U.S. patent application number 11/650628 was filed with the patent office on 2007-07-12 for aspiration thrombectomy catheter system, and associated methods.
This patent application is currently assigned to Smalling Medical Ventures, LLC. Invention is credited to Ron Smalling.
Application Number | 20070161963 11/650628 |
Document ID | / |
Family ID | 38233632 |
Filed Date | 2007-07-12 |
United States Patent
Application |
20070161963 |
Kind Code |
A1 |
Smalling; Ron |
July 12, 2007 |
Aspiration thrombectomy catheter system, and associated methods
Abstract
An aspiration thrombectomy catheter system includes an aspirator
and an aspiration catheter for insertion in a blood vessel. The
catheter has a shaft with a proximal end for connection with the
aspirator and a tapering distal end with a tip for insertion in the
vessel. A plurality of aspiration ports are arranged in sets along
the tapering distal end, for aspirating thrombus from the vessel.
At least one aspiration lumens within the shaft conducts thrombus
from the vessel, through the aspiration ports, to the aspirator.
Variably sized or shaped ports provide differing aspiration vectors
for enhanced thrombus removal. The aspiration thrombectomy catheter
additionally provides for uniform drug dispersion at a thrombotic
area, alone or in combination with aspiration of the thrombus. In
the event of an adverse reaction, drug dosage may be easily reduced
by aspirating dispersed drugs back into the catheter.
Inventors: |
Smalling; Ron; (Springfield,
MO) |
Correspondence
Address: |
LATHROP & GAGE LC
1845 S. NATIONAL, P.O. BOX 4288
SPRINGFIELD
MO
65101
US
|
Assignee: |
Smalling Medical Ventures,
LLC
|
Family ID: |
38233632 |
Appl. No.: |
11/650628 |
Filed: |
January 6, 2007 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60757790 |
Jan 9, 2006 |
|
|
|
Current U.S.
Class: |
604/269 |
Current CPC
Class: |
A61B 17/22 20130101;
A61B 2017/22084 20130101; A61B 2017/22079 20130101; A61B 2217/005
20130101; A61M 2025/0081 20130101; A61B 2017/22082 20130101; A61M
25/003 20130101; A61M 2025/0037 20130101; A61M 25/007 20130101;
A61M 25/0068 20130101; A61M 2025/0031 20130101 |
Class at
Publication: |
604/269 |
International
Class: |
A61M 25/00 20060101
A61M025/00 |
Claims
1. An aspiration thrombectomy catheter system, comprising: an
aspirator; and an aspiration catheter for insertion in a blood
vessel, the aspiration catheter having: a shaft with (a) a proximal
end for connection to the aspirator and (b) a tapering distal end
with a distal tip for insertion in the vessel; a plurality of
aspiration port sets arranged along the tapering distal end, each
of the aspiration port sets having a plurality of ports for
aspirating thrombus from the vessel, and at least one aspiration
lumens within the shaft, for conducting aspirated thrombus from the
vessel, through the aspiration ports, to the aspirator.
2. The system of claim 1, wherein the ports of each aspiration port
set differ in one or both of size and shape.
3. The system of claim 2, the differently sized or shaped
aspiration ports providing differing vector forces for aspiration
of thrombus.
4. The system of claim 3, the differently sized or shaped
aspiration ports including small, medium and large ports for
producing Venturi forces of varying strength to aspirate the
thrombus into the lumens.
5. The system of claim 1, the aspiration catheter comprising a dual
aspiration catheter having a first aspiration lumens and a second
aspiration lumens.
6. The system of claim 5, the plurality of aspiration port sets
comprising a proximal port set opening into the first aspiration
lumens, and a middle and a distal port set opening into the second
aspiration lumens; wherein the first aspiration lumens conducts
aspirated thrombus from the proximal port set to the aspirator and
the second aspiration lumens conducts aspirated thrombus from the
middle and distal port sets to the aspirator or a second
aspirator.
7. The system of claim 6, further comprising a first tube
connecting the first lumens to the aspirator and a second tube
connecting the second lumens to the aspirator or the second
aspirator.
