 5,807,331 and 5,833,650 disclose various
angioplasty catheters that include perfusion channels to produce
blood flow past the stenosis during the angioplasty procedure. Some
of these catheters utilize exterior, ex-vivo, pumps to create the
pressure gradient necessary for blood flow through the catheter
while the balloon is inflated. Others utilize sophisticated in-vivo
systems of valves, pumps, and multiple balloons in the distal end
of the catheter to control the direction of blood flow. While
conceptually advantageous to provide an attractive solution to the
problem of angioplasty-induced ischemia, these perfusion
angioplasty catheters have met very little acceptance in the
medical community. One problem is the increased size of such
catheters with respect to conventional angioplasty catheters, which
results from the added channels and apparatus required to perform
the perfusion function within the lumen of the catheter. Other
issues are greater cost and intricacy of use. Thus, most
cardiologists continue to utilize conventional angioplasty
catheters and strive to limited the time of the procedure as much
as possible.
[0008] Sometimes, as a result of a coronary angioplasty or a stem
placement, the arterial vessel collapses and blood flow to the
heart is completely blocked, creating a severe, life-threatening
emergency. Standard procedure in such situations requires the
immediate performance of coronary bypass surgery. In fact, a
patient found in such a predicament is rushed to the operating room
in the hope of restoring oxygenation to the heart in time to save
his or her life. Unfortunately, that is often not possible because
of the time delay involved in reaching the affected artery. This
invention is directed at solving this emergency problem.
BRIEF SUMMARY OF THE INVENTION
[0009] The primary objective of this invention is a method and
apparatus for immediately restoring some degree of blood flow
through a blood vessel that has become totally occluded as a result
of a failed angioplasty or stent placement procedure.
[0010] Another important goal of the invention is a method and
apparatus that provide sufficient blood flow through a collapsed
stenosis to prevent ischemia and improve the chances of a patient
for successful open-heart surgery.
[0011] Another objective of the invention is a procedure that can
be implemented in conjunction with and immediately following
conventional angioplasty or stent placement.
[0012] Still another objective is a procedure that utilizes
existing angioplasty and perfusion catheters and related
apparatus.
[0013] A final objective is a procedure that can be implemented
easily and economically according to the above stated criteria.
[0014] Therefore, according to these and other objectives, the
preferred embodiment of the present invention begins by utilizing a
conventional catheter to perform a balloon angioplasty procedure on
a stenotic blood vessel. In case of failure of the procedure and a
resulting complete occlusion of the vessel, the balloon catheter is
removed from the vessel while the guide wire and the guide catheter
are left in place. A perfusion catheter is immediately inserted
into the guide catheter and run past the stenosis using the guide
wire already in place. Blood is drawn from a side port in the
sheath introduced at the point of entry into the vascular system of
the patient, typically along the femoral artery, and is passed into
the perfusion catheter under normal arterial pressure. In the event
of loss of arterial pressure, the blood so drawn is passed through
an exterior pump for pressurization and re-injection in the
perfusion catheter. Thus, blood flow to the part of the vessel past
the occlusion can be reestablished within minutes of angioplasty or
stent-placement failure and the patient can be stabilized in
preparation for heart surgery.
[0015] Various other purposes and advantages of the invention will
become clear from its description in the specification that follows
and from the novel features particularly pointed out in the
appended claims. Therefore, to the accomplishment of the objectives
described above, this invention consists of the features
hereinafter illustrated in the drawings, fully described in the
detailed description of the preferred embodiment and particularly
pointed out in the claims. However, such drawings and description
disclose but one of the various ways in which the invention may be
practiced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a schematic drawing illustrating the typical
configuration of a catheter set up at the point of entry into the
vascular system of a patient.
[0017] FIG. 2 is a schematic drawing illustrating a balloon
angioplasty catheter, a guide catheter, and a guide wire extended
through the femoral artery and aorta of a patient to the site of a
stenosis in a coronary artery.
[0018] FIG. 3 is an enlarged schematic drawing illustrating a
balloon angioplasty catheter apparatus in use at the site of a
stenosis in a coronary artery.
[0019] FIG. 4 is a schematic drawing illustrating the ex-vivo set
up of the invention at the point of entry into the vascular system
of a patient.
[0020] FIG. 5 is a schematic drawing illustrating the placement of
a perfusion catheter through a patient's occluded coronary artery
following failure of a balloon angioplasty procedure.
[0021] FIG. 6 is an enlarged schematic drawing illustrating the
perfusion catheter of the invention in use at the site of a
stenosis in a coronary artery.
[0022] FIG. 7 is a schematic drawing of another embodiment of the
invention showing the contemporaneous use of a side port for
monitoring as well as supplying arterial blood to a perfusion
pump.
[0023] FIG. 8 is a flow chart of the steps of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
[0024] The present invention consists of a main inventive concept,
the realization that the normal set up for a conventional balloon
angioplasty is suitable for an emergency procedure to avoid
ischemia in a patient in case of severe failure of the angioplasty.
This concept of the invention provides immediate relief that makes
it possible for a cardiologist to stabilize the patient in
preparation for corrective heart surgery.
[0025] As used herein, the term "angioplasty catheter" is defined
to refer to any catheter used in surgical procedures designed to
enlarge the lumen of a vessel at the site of a stenosis. Referring
to the drawings, wherein like parts are designated throughout with
like numerals and symbols, FIG. 1 illustrates the typical set up
used for conducting a balloon angioplasty procedure on a patient P.
