U.S. patent application number 11/299992 was filed with the patent office on 2006-05-04 for expandable stent and delivery system.
Invention is credited to Angeli Escamilla, Donald K. Jones, Vladimir Mitelberg.
Application Number | 20060095213 11/299992 |
Document ID | / |
Family ID | 31949831 |
Filed Date | 2006-05-04 |
United States Patent
Application |
20060095213 |
Kind Code |
A1 |
Escamilla; Angeli ; et
al. |
May 4, 2006 |
Expandable stent and delivery system
Abstract
An expandable stent and delivery system is provided for
enhancing luminal dilation of a blood vessel and treating
aneurysms. The delivery system includes proximal, intermediate and
distal cylindrical members disposed on and spaced apart along an
elongated core member such that first and second gaps are formed.
The expandable stent includes anchor members which align with the
gaps. The expandable stent is mounted on the intermediate
cylindrical member, and the anchor members are disposed within the
gaps thereby locking the stent onto the core member.
Inventors: |
Escamilla; Angeli; (Miami,
FL) ; Jones; Donald K.; (Lauderhill, FL) ;
Mitelberg; Vladimir; (Aventura, FL) |
Correspondence
Address: |
PHILIP S. JOHNSON;JOHNSON & JOHNSON
ONE JOHNSON & JOHNSON PLAZA
NEW BRUNSWICK
NJ
08933-7003
US
|
Family ID: |
31949831 |
Appl. No.: |
11/299992 |
Filed: |
December 12, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10365282 |
Feb 12, 2003 |
7001422 |
|
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11299992 |
Dec 12, 2005 |
|
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60412867 |
Sep 23, 2002 |
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Current U.S.
Class: |
702/22 |
Current CPC
Class: |
A61F 2/91 20130101; A61F
2002/9155 20130101; A61F 2/95 20130101; A61F 2002/823 20130101;
A61B 17/12022 20130101; A61B 2017/1205 20130101; A61F 2002/8486
20130101; A61F 2250/0098 20130101; A61F 2002/91541 20130101; A61B
17/1214 20130101; A61F 2002/91558 20130101; A61F 2002/91533
20130101; A61F 2/966 20130101; A61F 2002/9665 20130101; A61F 2/915
20130101; A61B 17/12118 20130101 |
Class at
Publication: |
702/022 |
International
Class: |
G01N 31/00 20060101
G01N031/00; G06F 19/00 20060101 G06F019/00 |
Claims
1. A method for deploying an expandable stent within a blood vessel
to enhance luminal dilation of the blood vessel, the method
comprising the steps of: providing an expandable stent and delivery
system, said expandable stent mounted on at least one cylindrical
member along a core member of said delivery system, said stent
having at least one anchor member interlocked within at least one
gap along said core member, said gap formed by spaces between a
plurality of cylindrical members disposed on said core member, said
delivery system including a deployment catheter disposed about said
stent maintaining said stent in a constrained configuration;
inserting said expandable stent and delivery system into a blood
vessel; positioning said expandable stent adjacent to a blockage
area within said vessel; moving said deployment catheter proximally
allowing said stent to begin expanding within said vessel; further
moving said deployment catheter proximally allowing said stent to
fully deploy causing said vessel to increase luminal dilation; and,
removing said delivery system from said blood vessel.
2. A method for deploying an expandable stent within a blood vessel
to treat an aneurysm, the method comprising the steps of: providing
an expandable stent and delivery system, said expandable stent
mounted on at least one cylindrical member along a core member of
said delivery system, said stent having at least one anchor member
interlocked within at least one gap along said core member, said
gap formed by spaces between a plurality of cylindrical members
disposed on said core member, said delivery system including a
deployment catheter disposed about said stent maintaining said
stent in a constrained configuration; inserting said expandable
stent and delivery system into a blood vessel; positioning said
expandable stent adjacent to an aneurysm; moving said deployment
catheter proximally allowing said stent to begin expanding within
said vessel; further moving said deployment catheter proximally
allowing said stent to fully deploy causing said aneurysm to be
covered by said stent; and, removing said delivery system from said
blood vessel.