8. The system of claim 1, the shaft comprising a shoulder defining
a taper of the shaft to the distal tip.
9. The system of claim 1, further comprising a dispenser for
dispersing lytic agents through one or more of the aspiration port
sets to the thrombus.
10. A method for aspirating thrombus from a vessel, comprising:
advancing an aspiration catheter within the vessel until at least a
distal set of aspiration ports arranged along a tapering catheter
tip is proximate a thrombus; applying aspiration forces through at
least the distal set of aspiration ports to suction at least a
first portion of the thrombus into a first aspiration lumens;
advancing the aspiration catheter through unaspirated thrombus; and
applying aspiration forces via at least one second set of
aspiration ports arranged along the tapering catheter tip and
proximal to the distal set of aspiration ports, to suction at least
a second portion of the thrombus into the aspiration catheter.
11. The method of claim 10, further comprising withdrawing the
catheter through the thrombus while aspirating through one or more
of the distal and the at least one second set of aspiration
ports.
12. The method of claim 12, wherein applying aspiration forces
through the distal set of ports comprises activating a first
aspirator and applying aspiration forces through the at least one
second set of ports comprises activating a second aspirator.
13. The method of claim 12, further comprising dispersing lytic
agents at the thrombus through one or more of the distal set of
aspiration ports and the at least one second set of aspiration
ports, prior to applying the aspiration forces.
14. The method of claim 12, wherein advancing the aspiration
catheter comprises advancing the aspiration catheter over a guide
wire.
15. The method of claim 10, wherein suctioning at least a second
portion of the thrombus into the aspiration catheter comprises
suctioning at least the second portion into a second aspiration
lumens.
16. A method for aspirating thrombus from a vessel, comprising:
advancing an aspiration catheter within the vessel to an occluding
thrombus; dispersing one or more lytic agents from a first catheter
lumens to the thrombus via a first set of ports opening into the
first catheter lumens; and applying aspiration forces to the
thrombus via at least a second set of ports, the second set of
ports conducting aspirated thrombus into a second catheter
lumens.
17. The method of claim 16, further comprising repeating the steps
of dispersing and applying, to loosen and remove the thrombus from
the vessel.
18. The method of claim 16, further comprising applying aspiration
forces to the thrombus via a third set of ports, the third set of
ports differing from the second set of ports in one or both of size
and shape.
19. The method of claim 18, the different sizes or shapes of the
second and third sets of ports providing multiple aspiration
vortices for removing the thrombus from the vessel.
20. The method of claim 18, the third set of aspiration ports
opening into the second catheter lumens.
Description
RELATED APPLICATIONS
[0001] This application claims priority of U.S. Provisional
60/757,790, filed Jan. 6, 2005 and incorporated herein by
reference.
BACKGROUND
[0002] Coronary artery thrombus may be a cause of, or a culprit in,
acute coronary syndromes such as acute myocardial infarction and
unstable angina. The presence of thrombus in the coronary artery,
accompanying a significant artherosclerotic plaque narrowing,
complicates optimal revascularization by percutaneous techniques
such as angioplasty or stenting.
[0003] Distal embolization of thrombus into the distal coronary
artery macro and micro circulation, which may for example occur
during balloon angioplasty or coronary stenting, results in reduced
TIMI (Thrombolysis in Myocardial Infarction) flow. Reduced TIMI
flow or flow grade has been demonstrated to reduce patient outcomes
in such studies as the PAMI (Primary Angioplasty in Myocardial
Infarction) stent trials and the CADILLAC (Controlled Abciximab and
Device Investigation to Lower Late Angioplasty Complications)
clinical trials.
[0004] Dealing with coronary thrombus in these situations has been
the subject and focus of many pharmacologic and endovascular
techniques. Endovascular techniques of thrombus removal by
thrombectomy devices have been well studied and several existing
devices have been tried, such as the Possis AngioJet.RTM. System,
which theoretically allows a physician to infuse medication
directly into a thrombus and/or remove the thrombus through power
pulse aspiration. Unfortunately, clinical trials conducted with the
AngioJet.RTM. System have failed to demonstrate an advantage over
previous techniques for treating coronary thrombus, such as balloon
angioplasty prior to implantation of a stent.
