U.S. patent application number 11/593823 was filed with the patent office on 2007-03-29 for expandable stent having a dissolvable portion.
Invention is credited to Donald K. Jones.
Application Number | 20070073381 11/593823 |
Document ID | / |
Family ID | 35768244 |
Filed Date | 2007-03-29 |
United States Patent
Application |
20070073381 |
Kind Code |
A1 |
Jones; Donald K. |
March 29, 2007 |
Expandable stent having a dissolvable portion
Abstract
An expandable stent having a covering which exhibits the
characteristic of upon being activated by applying an agent to the
covering, dissolving to expose a portion of the underlying stent.
The stent may be placed across the neck of an aneurysm to seal the
aneurysm and thereafter a selected region of the covering may be
dissolved by an activating agent to permit blood to flow to
adjacent vessels.
Inventors: |
Jones; Donald K.;
(Lauderhill, FL) |
Correspondence
Address: |
PHILIP S. JOHNSON;JOHNSON & JOHNSON
ONE JOHNSON & JOHNSON PLAZA
NEW BRUNSWICK
NJ
08933-7003
US
|
Family ID: |
35768244 |
Appl. No.: |
11/593823 |
Filed: |
November 7, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10976412 |
Oct 28, 2004 |
7147659 |
|
|
11593823 |
Nov 7, 2006 |
|
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Current U.S.
Class: |
623/1.15 ;
623/1.46 |
Current CPC
Class: |
A61F 2002/061 20130101;
A61F 2/90 20130101; A61F 2250/0059 20130101; A61F 2/07
20130101 |
Class at
Publication: |
623/001.15 ;
623/001.46 |
International
Class: |
A61F 2/90 20060101
A61F002/90 |
Claims
1. An aneurysm treatment 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, a covering extending over a
portion of the expandable stent, said covering exhibiting the
characteristic of, upon being activated by applying an agent to
said covering, dissolving to expose a portion of the expandable
stent.
2. An aneurysm treatment device as defined in claim 1, wherein the
covering is formed of a material which is dissolvable when it comes
into contact with an activating agent.
3. An aneurysm treatment device as defined in claim 2, wherein said
expandable stent takes the form of a metallic skeletal tubular
member and said covering is formed from a polymer.
4. An aneurysm treatment device as defined in claim 3, wherein said
covering takes the form of ethylene vinyl alcohol and the
activating agent takes the form of dimethylsulfoxide.
5. An aneurysm treatment device as defined in claim 4, wherein the
covering takes the form of a thin film of ethylene vinyl alcohol
disposed on an outer surface of said expandable stent.
6. An aneurysm treatment device comprising: an expandable tubular
member having a thin wall, said wall of said tubular member is
formed of a material exhibiting the characteristic that when an
activating agent is applied to a portion of the wall of said
tubular member said portion of the wall dissolves to provide a
passageway through the wall.
7. An aneurysm treatment device as defined in claim 6, wherein the
wall of said expandable tubular member takes the form of ethylene
vinyl alcohol and the activating agent takes the form of
dimethylsulfoxide.
8. An aneurysm treatment device as defined in claim 7, wherein said
expandable tubular member takes the form of a thin film of ethylene
vinyl alcohol.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS(S)
[0001] This patent application is a divisional patent application
of U.S. patent application Ser. No. 10/976,412 (Attorney Docket No.
CRD5045USNP), filed on Oct. 28, 2004, entitled, "Expandable Stent
Having A Dissolvable Portion."
BACKGROUND OF INVENTION
[0002] 1. Field of the Invention
[0003] 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 methods
of use thereof.
[0004] 2. Description of the Prior Art
[0005] 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.
[0006] 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 or out of branching blood vessels. Thus, a covered stent may
not be suitable for treating an aneurysm at or near a bifurcated
blood vessel.
[0007] 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.
[0008] Also, U.S. patent application Ser. No. 10/696,667, filed on
Oct. 29, 2003 (Attorney Docket No. CRD5038), assigned to the same
assignee as the subject patent application discloses a covered
stent for treating an aneurysm which includes a skeletal stent
structure with removable slat members to permit blood to flow
through a bifurcated blood vessel. Upon deployment, one or more of
the slats may be removed to allow blood to flow through portions of
the stent structure while others of the slats are left in place to
seal the neck of an adjacent aneurysm. This patent application made
of record in the subject patent application and is hereby
incorporated and made a part of the subject application.
