U.S. patent application number 10/278753 was filed with the patent office on 2003-05-08 for buoyant tip aspiration catheter and methods of use.
This patent application is currently assigned to EMBOL-X, Inc.. Invention is credited to Murphy, Richard O..
Application Number | 20030088208 10/278753 |
Document ID | / |
Family ID | 23803868 |
Filed Date | 2003-05-08 |
United States Patent
Application |
20030088208 |
Kind Code |
A1 |
Murphy, Richard O. |
May 8, 2003 |
Buoyant tip aspiration catheter and methods of use
Abstract
A catheter comprising a flexible elongate tubular member having
a lumen communicating with a proximal end and a distal port at a
distal end. A chamber, filled with gas or fluid less dense than
blood, is mounted at the distal end. Methods of using the
aspiration catheter for removing embolic air or gaseous bubbles
within a body cavity are also disclosed.
Inventors: |
Murphy, Richard O.;
(Sunnyvale, CA) |
Correspondence
Address: |
O'MELVENY & MEYERS
114 PACIFICA, SUITE 100
IRVINE
CA
92618
US
|
Assignee: |
EMBOL-X, Inc.
Mountain View
CA
|
Family ID: |
23803868 |
Appl. No.: |
10/278753 |
Filed: |
October 22, 2002 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10278753 |
Oct 22, 2002 |
|
|
|
09454240 |
Dec 2, 1999 |
|
|
|
6468262 |
|
|
|
|
Current U.S.
Class: |
604/96.01 ;
604/35; 606/192 |
Current CPC
Class: |
A61M 2202/02 20130101;
A61M 2202/0014 20130101; A61M 25/10 20130101; A61M 2202/02
20130101 |
Class at
Publication: |
604/96.01 ;
606/192; 604/35 |
International
Class: |
A61M 029/00 |
Claims
What is claimed is:
1. A buoyant tip catheter, comprising: a flexible elongate tubular
member having a proximal end, a distal end, and a lumen
therebetween, the distal end having a port communicating with the
lumen; and a chamber mounted at the distal end and filled with a
first gas, wherein, during use, the distal end of the elongate
tubular member is inserted into a body cavity containing body fluid
and a second gas, the distal end is guided to the second gas, and
the second gas is removed from the body cavity through the port and
lumen.
2. The catheter of claim 1, further comprising an introducer.
3. The catheter of claim 2, wherein the introducer is a
cannula.
4. The catheter of claim 1, wherein the first gas is selected from
the group consisting of helium, nitrogen, and carbon dioxide.
5. The catheter of claim 1, further comprising a pump operatively
connected to the proximal end of the elongate tubular member and
communicating with the lumen.
6. The catheter of claim 1, wherein the elongate tubular member is
a thin-walled material selected from the group consisting of
thermal plastic, polyvinyl chloride, polyolefin, urethane, and
PEBAX.
7. The catheter of claim 1, wherein the elongate tubular member
further comprises a small wire helically wound to prevent
kinking.
8. The catheter of claim 1, wherein the chamber comprises a
toroidal balloon disposed about the distal end of the elongate
tubular member.
9. The catheter of claim 1, wherein the chamber comprises an
olive-shaped balloon disposed about the distal end of the elongate
tubular member.
10. The catheter of claim 1, wherein the chamber is a balloon, and
wherein the elongate tubular member further comprises an inflation
lumen communicating with the balloon.
11. The catheter of claim 1, wherein the chamber further comprises
an interior filled with foam.
12. The catheter of claim 1, wherein the body cavity is a blood
vessel or heart chamber.
13. The catheter of claim 1, wherein the body fluid is blood.
Description
[0001] This is a division of U.S. application Ser. No. 09/454,240,
filed Dec. 2, 1999, now U.S. Pat. No. 6,468,262. The contents of
each of the above-identified patents and applications are fully
incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to medical devices
for aspirating air or gas from a patient's body cavity, such as a
vessel or cardiac chamber. More particularly, the devices comprise
a catheter having a chamber filled with gas of low density and
mounted at a distal end of the catheter. The chamber provides
buoyancy to the catheter tip that seeks out and aspirates air or
gas in the body cavity.
