U.S. patent application number 12/013154 was filed with the patent office on 2008-05-08 for self-expanding, pseudo-braided intravascular device.
This patent application is currently assigned to ENDOSVASCULAR TECHNOLOGIES, INC.. Invention is credited to Peter S. Brown, David Hancock, Larry Voss.
Application Number | 20080109063 12/013154 |
Document ID | / |
Family ID | 28792257 |
Filed Date | 2008-05-08 |
United States Patent
Application |
20080109063 |
Kind Code |
A1 |
Hancock; David ; et
al. |
May 8, 2008 |
SELF-EXPANDING, PSEUDO-BRAIDED INTRAVASCULAR DEVICE
Abstract
A self-expanding, pseudo-braided device embodying a high
expansion ratio and flexibility as well as comformability and
improved radial force. The pseudo-braided device is particularly
suited for advancement through and deployment within highly
tortuous and very distal vasculature. Various forms of the
pseudo-braided device are adapted for the repair of aneurysms and
stenoses as well as for use in thrombectomies and embolic
protection therapy.
Inventors: |
Hancock; David; (San
Francisco, CA) ; Brown; Peter S.; (Palo Alto, CA)
; Voss; Larry; (San Jose, CA) |
Correspondence
Address: |
FULWIDER PATTON, LLP (ABBOTT)
6060 CENTER DRIVE
10TH FLOOR
LOS ANGELES
CA
90045
US
|
Assignee: |
ENDOSVASCULAR TECHNOLOGIES,
INC.
1525 O'Brien Drive
Menlo Park
CA
94025-1436
|
Family ID: |
28792257 |
Appl. No.: |
12/013154 |
Filed: |
January 11, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10650321 |
Aug 27, 2003 |
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12013154 |
Jan 11, 2008 |
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09532261 |
Mar 22, 2000 |
6632241 |
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10650321 |
Aug 27, 2003 |
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Current U.S.
Class: |
623/1.12 |
Current CPC
Class: |
A61B 2017/1205 20130101;
A61F 2/90 20130101; A61B 17/12022 20130101; D10B 2509/06 20130101;
D04C 3/48 20130101; A61B 17/12118 20130101; D04C 1/06 20130101;
D04C 7/00 20130101; A61B 17/12172 20130101; A61B 17/1214
20130101 |
Class at
Publication: |
623/001.12 |
International
Class: |
A61F 2/06 20060101
A61F002/06 |
Claims
1-27. (canceled)
28. A device for use in embolic protection, comprising: an elongate
filament configured into a pseudo-braided pattern and formed to
define a body having a generally tubular inferior portion and a
generally conical superior portion; and said proximal and distal
portions each being defined by a plurality of endless reversals of
direction of said filament.
29. The device of claim 28, further comprising: an elongate wire
having proximal and distal end portions; and said body configured
about said elongate wire, said generally conical superior portion
being affixed to said elongate wire.
30. The device of claim 29, further comprising a delivery catheter,
said delivery catheter having a generally tubular portion that is
adapted for receiving said body and said elongate wire.
31. The device of claim 29, further comprising a plurality of
loops, a first end of said loops engaging said inferior portion of
said body and a second end of said loops being affixed to said
elongate wire.
32. The device of claim 31, further comprising a collar, said
collar being joined to said plurality of loops.
33. The device of claim 32, wherein said collar is configured to
slide longitudinally along said elongate wire.
34. The device of claim 32, wherein said body is
self-expanding.
35. A thrombectomy device, comprising: an elongate filament
configured into a pseudo-braided pattern and formed to define a
body having a first end and a second end; and said first and second
ends each being defined by a plurality of endless reversals of
directions of said filament.
36. The device of claim 35, further comprising: an elongate wire,
said body being configured about said wire; and a collar configured
about said elongate wire in a slidable fashion, said collar affixed
to first said end of said body; wherein said second end of said
body is affixed to said elongate wire.
37. The device of claim 35, wherein said pseudo-braided pattern is
uniform along a length of said body.
38. The device of claim 35, wherein said pseudo-braided pattern is
varied along a length of said body.
39. The device of claim 35, wherein said body is
self-expanding.
40-42. (canceled)
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to self-expanding, knitted
devices and more particularly, to a self-expanding knitted device
for intravascular repair of distal and tortuous vasculature.