[0005] Other means of treating coronary thrombus include passive
aspiration by end-hole aspiration thrombectomy catheters such as
the Export aspiration catheter. The Export aspiration catheter
consists of a 5 French monorail catheter connected to an evacuated
20 ml syringe used to remove thrombotic debris. While rather
extensively used, the efficacy of this treatment is limited by
thrombus plugging the end hole during the procedure. Other, newer
passive aspiration catheters like the Diver CE (manufactured by V3,
Inc.) include a few side holes along the catheter body near the end
of the aspiration catheter; yet such catheters are apt to plug with
only slightly more thrombus than necessary to plug the passive
export catheter.
SUMMARY
[0006] The aspiration thrombectomy catheter system disclosed herein
may overcome problems associated with prior devices to provide
thrombus removal and drug dispersion in coronary arteries or
arterial conduits, such as saphenous vein bypass grafts or
peripheral arteries.
[0007] In one embodiment, an aspiration thrombectomy catheter
system includes an aspirator and an aspiration catheter for
insertion in a blood vessel. The aspiration catheter has a shaft
with (a) a proximal end for connection to the aspirator and (b) a
tapering distal end with a tip for insertion in the vessel. A
plurality of aspiration port sets, each having a plurality of ports
for aspirating thrombus from the vessel, are arranged along the
tapering distal end. At least one aspiration lumens within the
shaft conducts thrombus from the vessel, through the aspiration
ports, to the aspirator.
[0008] In one embodiment, a method for aspirating thrombus includes
advancing an aspiration catheter within a vessel until at least a
distal set of aspiration arranged along a distal portion of
tapering catheter tip is proximate a thrombus. Aspiration forces
are applied through at least the distal set of aspiration ports to
suction at least a first portion of the thrombus into a first
aspiration lumens. The aspiration catheter is advanced through
unaspirated thrombus and aspiration forces are applied via at least
one second set of aspiration ports arranged proximal to the distal
set of aspiration ports, along the tapering catheter tip, to
suction at least a second portion of the thrombus into the
aspiration catheter.
[0009] In one embodiment, a method for aspirating thrombus includes
advancing an aspiration catheter within a vessel to an occluding
thrombus. One or more lytic agents are dispersed from a first
catheter lumens to the thrombus via a first set of ports opening
into the first catheter lumens. Aspiration forces are applied to
the thrombus via at least a second set of ports, the second set of
ports conducting aspirated thrombus into a second catheter
lumens.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 depicts one embodiment of an aspiration thrombectomy
catheter system including an aspiration thrombectomy catheter.
[0011] FIG. 2 shows the aspiration thrombectomy catheter of FIG. 1
in a section of artery.
[0012] FIG. 3 is a flow-chart illustrating a method of aspirating
thrombus, for example using the aspiration thrombectomy catheter of
FIG. 1.
[0013] FIG. 4 illustrates drug dispersion proximate a thrombus,
with the aspiration thrombectomy catheter of FIGS. 1 and 2.
[0014] FIG. 5 is a flow-chart showing a method of delivering
thrombolytic drugs, for example using the aspiration thrombectomy
catheter of FIGS. 1, 2 and 4.
DETAILED DESCRIPTION
[0015] It is appreciated that the present teaching is by way of
example, not limitation. The illustrations herein are not limited
to use or application with a specific type of aspiration
thrombectomy catheter. Thus, although the instrumentalities
described herein are for the convenience of explanation, shown and
described with respect to exemplary embodiments, it is appreciated
that the principals herein may be equally applied in other
embodiments of aspiration thrombectomy catheters.
