Intravascular prosthesis with anti-thrombogenic coating

Claim 2

The stent of claim 1, wherein said irregular serpentine pattern (12,34,36) contains varying degrees of curvature in regions of said peaks and valleys adapted so that radial expansion of said adjacent cylindrical elements (12) is generally uniform around their circumferences during expansion of the stent (10) from its contracted condition to its expanded condition.

Claim 3

The stent of claim 1 or claim 2,wherein the degree of curvature along said peaks (36) and valleys (34) is determined relative to the anticipated level of stress created during expansion of the stent (10) from its contracted condition to its expanded condition.

Claim 4

The stent of any preceding claim, wherein the degrees of curvature along adjacent peaks (36) and valleys (34) of said irregular serpentine pattern (12,34,36) are different.

Claim 5

The stent of any preceding claim, wherein the degree of curvature along said peaks of said irregular serpentine pattern (12,34,36) is different in immediately adjacent regions.

Claim 6

A longitudinally flexible stent (10) for implanting in a body lumen and expandable from a contracted condition to an expanded condition, comprising: a plurality of adjacent cylindrical elements (12) which are independently expandable in the radial direction and arranged in alignment along a longitudinal stent axis; said cylindrical elements (12) formed in an serpentine wave pattern (12,34,36) transverse to the longitudinal axis and containing alternating peaks (36) and valleys (34); at least one interconnecting member (13) extending between adjacent cylindrical elements (12) and connecting them to one another; said serpentine wave pattern (12,34,36) configured in size and shape so that said cylindrical elements (12) generally expand in a uniform manner around their circumferences during expansion of the stent (10) from its contracted condition to its expanded condition; and an anti-thrombogenic coating covering said plurality of adjacent cylindrical elements (12) and said at least one interconnecting member (13), said anti-thrombogenic coating consisting of a parylene polymer selected from the group consisting of poly-(chloro-paraxylylene), poly-(dichloro-para-xylylene), and poly (paraxylylene).

Claim 7

The stent of claim 6, wherein the shape and size along said peaks (36) and valleys (34) is determined relative to the anticipated level of stress created during expansion of the stent (10) from its contracted condition to its expanded condition.

Claim 8

The stent of claim 6 or claim 7, wherein the shape and size along adjacent peaks (36) and valleys (34) of said serpentine pattern (12,34,36) are different.

Claim 9

The stent of any of claims 6 to 8, wherein the shape and size along said peaks (36) of said serpentine pattern (12,34,36) is different in immediately adjacent regions.

Claim 10

The stent of any preceding claim, wherein said curvature is chosen so that the bending stress developed at said peaks (36) and valleys (34) during radial expansion of said cylindrical elements (12) is uniform around the circumference of said cylindrical elements.

Claim 11

The stent of any preceding claim, wherein said at least one interconnecting member (13) connects a valley (34) of one cylindrical element (12) with a valley (34) of an adjacent cylindrical element (12).

Claim 12

The stent of any preceding claim, wherein said interconnecting member (13) is unitary with said valley (34) of one cylindrical element (12) and said valley (34) of said adjacent cylindrical element (12).

Claim 13

The stent of any preceding claim, wherein said adjacent cylindrical elements (12) are connected to each other by a plurality of said interconnecting members (13) whereby said stent (10) may expand from a first smaller diameter to a second enlarged diameter without appreciable change in overall length.

Claim 14

The stent of any preceding claim, wherein said cylindrical elements (12) cooperate to define a generally cylindrical surface and wherein said peaks (36) project outwardly from said surface upon expansion.

Claim 15

The stent of any preceding claim, wherein said stent (10) is formed of a biocompatible material selected from the group consisting of stainless steel, tungsten, tantalum, super-elastic nickel-titanium (NiTi) alloys, and thermoplastic polymers.

Claim 16

The stent of any preceding claim, wherein said stent (10) has a radial expansion ratio of about 1 up to about 4.0.

Claim 17

The stent of any preceding claim, wherein the stent is formed from a single piece of tubing (21).

Claim 18

A kit of parts for delivering an intraluminal stent in a body lumen comprising: an elongated stent delivery catheter (11) having a proximal end and a distal end, and an expandable member (14) adjacent the distal end; a longitudinally flexible stent (10) expandable from a contracted condition to an expanded condition, comprising: a plurality of adjacent cylindrical elements (12) which are independently expandable in the radial direction and arranged in alignment along a longitudinal stent axis; said cylindrical elements (12) formed in an irregular serpentine wave pattern (12,34,36) transverse to the longitudinal axis and containing a plurality of alternating peaks (36) and valleys (34); at least one interconnecting member (13) extending between adjacent cylindrical elements (12) and connecting them to one another; a coating covering said plurality of adjacent cylindrical elements (12) and said at least one interconnecting member (13), said coating consisting of a parylene polymer selected from the group consisting of poly-(chloro-para-xylylene), poly-(dichloro-para-xylylene), and poly (para-xylylene); said irregular serpentine pattern (12,34,36) containing varying degrees of curvature in regions of said peaks (36) and valleys (34) adapted so that radial expansion of said cylindrical elements (12) is generally uniform around their circumferences during expansion of the stent (10) 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 said body lumen.

Claim 19

A longitudinally flexible stent (10) for implanting in a body lumen and expandable from a contracted condition to an expanded condition, comprising: a plurality of adjacent cylindrical elements (12) which are independently expandable in the radial direction and arranged in alignment along a longitudinal stent axis; at least one interconnecting member (13) extending between adjacent cylindrical elements (12) and connecting them to one another; and a coating covering said plurality of cylindrical elements (12) and said at least one interconnecting member (13).

Claim 20

The stent of any of claims 1 to 5 or claim 19, wherein said coating is a parylene polymer selected from the group consisting of poly-(chloro-para-xylylene), poly-(dichloro-para-xylylene) and poly-(para-xylylene).