Abstract: Stents are coated with a polymer such that the polymeric coating binds the crossover points of the wires, or, in the case of a zig-zag stent, binds adjacent zig-zags of wires without occluding the interstices of the stent lattice. Suitable polymers include polyurethane, polycarbonate urethane, polyurethane urea, silicone rubber, polyisobutylene copolymer (with styrene, etc.), polyolefin, polyester, glycolated polyester, polyamide, amorphous polyamide, combinations of the above and the like. Biodegradable polymers such as polyisobuterate, polyvalerate, polylactic acid, polyglycolic acid and combinations of these are also suitable. The polymer can be reacted in place without a solvent, such as two component polyurethanes, or silicone rubbers, or the reacted polymer can be dissolved in an appropriate solvent, for example, dimethylacetamide for the polyurethanes, toluene for the polyolefins, or heptane for the silicone rubbers.

Abstract: A self-expanding stent for a medical device to be introduced into a cavity of a human body, is disclosed and includes a radially expandable and axially retractable tubular body (1), characterized in that the tubular body comprises first filaments (2, 3) which are arranged side by side in a number at least equal to two, wound along a first helicoid direction around a longitudinal axis (4) of the tubular body, and second flexible rigid filaments (5, 6) which are arranged side by side in a number at least equal to two, wound along a second helicoid direction opposite to the first, each multiple filament wound in one of the said directions crossing multiple filaments wound in the other direction according to a plaited arrangement. Methods for reproducibly forming the stent of the invention are disclosed.

Abstract: A self-expanding stent is provided for introduction into a cavity of a human body. The stent has a tubular body which is radially expansible and axially retractable between a working state and a resting state. The tubular body has first and second plaited filaments which provide a middle portion of a first diameter and two flared end portions of increasingly larger diameter as they extend away from the middle portion. Each flared end portion has an axial length along a longitudinal axis of the stent which is greater than an axial length of the portion of minimal diameter. Preferably, the middle portion is a single location, with the diameter of the stent increasing in both directions from that location to the ends of the stent. Different shaped stents are disclosed, including stents having generatrices taking the form of line segments angled relative to the longitudinal axis, and generatrices taking the form of a hyperbola segment or a circle arc segment.