[0016] For example, for ease of discussion, aspiration thrombectomy
catheter system 100 is described herein below with respect to
removal of coronary thrombus; however, those skilled in the art
will recognize, after reading and fully appreciating the present
disclosure, that system 100 may be equally applied for enhanced
thrombus removal elsewhere in the circulatory system. For example,
system 100 may be applied in: [0017] Removal of thrombus in the
carotid circulation, both extra-cranial and intra-cranial; [0018]
Removal of visceral thrombus, for example from arteries supplying
digestive organs and/or from arteries supplying the kidneys; [0019]
Removal of peripheral vascular thrombus, for example from the legs;
[0020] Thrombus removal in surgically created arterial venous
fistulas for hemodialysis, for example using cross-catheter
thrombectomy; [0021] Removal of thrombus from synthetic dialysis
access grafts; [0022] Removal of thrombus from surgically created
synthetic or native vein bypass grafts (both harvested and
transplanted and in-situ vein grafts); [0023] Removal of thrombus
from a stent; [0024] Removal of stenosis from a stent or surgically
created fistula, dialysis access or vein bypass graft; [0025]
Isolated and uniform drug dispersion through aspiration ports,
e.g., during any of the above procedures; and [0026] Readily
customizable dosage (e.g., amplification and/or reduction) as a
function of real-time patient response to dispersed drugs.
As used herein, the term "vessel" refers to any circulatory
conduit, including but not limited to the aforementioned arteries,
veins, fistulas, grafts and stents.
[0027] FIG. 1 shows an aspiration thrombectomy catheter system 100.
System 100 includes a catheter 102 having a shaft 104. Shaft 104
has one or more proximal ends (not shown; see however FIG. 4) for
connection with one or more aspirators, and a distal end or section
106. As shown in FIG. 1, a distal end 106 has a plurality of
aspiration holes or ports 108, arranged in a plurality of sets 110.
As used herein, a set of ports indicates two or more ports grouped
in close proximity to one another. In one embodiment, distal
section 106 includes three sets 110A-110C having ports 108A-C,
respectively. Sets 110A-C may be arranged as distal set 110A,
middle set 110B and proximal set 110C, with respective ports 108A
(distal ports), 108B (middle ports) and 108C (proximal ports)
opening into one or more aspiration port channels/lumens.
[0028] Distal end/section 106 of catheter 102 is for example
inserted into the circulatory system on a needle and advanced to an
occlusion in a small, medium or large artery; therefore, system 100
may be sized for the desired use (as used herein, the terms
"occlusion" and "occluding" may refer to partial or complete
occlusion or occluding of a vessel). Distal section 106, and
optionally all or a portion of shaft 104, may be formed or coated
with a smooth or low-friction material such as Teflon, to
facilitate advancement of catheter 102. Further, catheter 102 may
be configured as a single or a dual aspiration catheter. When
catheter 102 is a single lumen aspiration catheter, an aspirator
attaches to the proximal end of the catheter. When catheter 102 is
a dual lumen aspiration catheter, shaft 104 branches to form two
proximal ends for connection with one or more aspirators.
[0029] Distal section 106 tapers proximally to distally from a
shoulder 116 to a tip 118. Tip 118 and/or a portion or all of
distal section 106 is for example formed or covered with a soft
material 107 to minimize vessel trauma, while part or all of shaft
104 is stiffer, to prevent kinking and facilitate advancement and
torqueability of catheter 102 within a vessel, such as a coronary
artery. Walls 120 of shaft 104, and optionally distal section 106,
for example include medically acceptable rigid polymers,
co-polymers or metals, such as plated or unplated stainless steel,
ELGILOY, platinum, a shape-memory alloy such as nitinol, or
combination thereof. In one embodiment, shaft 104 is a flexible
tube reinforced with one or more of the above polymers, co-polymers
and/or metals. Such reinforcement materials may be wired, braided
or coiled through or within shaft 104. Proximal-to-distal
flexibility may be increased by decreasing braid, coil or wire
density from proximal end/s to distal section 106 or tip 118. A
degree of reinforcement within distal section 106 for example
provides for a soft-tipped catheter 102 that resists twisting or
wrapping of tip 118 and/or distal section 106 during advancement or
rotation.
