Prosthesis Seals and Methods for Sealing an Expandable Prosthesis

A stent-valve for transcatheter implantation to replace a cardiac valve, the stent-valve being compressible to a compressed configuration for delivery, and expandable to an operative state for implantation, the stent-valve comprising a stent, a plurality of leaflets defining a prosthetic valve, and a seal for sealing against surrounding tissue, wherein the seal comprises:

• a hollow sleeve/cuff arranged to extend in a circumferential direction substantially around the stent and containing swellable material that swells when contacted by blood to distend the hollow cuff, the hollow sleeve/cuff comprising an integral tubular structure.

A stent-valve for transcatheter implantation to replace a cardiac valve, the stent valve being compressible to a compressed configuration for delivery, and expandable to an operative state for implantation, the stent-valve comprising a stent, a plurality of leaflets defining a prosthetic valve, and a seal for sealing against surrounding tissue, wherein the external seal comprises:

• a hollow sleeve/cuff arranged to extend in a circumferential direction substantially around the stent and containing swellable material that swells when contacted by blood to distend the hollow cuff, comprising a laminate of (i) plastics film and (ii) a diffusion barrier layer to obstruct diffusion of liquids from outside the hollow sleeve/cuff to the hollow interior, the diffusion barrier layer comprising a layer comprising metal or a metal compound.

A stent-valve for transcatheter implantation to replace a cardiac valve, the stent valve being compressible to a compressed configuration for delivery, and expandable to an operative state for implantation, the stent-valve comprising a stent, a plurality of leaflets defining a prosthetic valve, and a seal for sealing against surrounding tissue, wherein the external seal comprises:

• a hollow sleeve/cuff arranged to extend in a circumferential direction substantially around the stent and containing swellable material that swells when contacted by blood to distend the hollow cuff, the hollow sleeve/cuff being configured to withstand post-implantation balloon expansion of the stent-valve against a calcified anatomy without substantial loss of structural integrity of the hollow cuff.

A stent-valve for transcatheter implantation to replace a cardiac valve, the stent valve being compressible to a compressed configuration for delivery, and expandable to an operative state for implantation, the stent-valve comprising a stent, a plurality of leaflets defining a prosthetic valve, and a seal for sealing against surrounding tissue, wherein the external seal comprises:

• a hollow sleeve/cuff arranged to extend in a circumferential direction substantially around the stent and containing swellable material that swells when contacted by blood to distend the hollow cuff, the hollow sleeve/cuff comprising a film made of liquid-impermeable material, the sleeve/cuff having one or more liquid admitting punctures made therein, prior to introduction of the stent-valve into the body of a patient, for admitting liquid into the seal.