U.S. patent application number 10/340181 was filed with the patent office on 2003-06-05 for cannula with flow diversion mechanism and methods of use.
This patent application is currently assigned to EMBOL-X, Inc.. Invention is credited to Lilly, Richard S., Murphy, Richard O..
Application Number | 20030105486 10/340181 |
Document ID | / |
Family ID | 25297518 |
Filed Date | 2003-06-05 |
United States Patent
Application |
20030105486 |
Kind Code |
A1 |
Murphy, Richard O. ; et
al. |
June 5, 2003 |
Cannula with flow diversion mechanism and methods of use
Abstract
A cannula is described that includes a diverter mechanism in the
form of a diffusion surface deployable from within the lumen of the
cannula and retractable from the lumen of the cannula. The
diffusion surface may take the form of a planar surface, a curved
surface, a membrane mounted on a wire ring, or a conical sleeve, or
any other suitable shape. In use, the cannula is inserted in a
vessel, the diffusion surface is deployed in the lumen of the
cannula beyond the distal end of the cannula, and blood flow is
passed through the cannula and against the diffusion surface.
Alternative devices and methods are also described.
Inventors: |
Murphy, Richard O.;
(Sunnyvale, CA) ; Lilly, Richard S.; (San Jose,
CA) |
Correspondence
Address: |
O'MELVENY & MEYERS
114 PACIFICA, SUITE 100
IRVINE
CA
92618
US
|
Assignee: |
EMBOL-X, Inc.
Mountain View
CA
|
Family ID: |
25297518 |
Appl. No.: |
10/340181 |
Filed: |
January 10, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10340181 |
Jan 10, 2003 |
|
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09846309 |
Apr 30, 2001 |
|
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6508826 |
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Current U.S.
Class: |
606/200 |
Current CPC
Class: |
A61F 2230/0006 20130101;
A61B 17/12136 20130101; A61B 2017/1205 20130101; A61F 2230/008
20130101; A61F 2230/0067 20130101; A61F 2/012 20200501; A61B
17/12109 20130101; A61F 2002/018 20130101; A61F 2/013 20130101 |
Class at
Publication: |
606/200 |
International
Class: |
A61M 029/00 |
Claims
What is claimed is:
1. A surgical method, comprising the steps of: inserting a cannula
into a blood vessel, the cannula comprising an elongate tubular
member having a proximal end, a distal end, and a lumen
therebetween; deploying an embolic protection filter through the
elongate tubular member and within the blood vessel; advancing a
diffusion surface from the lumen of the elongate tubular member
beyond the distal end of the elongate tubular member; flowing a
blood stream through the lumen of the elongate tubular member
against the diffusion surface, wherein the blood stream is
dispersed by the diffusion surface; and retracting the diffusion
surface into the lumen of the elongate tubular member.
2. The method of claim 1, wherein the blood vessel is an
artery.
3. The method of claim 2, wherein the artery is the aorta.
4. The method of claim 1, wherein the elongate tubular member is
angled at its distal end.
5. The method of claim 1, wherein the lumen is divided into more
than one lumen.
6. The method of claim 1, further comprising an occlusion member
deployable from the distal end of the elongate tubular member.
7. The method of claim 1, wherein the diffusion surface comprises a
membrane mounted on a flexible wire ring.
8. The method of claim 7, wherein the membrane is
semi-permeable.
9. The method of claim 8, wherein the membrane is a mesh.
10. The method of claim 7, wherein the membrane is impermeable.
11. The method of claim 1, wherein the diffusion surface is a
cone-shaped sleeve.
12. The method of claim 11, wherein the sleeve is an elastomeric
material.
13. The method of claim 1, wherein the diffusion surface comprises
a substantially flat surface mounted at a distal end of a flexible
elongate member.
14. The method of claim 13, wherein the flexible elongate member is
a wire.
15. The method of claim 13, wherein the surface is attached to the
flexible elongate member at substantially a 45.degree. angle.
16. A cannula, comprising: an elongate tubular member having a
proximal end, a distal end, and a lumen therebetween; an attachment
wire coupled to the distal end of the elongate tubular member; and
an expansion frame deployable from the distal end of the elongate
tubular member and attached to the distal end of the attachment
wire; wherein during use, the distal end of the elongate tubular
member is inserted into a vessel and the expansion frame is
expanded to fill the vessel lumen.
17. The cannula of claim 16, further comprising a mesh attached to
the expansion frame.
