U.S. patent application number 14/336898 was filed with the patent office on 2014-11-13 for methods and systems for performing thrombectomy procedures.
The applicant listed for this patent is Donald K. Jones, Vladimir Mitelberg. Invention is credited to Donald K. Jones, Vladimir Mitelberg.
Application Number | 20140336691 14/336898 |
Document ID | / |
Family ID | 47713179 |
Filed Date | 2014-11-13 |
United States Patent
Application |
20140336691 |
Kind Code |
A1 |
Jones; Donald K. ; et
al. |
November 13, 2014 |
METHODS AND SYSTEMS FOR PERFORMING THROMBECTOMY PROCEDURES
Abstract
Devices, systems and methods are provided for performing
intra-lumenal medical procedures in a desired area of the body.
Thrombectomy systems and methods of performing medical procedures
to re-establish the intravascular flow of blood are provided for
the treatment of ischemic disease states.
Inventors: |
Jones; Donald K.; (Dripping
Springs, TX) ; Mitelberg; Vladimir; (Austin,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Jones; Donald K.
Mitelberg; Vladimir |
Dripping Springs
Austin |
TX
TX |
US
US |
|
|
Family ID: |
47713179 |
Appl. No.: |
14/336898 |
Filed: |
July 21, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13589133 |
Aug 18, 2012 |
8784442 |
|
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14336898 |
|
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|
61525362 |
Aug 19, 2011 |
|
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Current U.S.
Class: |
606/194 |
Current CPC
Class: |
A61B 17/22032 20130101;
A61M 25/1002 20130101 |
Class at
Publication: |
606/194 |
International
Class: |
A61B 17/22 20060101
A61B017/22; A61M 25/10 20060101 A61M025/10 |
Claims
1. A thrombus removal system for use within the vasculature of a
mammal comprising: an elongate tubular flexible member having
proximal and distal ends and a lumen extending therethrough; a
balloon member having proximal and distal ends, a longitudinally
extending portion and a radially expanding retrieval portion where
said proximal end of said balloon member is secured to the distal
end of said flexible member, an elongate flexible tether member
slidably positioned within the lumen of said flexible member and
having proximal and distal ends wherein the distal end of said
tether member is coupled to the distal end of said balloon member,
said balloon member being operable by fluid pressure between a
first configuration where said balloon member is collapsed and the
distal end of said balloon member is everted and positioned within
the lumen of said flexible member proximal to the proximal end of
said balloon member and a second configuration where said balloon
member is inflated and the distal end of said balloon member
extends distal to the distal end of said flexible member.
2. The thrombus removal system of claim 1 wherein said retrieval
portion is positioned distal to said extending portion.
3. The thrombus removal system of claim 1 wherein said balloon
member includes a non-compliant material.
4. The thrombus removal system of claim 1 wherein said balloon
member includes a compliant material.
5. The thrombus removal system of claim 1 wherein said balloon
member comprises a metallic thin film.
6. The thrombus removal system of claim 1 wherein the diameter of
said extending portion is smaller than the diameter of said
flexible member.
7. The thrombus removal system of claim 1 wherein the diameter of
said extending portion is larger than the diameter of said flexible
member.
8. The thrombus removal system of claim 1 wherein the diameter of
said retrieval portion is larger than the diameter of said
extending portion.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Prov. Ser.
61/525,362 filed Aug. 19, 2011 which is hereby incorporated by
reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] The field of intralumenal therapy for the treatment of
vascular disease states has for many years focused on the use of
many different types of therapeutic devices. While it is currently
unforeseeable that one particular device will be suitable to treat
all types of vascular disease states, it may however be possible to
reduce the number of devices used for some disease states while at
the same time improve patient outcomes at a reduced cost. To
identify potential opportunities to improve the efficiency and
efficacy of the devices and procedures it is important for one to
understand the state of the art relative to some of the more common
disease states.
[0003] For instance, one aspect of cerebrovascular disease in which
the wall of a blood vessel becomes weakened. Under cerebral flow
conditions the weakened vessel wall forms a bulge or aneurysm which
can lead to symptomatic neurological deficits or ultimately a
hemorrhagic stroke when ruptured. Once diagnosed a small number of
these aneurysms are treatable from an endovascular approach using
various embolization devices. These embolization devices include
detachable balloons, coils, polymerizing liquids, gels, foams,
stents and combinations thereof.
