U.S. patent application number 13/675197 was filed with the patent office on 2013-03-21 for removable intravascular devices and methods of making and using the same.
This patent application is currently assigned to BOSTON SCIENTIFIC SCIMED, INC.. The applicant listed for this patent is Boston Scientific Scimed, Inc.. Invention is credited to Mel R. Beulke.
Application Number | 20130072962 13/675197 |
Document ID | / |
Family ID | 34920148 |
Filed Date | 2013-03-21 |
United States Patent
Application |
20130072962 |
Kind Code |
A1 |
Beulke; Mel R. |
March 21, 2013 |
REMOVABLE INTRAVASCULAR DEVICES AND METHODS OF MAKING AND USING THE
SAME
Abstract
An intravascular device, which may be a filter, that may include
a plurality of elongate members, each or several of the elongate
members may have one or more inwardly facing edges disposed at and
near the part of the intravascular device configured to contact the
vessel wall for cutting through the intima or other encapsulating
tissue, each of the elongate member may also include an anchoring
member or other desired components.
Inventors: |
Beulke; Mel R.;
(Bloomington, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Boston Scientific Scimed, Inc.; |
Maple Grove |
MN |
US |
|
|
Assignee: |
BOSTON SCIENTIFIC SCIMED,
INC.
Maple Grove
MN
|
Family ID: |
34920148 |
Appl. No.: |
13/675197 |
Filed: |
November 13, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10797879 |
Mar 10, 2004 |
8308750 |
|
|
13675197 |
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Current U.S.
Class: |
606/200 |
Current CPC
Class: |
A61F 2/01 20130101; A61F
2002/016 20130101; A61F 2230/0078 20130101; A61F 2230/005 20130101;
A61F 2/848 20130101; A61F 2230/0067 20130101 |
Class at
Publication: |
606/200 |
International
Class: |
A61F 2/01 20060101
A61F002/01 |
Claims
1. An intravascular filter having a central axis comprising an
elongate member; an anchoring member for anchoring the
intravascular filter to a vessel wall attached to the filter
member; and a cutting member disposed on the filter member and
generally facing towards the central axis.
Description
FIELD
[0001] This invention relates to intravascular devises and
particularly to intravascular devices which may be installed and
may optionally be subsequently removed.
BACKGROUND
[0002] Certain intravascular devices may be left in a body lumen
such as a blood vessel for a period of time. For example, a vena
cava filter may be implanted in the vena cava to capture blood
clots and other embolic debris and to retain the blood clots and
other embolic debris while they are lysed or until removed. It may
be desirable to leave this filter in place for a period of time
such as two or more weeks after an interventional procedure, and
then to remove the filter. These filters are often retained in
place by means of elongate members which contact the vessel wall.
The vessel wall frequently encapsulates the portion of the elongate
members which contact the wall with endothelial growth. Thus, if
removal is desired, it becomes necessary to free the elongate
members from this endothelial growth.
SUMMARY
[0003] One embodiment pertains to a filter which can be removed
from a vessel that has partially encapsulated it with minimal
trauma to the vessel. The filter of this embodiment is a Greenfield
style filter, though other filter configurations and other medical
devices are contemplated. The filter has one or more elongate
members configured to anchor to a vessel wall. Each elongate member
has a first end and a second end. Attached to the second end may be
an anchoring member for securing the filter to the vessel wall.
Extending along the elongate member from the second end is a
cutting edge. The cutting edge is directed towards a central
elongate axis of the filter and consequently away from the nearest
vessel wall.
[0004] A second embodiment pertains to a filter having one or more
elongate members with an inward facing cutting edge similar to the
first embodiment. The filter includes an inward facing cutting edge
on a portion of the elongate member which has a reduced profile, so
that the overall profile of that portion of the elongate member,
including the cutting edge, is no greater than that of another
portion of the elongate member.
[0005] Another embodiment pertains to a filter having one or more
elongate members similar to the first embodiment. Provided on these
elongate members are two or more cutting edges which may be
generally aligned and facing inwards. These two or more cutting
edges may be spaced apart from each other, providing gaps
therebetween.
[0006] Yet another embodiment pertains to a filter having one or
more elongate members similar to the first embodiment. At the end
of each of the elongate members is a anchoring member comprising a
hook, as will be described in more detail below. On the portion of
the hook that is generally parallel to the elongate member is
another cutting edge facing generally inwards.
[0007] Yet another embodiment pertains to a method of manufacture.
A filter having elongate members is provided. A portion of the
elongate members is worked to form an inward facing cutting edge.
This may be done, for example, by electron discharge machining
(EDM), by grinding, or by some other suitable process.
[0008] Yet another embodiment pertains to a second method of
manufacture. A filter having elongate members is provided. A blade
having a cutting edge is attached to an elongate member. This may
be done, for example, by laser welding. Additionally or
alternatively, a slot may be formed in the elongate member and a
cutting blade is partially inserted into the slot, leaving an
inward facing cutting edge exposed.