18. The cannula of claim 16, further comprising a diffusion surface
deployable from within the lumen of the elongate tubular member and
retractable into the lumen of the elongate tubular member.
19. The cannula of claim 18, wherein the diffusion surface
comprises a substantially flat surface mounted at a distal end of a
flexible elongate member.
20. The cannula of claim 16, wherein the lumen is divided into more
than one lumen.
Description
[0001] This is a continuation of U.S. patent application Ser. No.
09/846,309, filed Apr. 30, 2001, now U.S. Pat. No. 6,508,826, which
is expressly incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to medical devices
useful for cannulation of a vascular tissue, such as the aorta, and
for protecting against distal embolization during cardiovascular
procedures. More particularly, the devices minimize plaque
dislodgement and damage to a vessel wall during delivery of blood
to the vessel.
BACKGROUND OF THE INVENTION
[0003] Aortic cannulation is commonly employed during various
conventional or minimally invasive surgeries, such as coronary
artery bypass grafting, heart valve repair or replacement, septal
defect repair, pulmonary thrombectomy, atherectomy, aneurysm
repair, aortic dissection repair, and correction of congenital
defects, to establish cardiopulmonary bypass. After circulatory
isolation of the coronary blood flow from the peripheral vascular
system is established, a cannula is usually inserted in the
ascending aorta to deliver oxygenated blood from a
bypass-oxygenator to maintain blood flow to the peripheral organs,
e.g., the brain and kidneys. It is well recognized that one of the
complications associated with cardiovascular procedures is the
dislodgement of embolic materials generated during manipulation of
the aorta or the heart, thereby causing occlusion of the vessels
downstream from the aorta causing ischemia or infarct of the
organs, e.g., stroke. To minimize embolic complication, an arterial
filter is often temporarily deployed in the aorta distal to the
aortic cannula to capture embolic debris.
[0004] However, when oxygenated blood is delivered to the aortic
cannula through the bypass-oxygenator, blood exits the cannula with
a very high velocity, similar to a jet-like profile. When this jet
is directed toward the aortic wall, it may damage the aorta causing
aortic dissection or aneurysm. Furthermore, the jet may dislodge
plaque on the aortic wall, causing distal embolization and
peripheral organ infarction. When oxygenated blood is allowed to
flow into a filter, the jet may cause turbulent flow in the filter,
thereby washing out the emboli caught in the filter. As a result of
the swirling action by the jet, the emboli may escape around the
edges of the filter to cause distal embolization and result in
damage to peripheral organs, or may travel upstream to reach a
coronary artery and cause myocardial infarction.
[0005] New devices and methods are thus needed in aortic
cannulation to minimize embolic dislodgement and vascular wall
damage due to delivery of oxygenated blood to the aorta during
cardiovascular surgeries.
SUMMARY OF THE INVENTION
[0006] The invention provides devices and methods for reducing the
jet-like profile of blood delivered through a cannula and the
swirling of the blood within a filter. It will be understood that,
although the present invention is most useful in aortic cannulation
during cardiovascular surgeries, the devices and methods can be
used in any surgeries where delivery of fluid or blood through a
cannula can potentially damage the body tissue.
[0007] In a first embodiment, the cannula is an elongate tubular
member having a proximal end, a distal end, and a lumen
therebetween. A blast plate deployable from within the lumen of the
elongate tubular member is provided. The blast plate is retractable
into the lumen of the elongate tubular member after use. In certain
cases, the cannula is angled at its distal end, generally at a
90.degree. angle to the axis of the lumen at a proximal end. In
other cases, the cannula will further include a filter deployable
from the distal end of the cannula. The filter may be mounted on
the distal end of the cannula, or the filter can be mounted on a
separately insertable member, such as a guidewire. In other cases,
the cannula has more than one lumen extending from its proximal to
its distal end. In still other cases, the cannula further comprises
an occlusion member such as a balloon occluder, deployable from the
distal end of the cannula. As with the filter, the occluder can be
mounted on the cannula, or provided on a separately insertable
member, such as an occlusion catheter.