[0004] The most widely used embolization devices are detachable
embolization coils. These coils are generally made from
biologically inert platinum alloys. To treat an aneurysm, the coils
are navigated to the treatment site under fluoroscopic
visualization and carefully positioned within the dome of an
aneurysm using sophisticated, expensive delivery systems. Typical
procedures require the positioning and deployment of multiple
embolization coils which are then packed to a sufficient density as
to provide a mechanical impediment to flow impingement on the
fragile diseased vessel wall. Some of these bare embolization coil
systems have been describe in U.S. Pat. No. 5,108,407 to Geremia,
et al., entitled, "Method And Apparatus For Placement Of An Embolic
Coil" and U.S. Pat. No. 5,122,136 to Guglielmi, et al., entitled,
"Endovascular Electrolytically Detachable Guidewire Tip For The
Electroformation Of Thrombus In Arteries, Veins, Aneurysms,
Vascular Malformations And Arteriovenous Fistulas." These patents
disclose devices for delivering embolic coils at predetermined
positions within vessels of the human body in order to treat
aneurysms, or alternatively, to occlude the blood vessel at a
particular location. Many of these systems, depending on the
particular location and geometry of the aneurysm, have been used to
treat aneurysms with various levels of success. One drawback
associated with the use of bare embolization coils relates to the
inability to adequately pack or fill the aneurysm due to the
geometry of the coils which can lead to long term recanalization of
the aneurysm with increased risk of rupture.
[0005] Some improvements to bare embolization coils have included
the incorporation of expandable foams, bioactive materials and
hydrogel technology as described in the following U.S. Pat. No.
6,723,108 to Jones, et al., entitled, "Foam Matrix Embolization
Device", U.S. Pat. No. 6,423,085 to Murayama, et al., entitled,
"Biodegradable Polymer Coils for Intraluminal Implants" and U.S.
Pat. No. 6,238,403 to Greene, et al., entitled, "Filamentous
Embolic Device with Expansible Elements." While some of these
improved embolization coils have been moderately successful in
preventing or reducing the rupture and re-rupture rate of some
aneurysms, the devices have their own drawbacks. For instance, in
the case of bioactive coils, the materials eliciting the biological
healing response are somewhat difficult to integrate with the coil
structure or have mechanical properties incompatible with those of
the coil making the devices difficult to accurately position within
the aneurysm. In the case of some expandable foam and hydrogel
technology, the expansion of the foam or hydrogel is accomplished
due to an interaction of the foam or hydrogel with the surrounding
blood environment. This expansion may be immediate or time delayed
but is generally, at some point, out of the control of the
physician. With a time delayed response the physician may find that
coils which were initially placed accurately and detached become
dislodged during the expansion process leading to subsequent
complications.
[0006] For many aneurysms, such as wide necked or fusiform
aneurysms the geometry is not suitable for coiling alone. To
somewhat expand the use of embolization coils in treating some wide
necked aneurysms, stent like scaffolds have been developed to
provide support for coils. These types of stent like scaffolds for
use in the treatment of aneurysms have been described in U.S. Pat.
No. 6,605,111 to Bose et al., entitled, "Endovascular Thin Film
Devices and Methods for Treating Strokes" and U.S. Pat. No.
6,673,106 to Mitelberg, et al., entitled, "Intravascular Stent
Device". While these stent like devices have broadened the types of
aneurysms amenable to embolization therapy, utilization of these
devices in conjunction with embolization devices is technically
more complex for the physician, may involve more risk to the
patient and have a substantial cost increase for the healthcare
system.
[0007] To further expand the types of aneurysm suitable for
interventional radiological treatment, improved stent like devices
have been disclosed in U.S. Pat. No. 5,824,053 to Khosravi et al.,
entitled, "Helical Mesh Endoprosthesis and Method", U.S. Pat. No.
5,951,599 to McCrory, entitled, "Occlusion System for the
Endovascular Treatment of and Aneurysm" and U.S. Pat. No. 6,063,111
to Hieshima et al., entitled, "Stent Aneurysm Treatment System and
Method." When placed across the neck of an aneurysm the proposed
stent like devices purport to have a sufficient density through the
wall of the device to reduce flow in the aneurysm allowing the
aneurysm to clot, while at the same time having a low enough
density through the wall to allow small perforator vessels adjacent
to the aneurysm to remain patent. Stent devices of this nature
while having the potential to reduce treatment costs have not been
realized commercially due to the difficulty in manufacturing,
reliability in delivering the devices to the treatment site and an
inability to properly position the denser portion of the stent
device accurately over the neck of the aneurysm.