[0002] The vasculature of an animal or a human characteristically
suffers from a variety of maladies. Vessel walls can weaken and
become distended over time in response to blood flow and pressures,
thereby resulting in formation of aneurysms. Such aneurysms can
take on a myriad of forms. In particular, aneurysms may form at or
near bifurcated vessels creating enlarged areas about the
bifurcation, or may form a pocket, for example, in side walls of
vessels. Due to the complications associated with aneurysms that
rupture or otherwise fail, it is critical that an aneurysm be
treated expeditiously and effectively. Intravascular treatment
procedures include placing grafts within the aneurysm in a manner
to ensure that blood flows through the graft rather than through
the weakened vessel. Additionally, in the event that the aneurysm
is in the form of a pocket in the side wall of a vessel, a stent
might first be placed at the repair site then the pocket filled
with material such as coils.
[0003] Stenoses also typically form in vasculature of humans and
animals. Specifically, thrombotic or atherotic stenoses can form
nearly anywhere in the vasculature. Such narrowing of the vessel
is, of course, highly dangerous to the patient where the afflicted
vessel provides the sole blood flow access to critical parts of the
body. To treat such stenoses, a supporting structure can be placed
at the diseased site for the purpose of enlarging and holding open
the vessel. It is known in the art to employ stents for this
purpose.
[0004] Vessel occlusions can also be treated by employing devices
which are actuated to debulk and remove vessel occluding thrombi.
This procedure is generally referred to as a thrombectomy.
Typically, such devices are intravascularly advanced to the repair
site and manipulated to remove the unwanted material from the
vessel by physically engaging the thrombus and severing the same
from the vessel wall.
[0005] Due to procedures such as thrombectomies or due to the
natural, albeit undesirable, function of a patient's vasculature,
emboli may be found traveling through a blood vessel. Embolic
material can cause unwanted blockages or otherwise facilitate the
formation of an occlusion in a vessel which too, can be highly
dangerous to a patient. To address this problem, emboli-catching
filters can be intravascularly placed within vasculature to thereby
provide embolic protection. Such devices are often implanted
temporarily within vasculature and removed upon being satisfied
that the undesirable embolic material has been captured.
[0006] In certain situations, it is desirable to aid the formation
of thrombus. For example, devices may be placed within aneurysmal
spaces to slow and eventually cease blood flow therethrough. This
procedure is sometimes referred to as embolic therapy, the basic
thrust of which is to minimize or eliminate exposure of weakened
sections of vasculature to blood flow and pressure.
[0007] Unfortunately, many areas of vasculature are inaccessible by
a conventional intravascular repair means because the repair
devices typically employed are often too large or rigid to be
effectively advanced through tortuous vasculature or to vasculature
that is very distal to the site through which the vasculature is
accessed. Alternatively, in the event that there is success in
advancing the repair devices to the diseased portion or repair site
of the vasculature, conventional repair devices sometimes lack a
large enough expansion ratio and/or radial stiffness to accomplish
the necessary repair. Moreover, conventional devices can lack a
profile suited to avoid traumatic engagement with a vessel wall or
sufficient radiopacity so that remote observation is
impossible.
[0008] Thus, where an intravascular approach is not available to
the physician, invasive surgical techniques must be applied. To
with, a patient's chest, abdomen or cranium, for example, must be
directly traversed in a major surgical procedure.
[0009] Hence, those concerned with repair of diseased vasculature
have recognized the need for devices that can be employed to
effectively repair distal and highly tortuous vasculature. The
present invention fulfills these needs.
SUMMARY OF THE INVENTION
[0010] Briefly, and in general terms, the present invention
provides devices contemplated for the repair of highly tortuous and
distal vasculature. Basically, the invention is directed to a
self-expanding, pseudo-braided structure that is characterized by
having a large expansion ratio and high flexibility as well as an
improved radial strength accomplished through the advantageous
utilization of deflection energy.
[0011] In one preferred embodiment, the devices of the present
invention are fabricated from a single filament configured into a
repeating helical pattern that is interlaced into a mesh or
pseudo-braided tubular shape. The filament may embody an elongate
highly elastic and shape settable material. A reversal of direction
that the filament undergoes presents a blunt, rounded surface that
is atraumatic to vessel walls. The structure in the present
application is referred to as pseudo-braided. Braiding is the
interlacing of at least three wires at various angles to each other
to form a braid, whereas the present invention uses a single
filament that is interlaced with itself along the length of the
structure at various angles. It is within the scope of the
invention to interlace another filament or a plurality of other
filaments into the pseudo-braid formed by the single filament.
