U.S. patent application number 10/696667 was filed with the patent office on 2005-05-05 for expandable stent having removable slat members.
Invention is credited to Pino, Esteban, Pomeranz, Mark L..
Application Number | 20050096725 10/696667 |
Document ID | / |
Family ID | 34522907 |
Filed Date | 2005-05-05 |
United States Patent
Application |
20050096725 |
Kind Code |
A1 |
Pomeranz, Mark L. ; et
al. |
May 5, 2005 |
Expandable stent having removable slat members
Abstract
A medical device having an outer and an inner expandable stent
in which the inner expandable stent is coaxially disposed within
the outer expandable stent. The medical device further includes
three removable slat members carried by the outer stent and three
removable slat members carried by the inner expandable stent. The
removable slat members provide a substantially continuous cover for
the medical device and thus impede the flow of blood through the
walls of the medical device. When deployed within a blood vessel,
some of the slat members serve to cover an aneurysm and restrict
the blood flow into the aneurysm; however, one or more of the slat
members may be selectively removed to provide blood flow into a
branching blood vessel.
Inventors: |
Pomeranz, Mark L.; (Davie,
FL) ; Pino, Esteban; (Tampa, FL) |
Correspondence
Address: |
PHILIP S. JOHNSON
JOHNSON & JOHNSON
ONE JOHNSON & JOHNSON PLAZA
NEW BRUNSWICK
NJ
08933-7003
US
|
Family ID: |
34522907 |
Appl. No.: |
10/696667 |
Filed: |
October 29, 2003 |
Current U.S.
Class: |
623/1.12 ;
623/1.15 |
Current CPC
Class: |
A61F 2/90 20130101; A61F
2/852 20130101; A61F 2/91 20130101; A61F 2/07 20130101; A61F
2250/0059 20130101; A61F 2002/075 20130101; A61F 2250/0063
20130101; A61F 2/856 20130101 |
Class at
Publication: |
623/001.12 ;
623/001.15 |
International
Class: |
A61F 002/06 |
Claims
That which is claimed is:
1. A medical device comprising: an expandable stent which takes the
form of a small diameter skeletal tubular member having a thin
wall, said wall of said skeletal tubular member including a
plurality of cells which are formed by a plurality of
interconnected strut members; and, an elongated removable slat
member interwoven between at least two of said plurality of strut
members to temporarily attach said removable slat member to said
skeletal tubular member to thereby provide a cover for a portion of
the wall of said skeletal tubular member.
2. A medical device as defined in claim 1, including a plurality of
elongated removable slat members interwoven between said plurality
of strut members to temporarily attach said plurality of removable
slat members to said skeletal tubular member and to thereby provide
a cover for a portion of the wall of said skeletal tubular
member.
3. A medical device as defined in claim 2, including a plurality of
tethers each attached to one of said plurality of removable slat
members in order to selectively remove any one of said removable
slat members to thereby provide a selective passage for blood flow
through a portion of the wall of said skeletal tubular member.
4. A medical device as defined in claim 3, wherein said tethers are
removably attached to the removable slat members.
5. A medical device as defined in claim 3, wherein said tethers
take the form of elongated puller wires.
6. A medical device as defined in claim 3, wherein said tethers are
comprised of a bioabsorbable material.
7. A medical device comprising: an expandable stent which takes the
form of a hollow tubular member comprised of an expandable wire
frame having a peripheral surface; and, an elongated removable slat
member carried by said hollow tubular member and providing a cover
for a portion of the peripheral surface of said hollow tubular
member.
8. A medical device as defined in claim 7, including a tether
attached to said removable slat member so that said tether may be
pulled to remove said slat member from said hollow tubular
member.
9. A medical device as defined in claim 8, wherein said tether is
removably attached to said removable slat member.
10. A medical device as defined in claim 8, wherein said tether is
comprised of a bioabsorbable material.
11. A medical device as defined in claim 7, including a plurality
of removable slat members carried by said hollow tubular member to
thereby provide a cover for a portion of the peripheral surface of
said hollow tubular member.
12. A medical device as defined in claim 11, including a plurality
of tethers each attached to one of said plurality of removable slat
members in order to selectively remove any one of said plurality of
removable slat members.