[0008] Another cerebrovascular disease state is ischemia resulting
from reduced or blocked arterial blood flow. The arterial blockage
may be due to thrombus, plaque, foreign objects or a combination
thereof. Generally, soft thrombus created elsewhere in the body
(for example due to atrial fibrillation) that lodges in the distal
cerebrovasculature may be disrupted or dissolved using mechanical
devices and or thrombolytic drugs. While guidewires are typically
used to disrupt the thrombus, some sophisticated thrombectomy
devices have been proposed. For instance U.S. Pat. No. 4,762,130 to
Fogarty et al., entitled, "Catheter with Corkscrew-Like Balloon",
U.S. Pat. No. 4,998,919 of Schepp-Pesh et al., entitled,
"Thrombectomy Apparatus", U.S. Pat. No. 5,417,703 to Brown et al.,
entitled "Thrombectomy Devices and Methods of Using Same", and U.S.
Pat. No. 6,663,650 to Sepetka et al., entitiled, "Systems, Methods
and Devices for Removing Obstructions from a Blood Vessel"
discloses devices such as catheter based corkscrew balloons,
baskets or filter wires and helical coiled retrievers. Commercial
and prototype versions of these devices have shown only marginal
improvements over guidewires due to an inability to adequately
grasp the thrombus or to gain vascular access distal to the
thrombus (i.e. distal advancement of the device pushes the thrombus
distally).
[0009] Plaque buildup within the lumen of the vessel, known as
atherosclerotic disease, is not generally responsive to
thrombolytics or mechanical disruption using guidewires. The
approach to the treatment of neurovascular atherosclerotic disease
has been to use modified technology developed for the treatment of
cardiovascular atherosclerotic disease, such as balloons and
stents, to expand the vessel at the site of the lesion to
re-establish blood flow. For instance, U.S. Pat. No. 4,768,507 to
Fischell et al., entitled, "Intravascular Stent and Percutaneous
Insertion Catheter System for the Dilation of an Arterial Stenosis
and the Prevention of Arterial Restenosis" discloses a system used
for placing a coil spring stent into a vessel for the purposes of
enhancing luminal dilation, preventing arterial restenosis and
preventing vessel blockage resulting from intimal dissection
following balloon and other methods of angioplasty. The coil spring
stent is placed into spiral grooves on an insertion catheter. A
back groove of the insertion catheter contains the most proximal
coil of the coil spring stent which is prevented from springing
radially outward by a flange. The coil spring stent is deployed
when an outer cylinder is moved proximally allowing the stent to
expand. Other stent systems include those disclosed in U.S. Pat.
No. 4,512,338 to Balko, et al., entitled, "Process for Restoring
Patency to Body Vessels", U.S. Pat. No. 5,354,309 to Schnepp Pesch
et al., entitled, "Apparatus for Widening a Body Cavity" and U.S.
Pat. No. 6,833,003 to Jones et al., entitled, "Expandable Stent and
Delivery System". While the aforementioned devices may have the
ability to access the cerebrovasculature, they lack sufficient
structural coverage of the lesion to achieve the desired patency of
the vessel without the use of a balloon device.
SUMMARY OF THE INVENTION
[0010] In accordance with one aspect of the present invention there
is provided a medical device system for restoring patency of a body
lumen in a mammal. The thrombectomy system includes a thrombectomy
catheter having proximal and distal ends including a proximal hub,
a balloon member having proximal and distal ends, including a
longitudinally extending portion and a radially expanding retrieval
portion, where the balloon member proximal end is coupled to the
catheter distal end and an inflation source member coupled to the
proximal hub. The extending portion of the balloon member has an
inflated diameter which is smaller than the inflated diameter of
the retrieval portion. An elongate tether member is positioned
within the catheter lumen and preferably coupled to the balloon
member distal end. The tether member extends proximally through the
thrombectomy catheter lumen and proximal to the proximal end of the
hub assembly.
[0011] For delivery to a desired target site, the balloon member is
everted and positioned within the lumen of the thrombectomy
catheter such that the distal end of the balloon member is proximal
to the distal end of the catheter. The balloon member of the
delivery catheter is typically formed of a thin walled polymeric
tube in which the distal end of the tube has been enlarged and
sealed and the proximal end of the balloon member is coupled to the
distal end of the catheter such that the lumen of the catheter is
in fluid communication with the interior surface of the balloon.
