U.S. patent application number 10/230803 was filed with the patent office on 2004-03-04 for device for closure of a vascular defect and method of treating the same.
Invention is credited to Porter, Stephen.
Application Number | 20040044391 10/230803 |
Document ID | / |
Family ID | 31976586 |
Filed Date | 2004-03-04 |
United States Patent
Application |
20040044391 |
Kind Code |
A1 |
Porter, Stephen |
March 4, 2004 |
Device for closure of a vascular defect and method of treating the
same
Abstract
A device for the non-invasive treatment of a vascular defect.
The device includes at least one occlusive member having a first
unexpanded configuration and a second expanded configuration and at
least one securement member for securing the vaso-occlusive device
to a support structure at the location of the vascular defect.
Inventors: |
Porter, Stephen; (Fremont,
CA) |
Correspondence
Address: |
VIDAS, ARRETT & STEINKRAUS, P.A.
6109 BLUE CIRCLE DRIVE
SUITE 2000
MINNETONKA
MN
55343-9185
US
|
Family ID: |
31976586 |
Appl. No.: |
10/230803 |
Filed: |
August 29, 2002 |
Current U.S.
Class: |
623/1.1 |
Current CPC
Class: |
A61B 17/12022 20130101;
A61B 17/12172 20130101; A61B 17/1219 20130101; A61B 2017/1205
20130101; A61B 17/12118 20130101 |
Class at
Publication: |
623/001.1 |
International
Class: |
A61F 002/06 |
Claims
1. A device for the treatment of a vascular defect, said device
comprising: at least one occlusive member having a first unexpanded
configuration and a second expanded configuration; and at least one
securement member for securing said device to a support structure
at the location of the vascular defect.
2. The device of claim 1 wherein said support structure is a stent
or stent/graft.
3. The device of claim 2 wherein said support structure is a stent
of the self-expanding variety.
4. The device of claim 1 wherein said at least one securement
member, said at least one occlusive member, or both, are comprised
of a metal or metal alloy.
5. The device of claim 4 wherein said metal is a shape memory
metal.
6. The device of claim 1 wherein said at least one occlusive
member, said at least one securement member, or both, are formed
from a polymeric material.
7. The device of claim 1 wherein said at least one occlusive
member, at least one securement member, or both, are formed from a
biologically derived material.
8. The device of claim 1 wherein said occlusive member is formed
from a biologically derived material.
9. The device of claim 8 wherein said biologically derived material
is selected from the group consisting of collagen foams, harvested
vascular material, processed tissues and combinations thereof.
10. The device of claim 1 wherein said at least one occlusive
member is formed from a combination of at least one polymeric
material and at least one metal or metal alloy.
11. The device of claim 10 wherein said at least one occlusive
member is in the form of an umbrella, parabola, sphere or disc.
12. The device of claim 6 wherein said polymeric material is
selected from the group consisting of polyurethanes, polyolefins,
polyesters, polyamides, fluoropolymers, silicones, acrylics,
polypeptides, and mixtures thereof.
13. The device of claim 6 wherein said polymeric material is a
swellable polymeric material.
14. The device of claim 13 wherein said swellable polymeric
material is a hydrogel.
15. The device of claim 1 wherein said at least one securement
member and at least one occlusive member are formed from a
swellable polymeric material.
16. The device of claim 1 wherein said at least one securement
member swells in an aqueous environment.
17. The device of claim 16 wherein said at least one securement
member is formed from a hydrogel.
18. The device of claim 1 wherein said at least one occlusive
member and said at least one securement member are formed from a
swellable polymeric material or a compressed foam.
19. The device of claim 1 wherein at least a portion of said at
least one occlusive member has a braided, woven, knit, felt-like or
mesh configuration.
20. The device of claim 1 wherein said at least one occlusive
member blocks the flow of fluid to a defect in the vasculature.
21. The device of claim 1 wherein said vascular defect is an
arterial-venus fistula.
22. The device of claim 1 wherein said vascular defect is an
aneurysm.
23. The device of claim 1 further in combination with a
catheter.
24. The device of claim 1 further comprising at least one
radiopaque material.
25. The device of claim 1 further comprising at least one bioactive
material.
26. A vaso-occlusive device formed from a swellable material or a
compressed foam, said vaso-occlusive device having at least one
securement member.
27. The vaso-occlusive device of claim 26 wherein said at least one
occlusive member of said vaso-occlusive device is in the shape of
an umbrella, parabola, sphere or disc.