[0030] A wire 122 guides catheter 102 in a vessel, e.g., artery
200, FIG. 2. Catheter 102 may be a monorail or fixed wire catheter
(e.g., to allow for smaller diameters) or an over-the-wire
catheter. That is, wire 122 may be fixed with catheter tip 118,
with a set distance between tip 118 and a wire tip 124, or catheter
wire 122 may be a separate and unattached guide wire over which
catheter 102 rides.
[0031] In one embodiment, catheter 102 is an over-the-wire catheter
(for ease of illustration, the wire lumen of the catheter is not
shown). Over-the-wire catheters often ride in the center of
straight segments of an artery. As catheter 102 advances into an
arterial thrombus, vacuum forces provided at a certain magnitude
through ports 108A-C of tapering distal section 106 aspirate
thrombus, for example from the inside-out, via ports 108A, 108B and
108C. As distal section 106 encounters thrombus, vacuum forces
provided through ports 108A aspirate nearby thrombus. As thrombotic
material is generally cohesive, thrombus drawn into ports 108A
(and/or 108B, 108C) may pull additional thrombus into catheter 102.
Portions of thrombus that are not pulled into catheter 102 by
cohesion, e.g., portions that are too far away for aspiration
through ports 108A, may be drawn inward and closer to middle and/or
proximal ports 108B, 108C, by vacuum forces. As middle/proximal
ports 108B, 108C are positioned on wider portions of distal end 106
than ports 108A, aspiration is further facilitated as catheter 102
advances within the vessel and the distance between the vessel
walls and adhered thrombus, and ports 108A-108C successively
decreases. Increased proximity between remaining thrombus and ports
108B, 108C (e.g., provided both by inward pull through ports 108A
and the taper of distal section 106), for example allows the same
magnitude of vacuum force applied through distal ports 108A to
effectively aspirate remaining thrombus through ports 108B, 108C.
The effective surface area of thrombus aspirated is thereby
increased.
[0032] The tapering design of catheter 102 may further provide
increased thrombus-to-port contact or proximity over the prior art.
For example, prior art French catheters have essentially the same
diameter from proximal end to distal end. Aspiration ports of such
a prior art catheter are therefore located farther and farther from
remaining, unaspirated thrombus as the catheter advances in the
artery. A prior art catheter of essentially uniform diameter may be
unable to effectively remove intimal thrombus, whereas the tapering
design of catheter 102 provides increasing proximity between
distal-to-proximal aspiration ports and medial-to-intimal thrombus,
respectively, as catheter 102 advances therethrough. For example,
thrombus that is pushed or wedged away from distal aspiration
ports, such as ports 108 (e.g., pushed against the vessel wall by a
guide wire or fixed wire) may be aspirated via middle or proximal
ports 108B, 108C of catheter 102, whereas the prior art French
catheter may be unable to aspirate the displaced thrombus due to
the increased port-to-thrombus distance. In addition, Catheter
shoulder 116 may trap unaspirated thrombus, providing an extended
opportunity for aspiration through proximal ports 108C, e.g.,
during withdrawal of the catheter.
[0033] As shown in FIG. 1, catheter 102 has a proximal, or first
aspiration lumens 112 (hereinafter referred to as first lumens 112)
for aspiration through proximal ports 108C, and a middle-distal, or
second aspiration lumens 114 (hereinafter referred to as second
lumens 114) for aspiration through middle and distal ports 108B,
108A. Distal, middle and proximal ports 108A, 108B and 108C may be
sized, shaped and/or oriented differently from one another. FIG. 1
illustrates round distal ports 108A and elliptical middle and
proximal ports 108B, 108C of differing size and orientation.
However, other arrangements of port shapes and sizes are within the
scope hereof. For example, all of ports 108A-C may be elliptical,
with ports 108B, 108C of middle and proximal sets 110B, 110C
differing in orientation and/or size from distal ports 108A of set
110A. Alternately, ports of sets 110A-C may be similarly sized and
shaped, but differently oriented. Such variation in port size,
shape and/or orientation provide system 100 with a variety of
vortices and aspiration vector forces (directions and/or
magnitudes), for enhanced thrombus removal over prior art catheters
having fewer ports of essentially the same size, shape and
orientation. Sets of small ports for example enhance aspiration by
the Venturi effect, speeding flow of aspirated thrombus into
aspiration lumens 112/114, while larger port sets allow for
aspiration of larger thrombotic particles.