3. A method for resheathing an expandable stent within a blood
vessel, said method comprising the steps of: providing an
expandable stent and delivery system, said expandable stent mounted
on at least one cylindrical member along a core member of said
delivery system, said stent having at least one anchor member
interlocked within at least one gap along said core member, said
gap formed by spaces between a plurality of cylindrical members
disposed on said core member, said delivery system including a
deployment catheter disposed about said stent maintaining said
stent in a constrained configuration; inserting said expandable
stent and delivery system into a blood vessel; positioning said
expandable stent adjacent to a blockage area within said vessel;
moving said deployment catheter proximally allowing said stent to
begin expanding within said vessel; and, moving said deployment
catheter distally forcing said stent back onto said cylindrical
member of said delivery system; and, relocating said expandable
stent and delivery system.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS(S)
[0001] This patent application is a divisional patent application
of U.S. patent application Ser. No. 10/365,282, filed on Feb. 12,
2003, entitled, "Expandable Stent And Delivery System," which is a
nonprovisional patent application of U.S. provisional patent
application Ser. No. 60/412,867, filed on Sep. 23, 2002, entitled,
"Self-Expanding Stent And Delivery System."
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to intravascular expandable devices
and delivery systems for implantation within a vessel of the body,
and more particularly to an expandable stent and delivery system
which may be used in the treatment of blood vessel disorders. More
specifically, the expandable stent and delivery system may be used
in the treatment of blood vessel blockage and aneurysms which occur
in the brain.
[0004] 2. Description of the Prior Art
[0005] On a worldwide basis, nearly one million balloon
angioplasties were performed in 1997 to treat vascular disease,
including blood vessels clogged or narrowed by a lesion or
stenosis. The objective of this procedure is to increase the inner
diameter or cross-sectional area of the vessel passage, or lumen,
through which blood flows.
[0006] In an effort to prevent restenosis without requiring
surgery, short flexible cylinders or scaffolds, made of metal or
polymers, are often placed into a vessel to maintain or improve
blood flow. Referred to as stents, various types of these devices
are widely used for reinforcing diseased blood vessels, for opening
occluded blood vessels, and for defining an internal lumen to
relieve pressure in an aneurysm. Stents allow blood to flow through
the vessels at an improved rate while providing the desired lumen
opening or structural integrity lost by the damaged vessels. Some
stents are expanded to their proper size by inflating a balloon
catheter, referred to as "balloon expandable" stents, while others
are designed to elastically resist compression in a
"self-expanding" manner.
[0007] Balloon expandable stents and self-expanding stents are
generally delivered in a cylindrical form, compressed to a smaller
diameter and are placed within a vessel using a catheter-based
delivery system. When positioned at a desired site within a vessel,
these devices are expanded by a balloon, or allowed to
"self-expand," to the desired diameter.
[0008] U.S. Pat. No. 4,768,507 entitled, "Intravascular Stent and
Percutaneous Insertion Catheter System for the Dilation of an
Arterial Stenosis and the Prevention of Arterial Restenosis"
discloses a system used for placing a coil spring stent into a
vessel for the purposes of enhancing luminal dilation, preventing
arterial restenosis and preventing vessel blockage resulting from
intimal dissection following balloon and other methods of
angioplasty. The coil spring stent is placed into spiral grooves on
an insertion catheter. A back groove of the insertion catheter
contains the most proximal coil of the coil spring stent which is
prevented from springing radially outward by a flange. The coil
spring stent is deployed when an outer cylinder is moved proximally
allowing the stent to expand.
[0009] Also, U.S. Pat. No. 6,126,684 entitled, "Apparatus and
Methods for Placement and Repositioning of Intraluminal Prostheses"
discloses a delivery catheter for a radially compressible tubular
prosthesis including an elongated shaft slideably received within
an elongated sheath. The prosthesis is carried over the distal end
of the shaft where it is contained in a radially compressed
configuration by the sheath. Penetrating stay members on the
exterior of the shaft engage the proximal section of the prosthesis
allowing the prosthesis to be recaptured prior to full release of
the prosthesis.
[0010] Another stent and delivery system is disclosed in U.S. Pat.
No. 6,214,036 entitled, "Stent Which is Easily Recaptured and
Repositioned Within the Body." This patent discloses a
self-expanding stent which may be used in the treatment of aortic
aneurysms. This device includes longitudinal legs having a flange
which attaches to a delivery apparatus. The stent may be easily
recaptured after placement and repositioned to a new position
within the vessel. This patent, assigned to a related company, is
subsequently referred to and the disclosure therein is incorporated
and made a part of the subject patent application.