13. A medical device as defined in claim 12, wherein said plurality
of tethers are removably attached to said removable slat
members.
14. A medical device as defined in claim 12, wherein said tethers
takes the form of an elongated puller wire.
15. A medical device as defined in claim 12, wherein said tethers
are comprised of a bioabsorbable material.
16. A medical device comprised of: An outer expandable stent which
takes the form of a first hollow skeletal tubular member which
defines a first peripheral surface; a first plurality of removable
slat members carried by said first skeletal tubular member and
spaced apart at approximately equal distances around the first
peripheral surface of said first skeletal tubular member to thereby
provide a cover for a portion of said first peripheral surface; an
inner expandable stent which takes the form of a second hollow
skeletal tubular member which defines a second peripheral surface;
a second plurality of removable slat members carried by said second
skeletal tubular member and space apart at approximately equal
distances around the second peripheral surface of said second
skeletal tubular member to thereby provide a cover for a portion of
said second peripheral surface, said second skeletal tubular member
being coaxially disposed within said first skeletal tubular member
and being oriented such that said first plurality of removable slat
members and said second plurality of removable slat members form a
substantially continuous cover for said medical device; a first
plurality of tethers each attached to one of said first plurality
of removable slat members in order to selectively remove any one of
said first plurality of slat members to thereby provide a selective
passage for blood flow through the first peripheral surface; and, a
second plurality of tethers each attached to one of said second
plurality of removable slat members in order to selectively remove
any one of said second plurality of slat members to thereby provide
a selective passage for blood flow through the second peripheral
surface.
17. A medical device comprised of: an outer expandable stent which
takes the form of a first hollow skeletal tubular member which
defines a first peripheral surface and having a first plurality of
cells formed by a first plurality of interconnected strut members;
a first plurality of removable slat members interwoven between said
first plurality of strut members of said first skeletal tubular
member and spaced apart at approximately equal distances around the
first peripheral surface of said first skeletal tubular member to
thereby cover a portion of said first peripheral surface; an inner
expandable stent which takes the form of a second hollow skeletal
tubular member which defines a second peripheral surface and having
a second plurality of cells formed by a second plurality of
interconnected strut members; a second plurality of removable slat
members interwoven between said second plurality of strut members
of said second skeletal tubular member and spaced apart at
approximately equal distances around the second peripheral surface
of said second skeletal tubular member to thereby cover a portion
of said second peripheral surface, said inner expandable stent
being coaxially disposed within said outer expandable stent and
oriented such that said first plurality of slat members and said
second plurality of slat members form a substantially continuous
cover for said medical device; a first plurality of detachable
tethers each attached to one of said first plurality of slat
members in order to selectively remove any one of said first
plurality of slat members to thereby provide a selective passage
for blood flow through the first peripheral surface of said outer
expandable stent; and, a second plurality of detachable tethers
each attached to one of said second plurality of slat members in
order to selectively remove any one of said second plurality of
slat members to thereby provide a selective passage for blood flow
through the second peripheral surface of said inner expandable
stent.
18. A method of treating a vascular disease comprising the steps
of: providing a covered stent having an expandable tubular frame, a
cover member carried by said tubular frame and including a
detachable portion; inserting said covered stent into a blood
vessel of a patient; positioning said covered stent adjacent to a
diseased portion of said blood vessel; and, removing said
detachable portion of said cover member from said covered stent and
withdrawing said detachable portion from said blood vessel thereby
allowing blood to flow through a portion of the cover member of
said covered stent at the location of the detachable portion and
into surrounding blood vessels.
19. A method of treating an aneurysm comprising the steps of:
providing an expandable stent which takes the form of a skeletal
tubular member having a peripheral surface and a plurality of
removable slat members each carried by said skeletal tubular member
to provide a cover for a portion of said peripheral surface;
inserting said expandable stent into a blood vessel of a patient;
advancing said expandable stent through said blood vessel until
said expandable stent is aligned with and covering an aneurysm in
said blood vessel; and, removing one of said plurality of removable
slat members to thereby provide blood flow to a branching blood
vessel.