[0012] In another aspect of the invention, the pseudo-braided or
interlaced structure has a high expansion ratio with a low metal to
space ratio. A large expansion ratio is accomplished by the unique
single filament construction that provides additional springback
forces.
[0013] In other aspects of the invention, there are various methods
for terminating the filaments. Additionally, various methods are
contemplated for adjusting the radiopacity as well as the expansion
and spring characteristics of the pseudo-braided devices. Various
methods are also contemplated for improving coverage of the
pseudo-braided devices and enhancing the anchoring of the same
within distal and tortuous vasculature.
[0014] The self-expanding, pseudo-braided devices disclosed are
intended for use in addressing various maladies effecting
vasculature. In particular, the self-expanding, pseudo-braided
devices can be configured specifically to facilitate the repair of
aneurysms and stenoses as well as to act as filter or thrombectomy
devices.
[0015] These and other objects and advantages of the invention will
become apparent from the following more detailed description, when
taken in conjunction with the accompanying drawings of illustrative
embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a side view of a pseudo-braided device of the
present invention;
[0017] FIG. 2 is an end view of the pseudo-braided device shown in
FIG. 1;
[0018] FIG. 3 is a side view of a pseudo-braided device of the
present invention, depicting a device with a flared end;
[0019] FIG. 4 depicts a first embodiment of a filament
reversal;
[0020] FIG. 5 depicts a second embodiment of a filament
reversal;
[0021] FIG. 6 depicts a third embodiment of a filament
reversal;
[0022] FIG. 7 depicts a fourth embodiment of a filament
reversal;
[0023] FIG. 8 depicts a fifth embodiment of a filament
reversal;
[0024] FIG. 9 depicts a first embodiment of a method for joining
ends of a filament;
[0025] FIG. 10 depicts a second embodiment of a method for joining
ends of a filament;
[0026] FIG. 11 depicts a third embodiment of a method for joining
ends of a filament;
[0027] FIG. 12 depicts a fourth embodiment of a method for joining
ends of a filament;
[0028] FIG. 13 depicts a fifth embodiment of a method for joining
ends of a filament;
[0029] FIG. 14 depicts a sixth embodiment of a method for joining
ends of a filament;
[0030] FIG. 15 depicts a seventh embodiment of a method for joining
ends of a filament;
[0031] FIG. 16 depicts a eighth embodiment of a method for joining
ends of a filament;
[0032] FIG. 17 is a perspective view of a first alternative method
of forming a pseudo-braided device of the present invention;
[0033] FIG. 18 is a perspective view of a second alternative method
of forming a pseudo-braided device of the present invention;
[0034] FIG. 19 is a side view of a sectioned portion of a blood
vessel suffering from an aneurysm and a pseudo-braided device of
the present invention being deployed from a catheter;
[0035] FIG. 20 depicts the implantation of the device of FIG. 19
within a vessel;
[0036] FIG. 21 is a side view of a sectioned portion of a blood
vessel suffering from an aneurysm and a pseudo-braided device of
the present invention being deployed from an alternative embodiment
of a delivery catheter;
[0037] FIG. 22 is a side view of a sectioned portion of a blood
vessel suffering from a stenosis and a pseudo-braided device of the
present invention being deployed from a catheter;
[0038] FIG. 23 depicts the implantation of the pseudo-braided
device of FIG. 22 within a vessel;
[0039] FIG. 24 is a side view of a pseudo-braided device of the
present invention configured as an embolic protection device;
[0040] FIG. 25 depicts a side view of an alternate embodiment of
the pseudo-braided device of the present invention configured as an
embolic protection device;
[0041] FIG. 26 is a side view of a pseudo-braided device of the
present invention configured as a thrombectomy device;
[0042] FIG. 27 depicts a side view of an alternate embodiment of
the pseudo-braided device of the present invention configured as a
thrombectomy device;
[0043] FIG. 28 depicts a side view of yet another embodiment of the
pseudo-braided device of the present invention configured as a
thrombectomy device; and
[0044] FIG. 29 is a side view of a sectional portion of a portion
of a blood vessel suffering from an aneurysm and a pseudo-braided
device of the present invention configured to be placed within the
aneurysm.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] Turning now to the drawings, and particularly to FIGS. 1 and
2, there is shown a self-expanding pseudo-braided structure 50 of
the present invention. The pseudo-braided device 50 is contemplated
for use in highly tortuous and very distal vasculature of an animal
or human. Due to its novel structure, the pseudo-braided device 50
is flexible in a compressed configuration and conformable to
tortuous anatomy in a relaxed condition. Moreover, the device
embodies high flexibility and a large expansion capability while
providing sufficient radial force (i.e., hoop stiffness).