BACKGROUND OF THE INVENTION
[0003] Aspiration catheters are frequently used during surgical or
interventional procedures for removing air, fluid, and/or blood
from a patient's body cavity. During cardiovascular procedures,
such as coronary artery bypass grafting surgery, ventricular septal
defect repair, heart valve repair or replacement, ventricular
myomectomy (Bautista procedure), septal-myomectomy, aortic aneurysm
repair, or aortic thrombectomy, removal of air from a cardiac
chamber and/or the aorta is particularly important since distal
embolization of air may result in ischemia or infarction of
peripheral organs. Treatment of vascular stenosis using
endovascular procedures, e.g., angioplasty, stent deployment, or
atherectomy, is also associated with increased risk of air
embolization resulting in cerebral ischemia or infarction.
[0004] Current aspiration catheters are designed to remove fluid in
a body cavity. Removal of air, however, is difficult because the
air bubbles tend to accumulate against the vessel wall at a
position difficult to reach. Thus, air removal is often not
complete and patients remain at risk for air embolization.
[0005] Thus, there is a need for devices and methods which
effectively remove air within a patient's body tissue or cavity
during surgical or endovascular procedures.
SUMMARY OF THE INVENTION
[0006] The present invention provides a buoyant tip aspiration
catheter adapted for insertion into a patient's body cavity. The
catheter is most useful in removing air from a cardiac chamber,
e.g., the left atrium or left ventricle, and a vessel, including
arteries and veins of various sizes. It will be understood that the
catheter can also be used in removing air in any other body cavity,
e.g., biliary tree.
[0007] In a first embodiment, the catheter comprises a flexible
elongate tubular member that has a lumen communicating with a
proximal and a distal end. The tubular member is made from a
thin-walled material, e.g., thermal plastic, polyvinyl chloride,
polyolefin, or PEBAX. The distal end includes an aspiration port
that communicates with the lumen. A chamber, which is filled with a
gas, such as helium, hydrogen, or carbon dioxide, is mounted at the
distal end. In certain embodiments, the chamber comprises a
toroidal or annular balloon or an olive-shaped balloon that
communicates with an inflation lumen. In other embodiments, the
chamber can have the shape of a sphere or ellipse or any other
suitable geometric shape.
[0008] In another embodiment, the catheter is insertable through an
introducer, such as a cannula. The proximal end of the catheter is
connected to a pump that applies negative pressure to the lumen. In
certain embodiments, a small wire is helically wound within the
catheter to prevent kinking.
[0009] In a first method of using the aspiration catheter disclosed
herein for removing gas from fluid or blood within a body cavity,
the distal end of the catheter is inserted through an incision in
tissue, such as a vessel. The distal end is directed to and seeks
out the location of gas within the body cavity by the buoyant
chamber. The gas is then removed from the body cavity through the
distal port and lumen under suction. During cardiovascular
surgeries, such as heart valve repair or replacement, removal of
gaseous material from the cardiac chambers and aorta reduces a
patient's risk of peri-operative complication, such as
neurocognitive, e.g., stroke and delirium.
[0010] It will be understood that there are several advantages in
using the aspiration catheters and methods disclosed herein for
treating a vascular lesion. For example, the catheters (1) can be
inserted in arteries or veins of various diameter, (2) provide
near-total capture of embolic gaseous bubbles, thereby dramatically
reducing the risk of distal embolization, and (3) are insertable
through an introducer and can be used with other endovascular
devices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1A depicts an embodiment of the aspiration catheter for
removing gas within a body cavity according to the present
invention.
[0012] FIG. 1B depicts another embodiment of the aspiration
catheter having an olive-shaped distal end.
[0013] FIG. 1C depicts another embodiment of the aspiration
catheter having an angled distal end.
[0014] FIG. 2 depicts the catheter of FIG. 1A inserted in the
aorta.
[0015] FIG. 3 depicts the catheter of FIG. 1C inserted through an
angioplasty catheter.
[0016] FIG. 4 depicts the catheter of FIG. 1A inserted into the
left common carotid artery.
[0017] FIG. 5A depicts a guidewire having a gas-filled chamber at a
distal end.
[0018] FIG. 5B depicts the guidewire of FIG. 5A disposed within a
catheter.
