Variable flexibility stent

Details Variable flexibility stent Variable flexibility stent

1999-05-13

2001-09-11

Milano, Michael (Department: 3738)

Prosthesis (i.e., artificial body members), parts thereof, or ai

Arterial prosthesis

Having variable diameter

C623S001150

Reexamination Certificate

active

06287336

ABSTRACT:

FIELD OF THE INVENTION
This invention concerns a novel stent. More particularly, this invention concerns a stent having variable flexibility and stiffness.
BACKGROUND OF THE INVENTION
A common characteristic of many stents in the market is longitudinal axis symmetry. Some of the stents, such as the Medtronic WIKTOR™ stents and the Medtronic InStent CARDIOCOIL™ stents, have a spiral structure. Such spiral structures have a cyclic helical coil element called “pitch.” Other stents, such as the ACS MULTILINK™ stent, the Johnson & Johnson PALMAZ-SCHATZ™ stent, and the Medtronic Instent beSTENT™, are designed with a cyclic mesh element. Further stents such as the Johnson & Johnson Articulated Stent and the NIR stent have a double cyclic structure, that is, odd and even longitudinal elements where an odd element comes after an even element, and all the odd elements are identical and all the even elements are identical.
All the above stents have in common the characteristic of the uniformity of flexibility or durability for bending along the length of the stent.
Tests done on long stents loaded with bending stresses reveal a large bending moment in the central area of the stent. (See, for example,
FIGS. 1
a
-
1
f
.) Such stresses may cause fatigue-and even fracture at the center of the stent. On the one hand, significant stent flexibility is required during deployment while, on the other hand, significant rigidity is required in the expanded state of the stent. Since the bending moment increases from zero at the ends of the stent to a maximum value at the center, it has been determined that there is a need for a stent having a significant durability for bending at the exact place where the durability is required, that is, at the middle of the stent.
OBJECTS OF THE INVENTION
It is an object of this invention to provide a novel stent which does not have the disadvantages inherent in known stents.
It is also an object of this invention to provide a stent having variable flexibility and/or durability and/or stiffness.
It is further object of the invention to provide a stent having a large or significant durability for bending, i.e., rigidity or stiffness, at the middle portion of the stent.
These and other objects of the invention will become apparent to one skilled in the art from the discussion below.
SUMMARY OF THE INVENTION
The present invention provides for a novel stent which overcomes many of the disadvantages associated with various prior art stent designs which rely upon a stent construction which provides for a uniformly rigid construction or a uniform alternating rigid/less rigid construction. The invention provided for herein is directed to a stent having variable flexibility and moment along its length. The stent comprises portions of the stent having different bending and durability characteristics, as designed. In one embodiment of the invention, the members of the stent have components that have been designed to impart different load characteristics.


REFERENCES:
patent: 4776337 (1988-10-01), Palmaz
patent: 4816028 (1989-03-01), Kapadia et al.
patent: 4856516 (1989-08-01), Hillstead
patent: 4893623 (1990-01-01), Rosenbluth
patent: 4969458 (1990-11-01), Wiktor
patent: 4994071 (1991-02-01), MacGregor
patent: 5019085 (1991-05-01), Hillstead
patent: 5104404 (1992-04-01), Wolff
patent: 5116365 (1992-05-01), Hillstead
patent: 5135536 (1992-08-01), Hillstead
patent: 5178618 (1993-01-01), Kandarpa
patent: 5234457 (1993-08-01), Andersen
patent: 5282824 (1994-02-01), Gianturco
patent: 5293879 (1994-03-01), Vonk et al.
patent: 5314472 (1994-05-01), Fontaine
patent: 5342387 (1994-08-01), Summers
patent: 5366473 (1994-11-01), Winston et al.
patent: 5383892 (1995-01-01), Cardon et al.
patent: 5389106 (1995-02-01), Tower
patent: 5421955 (1995-06-01), Lau et al.
patent: 5443496 (1995-08-01), Schwartz
patent: 5449373 (1995-09-01), Pinchasik
patent: 5507767 (1996-04-01), Maeda et al.
patent: 5514154 (1996-05-01), Lau et al.
patent: 5527354 (1996-06-01), Fontaine et al.
patent: 5540712 (1996-07-01), Kleshinski et al.
patent: 5540713 (1996-07-01), Schnepp-Pesch et al.
patent: 5549662 (1996-08-01), Fordenbacher
patent: 5549663 (1996-08-01), Cottone, Jr.
patent: 5554181 (1996-09-01), Das
patent: 5591197 (1997-01-01), Orth et al.
patent: 5591198 (1997-01-01), Boyle et al.
patent: 5607442 (1997-03-01), Fischell et al.
patent: 5607445 (1997-03-01), Summers
patent: 5613981 (1997-03-01), Boyle et al.
patent: 5630829 (1997-05-01), Lauterjung
patent: 5636641 (1997-06-01), Fariabi
patent: 5643312 (1997-07-01), Fischell et al.
patent: 5653727 (1997-08-01), Wiktor
patent: 5681346 (1997-10-01), Orth et al.
patent: 5697971 (1997-12-01), Fischell et al.
patent: 5725572 (1998-03-01), Lam et al.
patent: 5728158 (1998-03-01), Lau et al.
patent: 5733303 (1998-03-01), Israel et al.
patent: 5735893 (1998-04-01), Lau et al.
patent: 5741327 (1998-04-01), Frantzen
patent: 5749919 (1998-05-01), Blanc
patent: 5755776 (1998-05-01), Al-Saadon
patent: 5759192 (1998-06-01), Saunders
patent: 5766238 (1998-06-01), Lau et al.
patent: 5776161 (1998-07-01), Globerman
patent: 5807404 (1998-09-01), Richter
patent: 5855600 (1999-01-01), Alt
patent: 0 800 801 A1 (1997-10-01), None
patent: WO 97/21399 (1997-06-01), None
patent: WO 97/25937 (1997-07-01), None
patent: WO 97/32543 (1997-09-01), None
patent: WO 98/18404 (1998-05-01), None

Affiliated with

Also associated with

Rating

Variable flexibility stent does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Variable flexibility stent, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Variable flexibility stent will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2468866