[0034] FIG. 2 shows system 100 in a section of artery 200 partially
occluded by thrombus 202. As wire 122 and catheter 102 advance
through thrombus 202, aspiration port sets 110A-110C successively
contact or come into proximity with innermost, middle and intimal
layers 204, 206, 208 of thrombus 202. Aspiration of innermost,
middle and intimal layers 204-208 may occur as illustrated by
directional aspiration arrows 210. Aspiration is facilitated by
increased thrombus-to-port contact or proximity provided by
catheter 102, thus facilitating removal of a greater thrombus
burden as the catheter advances through the vessel. The plurality
of ports 108A-C may also minimize plugging by organized or large
thrombus aggregates, as is seen with prior art end-hole catheters
or prior art catheters having fewer side ports.
[0035] The tapered design of catheter 102 may reduce distal
embolization of thrombus. For example, as a catheter advances
through thrombus, portions of the thrombus may be loosened, but not
aspirated. Prior art designs having substantially uniform catheter
or distal section diameter may not come into close enough proximity
to aspirate portions of thrombus clinging to the intima, for
example; however, this intimal thrombus may be loosened. The
loosened thrombus may break free and embolize in distal arterial
conduits. The tapering shaft of catheter 102 may reduce this distal
embolization because aspiration ports 108A-C come closer to the
vessel walls and any thrombus clinging thereto as the catheter
advances. Thrombus loosened during aspiration by ports 108A or 108B
is for example aspirated when ports 108C come into proximity or
contact with the loosened thrombus.
[0036] System 100 may also enhance thrombectomy when utilized in a
curved section of artery. Aspiration port sets 110A-C approach
thrombus on an arterial wall in closer and closer succession, due
to the tapering design of catheter 102. Thus, catheter 102 may thus
also remove thrombus 202 medially-to laterally in a curved section
of artery, as described herein above with respect to FIG. 2.
[0037] FIG. 3 is a flow chart illustrating a method 300 of
aspirating thrombus. An aspiration catheter, such as catheter 102
on wire 122, is inserted into an artery, in step 302. A tapering
distal end of the catheter, e.g., end 106 of catheter 102, is
advanced into the thrombus, in step 304. Thrombus is aspirated
through distal aspiration ports of the catheter and through an
aspiration lumens, for example ports 108A and second lumens 114, in
step 306. As the catheter is advanced further into the blocked
artery, middle ports such as ports 108B are brought into contact
with or proximal to unaspirated portions of the thrombus, in step
308. These portions are aspirated through an aspiration lumens,
such as second lumens 114, via the middle ports, in step 310.
Catheter 102 is advanced yet further into the blocked artery, such
that proximal ports of the catheter, e.g., ports 108C, are brought
into contact with or proximal to remaining portions of the thrombus
that were not aspirated through the middle ports, in step 312.
These remaining portions of thrombus are aspirated through an
aspiration lumens such as first lumens 112, via the proximal
aspiration ports, in step 314.
[0038] Continued aspiration during withdrawal of catheter system
100 may further enhance thrombus removal. Once the catheter has
traveled past thrombus, it may aspirate remaining thrombus during
withdrawal back through the artery. Catheter 102 may, for example,
trap remaining thrombus between the catheter shoulder 116 or shaft
104 and the arterial wall during an antegrade pass. The trapped
thrombus may then be aspirated through proximal-to-distal ports
108C-108A as the catheter is withdrawn. Accordingly, the catheter
is advanced until aspiration ports (such as port sets 110A-110C)
have passed through the thrombus, in step 316. The catheter is
withdrawn back through any remaining thrombus, in step 318. The
proximal, middle and distal aspiration ports aspirate remaining
thrombus, in step 320.