[0046] In a presently preferred embodiment, the pseudo-braided
device 50 of the present invention is formed from the single
filament 52. The filament 52 is configured into a repeating helical
pattern that is interlaced upon itself by passing the end of the
filament over then under the filament forming the helix as the end
of the filament is wound down and back up the length of the
structure to thereby form a generally tubular body 54. At the
crossings of the filament there can be local deformations formed as
the top wire is bent over the bottom wire however it has been
discovered that for most applications deformations are not
necessary to add spring force and resistance against fraying
because of the ends formed by the reversal of winding. The tubular
body 54 defines an interior lumen 56 and includes a first end 58
and second end 60.
[0047] It is also contemplated that the self-expanding
pseudo-braided structure can embody modified tubular
configurations. That is, as shown in FIG. 3, one end of the
self-expanding pseudo-braided structure 50 can include an increased
diameter section or flare 61. Alternatively, both ends of the
device can include a flare 61, such flares can have the same
general shape or one flare may be greater than the other.
[0048] The filament 52 is preferably an elongate, highly elastic
and shape settable member. In one preferred embodiment, the
filament 52 has a circular cross-sectional profile and can comprise
nickel titanium alloy, Eligiloy.TM., steel or other suitable
materials.
[0049] In order to assemble the pseudo-braided device 50, it is
contemplated that the filament 52 can be wrapped about a mandrel in
a first direction and in a helical fashion for a desired length
along the mandrel (not shown). Once the desired length is achieved,
the direction of winding is reversed.
[0050] Reversal of winding can be accomplished in a number of ways.
It is contemplated, however, that the reversal of winding present a
smooth, blunt surface that would be atraumatic to a vessel wall. As
shown in FIG. 4, such an atraumatic reversal can be accomplished
employing a simple arc 62. Atraumatic reversal can also be provided
by single 64 or double 66 loop backs as well as a figure-8 reversal
68 or a full-turn helical reversal 69 as shown in FIGS. 5-8,
respectively.
[0051] Various radii of curvature and length of loops can be
employed according to the application. The loops or hoops of the
various reversals contemplated can have a constant or irregular
radii of curvature and the loops can have an acute radius of
curvature (not shown). It is believed that minimizing stress
concentrations in the reversals may have the added benefit of
optimizing springback forces. Thus, stress concentration in the
reversals can also be varied for a particular application.
Moreover, in order to facilitate the reversal of direction of the
filament 52, the mandrel can have pegs extending therefrom at
desired intervals, about which the filament can be routed.
[0052] Once a reversal direction is made, the filament is
interlaced in an over/under fashion about itself in a helical
pattern in the reverse axial direction but same rotational
direction. The desired density of the wall 70 defining the tubular
body 54 is accomplished by altering the number of reversals and the
longitudinal spacing 72 of adjacent members wrapped in the helical
pattern. That is, the number of traversals, which is defined as the
portion of the filament 52 between two reversals of direction, can
be varied as can the number of revolutions per traversal.
Typically, the number of reversals at each end 58, 60 of the
tubular body 70 number from six (6) to twelve (12) and as much as
twenty (20).
[0053] Upon achieving a desired pseudo-braided pattern and wall
density, the ends 74, 76 of the filament 52 are joined. There are a
myriad of ways in which the ends 74, 76 can be joined. While the
figures illustrate such joining as occurring generally at the
middle of the pseudo-braided device 50, it is also contemplated
that such joining can occur at the ends of the structure or
anywhere in between. Ultimately, however, it is desired that the
joining of the ends 74, 76 of the filament 52 be accomplished in a
manner such that the vessel wall is presented with as atraumatic a
surface as necessary for a particular application, there is a low
profile, and no compromise in device function.