[0009] Yet another embodiment pertains to a method of use. A
medical device having elongate members such as a vena cava filter
is implanted in the vena cava, for example. The elongate members
retain the medical device in place and have inward facing cutting
edges disposed thereon. After a period, endothelial growth may
partially encapsulate the elongate members in a process called
neointimal hyperplasia. If removal is desired, the elongate members
may be urged radially inward, causing the cutting edges to cut
through the endothelial encapsulation. This defined cutting will be
less traumatic compared to removal of an embodiment which lacks
cutting edges and therefore must tear through any endothelial
encapsulation. The retrieval force needed will likely be less. The
medical device can then be compressed and removed from the vena
cava.
[0010] The above summary of some embodiments is not intended to
describe each disclosed embodiment or every implementation of the
present invention. The figures and detailed description which
follow more particularly exemplify these embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention may be more completely understood in
consideration of the following detailed description of various
embodiments of the invention in connection with the accompanying
drawings in which:
[0012] FIG. 1 is a perspective view of a vena cava filter according
to the invention;
[0013] FIG. 2 is a side view of a strut of the filter of FIG.
1;
[0014] FIG. 3 is a side view of an elongate member of an
intravascular device according to the invention;
[0015] FIG. 4 is a top view of an elongate member of an
intravascular device according to the invention;
[0016] FIG. 5 is a perspective view of a vena cava filter according
to the invention;
[0017] FIG. 6 is a side view of a strut of the filter of FIG. 5;
and
[0018] FIG. 7 is a diagrammatic view of a strut encapsulated in a
vessel wall.
DETAILED DESCRIPTION OF SELECTED EMBODIMENTS
[0019] The following detailed description should be read with
reference to the drawings, in which like elements in different
drawings are numbered identically. The drawings which are not
necessarily to scale, depict selected embodiments and are not
intended to limit the scope of the invention.
[0020] FIG. 1 is a perspective view of a vena cava filter 100
having an elongate member 102. Elongate member 102 may include an
anchoring member 104 disposed on the end. Detailed reference is
made to elongate member 102, but filter 100 may include additional
elongate members 106, which may be configured substantially like
elongate member 102. Filter 100 is selected to illustrate this
embodiment, but neither this embodiment or any embodiment is
limited to Filter 100. Other applications are contemplated. For
example, the embodiment may be readily adapted to other vena cava
filters. Indeed, the embodiment may be readily adapted to any
implantable medical device retained in position by elongate
members. Likewise, neither this embodiment or any embodiment is
limited to medical devices retained by generally straight elongate
members where an end of the elongate members is in contact with the
vessel wall. Embodiments are contemplated where the elongate member
contacts a vessel wall with a middle portion rather than an
extremity. Such an elongate member may be, for example, curved.
Embodiments, therefore, are contemplated with a wide variety of
medical devices of numerous configurations.
[0021] In the present embodiment, elongate member 102 may be made
from stainless steel or other suitable biocompatible materials such
as nickel-titanium alloys. Elongate member 102 has a generally
circular cross-section. Other suitable cross-sections are
contemplated. For example, elliptical or rectangular may be equally
or more suitable in certain applications. Elongate member 102 may
be, if desired coated with therapeutic agents. For example,
elongate member 102 may be coated with an agent to resist
neointimal hyperplasia.
[0022] Refer now to FIG. 2, which is an enlarged side view of an
end of elongate member 102. Anchor member 104 can be seen in
greater detail. Anchor member 104 has a hook shape with a barb 108
disposed on the end. The hook shape and bard 108 may be used to
retain filter 100 in a desired position. Disposed on elongate
member 102 is an edge 110. Edge 110 generally faces in towards the
center of filter 100 and away from the vessel wall. Edge 110 may be
disposed on a blade 112 or may be a shaped part of elongate member
102. For example, edge 110 may be formed by electron deposition
machining elongate member 102. Edge 110 may start near the hook end
of elongate member 102 and extend up a portion of elongate member
102. In one embodiment, edge 110 extends sufficiently up elongate
member 102 so that the a portion of edge 110 has little chance of
being encapsulated by a neointimal hyperplasia process. In other
words, edge 110 may extend far enough away from the vessel wall and
up elongate member 102 to keep exposed. Edge 110 should be sharp
enough to cut through vessel growth.
[0023] FIG. 3 is a side view of an elongate member 202 of an
intravascular device of another embodiment. Elongate member 202 may
be part of a vena cava filter or may be part of another
intravascular device. Elongate member may include an anchor member
204 and includes an edge 210. Edge 210 is disposed in a cut-out 214
of elongate member 204 and may be on a blade 212. The cut-out
serves to reduce the overall cross section of the elongate member
with the blade. In one embodiment, cut-out 214 is of sufficient
depth so that the cross-section of the portion of elongate member
202 with edge 210 does not extend beyond the portion of elongate
member 202 without a cut-out. Thus, the intravascular device may
have a reduced profile when compressed for insertion or
extraction.
