U.S. patent application number 10/851931 was filed with the patent office on 2004-10-28 for stent, method for processing stent, and method of stenting a patient.
Invention is credited to Daum, Wolfgang, Winkel, Axel.
Application Number | 20040211491 10/851931 |
Document ID | / |
Family ID | 7954090 |
Filed Date | 2004-10-28 |
United States Patent
Application |
20040211491 |
Kind Code |
A1 |
Daum, Wolfgang ; et
al. |
October 28, 2004 |
Stent, method for processing stent, and method of stenting a
patient
Abstract
The subject invention relates to a stent with respect to which
the occurrence of artifacts in nuclear spin tomography can be
reduced or avoided. The subject invention also pertains to the
etching of stents, incorporating titanium and/or titanium alloys,
that have been processed with tools containing magnetizing
components. The subject invention can also be useful for the
control of in-stent-restenosis by allowing imaging under nuclear
spin tomography to see in-stent-restenosis in the interior of the
subject stent.
Inventors: |
Daum, Wolfgang; (Groton,
MA) ; Winkel, Axel; (Schwerin, DE) |
Correspondence
Address: |
SALIWANCHIK LLOYD & SALIWANCHIK
A PROFESSIONAL ASSOCIATION
2421 N.W. 41ST STREET
SUITE A-1
GAINESVILLE
FL
32606-6669
US
|
Family ID: |
7954090 |
Appl. No.: |
10/851931 |
Filed: |
May 21, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10851931 |
May 21, 2004 |
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10091988 |
Mar 5, 2002 |
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6780338 |
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Current U.S.
Class: |
148/421 ;
148/DIG.51; 216/10; 623/1.15 |
Current CPC
Class: |
A61L 31/022 20130101;
A61F 2/82 20130101; Y10S 148/051 20130101; Y10S 623/901 20130101;
A61F 2/86 20130101; Y10T 29/49034 20150115 |
Class at
Publication: |
148/421 ;
623/001.15; 216/010; 148/DIG.051 |
International
Class: |
C22C 014/00; A61F
002/06 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 9, 2001 |
DE |
20104145.6 |
Claims
1-5. (canceled).
6. A stent, comprising: TIAl3V2.5, wherein the TIAl3V2.5 exhibits a
low incidence of artifacts in nuclear spin tomography.
7. The stent according to claim 1, wherein the stent consists
essentially entirely of TIAl3V2.5.
8. The stent according to claim 1, wherein the stent is viewable in
nuclear spin tomography.
9. The stent according to claim 1, wherein TIAl3V2.5 has the
following composition by weight: up to 0.08% C; up to 0.03%
N.sub.2; up to 0.15% O.sub.2; 2.0% to 3.0% V; 2.5% to 3.5% Al; up
to 0.25% Fe; less than 0.015% H.sub.2; and the balance Ti.
10. The stent according to claim 2, wherein TIAl3V2.5 has the
following composition by weight: up to 0.08% C; up to 0.03%
N.sub.2; up to 0.15% O.sub.2; 2.0% to 3.0% V; 2.5% to 3.5% Al; up
to 0.25% Fe; up to 0.015% H.sub.2; and the balance Ti.
11. A stent, comprising: TIAl6V4, wherein the TIAl6V4 exhibits a
low incidence of artifacts in nuclear spin tomography.
12. The stent according to claim 6, wherein the stent is expandable
with a balloon catheter.
13. The stent accrediting to claim 6, wherein the stent consists
essentially entirety of TIAl6V4.
14. The stent according to claim 6, wherein the TIAl6V4 has the
following composition by weight: up to 0.08% C; up to 0.05%
N.sub.2; up to 0.2% O.sub.2; 3.5% to 4.5% V; 5.5% to 6.75% Al; up
to 0.4% Fe; up to 0.015% H.sub.2; and the balance Ti.
15. The stent according to claim 8, wherein the TIAl6V4 has the
following up to 0.08% C; up to 0.05% N.sub.2; up to 0.2% O.sub.2;
3.5% to 4.5% V; 5.5% to 6.75% Al; up to 0.4% Fe; up to 0.015%
H.sub.2; and the balance Ti.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application
Ser. No. 10/091,988, filed Mar. 5, 2002, which claims the benefit
of German Application Serial No. 20104145.6, filed Mar. 9,
2001.
BACKGROUND OF INVENTION
[0002] The subject invention relates to a stent which exhibits a
low incidence of artifacts in nuclear spin tomography, and to a
process for treating stents that are processed with tools
containing magnetizing components such as iron.