The balloon member is preferably formed of a high strength
non-compliant polymeric material such as nylon, polyester and
others, however, metallic materials such as thin-film nitinol or
other alloys may also be suitable. The inflation source member is
coupled to the proximal end of the catheter and used to apply fluid
pressure to the lumen of catheter at a level sufficient to cause
the balloon member extending portion to extend longitudinally from
the catheter lumen and subsequently deploy and expand the capture
portion of the balloon member. The preferred fluids include liquids
such as saline although gases such as carbon dioxide gas may be
suitable for some system configurations. The amount of fluid
pressure required to inflate the balloon member is related to the
friction force between the balloon member inner surface and the
interior wall of the catheter lumen. The inflation source member
preferably takes the form of a syringe (threaded or non-threaded),
however other inflation sources such as a pressurized fluid source
having a valve assembly or a controllable fluid delivery pump are
also suitable.
[0012] In accordance with another aspect of the present invention
there is provided a balloon member for a thrombectomy system having
a longitudinally extending portion formed of a non-compliant
material and a radially expanding retrieval portion formed of a
compliant material. Suitable compliant materials include polymeric
elastomers such as silicones, urethanes, polyether block amide
(PEBAX) and synthetic rubbers including polyisoprene, nitrile,
chloroprene and ethylene propylene diene rubber.
[0013] In accordance with another aspect of the present invention
there is provided a balloon member for a thrombectomy system having
a longitudinally extending portion and a radially expanding
retrieval portion coupled to a thrombectomy catheter where the
inflated diameter of the extending portion is larger than the outer
diameter of the thrombectomy catheter.
[0014] In accordance with another aspect of the present invention
there is provided a balloon member for a thrombectomy system having
a longitudinally extending portion and a radially expanding
retrieval portion coupled to a thrombectomy catheter where the
inflated diameter of the extending portion is smaller than the
outer diameter of the thrombectomy catheter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a partial cross-sectional view of a thrombectomy
system according to an embodiment of the present invention.
[0016] FIG. 2A is an enlarged partial cross-sectional view of the
distal end of the thrombectomy system according to an embodiment of
the present invention.
[0017] FIG. 2B is an enlarged partial cross-sectional view of the
distal end of a thrombectomy system according to another embodiment
of the present invention.
[0018] FIG. 3A is a partial cross sectional view of a deployed
thrombectomy system according to an embodiment of the present
invention.
[0019] FIG. 3B is a partial cross sectional view of a deployed
thrombectomy system according to another embodiment of the present
invention.
[0020] FIG. 3C is a partial cross sectional view of a deployed
thrombectomy system according to yet another embodiment of the
present invention.
[0021] FIGS. 4A through 4F partial cross-sectional views
illustrating a method of delivering and deploying a thrombectomy
system within a vessel at a target site according to an embodiment
of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Methods and systems for capturing and removing an embolus or
thrombus from an area of the body are herein described. While the
terms "thrombectomy" and "thrombus" generally refer to removal of a
specific type of embolus, the usage herein should be considered
more broadly to include the removal additional types of emboli such
as plaque, solid tissue fragments, clots and foreign objects that
may block or restrict the normal flow of blood within the
vasculature. FIG. 1 illustrates a thrombectomy system 10 according
to an embodiment of the present invention. Thrombectomy system 10
includes an elongate catheter 20 having distal end 22, proximal end
24 including hub member 26 and lumen 28 extending therethrough.
Coupled to distal end 22 of catheter 20 is balloon member 30. An
elongate flexible tether member 32 coupled to balloon member 30 is
slidably positioned within lumen 28 and extends through hub member
26. Balloon member 30 has a delivery configuration in which it is
everted and positioned within lumen 28 of catheter 20 at distal end
22. Proximal end 24 of catheter 20 is coupled to hub member 26
which includes sealable valve 34 and inflation port 36.