[0054] As shown in FIGS. 9 and 10, one way of joining the end 74,
76 of the filament 52 is to twine them together. The ends 74, 76 of
the filament can also be joined by soldering or welding to form a
welded joint 78 as shown in FIG. 11. A preferred method of welding
is laser welding.
[0055] Alternatively, the ends 74, 76 of the filament 52 can be
joined utilizing potted tantalum powder 80, as depicted in FIG. 12.
In order to do so, the tantalum powder is first mixed with an
epoxy. Thereafter, the filament 50 is coated with the
tantalum/epoxy compound and left to cure.
[0056] Moreover, the ends 74, 76 of the filament 52 can be
configured into a linear slide arrangement 82 (see FIG. 13). In
such an arrangement, one filament end 74 is wrapped around the
other filament end 76 which remains straight or undeformed. This
means for joining the end 74, 76 of the filaments 52 has the
advantage of compensating for length mismatches. To wit, one wire
can move relative to the other.
[0057] The ends 74, 76 of the filament can also be formed with
flattened welding surfaces 84 (FIG. 14). These weld surfaces 84 are
then aligned and thereafter welded together by conventional
methods.
[0058] Finally, the ends 74, 76 of the filament 52 can be crimped
together using a sleeve 86 or are otherwise joined by way of a ball
member 88 (FIGS. 15 and 16). In both instances, a bore is provided
to receive both ends 74, 76 of the filament 52. In the case of the
sleeve 86 embodiment, the outer surface of the sleeve 86 can be
crimped to retain the sleeve 86 on the ends 74, 76 of the filament
52. A press fit is contemplated for the ball 88 and
configuration.
[0059] The assembled pseudo-braided device 50 embodies a number of
unique features. In particular, the reversal of the knit direction
provides a resilient response at the ends 58, 60 of the
pseudo-braided device 50 compared to that of other conventional
braided structures that have unconnected wire ends. That is,
reversals of direction act as a spring and tend to attempt to
return to pseudo-braided device to its original expanded shape.
This feature allows the pseudo-braided device 50 to be compressed
to smaller than ten (10) percent of its original diameter and once
released, to spring back to its original uncompressed
configuration. Accordingly, the pseudo-braided device 50 of the
present invention is characterized by having a very large expansion
ratio.
[0060] Embodying a very large expansion ratio provides the
pseudo-braided device 50 of the present invention with a number of
advantages. In particular, the pseudo-braided device 50 can be
delivered within vasculature using very small diameter catheters or
microcatheters. This in turn allows for the placement of the
pseudo-braided device 50 within very distal vasculature. Thus,
using microcatheters to deliver the pseudo-braided device 50
facilitates advancement through highly tortuous as well as very
narrow vessels such as in the cerebral vasculature.
[0061] Furthermore, the reversals of direction of the filament 50
tend to improve radial force (i.e., hoop stiffness) by forcing
deflection energy to bend the reversal arc as well as displace the
same. With particular reference to FIG. 4, reversals defined by
simple bends 62 embody relatively high stress concentrations at the
bend 62. Such high stress concentrations may be suitable for a
purpose requiring a particular deflection energy. In contrast,
reversals defined by full-turn helixes (FIG. 8), for example, tend
to distribute stress concentrations throughout the helix 69 and
therefore provide a different deflection energy. By comparison,
braided devices that lack reversals deflect in response to a load
much more readily than the ends 58, 60 of the pseudo-braided device
of the present invention and those braided devices only rely on
pivots at the crossings of the wires whereas the present invention
embodies crossings plus spring ends.
[0062] The crossing angle 90 can also be varied for a particular
application. The crossing angle 90 is defined by two portions of
the filament that cross each other. It is presently contemplated
that the crossing angle can range up to approximately 90 degrees or
more. It has been found that the braid angle directly affects
radial stiffness and conformability which can thus be optimized for
a particular application.
[0063] It has also been recognized that joining the ends 74, 76 of
the filament maintains filament alignment. Filament alignment is
important particularly when deploying the pseudo-braided device 50
in extremely tortuous vessels for a number of reasons. First, in
the event the filaments 52 were permitted to slide out of place,
weaker areas would be created in the pseudo-braided device 50.