28. A method of occluding a vascular defect having an opening, the
method comprising the steps of: a) deploying a support structure to
said vascular defect said support structure having an opening for
accepting a vaso-occlusive device; b) deploying a vaso-occlusive
device having at least one occlusive member having an expanded
configuration and an unexpanded configuration and at least one
securement member through said opening of said support structure
and through said opening of said vascular defect into said vascular
defect; and c) expanding said at least one occlusive member; and d)
anchoring said vaso-occlusive device to said support structure with
said at least one securement member.
29. The method of claim 28 wherein said support structure is a
stent or stent/graft having a plurality of struts.
30. The method of claim 28 wherein said support structure is a
straight or a bifurcated stent.
31. The method of claim 30 wherein said support structure is a
stent and said opening for accepting said vaso-occlusive device is
formed between said struts.
32. The method of claim 30 wherein said support structure is a
stent of the self-expanding variety.
33. The method of claim 28 wherein said at least one occlusive
member is polymeric.
34. The method of claim 28 wherein said at least one securement
member is metallic or polymeric.
35. The method of claim 34 wherein said at least one securement
member is formed from more than one strut-like element.
36. The method of claim 34 wherein said at least one securement
member is formed from a shape memory material or superelastic
material.
37. The method of claim 34 wherein said at least one securement
member is a swellable polymeric material.
38. The method of claim 37 wherein said at least one securement
member is a hydrogel.
39. The method of claim 28 wherein said vaso-occlusive device is
deployed with a microcatheter.
40. A method of closing and occluding an opening of an aneurysm
from a parent blood vessel, the method comprising the steps of: a)
deploying a support structure at the site of the aneurysm said
support structure having at least one opening for accepting a
vaso-occlusive device, said vaso-occlusive device having at least
one occlusive member which has an unexpanded configuration and an
expanded configuration and at least one securement member, said
support structure positioned at said opening of said aneurysm such
that said at least one opening of said support structure is aligned
with said opening of said aneurysm; b) deploying said
vaso-occlusive device wherein said at least one occlusive member is
in its unexpanded configuration, through said at least one opening
of said support structure and said opening of said aneurysm and
into said aneurysm; c) expanding said at least one occlusive member
of said vaso-occlusive device to its expanded state whereby said
vaso-occlusive device blocks said opening of said aneurysm from
said parent blood vessel in its expanded state; and d) anchoring
said vaso-occlusive device to said support structure with said at
least one securement member.
41. The method of claim 40 wherein said support structure is a
stent having a plurality of struts and said at least one opening is
formed between said struts.
42. The method of claim 40 wherein said stent is a self-expanding
stent.
43. The method of claim 40 wherein said vaso-occlusive device is
deployed with a microcatheter.
44. In combination, a vaso-occlusive device having at least one
securement member and a stent, the at least one securement member
secured to the stent.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to implantable
devices and methods for the treatment of vascular defects.
BACKGROUND OF THE INVENTION
[0002] Many minimally invasive or noninvasive interventional
medical devices and procedures have been used to treat defects in
the vasculature which are not easily reached by surgical
procedures. Such medical devices which are adapted for implantation
in body lumens in order to support weakened or occluded vessel
walls and allow fluid flow are well known and commercially
available. One such device is a vascular stent, for example. Stents
may be employed to prop up vessel walls and maintain openings in
vessels in the coronary system, the brain, the urinary, biliary,
esophageal, tracheal and bronchial tracts, and so forth.
[0003] However, in some situations, it is desirable to block fluid
flow. For example, one serious defect in the vascular system is an
aneurysm which is an area of a weakened vessel wall that causes a
bulge or bubble to protrude out in a radial direction from the
adjacent vessel. If untreated, an aneurysm may continue expanding
until it bursts, causing hemorrhage. It is therefore often
desirable to block fluid flow to the aneurysm.
[0004] Devices used for the treatment of such defects may be
referred to as vaso-occlusive devices and are commonly deployed to
the aneurysm site through the use of a catheter device.
Vaso-occlusive devices can have a variety of configurations, and
are generally formed of one or more elements that have a deployed
configuration for blocking blood flow which is different from their
configuration during delivery to the site.
[0005] Devices for bridging the necks of wide-necked or
narrow-necked aneurysms are found, for example, in U.S. Pat. No.
5,935,148, U.S. Pat. No. 6,063,070, U.S. Pat. No. 6,036,720, U.S.