[0023] A partial cross sectional view of distal end 22 of catheter
20 is shown in FIG. 2A. While not shown, the construction of
catheter 20 may utilize known catheter technologies that
incorporate braiding and or coiling using metallic or non-metallic
reinforcing filamentous materials to provide high strength while
maintaining catheter flexibility. The incorporation of lubricious
hydrophilic and or hydrophobic materials on the inner and or outer
surface of the catheter is considered to be within the scope of
known catheter construction techniques and suitable for use in a
thrombectomy system according to embodiments of the present
invention. Retaining member 38 is used to affix proximal end 40 of
balloon member 30 to catheter distal end 22. The inner diameter of
balloon member proximal end 40 is slightly larger than the outer
diameter of catheter distal end 22 thereby allowing distal end 22
to be inserted within proximal end 40. Retaining member 38 is shown
as a flexible filament (preferably polymeric) wound around proximal
end 40 and catheter distal end 22 securing balloon member 30 to
catheter 20. Balloon member proximal end 40 and distal end 22 may
be secured using other means such as heat fusing, multifilament
winds, ultrasonic welding and or gluing to insure a good bond and
seal. The distal end 42 of balloon member 30 is completely sealed
using any of the aforementioned techniques and positioned everted
within catheter lumen 28 proximal to balloon member proximal end
40. Balloon member 30 includes a proximally located longitudinally
extending portion 44 and a distally located radially expanding
retrieval portion 50.
[0024] FIG. 2B illustrates an alternate embodiment of the present
invention showing thrombectomy system 110. Thrombectomy system 110
includes an elongate catheter 120 having delivery portion 122 and
guidewire portion 124. Guidewire portion 124 having through lumen
126 extends proximally to the proximal end of catheter 120.
Alternatively guidewire portion 124 and lumen 126 may extend
proximally only a portion of the length of catheter 120 and have a
configuration suitable for use as a "rapid exchange" system
allowing system 110 to reach a target site over a guidewire that
has already been positioned at the target site. Delivery portion
122 includes lumen 128 extending from the proximal end to the
distal end of catheter 120. An elongate flexible tether member 132
is coupled to balloon member 130 and extends proximally through
catheter lumen 128. Securing member 138, shown as a wound filament,
affixes balloon member proximal end 140 to the distal end of
delivery portion 122. Balloon member proximal end 140 and the
distal end of delivery portion 122 may be secured using other means
such as heat fusing, ultrasonic welding, multifilament winds and or
gluing to insure a good bond and seal. The distal end 142 of
balloon member 130 is completed sealed using any of the
aforementioned techniques and positioned everted within catheter
lumen 128 proximal to proximal end 140.
[0025] FIG. 3A shows an enlarged partial cross sectional view of
the distal portion of thrombectomy system 10 including catheter 20
having distal end 22. Balloon member 30 is shown in an inflated
configuration longitudinally extending distal to catheter distal
end 22. In this configuration, balloon member distal end 42 is
positioned distal to balloon member proximal end 40. Extending
portion 44 of balloon member 30 has a diameter slightly smaller
than catheter 20 and ranges from about 0.4 to about 0.99 times the
diameter of catheter 20 and has a preferred range from about 0.5 to
0.9 times the diameter of catheter 20. Typically, the expanded
diameter of retrieval portion 50 is slightly larger than the inner
diameter of the vessel at a target site to insure that the
retrieval portion stays in contact with the vessel wall during the
thrombus removal process. Balloon member 30 is typically formed of
a thin walled polymeric tube having a proximal non-compliant
portion defining extending portion 44 coupled to a distal compliant
portion defining retrieval portion 50 that has been sealed. The
tube portions may be joined using known joining techniques such as,
thermal fusing, ultrasonic welding, gluing, and solvent bonding.
Suitable materials for the extending portion of balloon member 30
include high strength non-compliant polymeric material such as
nylon, polyester and others, however, metallic materials such as
thin-film nitinol or other alloys may also be suitable. Suitable
materials for the retrieval portion 50 of balloon member 30
includes compliant polymeric elastomers such as silicones,
urethanes, polyether block amide (PEBAX) and synthetic rubbers
including polyisoprene, nitrile, chloroprene and ethylene propylene
diene rubber.
[0026] FIGS. 3B and 3C are partial cross sectional views of
thrombectomy systems according to alternate embodiments of the
present invention that illustrate different configurations of
inflated extended balloon members. FIG. 3B shows an enlarged
partial cross sectional view of the distal portion of thrombectomy
system 210 including catheter 220 having distal end 222. Balloon
member 230 is shown in an inflated configuration longitudinally
extending distal to catheter distal end 222. In this configuration,
balloon member distal end 242 is positioned distal to balloon
member proximal end 240. Extending portion 244 of balloon member
230 has a diameter slightly smaller than catheter 220 and ranges
from about 0.4 to about 0.99 times the diameter of catheter 220 and
has a preferred range from about 0.5 to 0.9 times the diameter of
catheter 220. Typically, the expanded diameter of retrieval portion
250 is slightly larger than the inner diameter of the vessel at a
target site to insure that the retrieval portion stays in contact
with the vessel wall during the thrombus removal process. Balloon
member 230 is typically formed of a thin walled polymeric tube in
which the distal end of the tube has been enlarged and sealed.