20. A method of treating an aneurysm comprising the steps of:
providing a medical device including an outer expandable stent
which takes the form of a first skeletal tubular member which
defines a first peripheral surface, a first plurality of removable
slat members carried by said first skeletal tubular member to
provide a cover for a portion of said first peripheral surface, a
first plurality of tethers each attached to one of said first
plurality of slat members, an inner expandable stent which takes
the form of a second skeletal tubular member which defines a second
peripheral surface, a second plurality of removable slat members
carried by said second skeletal tubular member to provide a cover
for a portion of said second peripheral surface, and a second
plurality of tethers each attached to one of said second plurality
of slat members, said inner expandable stent being coaxially
disposed within said outer expandable stent and positioned such
that said first plurality of removable slat members and said second
plurality of removable slat members form a substantially continuous
cover for said medical device; inserting said medical device into a
blood vessel of a patient; advancing said medical device distally
through said blood vessel until said medical device is aligned with
and covering an aneurysm in said blood vessel; and, selectively
removing any one of said second plurality of removable slat members
by moving the tether attached to said removable slat member
proximally and thus allowing blood to flow into a branching blood
vessel.
21. A medical device comprising: an expandable stent which takes
the form of a small diameter skeletal tubular member having a thin
wall; a cover member carried by said skeletal tubular member
including a removable section; and, an elongated activation member
connected to said removable section for withdrawing the removable
section of the cover member from the skeletal tubular member in
order to permit blood to flow through a portion of the wall of the
skeletal tubular member.
22. A medical device as defined in claim 21, wherein said elongated
activation member is removably attached to said removable section
of the cover member.
23. A medical device as defined in claim 21, wherein said elongated
activation member takes the form of a puller wire.
24. A medical device as defined in claim 21, wherein said elongated
activation member is formed of a bioabsorbable material.
25. A medical device comprising: an expandable stent which takes
the form of a small diameter skeletal tubular member having a thin
wall, said wall of said skeletal tubular member including a
plurality of cells which are formed by a plurality of
interconnected strut members; a cover member carried by said
skeletal tubular member including a plurality of removable
sections; and, a plurality of elongated activation members each
connected to one of said removable sections for withdrawing a
selected one of said plurality of removable sections of said cover
member.
26. A medical device as defined in claim 24, wherein said elongated
activation member is removably attached to said removable section
of the cover member.
27. A medical device as defined in claim 24, wherein said elongated
activation member takes the form of a puller wire.
28. A medical device as defined in claim 24, wherein said elongated
activation member is formed of a bioabsorbable material.
29. A medical device comprising: an outer expandable stent which
takes the form of a first hollow skeletal tubular member having a
peripheral surface; a first cover member carried by said first
hollow skeletal tubular member, and covering a portion of the
peripheral surface of said first skeletal tubular member and said
first cover member including a first removable section; an inner
expandable stent which takes the form of a second hollow skeletal
tubular member having a peripheral surface and being disposed
coaxially within the first skeletal tubular member; a second cover
member carried by said second hollow skeletal tubular member and
covering a portion of the peripheral surface of said second
skeletal tubular member, said second cover member including a
second removable section, said first hollow skeletal tubular member
being oriented with respect to said second hollow skeletal tubular
member such that the first cover member and second cover member
cover substantially the entire peripheral surface of said
expandable stent; and, a first elongated activation member coupled
to said first removable section for withdrawing said first
removable section from said first hollow skeletal tubular member;
and, a second elongated activation member coupled to said second
removable section for withdrawing said second removable section
from said second hollow skeletal tubular member in order to permit
blood to flow through a portion of the peripheral surface of said
first hollow skeletal tubular member.
30. A medical device as defined in claim 28, wherein said elongated
activation member is removably attached to said removable section
of the cover member.
31. A medical device as defined in claim 28, wherein said elongated
activation member is removably attached to said removable section
of the cover member.
32. A medical device as defined in claim 28, wherein said elongated
activation member is removably attached to said removable section
of the cover member.
Description
BACKGROUND OF INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to intravascular stents and
methods of treating aneurysms, and more particularly, this
invention relates to a covered stent which may be modified to treat
an aneurysm located adjacent to a bifurcated blood vessel while
permitting blood to flow through the bifurcated vessel and method
of use thereof.
