Patent ID: 8172893

Claim:
An unexpanded stent comprising A) a tubular element having a longitudinal axis and B) a porous surface comprising an array of apertures in a repeating pattern, C) wherein the repeating pattern has mirror-image symmetry about a transverse axis orthogonal to the longitudinal axis, D) each of the apertures of the unexpanded stent extends predominantly in a longitudinal direction, E) each of the apertures is defined by a boundary which, at least one point of tangency, is tangent to a line which is (a) perpendicular to said longitudinal axis and (b) intersects said boundary at least two points other than the point of tangency, F) said boundary has six junctions with neighboring boundaries, three on one side of said transverse axis and three on the opposite side thereof, G) the aperture boundary has a concave-shaped portion and a convex-shaped portion which are aligned so that repeating patterns in a circumferential row of apertures are interlocked with respect to one another, H) the concave-shaped portion and the convex-shaped portion being interconnected by a pair of lateral walls, one on either side of said transverse axis, I) each of said lateral walls comprising a pair of S-shaped sections lying on one respective side of said transverse axis, and J) each of said S-shaped sections comprising an asymmetric pair of curved sections, K) wherein each of said curved sections comprises an arc of at least 180°.