Balloon member 230 is preferably formed of a high strength
non-compliant polymeric material such as nylon, polyester and
others, however, metallic materials such as thin-film nitinol or
other alloys may also be suitable.
[0027] FIG. 3C shows an enlarged partial cross sectional view of
the distal portion of thrombectomy system 310. Balloon member 330
is shown in an inflated configuration longitudinally extending
distal to catheter distal end 322. In this configuration, balloon
member distal end 342 and retrieval portion are positioned distal
to balloon member proximal end 340 and extending portion 344.
Extending portion 344 of balloon member 330 has a diameter slightly
larger than catheter 320 and ranges from about 1.0 to about 1.5
times the diameter of catheter 320 and has a preferred range from
about 1.05 to 1.3 times the diameter of catheter 320. Typically,
the expanded diameter of retrieval portion 350 is slightly larger
than the inner diameter of the vessel at a target site to insure
that the retrieval portion stays in contact with the vessel wall
during the thrombus removal process. Balloon member 330 is
typically formed of a thin walled polymeric tube in which the
distal end of the tube has been enlarged and sealed. Balloon member
330 is preferably formed of a high strength non-compliant polymeric
material such as nylon, polyester and others, however, metallic
materials such as thin-film nitinol or other alloys may also be
suitable.
[0028] FIGS. 4A through 4F illustrate a method of deploying a
retrieval assembly at a target site within a body lumen according
to one embodiment of the present invention. The thrombectomy system
10 is positioned within a vessel 400. Catheter distal end 22
including extendable balloon member 30 are positioned at a target
site adjacent to thrombus 410. An inflation source member (not
shown) is coupled to the proximal end of the catheter 20 and used
to apply fluid pressure to the lumen of catheter. The inflation
source member preferably takes the form of a syringe (threaded or
non-threaded), however other inflation sources such as a
pressurized fluid source having a valve assembly or a controllable
fluid delivery pump are also suitable. The preferred fluids include
liquids such as saline and radiopaque contrasts solutions however
gases such as carbon dioxide gas may be suitable for some system
configurations. As the applied fluid pressure increases to a
sufficient level, balloon member 30 begins to extend longitudinally
from the catheter lumen. As balloon member 30 extends
longitudinally from catheter 20, leading edge 415 of the balloon
member 30 may encounter thrombus 410. While shown as large
particle, thrombus 410 may have a varied composition that could
comprise organized clot, tissue, plaque soft clot or even foreign
objects. Dependant somewhat upon the size and composition of
thrombus 410 balloon member 30 may extend longitudinally through a
soft and compliant thrombus or between the inner vessel wall and a
more rigid thrombus. Leading edge 415 of balloon member 30 is well
suited to extend longitudinally between the more rigid thrombus and
the vessel wall without perforating the vessel. With continued
application of fluid pressure, balloon member 30 continues to
extend longitudinally until retrieval 50 is deployed and positioned
distal to thrombus 410. Once retrieval portion 50 is appropriately
deployed, application of additional fluid pressure is unnecessary.
As shown in FIG. 4E, thrombectomy system 10 including tether member
32 is pulled proximally causing retrieval portion 50 to engage the
distal side of thrombus 410. Tether member 32 ensures that
sufficient retraction force is applied directly to retrieval
portion 50 to move thrombus 410. Thrombectomy system 10 with
thrombus 410 may then be removed from the body. Alternatively,
thrombectomy system 10 with captured thrombus 410 may be pulled
proximally within larger catheter 420 having distal end 422 and
lumen 424. Suction may then be applied to lumen 424 thus aiding
retention of thrombus 410 during removal or to fragment and remove
thrombus 410.
[0029] Novel devices, systems and methods have been disclosed to
re-establish flow in a lumen of mammal. Although preferred
embodiments of the invention have been described, it should be
understood that various modifications including the substitution of
elements or components which perform substantially the same
function in the same way to achieve substantially the same result
may be made by those skilled in the art without departing from the
scope of the claims which follow.
* * * * *