[0011] U.S. Pat. No. 6,361,558 entitled, "Stent Aneurysm Treatment
System and Method" and assigned to the same assignee as the present
application discloses other stent devices. This patent discloses
vasculature stents of various configurations which may be used as
aneurysm covers for occluding, or partially occluding, aneurysms
located at various positions along the blood vessels.
SUMMARY OF THE INVENTION
[0012] In accordance with one aspect of the present invention,
there is provided an expandable stent and delivery system. The
delivery system includes an elongated core member having a proximal
cylindrical member disposed about the core member. An intermediate
cylindrical member is disposed about the core member generally
positioned distally from the proximal cylindrical member and spaced
apart from the proximal cylindrical member to form a first gap. A
distal cylindrical member is disposed about the core member
generally positioned distally from the intermediate cylindrical
member and spaced apart from the intermediate cylindrical member to
form a second gap.
[0013] The expandable stent includes at least one proximal leg
which extends proximally from the proximal end of the stent. The
stent also includes at least one distal leg which extends distally
from the distal end of the stent. The stent further includes at
least one anchor member attached to the proximal leg and at least
one anchor member attached to the distal leg. The anchor members
have a longitudinal length less than the longitudinal length of the
first and second gaps and are inwardly projected in a direction
toward the longitudinal axis of the stent. The stent is mounted on
the intermediate cylindrical member and positioned such that the
anchor members interlock within the gaps.
[0014] The delivery system further includes a deployment catheter
disposed about the core member such that the deployment catheter
constrains the expandable stent about the intermediate cylindrical
member causing the anchor members to be maintained in the gaps and
thereby causing the stent to be interlocked onto the core
member.
[0015] In accordance with another aspect of the present invention,
there is provided an expandable stent and delivery system. The
delivery system includes an elongated core member with a proximal
cylindrical member disposed about the core member. A distal
cylindrical member is disposed about the core member generally
positioned distally from the proximal cylindrical member and spaced
apart from the proximal cylindrical member to form a gap. The
expandable stent includes an anchor member attached to the stent.
The anchor member has a longitudinal length less than or
approximately equal to the longitudinal length of the gap and is
inwardly projected in a direction toward the longitudinal axis of
the stent. The stent is mounted on at least one cylindrical member
and positioned such that the anchor member interlocks within the
gap.
[0016] The delivery system further includes a deployment catheter
disposed about the core member such that the deployment catheter
constrains the expandable stent about at least one cylindrical
member causing the anchor member to be maintained in the gap and
thereby causing the stent to be interlocked onto the core
member.
[0017] In accordance with a further aspect of the present
invention, there is provided an expandable stent and delivery
system. The delivery system includes an elongated core member with
a plurality of cylindrical members disposed about the core member
and spaced apart to form a plurality of gaps. The expandable stent
includes a plurality of anchor members attached to the stent. The
anchor members have a longitudinal length less than the
longitudinal length of the gaps and are inwardly projected in a
direction toward the longitudinal axis of the stent. The stent is
mounted on at least one cylindrical member and positioned such that
the anchor members interlock within the gaps.
[0018] The delivery system further includes a deployment catheter
disposed about the core member such that the deployment catheter
constrains the expandable stent about at least one cylindrical
member causing the anchor members to be maintained in the gaps and
thereby causing the stent to be interlocked onto the core
member.
[0019] In accordance with another aspect of the present invention,
the intermediate cylindrical member takes the form of a flexible
cylindrical sleeve. The flexible cylindrical sleeve includes
reinforcement members located at the ends of the cylindrical sleeve
such that the reinforcement members resist deformation of the ends
of the cylindrical sleeve.
[0020] In accordance with a further aspect of the present
invention, the elongated core member is tapered such that the
proximal section of the core member has a diameter which allows the
core member to be pushed through a blood vessel and the distal
section of the core member has a diameter less than the diameter of
the proximal section of the core member.
[0021] In accordance with still another aspect of the present
invention, the expandable stent includes two proximal legs
extending proximally from the proximal end of the stent and two
distal legs extending distally from the distal end of the stent.
Two anchor members are attached to the proximal legs, and two
anchor members are attached to the distal legs. The anchor members
have longitudinal lengths less than the longitudinal lengths of the
gaps and are inwardly projected in a direction toward the
longitudinal axis of the stent.