[0003] 2. Description of the Prior Art
[0004] Expandable stents are widely used in the treatment of
vascular diseases. Typically, a stent is inserted into a stenosed
blood vessel after an angioplasty to prevent the restenosis of the
blood vessels. Expandable stents are also used as aneurysm covers.
When a stent is placed across an aneurysm, the blood flow into the
aneurysm is decreased. Decreased blood flow within an aneurysm
promotes the formation of a thrombus within the aneurysm which
ultimately aids in protecting the aneurysm from further expansion
or rupture.
[0005] Optimally, a covered stent is positioned across an aneurysm
to completely restrict the blood flow into the aneurysm. Such
covered stents, typically covered with a material such as PTFE
provide suitable aneurysm covers; however, these stents have
certain limitations. For example, covered stents impede blood flow
into branching blood vessels. Thus, a covered stent may not be
suitable for treating an aneurysm at or near a bifurcated blood
vessel.
[0006] Several patents and patent applications disclose covered
stents with various modifications which tend to avoid these
limitations inherent with typical covered stents. For example, U.S.
Pat. No. 6,030,414, entitled "Variable Stent and Method for
Treatment of Arterial Disease," discloses a covered stent having
predetermined and sized lateral openings for the treatment of
arterial disease at or around the intersection of multiple
arteries; U.S. Pat. No. 6,497,722, entitled "Method and Apparatus
for In-Vivo Tailored Stents Indicated For Use in Tortuous Anatomy,"
discloses a stent having a side opening to allow unimpeded blood
flow to a branching vessel at the point of stenting; and, U.S.
Patent Application Publication No. 2003/0074049, entitled "Covered
Stents and Systems for Deploying Covered Stents," discloses a
covered stent which may be perforated in order to allow blood flow
into a side branch or bifurcated vessel.
SUMMARY OF THE INVENTION
[0007] In accordance with one aspect of the present invention,
there is provided a medical device comprising an expandable stent
which takes the form of a small diameter skeletal tubular member
having a thin wall. The wall of the skeletal tubular member
includes a plurality of cells which are formed by a plurality of
interconnected strut members. Additionally, the medical device
includes an elongated removable slat member interwoven between at
least two of the plurality of strut members. The removable slat
member is temporarily attached to the skeletal tubular member and
provides a cover for a portion of the wall of the tubular member by
impeding the flow of blood through that portion of the wall of the
tubular member. Alternatively, the medical device includes a
plurality of elongated removable slat members interwoven between
the strut members of the expandable stent to form a continuous
cover around the periphery of the stent.
[0008] The medical device further includes a plurality of tethers,
each of which are removably attached to one of the plurality of
removable slat members in order to selectively remove any one of
the slat members from the stent. By removing a slat member, a
physician may selectively provide a passage of blood through the
wall of the stent. Preferably, the tethers are coated with a
radiopaque material so that the tether attached to a selected
removable slat member may be identified under fluoroscopy.
Alternatively, the tethers are formed from a bioabsorbable material
so that the tethers which are not removed with their corresponding
slat member, will biodegrade and be absorbed by the body.
[0009] In accordance with still another aspect of the present
invention, there is provided a medical device comprising an
expandable stent which takes the form of a hollow tubular member
comprised of an expandable wire frame. Additionally, the medical
device includes an elongated removable slat member carried by the
expandable wire frame. The removable slat member provides a cover
for a portion of the peripheral surface of the expandable wire
frame and impedes the flow of blood through that portion of the
peripheral surface. Preferably, a tether is attached to the
proximal end of the removable slat member. In addition, the tether
is removably attached to the slat member so that if the slat member
is not to be subsequently removed, the tether may be detached from
the slat member and removed from the body.
[0010] In accordance with another aspect of the present invention,
there is provided a medical device comprising an expandable stent
which takes the form of a small diameter skeletal tubular member
having a thin wall. The wall of the skeletal tubular member
includes a plurality of cells which are formed by a plurality of
interconnected strut members. The medical device also includes a
detachable section. The detachable section is temporarily attached
to the skeletal tubular member and provides a cover for a portion
of the wall of the tubular member by impeding the flow of blood
through that portion of the wall of the tubular member. Upon
removal of the detachable section from the wall of the stent, blood
is permitted to flow out of the portion of the wall which was
covered by the detachable section.