Those weaker areas would have an increased propensity to buckle.
Secondly, if filaments 52 were to slide out of place, the mesh
openings can become variable. As a result, there would be larger
openings in the mesh or interlaced structure in some places that
would reduce functionality of the device. Finally, if filaments
were permitted to slide out of place, catheter distortion during
deployment will likely increase. Thus, when the filaments 52 of the
pseudo-braided device maintain good alignment while in the
compressed condition, the individual radial forces of each filament
52 add together to form a consistent radial force in all directions
along the length of the pseudo-braided device 50.
[0064] It is also possible to produce a pseudo-braided device 50
that is comprised of one wire, where that one wire has variations
along its length that corresponds to specific pseudo-braiding
processes of a particular desired configuration. To wit, a wire
could be masked and chemically etched to produce a variable
diameter wire that corresponds to the pseudo-braided device 50
design of choice, such that for example, the bends of the filament
52 that comprise the ends of the pseudo-braided device 50 can be of
a smaller diameter than the wire that comprises the remainder of
the pseudo-braided device body 70. Additionally, the bends could be
of a larger diameter for providing a greater expansion rate and
radial force. These variations may advantageously create a
pseudo-braided device 50 with a desired strength, without
increasing its resistance to being pushed through a catheter lumen
in a compressed configuration.
[0065] This kind of design variation could be followed for other
attributes as well. For example, such as for non-thrombogenic
coatings, coatings laced with therapeutic drugs, plating processes
to selectively increase radiopacity, and plating processes to
selectively increase stiffness.
[0066] Alternatively, rather than a round profile, the filament 52
can be formed from a filament having various other cross-sectional
profiles. That is, the filament can comprise an oval, triangular,
rectangular, square, bowed, crescent moon, or tapered profiles. The
filament 52 itself can also be formed from a small diameter tube or
be configured into a coil along its length.
[0067] It is also recognized that the desired pseudo-braided
structure can be made from a plurality of filaments 52. Such
plurality of filaments 52 can be configured with a number of
reversals of varying types, so that the benefits associated
therewith can be used advantageously. The ends of these filaments
can also be joined together to provide atraumatic engagement with
vessel walls as discussed above.
[0068] When deploying the pseudo-braided device 50 of the present
invention within a patient's vasculature, it is desirable to be
able to remotely observe the placement thereof. Thus, it is
important that the pseudo-braided device 50 be sufficiently
radiopaque so that such remote observation is possible by
conventional methods such as fluoroscopy.
[0069] Referring now to FIGS. 15 and 16, the radiopacity of the
pseudo-braided device 50 can be enhanced by employing platinum or
other sufficiently radiopaque materials as the crimping sleeve 86
or the ball end 88. Platinum coils (not shown) could similarly be
wrapped about portions of the filament 52 to act as radiopaque
markers. Additionally, the filament 52 can be twined with one or
more platinum filaments along its length, thereby providing a
pseudo-braided device 50 that is radiopaque from one end to the
other.
[0070] Additionally, it is contemplated that in certain
applications, it may be desirable to plate the filament with gold
or platinum. The entirety of the tubular body 70 can be plated or
the reversals could be masked and the remainder of the body 70 be
plated. By thus masking the reversals, the desirable spring
characteristics of the pseudo-braided device 50 of the present
invention can be preserved.
[0071] Referring now to FIGS. 17 and 18, there is shown methods of
manufacturing the pseudo-braided device 50 of the present invention
in a manner to optimize vessel coverage for particular
applications. As shown in FIG. 17, a particular configuration of
the pseudo-braided device 50 can be formed by wrapping a filament
52 about a forming mandrel 92 such that there is tight winding at
an inferior end portion 94 and relatively looser winding at a
superior end portion 96. The tightly wound portion being
contemplated to provide the resultant pseudo-braided device 50 with
structure for anchoring and for increasing surface area for vessel
coverage. The more loosely wound portion provides a gradual
transition to the more tightly wound portion as well as a means for
more easily deploying the pseudo-braided device 50 when it is
released from a catheter.
