Expandable stents and method for making same

Claim 2

A longitudinally flexible stent for implanting in a body lumen and expandable from a contracted condition to an expanded condition, comprising: a plurality of adjacent cylindrical elements which are independently expandable in the radial direction and arranged in alignment along a longitudinal stent axis; said cylindrical elements formed in an serpentine wave pattern transverse to the longitudinal axis and containing alternating peaks and valleys; at least one interconnecting member extending between adjacent cylindrical elements and connecting them to one another; said serpentine wave pattern configured in size and shape so that said cylindrical elements generally expand in a uniform manner around their circumferences during expansion of the stent from its contracted condition to its expanded condition.

Claim 3

The stent of claim 1, wherein said curvature is chosen so that the bending stress developed at said peaks and valleys during radial expansion of said cylindrical elements is uniform around the circumference of said cylindrical elements.

Claim 4

The stent of any one of the preceding claims, wherein said at least one interconnecting member connects a valley of one cylindrical element with a valley of an adjacent cylindrical element.

Claim 5

The stent of claim 4, wherein said interconnecting member is unitary with said valley of one cylindrical element and said valley of said adjacent cylindrical element.

Claim 6

The stent of any one of the preceding claims, wherein the degrees of curvature and/or the shape and size along said peaks and valleys is determined relative to the anticipated level of stress created during expansion of the stent from its contracted condition to its expanded condition.

Claim 7

The stent of any one of the preceding claims, wherein the degrees of curvature and/or the shape and size along adjacent peaks and valleys of said serpentine pattern are different.

Claim 8

The stent of any one of the preceding claims, wherein the degrees of curvature and/or the shape and size along said peaks of said serpentine pattern is different in immediately adjacent regions.

Claim 9

The stent of any one of the preceding claims, wherein said adjacent cylindrical elements are connected to each other by a plurality of interconnecting members whereby said stent may expand from a first smaller diameter to a second enlarged diameter without appreciable change in overall length.

Claim 10

The stent of any one of the preceding claims, wherein said cylindrical elements cooperate to define a generally cylindrical surface and wherein said peaks project outwardly from said surface upon expansion.

Claim 11

The stent of any one of the preceding claims, wherein said stent is formed of a biocompatible material selected from the group consisting of stainless steel, tungsten, tantalum, superelastic NiTi alloys, and thermoplastic polymers.

Claim 12

The stent of any one of the preceding claims, wherein said stent has a radial expansion ratio of about 1 up to about 4.0.

Claim 13

The stent of any one of the preceding claims, wherein the stent is formed from a single piece of tubing.

Claim 14

The stent of any one of the preceding claims, wherein the stent is coated with a biocompatible coating.

Claim 15

A kit of parts for delivering an intraluminal stent comprising: an elongated stent delivering catheter having a proximal end and a distal end, and an expandable member adjacent the distal end; a stent as claimed in any one of claims 1 to 14; and means for expanding the expandable member to, in turn, radially expand said stent and implant said stent in a body lumen.

Claim 16

A kit of parts for delivering an intraluminal stent comprising: an elongated stent delivery catheter having a proximal end and a distal end, and an expandable member adjacent the distal end; a longitudinally flexible stent expandable from a contracted condition to an expanded condition, comprising: a plurality of adjacent cylindrical elements which are independently expandable in the radial direction and arranged in alignment along a longitudinal stent axis; said cylindrical elements formed in an irregular serpentine wave pattern transverse to the longitudinal axis and containing a plurality of alternating peaks and valleys; at least one interconnecting member extending between adjacent cylindrical elements and connecting them to one another; said irregular serpentine pattern containing varying degrees of curvature in regions of said peaks and valleys adapted so that radial expansion of said cylindrical elements is generally uniform around their circumferences during expansion of the stent from its contracted condition to its expanded condition; and means for expanding said expandable member to, in turn, radially expand said stent and implant said stent in a body lumen.