[0019] FIG. 5C depicts the catheter of FIG. 5B having an additional
infusion lumen.
[0020] FIG. 5D depicts the catheter of FIG. 5C having a curved
distal infusion tip.
[0021] FIG. 6 depicts a catheter having a finned rotating chamber
at a distal end.
[0022] FIG. 7A depicts another embodiment of the aspiration
catheter having a deflated balloon.
[0023] FIG. 7B depicts the aspiration catheter of FIG. 7A having an
inflated balloon.
[0024] FIG. 8 depicts a guidewire disposed within a catheter having
vented aspiration ports.
[0025] FIG. 9 depicts another embodiment of the aspiration catheter
having vented aspiration ports.
DETAILED DESCRIPTION
[0026] Referring now to the drawings, an embodiment of the
aspiration catheter for removing gas within a body cavity is
depicted in FIG. 1A. The catheter comprises a flexible elongate
tubular member 10 that has lumen 15 communicating with proximal end
11 and distal port 20 at distal end 13. Toroidal balloon 25, which
communicates with inflation lumen 26 and inflation port 27, is
mounted at distal end 12. Balloon 25 can be expanded by infusing
air, gas, or other fluid less dense than blood into the inflation
lumen port 27 and lumen 26 to provide buoyancy to the catheter
tip.
[0027] Another embodiment of the aspiration catheter having
olive-shaped chamber 30 at distal end 12 is shown in FIG. 1B.
Chamber 30 is filled with gas or foam to provide buoyancy to the
catheter tip. Tubular member 10 also includes helical wire 22 in
its wall to provide increased flexibility and prevent kinking of
the catheter.
[0028] FIG. 1C depicts another embodiment of the aspiration
catheter which has distal end 12 angled relative to proximal end 11
at flexible region 21 to facilitate removal of gas within a vessel.
When the catheter is inserted through an introducer or cannula,
distal end 12 and proximal end 11 assume a linear configuration at
region 21. Annular balloon 30 is mounted on distal end 12 to
provide buoyancy to the catheter tip.
[0029] In using the aspiration catheter of FIG. 1A to remove gas or
air within aorta 101, for example, distal end 12 is inserted
through the lumen of cannula 50 as depicted in FIG. 2. During
cardiopulmonary bypass, coronary blood flow is isolated from the
peripheral circulation by placement of aortic clamp 60 across aorta
101. Aortic cannula 50 is often inserted downstream of clamp 60 to
perfuse the peripheral organs, including the brain. Insertion of
cannula 50, which includes suture flange 51, often introduces air
or gas 100 within the aorta. The gas or air rises to the vessel
wall and is difficult to remove by use of a conventional aspiration
catheter. By inserting the catheter described herein having
toroidal balloon 25 mounted at distal end 12 into aorta 101, the
gas or fluid inside balloon 25 allows distal end 12 to be buoyant
compared to blood and to rise to the location of gas 100. The
proximal end of the catheter is then attached to a vacuum and gas
100 is removed through port 20 and lumen 15 of the catheter under
negative pressure. In this way, near complete removal of air 100
can be achieved, and distal embolization of gas can be minimized
when aortic clamp 60 is removed to re-established aortic flow.
Alternatively, the catheter can also be used to aspirate other
embolic debris, e.g., calcium, thrombi, atheromatous plaque, and/or
tissue debris, by deflating balloon 25 by removing gas or fluid
from its inflation lumen.
[0030] The aspiration catheters disclosed herein can also be used
to remove air or gas during endovascular procedures, e.g.,
angioplasty, atherectomy, or stent deployment. In FIG. 3, the
catheter of FIG. 1C is inserted through lumen 77 of angioplasty
catheter 70. In removing atheromatous lesion 105 in aorta 101, for
example, filter 76 is inserted downstream of lesion 75 to provide
protection against distal embolization. However, the protection is
often incomplete. After lumenal patency is re-established by
expanding angioplasty balloon 75 mounted at distal end 71 of
angioplasty catheter 70, distal end 12 of the aspiration catheter
is inserted through lumen 77 of catheter 70. The distal end and
proximal end of tubular member 10 assume a linear configuration
during its insertion within catheter 70. When the aspiration
catheter is deployed in aorta 101, distal end 12 is angled relative
to the proximal end. The angled configuration and relatively
buoyant annular balloon 30 guide the catheter tip to gas 100. After
gas 100 is removed under suction from the aspiration catheter,
angioplasty catheter 70 and catheter 10 are removed. Filter 76 is
then collapsed and, with the entrapped embolic debris, is
removed.