Access to a blood vessel 10, normally a femoral artery, is obtained
percutaneously in the groin area 12 of the patient by inserting a
sheath 14 having a diameter compatible with the size of the vessel
and the size of the catheter to be used in the procedure. The
sheath 14, in a portion external to the incision 12, includes a
side port 16 for withdrawal of blood for periodic sampling, if
tests are requires, and for monitoring the patient's blood pressure
by an appropriate pressure gauge 18.
[0026] The angioplasty procedure involves the introduction of a
guide catheter 20 into the vessel 10 through an exterior main port
22 of the sheath 12. As shown in FIG. 2, the guide catheter 20 is
run up the femoral artery all the way to the heart H, to the osteum
24 of the artery that contains the stenosis to be treated (the left
coronary artery is shown for illustration). Once the guide catheter
20 is in place, a guide wire 26 is threaded through the guide
catheter into the occluded vessel 10 and past the stenosis 28.
Using the guide wire, a balloon catheter 30 is then passed over the
guide wire through the guide catheter and placed with its tip past
the stenosis 28 such that the balloon 32, incorporated in the
distal end of the catheter, overlaps the occlusion. As illustrated
in FIG. 3, the balloon 32 is then inflated by means of a fluid
pumped into the balloon catheter 30 through appropriate control
means 34 (FIG. 1) to expand the lumen of the artery 36 at the site
of the stenosis 28. Obviously, blood flow through the artery 36 is
essentially stopped while the balloon 32 is inflated. After
treatment, the balloon is deflated and the catheter 30 is extracted
using the guide catheter as a protective sleeve and the guide wire
as a directional rail. The guide catheter and the guide wire are
both left in place during the removal of the balloon catheter.
[0027] The intent of the angioplasty procedure is that, upon
deflation of the balloon 32 and removal of the catheter 30, the
enlarged opening at the site of the stenosis in the artery remain
expanded and permit normal blood flow. If a stent is to be placed
in the artery, the procedure follows the angioplasty and is carried
out using the same guide wire 26 and guide catheter 20 used for the
angioplasty. In some instances, though, one of these procedure is
not successful and the artery occludes and produces a total
blockage that could result into severe and life-endangering
ischemia of heart tissue. Immediate action is necessary to save the
life of the patient.
[0028] According to the present invention, a conventional perfusion
catheter is immediately introduced into the guide catheter 20 and
run all the way past the stenosis 28 using the guide wire 26
already in place, as illustrated in FIGS. 4-6. In essence, a
perfusion catheter 38 is used in replacement of the balloon
catheter 30 within the system already in place in the patient P.
Because the distal end of the guide wire 26 remains in the artery
36 past the site of the stenosis 28, the advancement of the
perfusion end 40 of the perfusion catheter past the occlusion is
easily accomplished simply by pushing it through, as shown in FIG.
6. As would be clearly understood by one skilled in the art, the
end 40 need to be advanced such that the perfusion orifices 42
distributed throughout its distal end 40 are beyond the vessel
occlusion for injection of blood into that area of the artery
36.
[0029] Passage of blood through the perfusion catheter is effected
by normal arterial pressure or by a pump 44 connected to the
external proximal end 46 of the perfusion catheter, as seen in FIG.
4. A separate arterial line may be tapped as a source for the
perfusion catheter but, in the preferred embodiment of the
invention, the suction side of the perfusion pump 44 is connected
to the side port 16 which is already in place and available to
provide arterial blood for perfusion beyond the arterial blockage
area, as indicated by the arrows A shown in FIG. 6. As such, a
system is readily in place to transform conventional balloon
angioplasty apparatus into an emergency perfusion device for
combatting arterial occlusions resulting from the angioplasty.
Typically, a pump capable of delivering 40-60 cc/min through the
perfusion end 40 is adequate to practice the invention. This system
provides immediate blood flow to the heart of the patient during
the critical time after a failed angioplasty and before coronary
artery bypass surgery is possible. In addition, through the
external pump 44, blood can continue to be perfused into the distal
portion of the artery 36 even when the patient experiences low
blood pressure or ventricular dysrhythmias. This property greatly
reduces the risk of heart tissue ischemia, cardiac failure, and
even death.
[0030] Since the possibility of failure of an angioplasty or
stent-placement procedure is always contemplated, a preferable
arrangement, illustrated in FIG. 7, consists of coupling the intake
48 of pump 44 to the line 50 already connected to the side port 16
for monitoring purposes, so that a source of arterial blood is
already hooked up for perfusion during the angioplasty procedure.
Appropriate valves 52 and 54 are provided to control or switch the
blood flow between the pump 44 and the monitoring equipment 18. An
additional valve 56 and port 58 may be provided to alternatively
connect the perfusion catheter 38 directly to the line 50 (i.e.,
bypassing the pump 44), if sufficient arterial pressure is present
for perfusion at the desired rate.
[0031] The steps of the procedure of the invention are illustrated
in the chart of FIG. 8 in the context of perfusion following a
failed angioplasty.
[0032] Various changes in the details, steps and components that
have been described may be made by those skilled in the art within
the principles and scope of the invention herein illustrated and
defined in the appended claims. Therefore, while the present
invention has been shown and described herein in what is believed
to be the most practical and preferred embodiments, it is
recognized that departures can be made therefrom within the scope
of the invention, which is not to be limited to the details
disclosed herein but is to be accorded the full scope of the claims
so as to embrace any and all equivalent processes and products.
* * * * *