Pat. No. 6,063,104 and U.S. Pat. No. 6,139,564. These devices may
also be used to stabilize the placement of vaso-occlusive devices
such as helically wound coils in the aneurysm or may be used to, at
least partially, close the aneurysm neck. The aneurysm neck bridge
or retainer assemblies described in the patents above may be
delivered to the aneurysm in a variety of different ways, but
preferably are attached to an electrolytically severable joint for
their deployment. After deployment of the neck bridge or retainer,
the aneurysm is at least partially filled with a vaso-occlusive
device such as a helically wound coil. The vaso-occlusive devices
may also be delivered to the aneurysm using a number of different
methods such as by a core wire which is linked to the coils by an
electrolytically severable joint or a mechanically severable joint.
The vaso-occlusive devices may also be simply pushed into the
aneurysm. The success of such devices as those described above, may
depend on several factors, however, including whether or not the
device can migrate out of the aneurysm through the neck of the
aneurysm.
[0006] Another example of a vaso-occlusive device applicable to the
treatment of an aneurysm is a covered stent or a stent-graft.
Covered stents have a limited usefulness due to the stiffness of
the device, and synthetic grafts themselves have a tendency to
occlude when employed in small blood vessels. Arteries where there
is an aneurysm typically have a lot of branching, and when
employing a covered stent, there is a further risk of occluding the
small branch vessels airising from the parent artery rather than
simply blocking the neck of the aneurysm as desired.
[0007] Thus, it would be beneficial to have a vaso-occlusive device
that can be delivered to an aneurysm or other body vessel in a
primary unexpanded configuration, wherein such device can be
deployed and released to assume a secondary, expanded configuration
which occludes the neck of the aneurysm, and which can be anchored
at the site of the aneurysm so that it does not migrate from the
site.
SUMMARY OF THE INVENTION
[0008] The present invention relates generally to a vaso-occlusive
device which is adapted to be inserted into a portion of a
vasculature for treatment of a body vessel such as an aneurysm, and
to methods of using the device. The vaso-occlusive device of the
present invention is generally employed in combination with a
support structure such as a stent, stent-graft, and the like. The
device is designed in such a way that it may be readily anchored at
the site of the vascular defect to prevent migration of the device.
Of course, more than one support structure may be employed in a
given procedure as well.
[0009] The vaso-occlusive device of the present invention includes
at least one occlusive member having a first unexpanded
configuration and a second expanded configuration, and at least one
securement member for securing the device to a stent, stent-graft,
or the like, in order to prevent migration of the fluid
flow-occluding device from the site of the vascular defect.
[0010] The device is retained within or as a part of a
microcatheter system in an unexpanded configuration to cross the
neck of the aneurysm, and then once across the neck, the device may
be allowed to expand by pulling back the microcatheter, pulling
back a shaft about the microcatheter, or by employing a pusher
device.
[0011] The device may be formed of a variety of materials
including, but not limited to flexible polymeric materials and
metallic materials including shape memory materials, superelastic
materials, compressed foams, swellable materials, braided or woven
materials and meshes formed from both polymeric materials and shape
memory alloys, for example, and so forth. Suitably, the materials
are biocompatible.
[0012] Bioactive materials or materials having incorporated
bioactive agents may also be employed in the construction of the
device according to the present invention.
[0013] The device may be employed in minimally invasive,
interventional procedures for the treatment of a vascular defect
where it is desirable to block the flow of fluid, if not completely
then to a substantial degree, into the defective area of the
vessel.
[0014] In one embodiment, the method includes deploying a support
structure to the site of the vascular defect, deploying the
vaso-occlusive device to the site of the vascular defect, inserting
the vaso-occlusive device into the vascular defect through an
opening in the support structure, deploying at least one occlusive
member, and deploying at least one securement member.
[0015] Suitably, both the support structure and the vaso-occlusive
device are deployed using a catheter.
[0016] These and other aspects and advantages of the invention will
become apparent from the following detailed description and the
accompanying drawings, which illustrate by way of example the
features of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 illustrates one embodiment of a vaso-occlusive device
according to the present invention.
[0018] FIG. 2 is a depiction of a stent located in a blood vessel
at the site of an aneurysm prior to deployment of a vaso-occlusive
device according to the present invention.
[0019] FIG. 3 illustrates initial delivery of a catheter device
with the vaso-occlusive device of the present invention retained
therein.
[0020] FIG. 4 illustrates initial deployment of the vaso-occlusive
device released from the catheter but in an unexpanded state.