[0022] In accordance with another aspect of the present invention,
the proximal cylindrical member and the distal cylindrical member
take the form of flexible coils.
[0023] In accordance with a further aspect of the present
invention, a method is provided for deploying an expandable stent
within a blood vessel to enhance luminal dilation of the blood
vessel or to treat an aneurysm. The method includes the step of
providing an expandable stent and delivery system. The expandable
stent is mounted on at least one cylindrical member along a core
member of the delivery system. The stent has at least one anchor
member which is interlocked within at least one gap along the core
member. The gaps are formed by spaces between a plurality of
cylindrical members disposed on the core member. The delivery
system includes a deployment catheter disposed about the stent
which maintains the stent in a constrained configuration.
[0024] The method further includes the step of inserting the
expandable stent and delivery system into a blood vessel and
positioning the expandable stent adjacent to a blockage area or
aneurysm within the vessel. The method also includes moving the
deployment catheter proximally allowing the stent to begin
expanding within the vessel, then again moving the deployment
catheter proximally allowing the stent to fully deploy causing the
vessel to increase in luminal dilation or causing the stent to
cover the aneurysm. Finally, the method includes removing the
delivery system from the blood vessel.
[0025] In accordance with still another aspect of the present
invention, a method is provided for resheathing an expandable stent
onto a delivery system within a blood vessel. The method includes
the step of providing an expandable stent and delivery system. The
expandable stent is mounted on at least one cylindrical member
along a core member of the delivery system. The stent has at least
one anchor member interlocked within at least one gap along the
core member. The gap is formed by spaces between a plurality of
cylindrical members disposed on the core member. The delivery
system includes a deployment catheter disposed about the stent
which maintains the stent in a constrained configuration. The
method further includes inserting the expandable stent and delivery
system into the vessel. The method also includes moving the
deployment catheter proximally allowing the stent to begin
expanding within the vessel. In addition, the method includes
moving the deployment catheter distally which forces the stent back
onto the cylindrical member of the delivery system. Finally, the
method includes removing the stent and delivery system from the
blood vessel or repositioning the stent and delivery system within
the blood vessel.
[0026] These and other aspects of the present invention and the
advantages thereof will be more clearly understood from the
foregoing description in drawings of a preferred embodiment of the
present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is an enlarged partial sectional view of an
expandable stent and delivery system in accordance with the present
invention;
[0028] FIG. 2 is an enlarged partial sectional view of the delivery
system with an intermediate cylindrical member which takes the form
of a helically wound flexible coil;
[0029] FIG. 3 is an enlarged partial sectional view of the delivery
system with an intermediate cylindrical member which takes the form
of a flexible cylindrical sleeve;
[0030] FIG. 4 is an enlarged partial sectional view of the
expandable stent and delivery system disposed within a blood vessel
and aligned adjacent to vessel blockage;
[0031] FIG. 5 is an enlarged partial sectional view of a deployment
catheter moved proximally with the proximal section of the
expandable stent compressed within the deployment catheter and the
distal section of the expandable stent expanded within the
vessel;
[0032] FIG. 6 is an enlarged sectional view of the deployment
catheter moved proximally with the expandable stent expanded within
the vessel;
[0033] FIG. 7 is an enlarged sectional view of the stent expanded
within the vessel and the delivery system removed from the
vessel;
[0034] FIG. 8 is an enlarged partial sectional view of the
expandable stent and delivery system disposed within a blood vessel
and aligned adjacent to an aneurysm;
[0035] FIG. 9 is an enlarged partial sectional view of the a
deployment catheter moved proximally with the proximal section of
the expandable stent constrained within the deployment catheter and
the distal section of the expandable stent expanded within the
vessel;
[0036] FIG. 10 is an enlarged sectional view of the deployment
catheter moved proximally with the expandable stent expanded within
the vessel and covering the mouth of the aneurysm;
[0037] FIG. 11 is an enlarged sectional view of the stent expanded
within the vessel and covering the aneurysm;
[0038] FIG. 12 is an enlarged sectional view of the stent expanded
within the vessel and a microcatheter inserted through the wall of
the stent and into the aneurysm; and,
[0039] FIG. 13 is an enlarged sectional view of the stent expanded
within the vessel and covering the aneurysm with an embolic coil
deployed within the aneurysm.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0040] FIG. 1 illustrates an expandable stent 10 and delivery
system 12. The delivery system 12 includes a deployment catheter 14
which is an elongated tube with a lumen 16. The lumen 16 of the
deployment catheter 14 has a diameter in the range of 0.010 inches
to 0.25 inches with a preferred diameter of approximately 0.021
inches. Preferably, the proximal section 18 of the deployment
catheter 14 is formed of a nylon material having a durometer in a
range of about 60D to 75D. The proximal section 18 is sufficiently
flexible to traverse a blood vessel, but is sufficiently rigid so
that it can be pushed distally through a blood vessel. The distal
section 22 of the deployment catheter 14 is preferably formed of a
pellethane material having a durometer of between 25D and 55D with
a durometer of 40D being the preferred durometer.