[0011] In accordance with a further aspect of the present
invention, there is provided a medical device having an outer
expandable stent which takes the form of a first hollow skeletal
tubular member comprised of a first expandable wire frame, and a
first plurality of removable slat members carried by the first
expandable wire frame. The first plurality of removable slat
members are preferably spaced apart at approximately equal
distances along the first peripheral surface of the first skeletal
tubular member to thereby cover a portion of the first peripheral
surface of the first skeletal tubular member. The medical device
further includes an inner expandable stent which takes the form of
a second hollow skeletal tubular member having an inner expandable
wire frame, and a second plurality of removable slat members
carried by the second expandable wire frame. The second plurality
of removable slat members are space apart at approximately equal
distances along the second peripheral surface of the second
skeletal tubular member to thereby cover a portion of the second
peripheral surface of the second skeletal tubular member. The inner
expandable stent is coaxially disposed within the outer expandable
stent and is oriented with respect to the outer expandable stent
such that the first plurality of slat members and the second
plurality of slat members form substantially a continuous cover for
the medical device. Preferably, the medical device includes a
plurality of tethers. Each of said plurality of tethers is attached
to one of the plurality of slat members in order to remove a
selected one of the slat members from the medical device.
[0012] In accordance with still another aspect of the present
invention, there is provided a medical device having an outer
expandable stent. The outer expandable stent takes the form of a
first hollow skeletal tubular member comprised of a first plurality
of cells formed by a first plurality of interconnected strut
members, and a first plurality of removable slat members interwoven
between the first plurality of strut members along the first
longitudinal axis of the first skeletal tubular member. The first
plurality of removable slat members are spaced apart at
approximately equal distances along the first peripheral surface of
the first skeletal tubular member to thereby cover a portion of the
first peripheral surface of the first skeletal tubular member. The
medical device further includes an inner expandable stent which
takes the form of a second hollow skeletal tubular member comprised
of a second plurality of cells formed by a second plurality of
interconnected strut members, and a second plurality of removable
slat members interwoven between the second plurality of strut
members along the second longitudinal axis of the second skeletal
tubular member. The second plurality of removable slat members are
space apart at approximately equal distances along the second
peripheral surface of the second skeletal tubular member to thereby
cover a portion of the second peripheral surface of the second
skeletal tubular member. The inner expandable stent is coaxially
disposed within the outer expandable stent and oriented with
respect to the outer stent such that the first plurality of slat
members and the second plurality of slat members form substantially
a continuous cover for the medical device. In addition, the medical
device includes a plurality of detachable tethers, each attached to
one of the slat members in order to remove a selected one of the
slat members from the medical device.
[0013] In accordance with another aspect of the present invention,
there is provided a method of treating an aneurysm. The method
includes the steps of inserting a covered stent into a blood vessel
of a patient, positioning the covered stent adjacent to a diseased
portion of the blood vessel such as an aneurysm, and removing and
withdrawing a detachable portion of the side wall of the covered
stent. By removing the detachable portion of the side wall of the
covered stent, blood may flow through that portion of the wall of
the stent and into surrounding blood vessels which branch from the
main blood vessel.
[0014] In accordance with still another aspect of the present
invention, there is provided a method of treating an aneurysm. The
method includes the steps of inserting an expandable stent having
removable side slat members into a blood vessel of a patient,
advancing the expandable stent distally through the blood vessel
until the stent is aligned with and covering an aneurysm in the
blood vessel, and selectively removing any one of the removable
slat members. By removing the slat member, blood is permitted to
flow through the peripheral surface of the stent and into branching
blood vessels while maintaining a covering for the aneurysm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is an enlarged elevational view of a medical device
comprised of an outer and an inner expandable stent each having
three removable slat members;
[0016] FIG. 2 is an enlarged elevational view of the outer
expandable stent only with three removable slat members;
[0017] FIG. 3a, FIG. 3b, and FIG. 3c are enlarged cross-sectional
views of the medical device illustrated in FIG. 1 illustrating an
inner and outer expandable stent and slat members carried by the
stents prior to expansion, upon expansion, and upon removal of two
slat members, respectively;
[0018] FIG. 4 is an enlarged view of the medical device deployed
within a blood vessel and positioned across an aneurysm at a vessel
bifurcation prior to removal of any slat member;
[0019] FIG. 5 illustrates the medical device within a blood vessel
after partial removal of two slat members; and,
[0020] FIG. 6 shows the medical device having two slat members
fully removed in order to permit blood flow into a branching blood
vessel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] FIG. 1 illustrates a medical device 10 which may be used to
treat an aneurysm, such as an aneurysm within the brain, occurring
in a blood vessel at or near a bifurcation in the blood vessel. In
the preferred embodiment of the present invention, the medical
device 10 is comprised of an outer expandable stent 12 and an inner
expandable stent 14 coaxially disposed within the outer expandable
stent 12. Additionally, the medical device 10 includes a first
plurality of removable slat members 16a, 16b, 16c carried by the
outer expandable stent 12 and a second plurality of removable slat
members 18a, 18b, 18c carried by the inner expandable stent 14.