[0021] FIG. 5 illustrates one embodiment of the occlusive member of
the vaso-occlusive device of the present invention in an expanded
state.
[0022] FIG. 6 illustrates one embodiment of the vaso-occlusive
device of the present invention positioned at the neck of an
aneurysm.
[0023] FIG. 7 illustrates one embodiment of the vaso-occlusive
device of the present invention in an expanded state with the
securement member released and in position.
[0024] FIG. 8 illustrates a vaso-occlusive device according to the
present invention, in combination with a catheter delivery
device.
[0025] FIG. 9 illustrates the device of FIG. 8 during
deployment.
[0026] FIG. 10 illustrates the vaso-occlusive device of FIG. 8
after deployment.
[0027] FIG. 11 is an expanded view of one embodiment of the
securement member prior to deployment.
[0028] FIG. 12 is an expanded view of the same securement member as
in FIG. 11 but in a deployed configuration.
[0029] FIG. 13 illustrates an alternative embodiment of the
securement member of the vaso-occlusive device of the present
invention prior to release from the catheter.
[0030] FIG. 14 illustrates the same securement member as shown in
FIG. 13, but after release from the catheter.
[0031] FIG. 15 illustrates another alternative embodiment wherein
both the occlusive member and the securement member are formed of
the same material.
[0032] FIG. 16 illustrates the same device as shown in FIG. 15 with
both the occlusive member and the securement member deployed.
[0033] FIG. 17 illustrates a specialized opening which may be
formed in a stent for accepting the vaso-occlusive device.
DETAILED DESCRIPTIONS OF THE PREFERRED EMBODIMENTS
[0034] While this invention may be embodied in many different
forms, there are described in detail herein specific embodiments of
the invention. This description is an exemplification of the
principles of the invention and is not intended to limit the
invention to the particular embodiments illustrated.
[0035] Turning now to the figures, FIG. 1 illustrates generally at
100, one embodiment of the vaso-occlusive device according to the
present invention in which the occlusive member 20 is in a fully
expanded form, but the securement member 30 has not yet been
released from the catheter 50. The top of the securement member 30
is visible. A pusher wire 22 is shown disposed within the catheter
lumen.
[0036] Also seen in FIG. 1 is a severable junction 40 for severing
the connection between a catheter delivery device 50 and the
vaso-occlusive device 100 after deployment of vaso-occlusive device
100. Junction 40 may be severed using any of a variety of different
methods including, but not limited to, electrolytic corrosion,
mechanical actuation, hydraulic pressure, thermal processes,
electromagnetic energy, and so forth as described above. Other
methods of detachment known to those of skill in the art but not
described herein may also be employed in releasing the device of
the present invention. Severable junctions which may be employed in
the present invention are described, for example, in U.S. Pat. No.
5,122,136, U.S. Pat. No. 5,354,295, U.S. Pat. No. 5,540,680, U.S.
Pat. No. 5,855,578, U.S. Pat. No. 5,895,385, U.S. Pat. No.
5,925,037, U.S. Pat. No. 5,944,714, U.S. Pat. No. 5,947,963, U.S.
Pat. No. 5976126, U.S. Pat. No. 6,010,498, U.S. Pat. No. 6,066,133
and U.S. Pat. No. 6,083,220, each of which is incorporated by
reference herein in its entirety.
[0037] FIGS. 2-7 illustrate a series of steps involved in the
deployment of the vaso-occlusive device 100 according to the
present invention. Beginning with FIG. 2, a support structure, in
this embodiment a stent 10, is shown deployed within a blood vessel
12 at the site of a vessel defect or aneurysm 14 and located at the
opening or neck 19 of the aneurysm 14. The stent 10 has a plurality
of stent struts 15 having openings 17 therebetween. Stent 10 is in
its expanded configuration within blood vessel 12. An occlusive
device according to the present invention may be formed and
configured such that it may be deployed through the openings 17
between struts 15.
[0038] While the above stent is shown for illustrative purposes
only, it is important to note that any stent design may be employed
herein.
[0039] FIG. 3 illustrates the initial delivery of one embodiment of
the device of the present invention (not visible in FIG. 2) in an
unexpanded state through the use of a microcatheter device 50, such
as a microcatheter. The microcatheter 50 is guided through blood
vessel 12 and through stent 10 and is then threaded through an
opening 17 located between stent struts 15 and into the aneurysm
14. The vaso-occlusive device 10 (not shown) may be rolled,
compressed or otherwise unexpanded into a form that can be pushed
through and retained in microcatheter 50. In FIG. 4, the
microcatheter 50 can be seen shown disposed within stent 10 in
blood vessel 12 and projecting upward through opening 17 formed by
struts 15 and into aneurysm 14. The securement member 30 can be
seen at the distal tip 55 of microcatheter 50.