[0041] The delivery system 12 includes a winged hub 24 coupled to
the proximal section 18 of the deployment catheter 14. The winged
hub 24 may be made from plastic and aids in the insertion of the
deployment catheter 14 into a blood vessel. The delivery system 12
also includes an elongated core member 26 which is a wire
preferably made of Nitinol but may also be made from other metal
alloys or a polymer material. The core member 26 is slideably
disposed within the lumen 16 of the deployment catheter 14. The
core member 26 may have a long taper or may have multiple tapers to
give the proximal section 28 of the core member 26 a greater
diameter than the distal section 30 of the core member 26.
Preferably, the diameter of the proximal section 28 of the core
member 26 is approximately 0.016 inches while the diameter of the
distal section 30 is about 0.002 inches. The greater diameter of
the proximal section 28 gives the core member 26 sufficient
stiffness to be pushed through the deployment catheter 14, and the
smaller diameter of the distal section 30 provides flexibility for
the core member 26 to traverse narrow blood vessels.
[0042] The delivery system 12 further includes a proximal
cylindrical member 32 disposed about the distal section 30 of the
core member 26. Preferably, the proximal cylindrical member 32 is a
helically wound flexible coil with an outside diameter of about
0.016 inches. The coil may be made of a polymer material but the
preferred material is metal. An intermediate cylindrical member 34
(located within the stent and not seen in this figure) is also
disposed about the core member 26 distally from the proximal
cylindrical member 32 and spaced apart from the proximal
cylindrical member 32. The intermediate cylindrical member 34 may
be a cylindrical sleeve or a coil with an outside diameter of
approximately 0.012 inches. The space between the proximal and
intermediate cylindrical members 32 and 34 along the core member 26
forms a first gap 36. The length of the first gap 36 may range from
0.019 inches to 0.19 inches with a preferred length of 0.040
inches.
[0043] A distal cylindrical member 38 is also disposed about the
core member 26 distally from the intermediate cylindrical member 34
and spaced apart from the intermediate cylindrical member 34.
Preferably, the distal cylindrical member 38 is a helically wound
flexible coil with an outside diameter of about 0.016 inches. The
coil may be made of a polymer material but the preferred material
is metal. The space between the intermediate and distal cylindrical
members 34 and 38 along the core member 26 forms a second gap 40.
The length of the second gap 40 may range from 0.019 inches to 0.19
inches with a preferred length of 0.040 inches. The distal
cylindrical member 38 may also be shapeable so that the core member
26 may be used as a guidewire. For example, the distal cylindrical
member 38 may be slightly angled to permit the core member 26 to
navigate through the vasculature of the body.
[0044] An expandable stent 10 is mounted on the intermediate
cylindrical member 34. The expandable stent 10 may take on many
different patterns or configurations. Examples of such stents are
disclosed in U.S. Patent Application, "Intravascular Stent Device"
filed Jun. 5, 2002. The disclosures in these applications are
incorporated herein by reference. The expandable stent 10 is
preferably laser cut from a tubular piece of Nitinol and thereafter
treated so as to exhibit superelastic properties at body
temperature. The expandable stent 10 may include proximal and
distal legs 44 and 46 that are attached to the proximal and distal
ends 48 and 50 of the stent 10 and extend along the longitudinal
axis of the stent 10. The expandable stent 10 also includes anchor
members 52 which are either attached to the ends 48 and 50 of the
stent 10 or to the proximal and distal legs 44 and 46 of the stent
10. In addition, anchor members 52 may be positioned at other
locations along the stent between ends 48 and 50. The anchor
members 52 may be projections made from polymer or metallic
material which extend generally parallel to the longitudinal axis
the stent 10 and extend downward toward the longitudinal axis of
the stent 10.