[0039] Steps 302-320 need not be performed in the order described
in connection with FIG. 3. For example, thrombus may be aspirated
through aspiration ports while catheter 102 is simultaneously and
continually advanced through a thrombus. Also, not all of steps
302-320 need necessarily be performed for effective thrombus
removal. For example, if thrombus is completely removed during an
antegrade pass therethrough, it may not be necessary to aspirate
while withdrawing catheter 102.
[0040] The proximal end or ends of catheter 102 are connectable
with an infusion device, such as a syringe, allowing use of
thrombectomy catheter system 100 in thrombolysis, for example to
lyse deep and superficial venous thrombi, or in cross-catheter
thrombolysis in surgically created arterial venous fistulas. A
lytic agent or agents, e.g., Reteplase or Alteplase, is infused via
aspiration lumens 112 and/or 114, for precise and uniform
dispersion through ports 108A-108C. FIG. 4 depicts an aspiration
thrombectomy catheter system 400 for removing thrombus from
partially occluded vessel 200. Vessel 200 is for example blocked by
thrombus 202 as described above with respect to FIG. 2. Catheter
102 is inserted into vessel 200 and advanced to thrombus 202.
Catheter 102 may again be an over-the-wire or a fixed wire
catheter. In one embodiment, catheter 102 is a fixed wire or
monorail catheter 102, with wire 122 securely formed with catheter
tip 118 (see FIG. 1). Wire 122 guides distal section 106 to and/or
partially through thrombus 202, where aspiration may be applied as
previously described.
[0041] Optionally or additionally, catheter 102 connects to a drug
dispenser or drug delivery apparatus, such as a gravity flow
system, an automated or manually operable pump, a syringe or other
intravenous drug dispenser. Such a dispenser is illustratively
shown in FIG. 4 as a syringe 402 (not to scale). Once distal
section 106 is positioned as desired, relative to the thrombus,
lytic agents are for example delivered through lumens 112 and/or
114 and out one or more of port sets 110A-110C, as indicated by
dispersion arrows 404. System 400 thus provides isolated drug
delivery with uniform dispersion from each port 108A-108C, at the
occluded/thrombotic area. Alternately, system 400 provides targeted
drug delivery via selected ports or port sets 108, 110, while
remaining ports or port sets may be used in aspirating loosened
thrombus, delivering complementary lytic agents, e.g., in sequence,
or reducing dosage in the event of overdose or adverse patient
reaction.
[0042] In one embodiment, lumens 114 connects with or extends into
tubing 406 which in turn connects to syringe 402. Tubing 406 for
example conducts a thrombolytic, antibiotic or otherwise
therapeutic drug from syringe 402, through lumens 114, to proximal
ports 108C. Should an adverse reaction such as bleeding occur,
dosage may be quickly reduced by aspirating the delivered drug back
through proximal ports 108C, for example by drawing back on syringe
402. It will be understood that lumens 112 may likewise connect,
via tubing 408, to a drug or lytic agent dispenser or delivery
system such as a second syringe, to facilitate delivery of desired
drug combinations or sequences, e.g., via middle and distal ports
108B, 108A. Likewise, one of lumens 112, 114 may connect via tubing
406, 408 with an aspirator while the other of lumens 112, 114
connects with the drug dispenser. In the case of an adverse drug
reaction, dosage may be quickly reduced by aspirating drugs
released via one set of ports 110 back through another set of ports
110. For example, lytic drugs delivered to lumens 114 and dispersed
through proximal ports 108C may be aspirated back through distal
and middle ports 108A, 108B, in communication with lumens 112.
Aspiration thrombectomy catheter system 400 may also be used to
alternately or simultaneously disperse lytic agents and
remove/aspire thrombus loosened by the lytic agents. Likewise, a
combination of ports 108A-C may be used in aspiration or drug
dispersion.
[0043] FIG. 5 is a flowchart illustrating one method 500 for
removing thrombus with an aspiration thrombectomy catheter. In step
502 an aspiration thrombectomy catheter is inserted into a vessel.
In step 504, the catheter is advanced to a thrombus. In one example
of steps 502, 504, catheter 102 is inserted into an artery and
advanced until distal section 106 contacts or is proximate the
thrombus. When the catheter is in position, e.g., distal section
106 is proximate or contacting the thrombus, drugs are dispersed,
in step 506. In one example of step 506, drugs are applied to
tubing 406 via a drug dispenser. Drugs travel into lumen 112 and
out of ports 108C.