[0040] In FIG. 4, vaso-occlusive device 100 is shown in the initial
stage of being released from microcatheter 50 by use of a pusher
wire 22 (not shown). The occlusive member 20 is still in an
unexpanded configuration. The securement member 30 is also in its
unexpanded configuration. Reference numeral 40 represents a
detachable or severable junction which can be severed using a
number of different mechanisms including, but not limited to,
electrolytic corrosion, mechanical actuation, hydraulic pressure,
thermal processes, electromagnetic energy, and so forth as
described above. It is at this junction 40 that the vaso-occlusive
device 100 is eventually detached from pusher wire 22 (not shown)
which is disposed inside microcatheter 50. Other methods of
detachment not described herein, but known in the art, may also be
employed in detaching the device of the present invention.
[0041] As noted above, severable junctions are described, for
example, in U.S. Pat. No. 5,122,136, U.S. Pat. No. 5,354,295, U.S.
Pat. No. 5,540,680, U.S. Pat. No. 5,855,578, U.S. Pat. No.
5,895,385, U.S. Pat. No. 5,925,037, U.S. Pat. No. 5,944,714, U.S.
Pat. No. 5,947,963, U.S. Pat. No. 5,976,126, U.S. Pat. No. 6010498,
U.S. Pat. No. 6,066,133 and U.S. Pat. No. 6,083,220, each of which
is incorporated by reference herein in its entirety.
[0042] Upon release from microcatheter 50, occlusive member 20
expands as shown in FIG. 5. Occlusive member 20 may be made
expandable upon release using any number of methods known in the
art. For example, shape memory materials including both polymeric
and metallic materials may be employed, materials which are
swellable in an aqueous environment may be employed, compressed
foams, braided, woven, knit, felt-like materials, meshes, and so
forth, may also be employed. In this particular embodiment,
occlusive member 20 is shown in an umbrella-like form. However,
occlusive member 20 may be in the form of a disc, parabola, sphere,
or the like providing that it is of a configuration to block or
bridge the neck 19 of aneurysm 14 so that no fluid, or
substantially no fluid, may flow between vessel 12 and aneurysm 14.
Suitable materials for formation of such an occlusive member
include flexible polymeric materials, for example. Securement
member 30, is also not yet in its deployed configuration.
[0043] Occlusive member 20 is then pulled back until it comes in
contact with stent 10 and is now blocking the opening or neck 19 of
aneurysm 14 as shown in FIG. 6. At this point, securement member
30, is at least partially protruding through the opposite side of
the stent struts 15 as the occlusive member 20, and is still in an
unexpanded configuration.
[0044] The securement member 30 is then released by pulling back on
the catheter device 50 while maintaining the position of the pusher
wire 22 as shown in FIG. 7. The securement member 30 upon release
from the catheter device 50 expands. In its expanded configuration,
securement member 30 anchors the vaso-occlusive device 100 to the
stent 10. The securement member 30 is located on the opposite side
of the stent struts 15 as the occlusive member 20. Securement
member 30 may operate in one of several different ways. Desirably,
the securement member 30 operates by either expanding to the point
at which it may no longer fit back through the opening 17 between
stent struts 15 through which it initially came, or it may be
constructed of a shape memory material, for example, that remains
inside the microcatheter 50 until deployment of the occlusive
member 20. Thus, it does not deploy until the occlusive member 20
is deployed.
[0045] In FIG. 7, the microcatheter 50 is shown being drawn away
from the vaso-occlusive device, releasing the securement member 30
which then lays open and flat against the stent struts 15. The
securement member 30 extends through and is located on the opposite
side of the occlusive member 20 and effectively anchors the
vaso-occlusive device 100 into position.
[0046] FIG. 8 illustrates generally at 110 a catheter delivery
device having a vaso-occlusive device 100 disposed inside a
retractable sheath 116 at the distal end 112 of the catheter
delivery device 110. The catheter device has a tubular support
structure 114. In this embodiment, a guidewire 75 is first
positioned inside the vasculature. The catheter delivery device 110
is then maneuvered through the vasculature over the guidewire 75 to
the site of the vascular defect (not shown) wherein a support
structure such as a stent, has already been positioned. The
catheter delivery device 110 is then maneuvered between struts 15
of the stent structure and is positioned in the vascular defect
(not shown). In FIG. 8, the catheter delivery device 110 is shown
positioned between two struts 15. The vaso-occlusive device is not
yet deployed.