[0072] FIG. 18 additionally depicts a wavy midsection 98 which is
contemplated for use in also increasing coverage when the
pseudo-braided device is deployed within a vessel. The waves can
generally resemble a sinusoidal path and can also take on an
undulating serpentine pattern. Such waves 98 can alternatively
extend the length of the filament thereby providing the
pseudo-braided device with increased coverage throughout its
length. Such waveforms are created by threading the filament
through a mesh setting shape then again wrapping the filament about
a mandrel again setting the shape.
[0073] It has also been recognized that the waveforms like those
shown in FIG. 18 can be spanned with a highly elastic material for
the purpose of again improving coverage. As with the closely wound
filament embodiment, the waves can additionally improve anchoring
capabilities by enhancing in a circumferential direction, the
traction between the vessel wall and the pseudo-braided device
50.
[0074] The pseudo-braided device 50 of the present invention has
applications in a number of areas including operating as an
aneurysm cover, in conjunction with thrombotic and artherotic
stenosis therapy, as an embolic protector, as a thrombectomy device
and in embolic therapy. As stated, due to its high expansion ratio
and superior flexibility, the pseudo-braided device 50 can be
placed within vasculature and advanced deep within the patient's
anatomy to a repair site. Once there, the pseudo-braided device 50
can be deployed within highly tortuous vascular for the purpose of
addressing the particular malady effecting the vessel. As shown in
FIGS. 19 and 20, the pseudo-braided device 50 of the present
invention can be advanced within a blood vessel 100 using a
delivery catheter 102. Due to the ability to reduce the
pseudo-braided device 50 to less than 10 percent of the expanded
diameter, microcatheters can be utilized for this purpose. In a
preferred embodiment, the delivery catheter is contemplated to
include or cooperate with a pusher 103 that operates to facilitate
relative movement between the pseudo-braided device 50 and the
delivery catheter 102.
[0075] In an alternate configuration (See FIG. 21), a compressed
stent has a lumen that a standard guidewire 201 can freely pass
through. This allows improved access. When ready, the guidewire 201
can be withdrawn and replaced with the push wire 200 or the
guidewire 201 can have a proximally placed pushing ring 202 that
accomplishes the ejection of the pseudo-braided device from the
delivery catheter 102.
[0076] Upon advancing the delivery catheter 102 to a repair site
104, the pseudo-braided device is deployed from a distal end 106 of
the delivery catheter 102 (FIG. 20). It is contemplated that any
number of conventional means may be employed to eject the
pseudo-braided device from the delivery catheter 102, including but
not limited to a pusher device (not shown) configured coaxially
within the delivery catheter 102 which operates to engage a
proximal end 58 of the pseudo-braided device 50 while withdrawing
the delivery catheter 102 proximally.
[0077] As stated, the pseudo-braided device 50 of the present
invention is also particularly suited to operate as an aneurysm
cover. As shown in the figures, the pseudo-braided device 50 can be
deployed to overlay an opening 108 to an aneurysm 110 formed in a
sidewall of a vessel. By being so positioned, the pseudo-braided
device 50 can redirect flow from entering the aneurysm, become
covered with endothelium cells and seal off the opening into the
aneurysm, or retain embolic coils 112 or other thrombus producing
materials inserted in the aneurysm sack 110. It is to be noted that
it is preferred to implace the pseudo-braided device 50 prior to
embolic material as the same prevents prolapse of material into the
parent vessel.
[0078] Using similar methods, the pseudo-braided device 50 of the
present invention could additionally be employed to repair
thrombotic or artherotic stenoses 14 found in a blood vessel 100
(See FIGS. 22 and 23). Due to its high expansion ratio and enhanced
radial strength (i.e., hoop strength), the pseudo-braided device 50
can be deployed across the stenosis 114 and be allowed to
self-expand to thereby press the thrombotic or artherotic material
forming the stenoses against the walls of the vessel 100. By doing
so, the pseudo-braided device operates to hold open and enlarge the
vessel 100 at the repair site.
[0079] By reconfiguring the basic structure of the pseudo-braided
device 50, as previously mentioned, the advantages provided by the
present invention can be used to address other maladies effecting
vessels. More specifically, the pseudo-braided device 50 can be
reconfigured as an embolic protection device 120. With reference to
FIGS. 24 and 25, a superior end portion 122 of the contemplated
embolic protection devices can be necked down so as to form a
generally conical profile. Such necking could be accomplished by
way of altering the manufacturing process or the superior end 122
of the pseudo-braided structure can simply be restrained to a
relatively smaller cross-sectional profile by way of adhesion or
mechanical devices. It is contemplated that the superior end 120 of
the embolic protection device 120 be affixed by conventional means
to an elongate member 124 that is positionable within a delivery
catheter similar to that depicted in FIGS. 19-23. The inferior end
126 of the embolic protection device 120, in its expanded form,
provides a generally circular, cross-sectional profile, opening for
receiving blood flow.