SUMMARY OF THE INVENTION
[0009] In accordance with one aspect of the present invention there
is provided an aneurysm treatment device including 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
defines a plurality of cells which are formed by a plurality of
interconnected strut members. Also, a covering extends over a
portion of the expandable stent. The covering exhibits the
characteristic of, upon being actuated by applying an activating
agent to the covering, dissolving to thereby expose a portion of
the expandable stent.
[0010] In accordance with another aspect of the present invention,
the expandable stent takes the form of a metallic structural
tubular member and the covering is formed from a polymer, such as
ethylene vinyl alcohol. The activating agent may take the form of
dimethylsulfoxide. If the activating agent is applied to a
selective portion of the coating that portion dissolves to expose
the underlying porous stent to permit blood to flow through the
stent while the balance of the stent remains intact to cover an
aneurysm.
[0011] In accordance with another aspect of the present invention,
there is provided a method of treating an aneurysm including the
method steps of providing an expandable stent including a skeletal
tubular member having a covering disposed onto the skeletal tubular
member, inserting the expandable stent into the blood vessel of a
patient, advancing the expandable stent until the covering on the
stent is aligned with and covers an aneurysm in the blood vessel,
expanding the expandable stent so that the covering extends across
the neck of an aneurysm, and applying an activating agent to a
portion of the covering to cause that portion of the covering to
dissolve to expose a portion of the underlying stent in order to
permit blood to flow through that portion of the stent while
maintaining a seal across the aneurysm.
[0012] In accordance with another aspect of the present invention
there is provided a method for treating an aneurysm including the
steps of providing an expandable stent including a skeletal tubular
member having a covering disposed onto the skeletal tubular member,
inserting said expandable stent into a blood vessel of a patient,
advancing the expandable stent until the covering on the stent is
aligned with and covers an aneurysm in the blood vessel and also
covers a branching blood vessel, expanding the skeletal tubular
member so that the covering extends across the neck of the aneurysm
and across a branching vessel, inserting a drug delivery catheter
into the branching vessel and advancing the distal tip of the drug
delivery catheter to have position proximate to a portion of the
covering of the stent which extends across the branching vessel,
and applying an activating agent through the drug delivery catheter
to that portion of the covering to thereby cause that portion of
the covering to dissolve and expose a portion of the porous tubular
member thereby permitting blood to flow to or from the branching
vessel.
[0013] In accordance with still another aspect of the present
invention, there is provided an aneurysm treatment device which
includes an expandable tubular member having a thin wall and in
which the wall of the tubular member is formed of a material which
exhibits the characteristic that when an activating agent is
applied to a portion of the wall of the tubular member that portion
of the wall dissolves to provide a passageway through the wall. The
wall of the expandable tubular member may be formed of ethylene
vinyl alcohol and the activating agent may take the form of
dimethylsulfoxide.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is an enlarged oblique view of a covered stent device
comprised of an expandable skeletal support member and a outer
covering which extends over a portion of the support member;
[0015] FIG. 2 is an enlarged elevational view of the covered stent
placed adjacent to the neck of an aneurysm and across a main artery
at a bifurcation;
[0016] FIG. 3 is an enlarged elevational view of the covered stent
illustrating an activating agent being applied to a portion of the
covering device at a branching vessel; and, FIG. 4 is an enlarged
elevational view of the covered stent with a portion of the
covering removed to expose the underlying porous skeletal
stent.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] FIG. 1 illustrates an expandable covered stent 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
covered stent 10 is comprised of an expandable skeletal stent 12
and an outer covering 14 disposed on the outer surface of the
skeletal stent 12.
[0018] More particularly, the skeletal stent 12 includes a
plurality of cells which are formed by a plurality of
interconnected strut members to thereby define a structure which
may be placed into a vessel and after being properly aligned may
then be expanded. The skeletal stent 12 may either take the form of
a balloon expandable stent or a self-expanding stent. An example of
such a self expanding stent is disclosed in U.S. Pat. No.