[0047] In FIG. 9, the retractable sheath 116 is shown in a
partially pulled back position releasing the occlusive member 20 of
the vaso-occlusive device 100.
[0048] In FIG. 10, the retractable sheath 116 has been pulled back
all the way further releasing the securement member 30 of the
vaso-occlusive device 100.
[0049] The vaso-occlusive device 100 as shown in FIGS. 8-10,
illustrates an embodiment of the vaso-occlusive device in which the
occlusive member 20 has a frame 118 which in its unexpanded state
as shown in FIG. 8 and in an expanded state as shown in FIG. 10, is
similar to an umbrella. The frame 118 has individual spokes 120
which in the expanded state support the canopy 122 of the
umbrella-like structure.
[0050] FIG. 11 illustrates one embodiment of the securement member
30 of the vaso-occlusive device of the present invention in which
securement member 30 is formed from a swellable material such as a
hydrogel which swells upon exposure to an aqueous environment, or
one with memory such as a compressed foam wherein the material
returns to its original shape upon release from the microcatheter
50. In FIG. 11, securement member 30 is shown just released from
microcatheter 50 and is not yet in its expanded configuration.
Struts 15 are shown on either side of the securement member 30.
FIG. 12 illustrates the same securement member 30 as in FIG. 11,
but in a deployed configuration. Struts 15, are now located between
occlusive member 20, which is now in an expanded configuration, and
securement member 30, which is also in a deployed configuration.
FIG. 12 shows the securement member 30 wherein it is anchored to
the stent by "wrapping" itself around the stents struts 15 in its
deployed state. Occlusive member 20, may also be formed from the
same swellable material, or the same material having memory as
securement member 30. It may also be formed of a different
material.
[0051] FIG. 13 illustrates an alternative embodiment of the
vaso-occlusive device of the present invention in which the
securement member 30 is formed from strut-like elements 60 which
are held inside microcatheter 50. The struts 15 may be leaf shaped
(as shown) on a flattened helical form, or may be any shape which
can be compressed to fit within a microcatheter and can expand to a
shape which cannot fit through the openings in the strut 15. When
microcatheter 50 is pulled back from stent 10, the strut-like
elements 60, are released and open, laying flat against stent
struts 15 as shown in FIG. 14. In this embodiment, strut-like
elements 60 of securement member 30, may be formed of a shape
memory material such as NITINOL.RTM., or may be formed from a
superelastic material.
[0052] Also visible in FIG. 14, is a severable junction 40 which is
described above. Severable junction 40, in this embodiment, is
shown in contact with occlusive member 20, as opposed to the
embodiment shown in FIGS. 11 and 12, in which severable junction
40, is shown in contact with securement member 30.
[0053] FIG. 15 illustrates an embodiment of the vaso-occlusive
device of the present invention in which both the occlusive member
20 and the securement member 30 are formed from a single material.
In this embodiment, a material which swells upon exposure to an
aqueous environment. Such materials include, for example,
hydrogels, compressed foams, or the like. Swellable materials are
discussed in more detail below. As shown in FIG. 15, both the
occlusive member 20 and the securement member 30 have been released
using the pusher wire, and they begin to swell. The vaso-occlusive
device 100 is then brought down into the neck of the aneurysm such
that the securement member 30 is on the opposite side of the stent
struts 15 from the occlusive member 20. The swelling continues and
the device blocks the aneurysm. The device is in its fully expanded
configuration in FIG. 16. As can be seen from FIG. 16, the
securement member 30 is on one side of the struts 15 and the
occlusive member 20 is on the opposite side and actually in the
aneurysm (not shown). In this manner, the securement member 30
anchors the vaso-occlusive device 100 to the stent.
[0054] In another embodiment, rather than deploying the
vaso-occlusive device 100 (only shown in partial view) through
openings formed between stent struts, the stent may be made with a
specialized opening 70 for accepting the vaso-occlusive device 100
of the present invention as shown in FIG. 17.
[0055] Again, in FIGS. 15-17, a severable junction 40 is shown for
detaching vaso-occlusive device 100 from catheter delivery device
50.
[0056] While in the embodiments described above, only one
securement member has been employed in each embodiment, one or more
securement members may be employed in the present invention.