[0022] The medical device 10, as illustrated, includes a total of
six removable slat members, but it should be appreciated that the
medical device 10 may include more or less slat members depending
upon the size of the stent and the application of the device. The
removable slat members 16a, 16b, 16c, 18a, 18b, and 18c are
preferably formed of a material such as PTFE, often used in grafts,
but may be formed of other polymeric or metallic materials.
Attached to the proximal portion of each removable slat member 16a,
16b, 16c is one of a first set of detachable tethers 20a, 20b, 20c,
respectively, and attached to the proximal portion of each of the
other removable slat members 18a, 18b, 18c is one of a second set
of detachable tethers 22a, 22b, 22c, respectively.
[0023] For illustrative purposes only, FIG. 2 illustrates the
medical device 10 without the inner expandable stent 14. The inner
expandable stent 14 is identical to the outer expandable stent 12,
except that it is of a slightly smaller diameter. The outer
expandable stent 12 takes the form of a hollow skeletal tubular
member comprised of an expandable wire frame 24. The wire frame 24
is preferably formed of Nitinol material and is thereafter
heat-treated so as to exhibit superelastic properties at body
temperature. Alternatively the wire frame may be formed of other
metallic or polymeric materials. The peripheral surface 25 of the
wire frame 24 is comprised of a plurality of cells 26 which are
formed by a plurality of interconnected strut members 28 which may
take on many different patterns and configurations. Examples of
such patterns and configurations are disclosed in U.S. patent
application Ser. Nos. 10/163,116; 10/163,248; and 10/425,380,
entitled "Intravascular Stent Device," filed on Jun. 5, 2002, Jun.
5, 2002 and Apr. 29, 2003, respectively, and assigned to the same
assignee as the present patent application. Alternatively, the wire
frame 24 may take the form of a simple helically wound coil.
Interwoven between the interconnected strut members 28 of the outer
expandable stent 12 are three removable slat members 16a, 16b, 16c.
The removable slat members 16a, 16b, 16c provide a cover for a
portion of the peripheral surface 25 of the wire frame 24. When
implanted into a blood vessel, the covered portion of the outer
stent 12 will impede blood flow through the surface 25 of the outer
stent 12.
[0024] Attached to the proximal section of each removable slat
member 16a, 16b, 16c is one of a plurality of detachable tethers
20a, 20b, 20c. The detachable tethers 20a, 20b, 20c are used to aid
in the removal of the slat members 16a, 16b, 16c once the stent has
been placed into a blood vessel. The detachable tethers 20a, 20b,
20c preferably take the form of a stainless steel wire coated with
a radiopaque material. Alternatively, the detachable tethers 20a,
20b, 20c may be formed of a bioabsorbable polymeric material.
Additionally, the detachable tethers 20a, 20b, 20c may be detached
from the removable slat members 16a, 16b, 16c by mechanical,
chemical, or electromagnetic means.