[0045] Preferably, the anchor members 52 are helically wound
flexible coils and made of a radiopaque material for use during
fluoroscopic visualization. As the expandable stent 10 is
positioned and mounted on the intermediate cylindrical member 34,
the anchor members 52 attached to the proximal end 48 or proximal
legs 44 of the stent 10 align with and are disposed within the
first gap 36. Similarly, the anchor members 52 attached to the
distal legs 46 of the stent 10 align with and are disposed within
the second gap 40. In this configuration, the expandable stent 10
is locked in place and can be pushed and pulled through the
deployment catheter 14 without damaging or deforming the stent
10.
[0046] It should be understood that the expandable stent 10 of the
present invention may alternatively be coated with an agent, such
as heparin or rapamycin, to prevent stenosis or restenosis of the
vessel. Examples of such coatings are disclosed in U.S. Pat. Nos.
5,288,711; 5,516,781; 5,563,146 and 5,646,160. The disclosures in
these patents are incorporated herein by reference.
[0047] FIG. 2 illustrates the delivery system 12 without the
expandable stent. The delivery system 12 includes an elongated core
member 26 disposed within a lumen 16 of the deployment catheter 14.
Proximal, intermediate and distal cylindrical members 32, 34 and 38
are disposed about the core member 26 and spaced apart from each
other such that first and second gaps 36 and 40 are formed. In the
embodiment shown in this figure, the intermediate cylindrical
member 34 is a helically wound flexible coil. Preferably, the
flexible coil is made of a metallic material and has a length
approximately equal to the length of the expandable stent 10. When
the expandable stent (not shown) is mounted on the intermediate
cylindrical member 34, the stent is constrained about the coil by
the deployment catheter 14. In this configuration, the stent and
delivery system 12 remain sufficiently flexible to traverse
tortuous blood vessels.
[0048] FIG. 3, like FIG. 2, illustrates the delivery system 12
without the expandable stent. However, in the embodiment shown in
this figure, the intermediate cylindrical member 34 is a flexible
cylindrical sleeve. Preferably, the cylindrical sleeve is made of a
polymer material and has a smooth outer surface. The length of the
cylindrical sleeve is approximately equal to the length of the
expandable stent. When the expandable stent (not shown) with a drug
coating is mounted on the intermediate cylindrical member 34, the
stent is constrained about the cylindrical sleeve by the deployment
catheter 12. In this configuration, the drug coating on the
expandable stent is protected from damage caused by friction
between the stent and a non-smooth intermediate cylindrical member
34 and friction between various components of the stent itself.
[0049] Reinforcing members 42 may be disposed on the ends of the
proximal, intermediate and distal cylindrical members 32, 34 and
38. The reinforcing members 42 may take the form of rings or disks
and may be made of a polymer or metallic material, but preferably
the reinforcing members 42 are made of the same material as the
cylindrical members 32, 34 and 38. The reinforcing members 42
provide support to the ends of cylindrical members 32, 34 and 38 so
that the ends resist deformation.
[0050] FIG. 4 illustrates the expandable stent 10 and delivery
system 12 positioned within a blood vessel 20. The expandable stent
10 is mounted on the intermediate cylindrical member 34 (located
within the stent and not seen in this figure). The anchor members
52 on the proximal end 48 of the stent 10 are disposed in the first
gap 36, while the anchor members 52 on the distal end 50 of the
stent 10 are disposed in the second gap 40. In this position, the
stent 10 is locked into place on the core member 26. The expandable
stent 10 is generally aligned with a blockage area 54 of the blood
vessel 20.
[0051] FIG. 5 illustrates the expandable stent 10 partially
deployed within the blood vessel 20. The deployment catheter 14 is
moved proximally causing the anchor members 52 on the distal end 50
of the stent 10 to exit the second gap 40 thereby allowing the
stent 10 to partially deploy.
[0052] FIG. 6 illustrates the expandable stent 10 fully deployed
within the blood vessel 20 and the delivery system 12 still within
the vessel 20. The deployment catheter 14 is moved proximally
causing the anchor members 52 on the proximal end 48 of the stent
10 to exit the first gap 36 thereby allowing the stent 10 to become
fully deployed.