Securement members of any shape may be employed.
[0057] Further, support structures of any shape may be employed.
For example, linear, Y-shaped, T-shaped stents, and so forth may be
employed.
[0058] The occlusive portion of the device according to the present
invention may be manufactured from any of a variety of materials
including, but not limited to, polymeric materials. Examples of
useful polymeric materials include both synthetic and natural
materials. Further, the materials may be biocompatible and/or
biodegradable materials. Examples of useful polymer materials
include, but are not limited to, polyolefins including polyethylene
and polypropylene, polyesters such as
polyethyleneterephthalate(PET) and polybutylene terephthalate
(PBT), polyurethanes, acrylics, polypeptides, polyethers,
polyamides, fluoropolymers such as expanded
polytetrafluoroethylene, and so on and so forth.
[0059] Swellable polymeric materials find utility herein. Such
materials include those which are known to expand and become
lubricious in aqueous fluids including, for example, a class of
materials referred to generally as hydrogels may also be employed
in the manufacture of the device according to the present
invention. Such materials include hydrophilic, macroporous,
polymeric, hydrogel foam material. Examples of such materials
include, but are not limited, polyvinylpyrrolindone, polyethylene
oxide and its copolymers with polypropylene oxide, polyacrylic
acids, polyvinyl alcohols, hyaluronic acid, heparin, chondroitin
sulfate, pectinic acid, carboxyl-derivatized polysaccharides,
polyhydroxy ethyl methacrylate, polyacrylamide, hydrolyzed
polyacrylonitriles, polymethacrylic acid, polyethylene amines,
polysaccharides, and copolymers and combinations thereof, and so
forth.
[0060] One particular example of a swellable material includes a
swellable foam matrix formed as a macroporous solid is described in
U.S. Pat. No. 5,750,585 which is incorporated by reference herein
in its entirety. This material includes a foam stabilizing agent
and a polymer or copolymer of a free radical polymerizable
hydrophilic olefm monomer cross-linked with up to about 10% by
weight of a multiolefin-functional cross-linking agent.
[0061] Naturally based materials or those which are biologically
derived which find utility herein include, but are not limited to,
collagen foams, harvested vascular material, films constructed from
processed tissues, and so forth.
[0062] Shape memory materials are suitable for use in formation of
the vaso-occlusive device of the present invention. Shape memory
materials may be polymeric or metallic. Shape memory materials have
the ability to remember their original shape, either after
mechanical deformation, or by cooling and heating. Such materials
are said to undergo a structural phase transformation. Typically,
shape memory polymers (SMPs) are found to be segregated linear
block co-polymers having a hard segment and a soft segment wherein
the hard segment is crystalline, with a defined melting point, and
the soft segment is amorphous, with a defined glass transition
temperature. However, the hard segment may be amorphous and have a
glass transition temperature rather than a melting point, and the
soft segment may be crystalline and have a melting point rather
than a glass transition temperature. The melting point or glass
transition temperature of the soft segment is substantially less
than the melting point or glass transition temperature of the hard
segment. Some examples of shape memory polymers include, but are
not limited to, those formed from polyethers, polyacrylates,
polyamides, polysiloxanes, polyurethanes, polyether amides,
polyurethane/ureas, polyether esters, urethane/butadiene
copolymers, polynorbornenes, and mixtures thereof. See, for
example, U.S. Pat. No. 5,506,300, U.S. Pat. No. 5,145,935, U.S.
Pat. No. 5,665,822, and U.S. Pat. No. 6,388,043 each of which is
incorporated by reference herein in its entirety.
[0063] Shape memory metals suitable for use herein include the
alloys of TiNi (NITINOL.RTM.), CuZnAl, and FeNiAl, for example.
These materials undergo a structure phase transformation referred
to as a martensitic transformation.
[0064] Compressed foams may also be employed in the present
invention because they have the ability to return to their original
shape. Both open and closed cell foams may be employed. Materials
satisfactory for use in compressed foams include, but are not
limited to medical grade silicones and polyurethanes. As described
above, natural materials such as collagens, may also be employed to
make a compressed foam material.
[0065] Bioactive materials or materials having incorporated
bioactive agents which facilitate aneurysm healing may also be
employed in the construction of the device. Bioactive materials
include agents which illicit a biological response within a
patient. Such bioactive include therapeutic agents and drugs, for
example. These agents may promote healing, tissue growth, cell
growth, and so forth.