[0025] FIGS. 3a, 3b, and 3c show cross-sectional views of the
medical device 10. In FIG. 3a, the medical device 10 is in a
compressed state. While in a compressed state, the medical device
10 may be delivered to a diseased blood vessel using a catheter
based delivery system. As shown, the inner expandable stent 14 is
coaxially disposed within the outer expandable stent 12. The first
plurality of removable slat members 16a, 16b, 16c are carried by
the wire frame 24 of the outer expandable stent 12. The removable
slat members 16a, 16b, 16c are preferably interwoven between the
strut members 28 of the outer expandable stent 12. Similarly, the
second plurality of removable slat members 18a, 18b, 18c are
carried by the wire frame 24 of the inner expandable stent 14 and
are preferably interwoven between the strut members 28 of the inner
expandable stent 14.
[0026] The inner expandable stent 14 is aligned within the outer
expandable stent 12 such that when expanded, as shown in FIG. 3b,
the removable slat members 16a, 16b, 16c, 18a, 18b, and 18c form a
continuous cover for the medical device 10. When the medical device
10 is deployed within a blood vessel, the removable slat members
16a, 16b, 16c, 18a, 18b, and 18c impede the flow of blood through
the peripheral surface of the medical device. By removing one of
the slat members 16a, 16b, 16c, 18a, 18b, and 18c, an opening would
be provided through the portion of the medical device 10 covered by
the removed slat member. Thus, a physician may re-establish patency
in a branching blood vessel while impeding blood flow through other
portions of the medical device 10.
[0027] FIG. 3c shows a cross-sectional view of the medical device
10 having two removable slat members 16b, 18b removed from the
medical device. The removal of the slat members 16b, 18b uncovers a
portion of the peripheral surfaces of the expandable stents 12, 14.
Thus, an opening 36 is formed for which blood may flow through the
medical device 10 and into branching blood vessels.
[0028] FIG. 4 illustrates a medical device 10 positioned adjacent
an aneurysm 32 at a bifurcation of a blood vessel 30 within the
brain of a patient. The removable slat members 16a, 16b, 16c, 18a,
18b, and 18c cover the medical device 10 and block the flow of
blood through the peripheral surface of the medical device. As
shown, the medical device 10 prevents blood flow into the adjacent
aneurysm 32. By restricting the blood flow into the aneurysm 32,
thrombus forms within the aneurysm and the pressure on the wall of
the aneurysm is relieved; however, the blood flow to a branching
blood vessel 34 has also been restricted.
[0029] FIG. 5 shows how patency to the branching blood vessel 34 is
re-established. The detachable tether 20b is moved proximally,
thereby pulling removable slat member 16b proximally through the
medical device 10. When the distal end 35 of the removable slat
member 16b is moved past the branching blood vessel 34, blood flow
returns to the branching blood vessel through the opening 36
through the peripheral surface of the medical device 10.
Additionally, the removable slat member 18b is removed by pulling
the detachable tether 22b proximally until the distal end 37 of the
slat member 18b has passed the branching blood vessel 34. The
removal of the slat member 18b further uncovers the medical device
10 and allows for increased blood flow into surrounding blood
vessels. In this fashion, patency may be re-established to
surrounding blood vessels while still covering the aneurysm 32.
[0030] Illustrated in FIG. 6 is the medical device 10 deployed
within the bifurcated blood vessel 30 and having two slat members
16b, 18b removed from the medical device. The remaining slat
members 16a, 16c, 18a, and 18c cover the portion of the medical
device 10 which is adjacent to the aneurysm 32. As shown, blood may
flow through the opening 36 in the medical device 10, but blood may
not flow into the aneurysm 32.
[0031] Also provided is a method of treating an aneurysm including
the steps of inserting the medical device 10 into the diseased
blood vessel 30 of a patient, advancing the medical device distally
through the blood vessel until the medical device is aligned with
and covering an aneurysm 32 in the blood vessel, and selectively
removing any one of the plurality of removable slat members 16a,
16b, 16c, 18a, 18b, and 18c by moving the tether 20a, 20b, 20c,
22a, 22b, and 22c attached to the selected slat member proximally
and thus allowing blood flow through the peripheral surface of the
medical device and into a branching blood vessel 34.
[0032] A novel medical device and method to treat an aneurysm at a
bifurcation has been disclosed. Although a preferred embodiment of
the present invention has been described, it should be understood
that various modifications such as for example removal of the
detachable section by an electrical or electrolytic process, by a
hydraulic process or by other mechanical processes may be made by
one skilled in the art without departing from the scope of the
claims which follow.
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