[0003] In today's stent technology it is desirable to use
cardiovascular stents that are able to adequately prop open the
vessel and that can be accurately positioned. It would be desirable
to use stents that can be viewed with nuclear spin tomography.
However, traditional stents are made of stainless steel and show
distinct image distortions, or so called artifacts. These artifacts
occur when materials with high magnetic susceptibility are
used.
BRIEF SUMMARY OF THE INVENTION
[0004] The subject invention relates to a stent with respect to
which the occurrence of artifacts in nuclear spin tomography can be
reduced or avoided. The subject invention also pertains to the
etching of stents, incorporating titanium and/or titanium alloys,
that have been processed with tools containing magnetizing
components. As processing the stents with tools containing
magnetizing components can result in some amount of the tool
material rubbing off the tools onto the stent, etching the stent in
an etch solution that etches the magnetizing component materials of
the tools can reduce the amount of the magnetizing component
materials of the tools on the surface of the stent and, therefore,
reduce the incidence of artifacts from the stent.
[0005] The subject invention can also be useful for the control of
in-stent-restenosis by allowing imaging under nuclear spin
tomography to see in-stent-restenosis in the interior of the
subject stent.
DETAILED DESCRIPTION OF THE INVENTION
[0006] In a specific embodiment, the subject stent can incorporate
an alloy of 3 percent aluminum by weight and 2.5 percent vanadium
by weight, with the remainder being titanium, known as material
TIAl3V2.5 or material No. 3.7194 or 253.7195 (ASTM Grade 9), where
ASTM is the American Society for Testing and Materials. As known in
the art, the composition of titanium alloy TIAl3V2.5, also known as
Ti3Al2.5V and ASTM Grade 9, is shown in Table I.
1 TABLE I Content (weight %) C up to 0.08% N.sub.2 up to 0.03%
O.sub.2 up to 0.15% V 2.0-3.0% Al 2.5-3.5% Fe up to 0.25% H.sub.2
up to 0.015% Ti balance
[0007] The use of TIAl3V2.5 to produce this embodiment of the
subject stent results in a stent that produces especially few image
artifacts and has sufficient hardness to be suitable for
interventional instruments used in nuclear spin tomography.
[0008] In another specific embodiment, the subject stent can
incorporate an alloy referred to as ASTM Grade 5 (also known as ISO
3.765 or 3.7165). The alloy according to ASTM Grade 9 is harder
than an alloy according to ASTM Grade 5, which can have the
following components: 90% titanium, 6% aluminum, and 4% vanadium.
As known in the art, the composition of titanium alloy known as
ASTM 5 is shown in Table II.
2 TABLE II Content (weight %) C up to 0.08% N.sub.2 up to 0.05%
O.sub.2 up to 0.2% V 3.5-4.5% Al 5.5-6.75% Fe up to 0.4% H.sub.2 up
to 0.015% Ti balance
[0009] The ASTM Grade 5 material is more flexible than the ASTM
grade 9 material and is, therefore, more suitable for expanding a
stent with the help of a balloon catheter.
[0010] Stents, incorporating materials that are made to be artifact
free, that are created with tools containing magnetizing components
typically show an increase in screen artifacts. This increase in
artifacts is due to some amount of the tool material rubbing off
the tool onto the stent during the processing of the stent with the
tools. A reduction of surface magnetism of the stent can be
achieved through dipping in etching solutions that etch the
materials the tools are made of. The rub-off from the tools is
eliminated by the wet chemical etching solution. In a specific
embodiment, such an etching solution, that removes iron impurities
can consist of, for example, 3 parts hydrochloric acid and 2 parts
saltpeter acid. This etching solution can be further reduced with
additional parts water in the etching process.
[0011] Stents manufactured in accordance with the subject
invention, in the manner described herein, can be ideally observed
in nuclear spin tomography units incorporating a magnetic flux
density>1.0 Testa. In a specific embodiment, unexpanded stent
having a diameter of 1 mm was balloon expanded to a diameter of 4
mm, and it was possible to clearly see all the stent struts, or the
so-called strats. It was also possible to get a good look inside
the expanded stent. Advantageously, so-called in-stent-restenosis
in the interior, or inner lumen, of the stent can be seen when a
stent has been treated in accordance with the subject invention.
The ability to see in-stent-restenosis in the interior of the stent
can be useful for the control of in-stent-restenosis.
* * * * *