6,673,106, entitled, "Intravascular Stent Device," and an example
of a stent and stent deployment system is disclosed in U.S. patent
application Ser. No. 10/365,288, entitled, "Expandable Stent And
Delivery System," filed on Feb. 12, 2003, Attorney Docket No.
CRD1062. This patent and patent application are assigned to the
same assignee as the present patent application and are hereby made
of record and incorporated by reference into the present patent
application.
[0019] The outer covering 14 preferably takes the form of a
polymer, such as a thin film of ethylene vinyl alcohol which may be
bonded to the surface of the skeletal stent 12. This covering, as
will be described in more detail, serves to cover the neck of the
aneurysm. This material exhibits the characteristic of, upon being
activated by applying an agent to the covering, dissolving to
expose a portion of the underlying expandable stent.
[0020] FIG. 2 illustrates the covered stent 10 of FIG. 1 positioned
within a blood vessel such that the outer covering 14 extends
across the neck of an aneurysm 16. As with almost all vascular
stents, the covered stent is initially compressed and is passed
through the vessel and is then expanded with a balloon catheter or
is permitted to self expand into the position as shown. Also, since
the aneurysm 16 occurs at a location adjacent to a parent vessel 18
which serves to feed the branch vessels 20, 22, with the placement
of the stent with the outer covering 14 covering the neck of the
aneurysm 16, it will also obstruct the flow of blood from the
parent vessel 18 into the branching vessels 20, 22. Aneurysms
frequently occur at a bifurcated junction vessels, therefore, it
should be observed that one of the major advantages of the present
invention is that of providing a covered stent which serves to
provide a covering for the neck of the aneurysm while at the same
time being modified to allow blood to flow from a bifurcated vessel
to other vessels. This modification will be explained in more
detail with respect to the following drawings.
[0021] FIG. 3, which is similar to FIG. 2, illustrates the covered
stent 10 which extends from the branch vessel 20 to the branch
vessel 22 and is positioned so that the outer covering 14 occludes
both the aneurysm 16 and the parent vessel 18. Once the covered
stent 10 is properly placed within the blood vessels, a drug
delivery catheter 24 may be inserted into the vasculature and
passed through the parent vessel 18 so that the distal end 24a of
the drug delivery catheter is positioned in proximity to the outer
covering 14 of the covered stent 10 at a region 24a where the outer
covering 14 occluded the parent vessel 18. With the outer covering
14 formed of a thin film of ethylene vinyl alcohol, preferably an
activating agent 26 such as, for example, dimethylsulfoxide, is
applied to the outer covering 14 in the region where the outer
covering 14 occludes the parent vessel 18.
[0022] FIG. 4 illustrates the covered stent 10 after application of
the activating agent and, as is apparent, the activating agent, or
dimethylsulfoxide, has dissolved the covering formed of ethylene
vinyl alcohol in the desired region of the parent vessel 18 to
thereby expose the underlying porous skeletal stent 12 at location
28. The drug delivery catheter 24 is then removed from the
vasculature, with the result that the covered stent 10 serves to
occlude the neck of the aneurysm 16 while permitting blood to flow
through the parent vessel 18 and into the branch vessels 20,
22.
[0023] In summary, the device of the present invention may be used
to treat an aneurysm by providing an expandable stent including a
skeletal tubular member having a covering disposed onto the
skeletal member, inserting the expandable stent into a blood vessel
of a patient, advancing the expandable stent until the covered
stent is aligned with and covers an aneurysm in the blood vessel,
expanding the skeletal tubular member so that the covering extends
across the neck of the aneurysm, and applying an activating agent
to a portion of the covering to cause that portion of the covering
to dissolve and expose a portion of the underlying skeletal tubular
member. Once this method has been performed, the remaining portion
of the covering serves as a seal for the aneurysm while permitting
blood to flow through all of the adjacent vessels.
[0024] 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 a portion
of the covering by an electrical or electrolytic process, by a
heating process or by other processes may be made by one skilled in
the art without departing from the scope of the claims which
follow.
* * * * *