[0080] In one embodiment of the embolic protection device 120 (FIG.
25), a plurality of proximally extending filaments or wire loops
128 are routed about portions of the filament defining the inferior
end 126 of the embolic protection device 120. Proximal ends 129 of
the loops can be affixed to a collar that is intended to slide
along the elongate member 124. Independent control of the collar is
also contemplated such that a separate actuator (not shown) which
extends to the operator can be supplied to manipulate the position
of the collar along the elongate member 124. In either case, the
loops 128 are provided in the event additional control of the
opening and closing of the embolic protection device 120 is
desired.
[0081] Upon advancing the embolic protection device 122 to a
desirable location within a patient's vasculature, the elongate
member 124 is held stationary while the delivery catheter (not
shown) is withdrawn proximally. The inferior end portion 26 and a
tubular midsection 130 of the embolic protection device 122 are
then permitted to self-expand against the walls of the vessel into
which the device is deployed. The fully opened embolic protection
device 120 permits blood to flow into its interior and through its
pseudo-braided walls but acts as a barrier to emboli passing
through the blood. That is, emboli entering the embolic protection
device 120 are captured by its pseudo-braided structure. The
captured emboli can thereafter be removed from the patient's
vasculature when the embolic protection device 120 is removed or
other conventional means such as suction devices can be employed to
remove the emboli.
[0082] Turning now to FIGS. 26-28, there are shown various
embodiments of the present invention configured as thrombectomy
devices 148. Such thrombectomy devices 148 can be advanced and
deployed within a patient's vasculature using the delivery catheter
depicted in FIGS. 19-23. With specific reference to FIG. 26, the
pseudo-braided device of the present invention can be attached at
its ends 140, 142 by way of collars 144 to an elongate member 146
to thereby form one embodiment of a thrombectomy device 148. Upon
deployment and expansion within a target vessel, the thrombectomy
device assembly 148 provides a mid-section 150 that is well-suited
for engaging and, upon rotation of the device, shearing thrombus
from a vessel wall. In order to facilitate self-expansion, one
collar 144 is permitted to slide along the elongate member 146,
while the other collar is longitudinally fixed thereto.
[0083] As shown in FIGS. 27 and 28, the thrombectomy devices 148
may also embody pseudo-braided portions of varied density. For
example, the more densely pseudo-braided midsection 152 of the
device depicted in FIG. 27 is particularly suited for accomplishing
the thrombectomy whereas its less densely pseudo-braided superior
end portion 154 is intended for capture of emboli. The thrombectomy
device 148 of FIG. 28 embodies a less densely pseudo-braided
midsection contemplated for macerating a thrombus adhering to a
blood vessel wall whereas its superior end portion 160, being more
densely pseudo-braided, is configured for removal and capture of
emboli.
[0084] The pseudo-braided device 50 of the present invention can
also be closed at each of its ends to form an expandable spherical
shape that is suited as an embolic therapy device 170. With
reference to FIG. 29, such an embolic therapy device can be
advanced within a vessel using a delivery catheter 102. The embolic
therapy device 170 can then be deployed within an aneurysm sack 110
and permitted to self-expand to thereby facilitate thrombus
formation. A conventional releasable connection 172 to an elongate
delivery assembly sub-component 174 is contemplated so that the
embolic therapy device 170 can remain in the aneurysm 110 when the
delivery assembly is removed from the patient.
[0085] In view of the foregoing, it is clear that the
pseudo-braided device of the present invention is useful in
numerous of applications. Moreover, due to its high expansion ratio
and flexibility, the pseudo-braided device of the present invention
can be employed to repair very distal as well as tortuous portions
of a patient's vasculature.
[0086] It will be apparent from the foregoing that, while
particular forms of the invention have been illustrated and
described, various modifications can be made without departing from
the spirit and scope of the invention. Accordingly, it is not
intended that the invention be limited, except as by the appended
claims.
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