[0024] FIG. 4 is a top view of an elongate member 302 of an
intravascular device according to the invention. Elongate member
302 includes an anchor member 304, which may be similar to anchors
members previously described or may be another suitable anchor
member. Elongate member includes an inward facing edge 310 and
anchor member 304 includes an inward facing edge 316. Thus, both
edges should face away from the portion of elongate member 302 and
anchor member 304 which are configured to contact the vessel wall.
Edges 310 and 316 are susceptible to several contemplated
variations. For example, in the pictured embodiment, the edges are
substantially straight and are disposed on substantially straight
portions of elongate member 302 and anchor member 304. In another
embodiment, edges 310 and 316 may extend to join and form one
continuous edge, curving between the elongate member and the anchor
member. In another embodiment, there may be a third edge between
edges 310 and 316, which may be disposed at a different angle and
yet still away from the vessel wall. For example, this third edge
may be disposed more towards the direction in which the
intravascular device may be retracted. In another embodiment, this
third edge may smoothly join with edges 310 and 316.
[0025] FIG. 5 is a perspective view of a thrombosis filter 400,
which includes several elongate members 402 having anchoring
members 404. FIG. 6 is a perspective view of an elongate member
402. Elongate member 402 includes a blade 412 having two or more
separated, inward facing edges 410. Edges 410 may be separate by a
break 418 in the blade. Break 418 may be a complete gap between two
sections of blade 412 or may be a partial removal of material. For
example, break 418 may be a v-shaped or u-shaped slot between two
portions of the blade. In another embodiment, break 418 is a slight
radial offset between two sections of blade 412 and may not include
a longitudinal gap. Break 418 may be created by removing material
during the shaping of the blade or by removing material after the
blade is assembled and joined. Break 418 may also be created by
assembling the blade to the elongate member in several pieces.
[0026] Other embodiments are contemplated. One example embodiment
of an intravascular device has elongate members where an edge that
faces generally inwards is set in a cut-out of the elongate member
to reduce the overall profile, where that edge also includes one or
more gaps. In another embodiment, one or more of the elongate
members may be coated with a therapeutic agent, such as an
anti-angiogenesis drug or other desired agent. In another
embodiment, the intravascular device has elongate members with
inward facing edges and anchor members configured to easily break
away from the device. The embodiments herein described are only a
limited selection of the contemplated embodiments and serve to
illustrate the invention and show the broad applicability of the
invention to many embodiments.
[0027] FIG. 7 is a diagrammatic view of a portion of elongate
member 102 after vena cava filter 100 has been installed in a vena
cava for a period of time sufficient for neointiminal hyperplasia
to occur. Elongate member 102 includes anchor member 104 and edge
110, which edge is disposed on blade 112. The wall of the vena cava
includes the adventitia 120, the media 122 and the intima 124. It
is this last layer, intima 124, that encapsulates the anchor member
and a portion of elongate member. As can be seen, edge 110 faces
away from the wall of the body vessel and towards the vessel
centerline. Egde 110 is configured to extend beyond the portion of
elongate member 102 likely to be encapsulated by intima 124 and
expected neointimal hyperplasia.
[0028] When removal of vena cava filter 100 is desired, it may be
accomplished by the following process, or by another suitable
process. Vena cava filter 100 may be held to prevent undesired
longitudinal motion, perhaps by grasping the filter with a
retention device on the end of a guide wire or by other suitable
method. Elongate member is urged inward. This urging may be
accomplished by the action of a catheter upon the elongate member,
for example. When a catheter is slid over the vena cava filter, the
inner lip of the catheter end will provide a force on the elongate
member that will tend to move the elongate member inwards. When the
elongate member is urged inward, edge 102 may cut through intima
124, and thus provide a passage for the end of the elongate member
and the anchor member through the intima. By cutting rather than
tearing a passage through the intima, trauma to the vessel wall may
be reduced. Trauma is reduced because a cut is generally less
traumatic to tissue than a tear. Trauma is also reduced because a
cut may be created using less force than a tear, and thus the
surrounding tissue is subjected to less force. Also, less force
needs to be delivered via the catheter. Thus, removal is possible
in more situations. The urging of the elongate member may be done
using one full motion, or may be done using smaller, reciprocating
motions if desired. By providing a configuration where the edge
extends from the intima into the vessel lumen, a spot on the vessel
wall is provided where the cut may be readily started. When the
intima is cut, the end portion of elongate member 102 and anchor
member 104 may be readily removed from the vessel wall and the vena
cava filter may then be compressed and removed.
[0029] Numerous advantages of the invention covered by this
document have been set forth in the foregoing description. It will
be understood, however, that this disclosure is, in many respects,
only illustrative. Changes may be made in details, particularly in
matters of shape, size, and arrangement of parts or order of steps
without exceeding the scope of the invention. The invention's scope
is, of course, defined in the language in which the appended claims
are expressed.
* * * * *