Abstract: An expandable sleeved stent comprises a stent and a sleeve. The stent comprises a tubular body with: first and second axial ends; a latticed peripheral wall; and at least two arms that, upon radial expansion of the tubular body from a crimped condition to an expanded condition, protrude radially from the latticed peripheral wall, the free end of each arm being radially displaceable relative to the adjacent latticed peripheral wall. The sleeve: (a) extends from the first axial end of the tubular body and circumferentially covers at least a portion of the radial outer surface of the latticed peripheral wall between the free ends of the arms and the first axial end of the tubular body; (b) bridges the spaces between the portions of the latticed peripheral wall adjacent the arms; and the free ends of the arms; and (c) is secured to either: (i) the arms; or (ii) the tubular body in the vicinity between the free ends of the arms and the second axial end of the tubular body.

Abstract: Partially crosslinked polyurethane polymers comprising diisocyanates and aliphatic hydrocarbon soft segments with a short-chain diol chain extender and a multifunctional amine and/or alcohol crosslinker to provide a polyurethane polymer with useful properties for the production of medical implant devices such as heart valves, are described. The polymers have an unexpected linear elastic region in a range from 5-100% and preferably between 10-35%. In some embodiments the polyurethanes are a thermally convertible gel formulation which may be converted to a liquid formulation by extended heating to render the polymer suitable for solvent processing techniques such as casting, spraying, spinning, etc. The invention also provides for living hinge polyurethane polymers which are thermally modifiable from a gel to a liquid and reaction injection moulded (RIM) polyurethanes with an enhanced flex life.

Abstract: Partially crosslinked polyurethane polymers comprising diisocyanates and aliphatic hydrocarbon soft segments with a short-chain diol chain extender and a multifunctional amine and/or alcohol crosslinker to provide a polyurethane polymer with useful properties for the production of medical implant devices such as heart valves, are described. The polymers have an unexpected linear elastic region in a range from 5-100% and preferably between 10-35%. In some embodiments the polyurethanes are a thermally convertible gel formulation which may be converted to a liquid formulation by extended heating to render the polymer suitable for solvent processing techniques such as casting, spraying, spinning, etc. The invention also provides for living hinge polyurethane polymers which are thermally modifiable from a gel to a liquid and reaction injection moulded (RIM) polyurethanes with an enhanced flex life.