[0008] The blast plate typically comprises a generally flat or
curved surface, and may comprise a membrane mounted on a flexible
wire ring. The membrane generally comprises a semi-permeable
material. In certain cases the member is a mesh material. In still
other cases, the membrane is made of an impermeable material. While
in certain cases the blast plate is formed in the shape of a planar
surface defined by a wire ring, in other cases the blast plate is a
cone-shaped sleeve. The sleeve can be made of an elastomeric
material. The blast plate may also take the form of a substantially
flat surface mounted at the distal end of a flexible or an
inflexible elongate member. For example, the blast plate may be
fixed to the end of a wire. The blast plate will be angled relative
to the elongate member, and the angle may be selected from a
45.degree. angle, a 50.degree. angle, a 55.degree. angle, a
60.degree. angle, a 65.degree. angle, a 70.degree. angle, a
75.degree. angle, an 80.degree. angle, an 85.degree. angle, or a
90.degree. angle.
[0009] In use, the surgeon inserts the cannula into a body cavity,
e.g., a blood vessel. It will be understood that the cannula may
comprise a standard commercially available cannula, or any of the
novel cannula described herein. The surgeon will then advance a
blast plate or dispersion mechanism through the lumen of the
cannula and beyond the distal end of the cannula. The surgeon then
flows a stream of fluid, e.g., blood, through the lumen of the
cannula. The blood flow hits the blast plate, and the blood stream
is diffused and dispersed by the blast plate without jetting
against the wall of the aorta. After the infusion procedure is
complete, the surgeon retracts the blast plate into the lumen of
the cannula.
[0010] It will be understood that the methods of use have
particular application where the body cavity is a blood vessel,
where the blood vessel is an artery, and where the artery is the
aorta. It will further be understood that there are several
advantages to using the diffusion-diversion devices and methods
described herein. For example, by dispersing the stream of blood
flow, the devices and methods (1) avoid "sand blasting" embolic
debris from the lumen of the vessel, (2) avoid the swirling of
blood that may carry embolic debris upstream during CABG to the
coronary arteries, where myocardial ischemia can occur, (3) avoid
turbulence that can force embolic debris around the periphery of a
deployed filter to cause distal embolization which can results in
stroke, renal failure, or other organ damage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1A depicts a cannula having a blast plate deployed
within an artery.
[0012] FIG. 1B depicts an end view of the artery and cannula of
FIG. 1A.
[0013] FIG. 1C depicts a cannula with blast plate deployed within
an artery, and a separately deployed filter through a second
cannula.
[0014] FIG. 1D depicts a cannula having a filter and a blast plate
deployed through separate lumens of the cannula.
[0015] FIG. 1E depicts removal of the blast plate of FIG. 1D.
[0016] FIG. 2A depicts a blast plate comprising a membrane mounted
on a flexible wire ring.
[0017] FIG. 2B depicts an end view of the artery and cannula of
FIG. 2A.
[0018] FIG. 3A depicts a diverter that comprises a cone-shaped
sleeve.
[0019] FIG. 3B depicts the diverter of FIG. 3A deployed within a
filter.
[0020] FIG. 3C depicts an end view of the diverter and filter of
FIG. 3B.
[0021] FIG. 3D depicts an oblique view of the diverter and filter
of FIG. 3B.
[0022] FIG. 4A depicts a standard cannula and filter without a
diverter.
[0023] FIG. 4B depicts a filter and cannula having a windsock
embolic trap incorporated in the filter.
[0024] FIG. 4C depicts the use of the device of FIG. 4B in the
ascending aorta.
DETAILED DESCRIPTION
[0025] A first cannula with flow diverter is depicted in FIG. 1A.
Cannula 10 having distal end 11 is deployed through an incision in
vessel 99, in certain cases the aorta. Blast plate 20 is fixed to
elongate wire 21 at bond 22. Blast plate 20 is deployed through
lumen 13 of cannula 10. Blood flow exits cannula 10, impacts blast
plate 20, and is scattered as shown by the arrows surrounding blast
plate 20. FIG. 1B depicts an end view of the diverter and cannula
of FIG. 1B. As shown in FIG. 1A, blast plate 20 is not necessarily
flat but can take on a curvilinear configuration.
[0026] FIG. 1C shows a cannula and diverter deployed within vessel
99, and a separate filter cannula. Filter cannula 30 carries
separately insertable elongate member 43 having expansion frame 41
and mesh 40 disposed at a distal end of elongate member 43.
Expansion frame 41 is attached to elongate member 43 through active
anchor wire 42. It will be understood that anchor wire 42 allows
expansion frame 41 to expand to fill the lumen of vessel 99. Mesh
40 is attached at an edge to expansion frame 41. In other devices,
expansion frame 41 may be directly connected to elongate member 43.