[0044] The patient undergoing method 500 is monitored, in step 508,
e.g., for bleeding or other adverse reactions to lytic drugs. If
(decision 510) an adverse reaction occurs, released drugs are
aspirated, in step 516. In one example of step 516, upon
determining that an overdose or adverse reaction has occurred,
released lytic drugs are aspirated back into catheter 102 via
distal and medial aspiration ports 108A, 108C. Lumen 114, in
contact with ports 108A, 108C, connects with tubing 408 which in
turn connects with an aspirator, such as a syringe. The aspirator
or syringe is activated to "vacuum" the lytic drugs from the
vessel.
[0045] Dotted box 517 indicates optional steps during or in
combination with aspiration step 516. In optional step 518, the
catheter is advanced until all aspiration ports have passed through
the thrombus. In step 520, the catheter is withdrawn through the
thrombotic area. Steps 518, 520 may be repeated as desired to
facilitate aspiration of a thrombolytic agent that has dispersed
within the vessel, or to aspirate thrombus loosened by the
thrombolytic agent, as described below.
[0046] Returning to method 500, if (decision 510) there is no
adverse reaction or overdose and if (decision 512) drug delivery is
complete, method 500 continues with decision 514. If (decision 514)
thrombus is to be aspirated, aspiration commences in step 516.
Optional steps 518, 520 may be repeated until the desired or
maximum amount of thrombus has been removed from the vessel. In one
example of steps 516-520, where aspiration is desirable, tubing 404
is disconnected from the aforementioned drug dispenser or delivery
system, e.g., syringe 402, FIG. 4, is switched to an aspiration
mode. As catheter 102 is advanced through (step 518) and withdrawn
from (step 520) the thrombotic area, vacuum forces are applied via
aspiration ports 108A, 108B and 108C until the thrombus is
satisfactorily removed from the vessel walls. Once the thrombus is
satisfactorily aspirated, the catheter is removed, in step 522. In
one example of step 522, catheter 102 is withdrawn from the body of
a patient undergoing method 500.
[0047] In one example of steps 506-522, a thrombolytic agent is
dispersed via distal port set 110A, FIG. 1. As noted, distal port
set 110A may open into a lumens independent of the lumen or lumens
associated with middle and proximal port sets 110A, 110B. If
desired, a second thrombolytic agent is dispersed via middle or
proximal port sets 110A, 110B. The second thrombolytic agent may be
dispersed synchronously with the agent dispersed via distal ports
108A, or the two agents may be alternated or pulsed to achieve a
desired drug combination or amount proximate the thrombus.
[0048] When drug delivery, or a drug delivery cycle, is complete,
thrombus loosened by drug therapy is for example aspirated as
described above, through one or more of port sets 110A-110C.
Catheter 102 may be advanced and withdrawn back and forth through
the thrombotic region during (or interspersed with) aspiration), to
enhance thrombus removal. Catheter 102 may likewise be rotated such
that port sets 110A-C along distal section 106 vacuum the entire
inner circumference of the vessel. When thrombus is satisfactorily
removed, catheter 102 is withdrawn from the patient's body, step
522.
[0049] Although not shown in FIG. 5 (for ease of illustration), it
will be recognized that drug delivery step 506 and aspiration steps
516-520 may be repeated as desired prior to removal of catheter 102
(step 522). For example, where decision 516 pertains to one of
multiple drug delivery cycles, method 500 may move from aspiration
steps 516, 518 or 520 back to drug dispersion at step 506.
[0050] Changes may be made in the above systems and structures
without departing from the scope thereof. It should thus be noted
that the matter contained in the above description and/or shown in
the accompanying drawings should be interpreted as illustrative and
not in a limiting sense. The following claims are intended to cover
generic and specific features described herein, as well as all
statements of the scope of the present system and structures,
which, as a matter of language, might be said to fall
therebetween.
* * * * *