[0031] Removal of embolic air or gaseous bubbles is particularly
important in carotid procedures, such as carotid endarterectomy or
angioplasty. Air embolization is a common cause of stroke or
cerebral ischemia. FIG. 4 depicts the catheter of FIG. 1A inserted
through left femoral artery 111 into left common carotid artery 112
during endovascular procedures. The catheter may carry filter 76 at
a distal end to be placed downstream. Alternatively, the filter can
be replaced by an occluder or a vessel clamp. Proximal end 11 of
the catheter is connected to pump 80 that provides suction to lumen
15 and port 20 for removal of gas or air 100 generated within left
common carotid artery during endovascular procedures.
Alternatively, gas is removed from the vessel by reason of the
pressure differential between blood pressure inside the vessel and
atmospheric pressure outside the vessel. Where the system relies on
this pressure differential, no external pump is needed.
[0032] The buoyant chamber may be integral with the aspiration
catheter as described above, or mounted on a separately insertable
guidewire as shown in FIGS. 5A through 5D.
[0033] In FIG. 5A, guidewire 85 has chamber 25 mounted at a distal
end. Chamber 25 communicates with lumen 87, which communicates with
infusion port 86 at a proximal end of guidewire 85. In an
alternative construction, chamber 25 is pre-filled, and does not
require an inflation lumen. FIG. 5B shows guidewire 85 disposed
within lumen 15 of aspiration catheter 10. FIG. 5C shows aspiration
catheter 10 having proximal infusion port 89 communicating with
infusion lumen 88, which in turn communicates with distal infusion
port 90. FIG. 5D shows another embodiment of distal infusion port
90 having a curved construction. The jet of fluid, e.g. saline or
Ringer's lactate, delivered by infusion port 90 creates vortex flow
for enhancement of aspiration.
[0034] FIG. 6 depicts another embodiment of aspiration catheter 10
having one or more finned rotating member 92 included at its distal
end. The number of fins can range from 2 to 10 or more, and
typically 3-5 fins are used. The finned rotating member causes
turbulence in the heart chamber and the aorta, thereby mixing air
or gaseous emboli with blood to facilitate aspiration.
[0035] FIGS. 7A and 7B depict another embodiment of the distal end
of aspiration catheter 10. FIG. 7A shows balloon 25 deflated. FIG.
7B shows inflated balloon 25. Notably, the distal most edge of
balloon 25, shown here as 91, extends distally beyond distal port
20 of aspiration catheter 10.
[0036] FIG. 8 shows alternative catheter 10 having a plurality of
distal vents 95 which comprise the aspiration ports. Optionally,
guidewire 85 extends through lumen 15 of catheter 10 and distally
beyond vents 95. FIG. 9 shows an olive-shaped balloon 25 mounted on
the distal end of catheter 10 having vents 95 for aspiration of
gas.
[0037] The length of the aspiration catheter will generally be
between approximately 20 and 100 centimeters, preferably between
approximately 40 and 60 centimeters. The inner diameter of the
aspiration catheter will generally be between approximately 0.1 and
0.3 centimeters, preferably approximately 0.15 and 0.2 centimeters.
The outer diameter of the toroidal or annular balloon will
generally be between approximately 0.1 and 0.8 centimeters,
preferably approximately 0.2 and 0.5 centimeters. The foregoing
ranges are set forth solely for the purpose of illustrating typical
device dimensions. The actual dimensions of a device constructed
according to the principles of the present invention may obviously
vary outside of the listed ranges without departing from those
basic principles.
[0038] Although the foregoing invention has, for purposes of
clarity of understanding, been described in some detail by way of
illustration and example, it will be obvious that certain changes
and modifications may be practiced which will still fall within the
scope of the appended claim. It will also be understood that each
feature of each embodiment discussed herein, and of each reference
cited herein, can be used in combination with the features of any
other embodiment.
* * * * *