In this manner, the filter mechanism is separately insertable
through cannula 30, which is introduced as a separate stick on
vessel 99.
[0027] FIG. 1D depicts cannula 10 having first lumen 13 and second
lumen 12. First lumen 13 is adapted for insertion of diverter
mechanism 20. Second lumen 12 is adapted to receive and pass a
separately insertable filter disposed at the distal end of an
elongate member. FIG. 1E depicts blast plate 20 being withdrawn
through lumen 13 of cannula 10.
[0028] In certain alternative embodiments, diverter 20 or
alternately the filter/diverter may be stored in lumen 13 through
which blood flows, so that the onset of flow causes diverter
mechanism 20 and/or the filter to move distally and deploy once
ejected from the tip of the cannula. The mechanism may be tethered
to the cannula and may be removed with the cannula or withdrawn
back into lumen 13 using a wire.
[0029] FIG. 2A shows an alternative construction of a diverter
mechanism and filter protection device. The diverter comprises wire
ring 23 fixed to elongate member 21 at bond 22. An impermeable or
semi-permeable material 24 covers wire ring 23 and acts as a blast
plate for existing blood flow. Filter 40 includes expansion frame
41 and cantilever 42. The reader is referred to Ambrisco et al.,
U.S. Pat. No. 6,007,557, incorporated as if set forth in its
entirety herein, for details on the design of a cantilever-based
expansion frame. FIG. 2B depicts an end view of a membrane blast
plate as shown in FIG. 2A.
[0030] FIG. 3A shows cannula 10 having angled distal end 11
disposed within vessel 99. Diverter 20 takes the form of
cone-shaped sleeve 25 formed of an impermeable or semi-permeable
material. Sleeve 25 is open at proximal end 26 for receiving blood
flow from arterial return cannula 10. Sleeve 25 disperses the jet
stream of blood as shown by the arrows surrounding sleeve 25. FIG.
3B shows sleeve 25 used with filter 40 mounted on expansion frame
41. FIG. 3C depicts an end view of the filter with the cone-shaped
sleeve of FIG. 3B. Sleeve 25 is connected to elongate member 28 by
struts 27. Elongate member 28 and sleeve 25 are separately
insertable through cannula 10. Filter 40 and expansion frame 41 may
be separately insertable or may be mounted on the distal region of
cannula 10. FIG. 3D shows an oblique view of the cannula,
cone-shaped diverter sleeve, and filter of FIG. 3B.
[0031] FIG. 4A depicts standard cannula 10 and filter 50, without
diverter capabilities. Unscattered blood flow from cannula 10
creates turbulence within filter 50 that may cause emboli to escape
downstream, and may carry other emboli upstream where they can
become lodged in the coronary arteries, resulting in myocardial
ischemia or infarct. FIG. 4B shows a filter construction that traps
emboli to prevent movement within turbulent blood flow. Expansion
frame 41 is attached to filter mesh 60 that includes reservoir tip
61 (in the shape of a windsock) for retaining captured emboli. This
design will immobilize emboli and minimize the opportunity for
proximal and distal embolization.
[0032] FIG. 4C shows the use of a filter with reservoir tip in the
ascending aorta. Expansion frame 41 is deployed through cannula 10
upstream the takeoff for right brachiocephalic artery 96, left
common carotid artery 97, and left subclavian artery 98. Filter 60
includes reservoir tip 61. After filter 60 is deployed, arterial
return is provided through cannula 10. After termination of
arterial return flow, expansion frame 41 and filter 60 are removed
through cannula 10 before removing cannula 10. These devices will
find application in any surgeries that can make use of arterial
cannulation and/or filter protection, including coronary artery
bypass grafting, heart valve repair or replacement, septal defect
repair, pulmonary thrombectomy, atherectomy, aneurysm repair,
aortic dissection repair, and correction of congenital defects.
[0033] The length of the cannula will generally be between 15 and
60 centimeters, preferably approximately between 25 and 40
centimeters. The inner diameter of the cannula lumen will generally
be between 0.5 and 1.5 centimeters, preferably between 0.5 and 1.0
centimeters. The diameter of the expanded filter will generally be
between 0.3 and 3.0 centimeters, preferably approximately 2.0 and
2.5 centimeters for use in the aorta. 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.
[0034] Although the foregoing invention has, for the purposes of
clarity and 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 claims. For example, the devices and methods
of each embodiment can be combined with or used in any of the other
embodiments.
* * * * *