[0053] FIG. 7 illustrates the expandable stent 10 deployed within
the blood vessel 20 with the delivery system 12 removed from the
blood vessel 20. The expanding force of the stent 10 pushes the
blockage area 54 radially outward thereby opening the blood vessel
20 for greater blood flow.
[0054] FIG. 8 illustrates the expandable stent 10 and delivery
system 12 positioned within a blood vessel 20 and aligned with an
aneurysm 56. The expandable stent 10 is mounted on the intermediate
cylindrical member 34 (located within the stent and not seen in
this figure). The anchor members 52 on the proximal end 48 of the
stent 10 are disposed in the first gap 36, while the anchor members
52 on the distal end 50 of the stent 10 are disposed in the second
gap 40. In this position, the stent 10 is locked into place on the
core member 26. The expandable stent 10 is generally aligned with
an aneurysm 56.
[0055] FIG. 9 illustrates the expandable stent 10 partially
deployed within the blood vessel 20. The deployment catheter 14 is
moved proximally causing the anchor members 52 on the distal end 50
of the stent 10 to exit the second gap 40 thereby allowing the
stent 10 to partially deploy and to begin covering the aneurysm
56.
[0056] FIG. 10 illustrates the expandable stent 10 fully deployed
within the blood vessel 20 and the delivery system 12 still within
the vessel 20. The deployment catheter 14 is moved proximally
causing the anchor members 52 on the proximal end 48 of the stent
10 to exit the first gap 36 thereby allowing the stent 10 to become
fully deployed and cover the aneurysm 56.
[0057] FIG. 11 illustrates the expandable stent 10 deployed within
the blood vessel 20 with the delivery system 12 removed from the
blood vessel 20. The expanded stent 10 covers the mouth of the
aneurysm 56.
[0058] FIG. 12 illustrates the expandable stent 10 deployed with
the blood vessel 20 with a microcatheter 58 inserted into the blood
vessel 20, through the wall of the stent 10, and into the aneurysm
56. In this position, embolic agents and medical devices may be
delivered into the aneurysm 56.
[0059] FIG. 13 illustrates the expandable stent 10 deployed with
the blood vessel 20 and covering the aneurysm 56. An embolic coil
60 is deployed within the aneurysm 56 and is confined within the
aneurysm 56 by the expandable stent 10.
[0060] The present invention is useful for positioning an
expandable stent within a blood vessel to enhance luminal dilation
of the vessel or to treat an aneurysm. To deploy the expandable
stent, first the stent is mounted about the intermediate
cylindrical member along the core member. The anchor members
attached to the ends of the stent are aligned with the first and
second gaps which are formed by the proximal, intermediate, and
distal cylindrical members. The expandable stent is interlocked
onto the core member while the deployment catheter is disposed
about the stent holding the stent in its constrained configuration.
The delivery system is then inserted into the blood vessel until
the stent is aligned with the blockage area or aneurysm which is to
be treated. Once positioned, the deployment catheter is moved
proximally which allows the distal portion of the stent to begin
expanding and permits the anchor members attached to the distal
legs of the stent to become released from the second gap. During
expansion, the distal portion of the stent comes in contact with
the wall of the blood vessel. The deployment catheter is again
moved proximally until the proximal portion of the stent expands
and allows the anchor members attached to the proximal legs of the
stent to become released from the first gap. The stent is now fully
deployed and the delivery system may be withdrawn from the blood
vessel.
[0061] The present invention is also useful in resheathing the
expandable stent during the deployment process. Here, the stent is
positioned on the core member as described above. Once the delivery
system is positioned within the blood vessel at the blockage area
or aneurysm to be treated, the deployment catheter is moved
proximally to allow the distal portion of the stent to expand. If
the deployment catheter is not moved proximally beyond the anchor
members attached to the proximal legs of the stent, then the stent
remains interlocked on the core wire. In this configuration, the
stent can be resheathed and deployed at a different location within
the blood vessel. To do this, the deployment catheter is moved
distally forcing the stent back onto the intermediate cylindrical
member and positioning the anchor members attached to the distal
legs of the stent to become interlocked within the second gap. In
this configuration, the expandable stent and delivery system may be
withdrawn or repositioned within the blood vessel.
[0062] A novel system has been disclosed in which an expandable
stent is positioned within a blood vessel. Although a preferred
embodiment of the invention has been described, it is to be
understood that various modifications may be made by those skilled
in the art without departing from the scope of the claims which
follow.
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