[0066] The vaso-occlusive device, in particular, the occlusive
member, may be formed with a braided, woven, or mesh
configuration.
[0067] Copolymers, and crosslinkable versions of the above
described materials may also be suitable for use herein. And, of
course, mixtures of the various materials described above may also
be employed in the manufacture of the device according to the
present invention.
[0068] A single material may be employed in forming both the
occlusive member and the securement member, or different materials
may be employed as described in some of the embodiments above.
Additionally, one or more materials may be employed in forming only
the occlusive member and/or the securement member. For example, in
a further embodiment, the occlusive member may be formed of a
combination of at least one polymeric material and at least one
metal. In this embodiment, a metallic material such as a shape
memory alloy, is employed to form the strut parts of an umbrella
like structure which has an occlusive member similar to the canopy
of an umbrella, and further has a frame including a plurality of
spokes for providing support to the canopy. The canopy is formed of
a polymeric material while the frame may be formed a metallic
material or a polymeric material, for example. The frame and canopy
have an expanded configuration and an unexpanded configuration for
delivery.
[0069] The above lists of materials are intended for illustrative
purposes only and are by no means exhaustive. One of ordinary skill
in the art knows materials of the types described above.
[0070] The material from which the vaso-occlusive device is formed,
or the vaso-occlusive device itself may be modified, or provided
with additives, to make the vaso-occlusive device visible by
conventional imaging techniques. For example, the device may be
rendered visible using fluoroscopic techniques, rendered MRI
visible, or both. This can be accomplished through the use of
markers such as wire windings, marker bands, rivets, plugs, and so
forth, or the radiopaque or MRI visible materials may be
incorporated into the material from which the vaso-occlusive device
is formed. Any suitable radiopaque or MRI visible material may be
employed.
[0071] Suitable materials for providing radiopacity to the device
include, but are not limited to, platinum, rhodium, palladium,
rhenium, iridium, tantalum, tungsten, gold, silver, alloys of these
metals, as well as polymeric materials with barium, for example.
Radiopacity is desirable for visualization of the device for
purposes of positioning the device at the site of the defect and to
position inside the defect and for proper anchoring of the
device.
[0072] The invention is further directed to the combination of a
vaso-occlusive device having at least one securement member and a
stent, where the at least one securement member is secured to the
stent. Also, the invention is directed to the combination of a
delivery catheter and a vaso-occlusive device having at least one
securement member.
[0073] The invention is further directed to a method of occluding a
vascular defect having an opening. The method comprises the steps
of:
[0074] a) deploying a support structure, as discussed above, to the
vascular defect, the support structure having an opening for
accepting a vaso-occlusive device;
[0075] b) deploying a vaso-occlusive device having at least one
occlusive member having an expanded configuration and an unexpanded
configuration, as discussed above and at least one securement
member, as discussed above, through the opening of the support
structure and through the opening of the vascular defect into the
vascular defect;
[0076] c) expanding the at least one occlusive member; and
[0077] d) anchoring the vaso-occlusive device to the support
structure with the at least one securement member.
[0078] The invention is also directed to a method of closing and
occluding an opening of an aneurysm from a parent blood vessel. The
method comprises the steps of:
[0079] a) deploying a support structure, as discussed above, at the
site of the aneurysm, the support structure having at least one
opening for accepting a vaso-occlusive device as discussed above,
the vaso-occlusive device having at least one occlusive member
which has an unexpanded configuration and an expanded configuration
and at least one securement member, the support structure
positioned at the opening of the aneurysm such that the at least
one opening of the support structure is aligned with the opening of
the aneurysm;
[0080] b) deploying the vaso-occlusive device wherein the at least
one occlusive member is in its unexpanded configuration, through
the at least one opening of the support structure and the opening
of the aneurysm and into the aneurysm;
[0081] c) expanding the at least one occlusive member of the
vaso-occlusive device to its expanded state whereby the
vaso-occlusive device blocks the opening of the aneurysm from the
parent blood vessel in its expanded state; and
[0082] d) anchoring the vaso-occlusive device to the support
structure with the at least one securement member.
[0083] The above disclosure is intended for illustrative purposes
only and is not exhaustive. The embodiments described therein will
suggest many variations and alternatives to one of ordinary skill
in this art. All these alternatives and variations are intended to
be included within the scope of the attached claims. Those familiar
with the art may recognize other equivalents to the specific
embodiments described herein which equivalents are also intended to
be encompassed by the claims attached hereto.
* * * * *