초록 ▼

Expandable heart valves for minimally invasive valve replacement surgeries are disclosed. The valves are rolled into a first, contracted configuration for minimally invasive delivery using a catheter, and then unrolled or unfurled at the implantation site. One-and two-piece stents may be used in con

Expandable heart valves for minimally invasive valve replacement surgeries are disclosed. The valves are rolled into a first, contracted configuration for minimally invasive delivery using a catheter, and then unrolled or unfurled at the implantation site. One-and two-piece stents may be used in conjunction with a plurality of flexible leaflet-forming membranes. The stents may include an annulus section, a sinus section with the membranes attached over sinus apertures, and an outflow section. Lockout tabs and making slots secure the stents in their expanded shapes. Alignment structure ensures concentric unfurling of the stent. Anchoring elements at the stent edges or in the stent body secure the valve within the annulus. A method of manufacture includes shape setting the sheet-like stent to ensure an outward bias during deployment. The stent may also include dear tracks for engagement with a gear mechanism for deployment. The stent is desirably made of a superelastic material such as Nitinol and may have areas removed or thinned to reduce the bending stresses when rolled into its small spiral for catheter delivery.

대표청구항 ▼

What is claimed is: 1. A method of prosthetic heart valve implantation at an aortic annulus, comprising: delivering a rolled prosthetic heart valve to an aortic annulus, the prosthetic heart valve including a stent body having a spirally-wound contracted, first configuration with a first diameter c

What is claimed is: 1. A method of prosthetic heart valve implantation at an aortic annulus, comprising: delivering a rolled prosthetic heart valve to an aortic annulus, the prosthetic heart valve including a stent body having a spirally-wound contracted, first configuration with a first diameter configured for advancement to the aortic annulus and an unwound expanded, second configuration with a maximum second diameter, the prosthetic heart valve further including three flexible membranes attached to the stent body that form heart valve leaflets in the expanded configuration and portions of the stent body between the leaflets defining axially extending commissures; unfurling the prosthetic heart valve from the spirally-wound contracted, first configuration to the unwound expanded, second configuration at the aortic annulus; and positioning the prosthetic heart valve such that the stent body commissures align with native commissures of the aortic annulus. 2. The method of claim 1, further including anchoring the prosthetic heart valve in its expanded configuration to the aortic annulus. 3. The method of claim 1, wherein native heart valve leaflets of the aortic annulus are left in place and the step of unfurling causes the prosthetic heart valve to contact and outwardly compress native leaflets. 4. The method of claim 1, wherein the step of unfurling further includes ensuring that the prosthetic heart valve remains generally tubular throughout the step of unfurling. 5. The method of claim 1, further including at least one guide on the stent body to ensure the stent body remains generally tubular throughout the step of unfurling. 6. The method of claim 1, wherein the stent body has an annulus section on an inflow end, a sinus section, and an outflow section, the sinus section being between the annulus section and outflow section and having a plurality of sinus apertures. 7. The method of claim 6, wherein the flexible membranes each include an arcuate cusp edge and a free edge, the arcuate cusp edges of the leaflets being attached around one of the sinus apertures. 8. The method of claim 1, wherein the flexible membranes are formed of bioprosthetic tissue. 9. A method of prosthetic heart valve implantation, comprising: positioning a rolled prosthetic heart valve at a heart valve annulus, the prosthetic heart valve including a stent body having a spirally-wound contracted, first configuration with a first diameter configured for advancement to the heart valve annulus and an unwound expanded, second configuration with a maximum second diameter, the prosthetic heart valve further including a plurality of flexible, bioprosthetic tissue membranes attached to the stent body that form heart valve leaflets in the expanded configuration, wherein there are three flexible, bioprosthetic tissue membranes that form three heart valve leaflets in the expanded configuration of the stent body, and the stent body further defines axially extending commissures between the three leaflets; and unfurling the prosthetic heart valve from the spirally-wound contracted, first configuration to the unwound expanded, second configuration at the heart valve annulus. 10. The method of claim 9, further including anchoring the prosthetic heart valve in its expanded configuration to the heart valve annulus. 11. The method of claim 9, wherein native heart valve leaflets of the heart valve annulus are left in place and the step of unfurling causes the prosthetic heart valve to contact and outwardly compress native leaflets. 12. The method of claim 9, wherein the step of unfurling further includes ensuring that the prosthetic heart valve remains generally tubular. 13. The method of claim 9, further including the step of locking the prosthetic heart valve in its expanded configuration. 14. The method of claim 9, wherein the stent body has an annulus section on an inflow end, a sinus section, and an outflow section, the sinus section being between the annulus section and outflow section and having a plurality of sinus apertures. 15. The method of claim 9, wherein the prosthetic heart valve is configured to be disposed on a distal end portion of a catheter for positioning the prosthetic heart valve at the heart valve annulus. 16. The method of claim 9, further including at least one anchoring element extending radially outward from the stent body for preventing axial migration of the prosthetic heart valve after implantation. 17. The method of claim 9, wherein the flexible membranes each include an arcuate cusp edge and a free edge, and each arcuate cusp edge attaches to the stent body such that the leaflets billow inward upon blood flow in one direction to coapt along an axis of the valve and form fluid occluding surfaces. 18. A method of prosthetic heart valve implantation, comprising: providing a rolled prosthetic heart valve having a sheet-like stent body with lockout tabs and slots, the stent body having a spirally-wound contracted, first configuration with a first diameter for delivery to a heart valve annulus and an unwound expanded, second configuration wherein the tabs engage the slots to prevent contraction as well as further expansion, wherein the stent body has an annulus section on an inflow end, a sinus section, and an outflow section, the sinus section being between the annulus section and outflow section, and having a plurality of sinus apertures, and wherein the prosthetic heart valve comprises a plurality of flexible biocompatible membranes incorporated into the stent body that form heart valve leaflets in the expanded configuration, and wherein the flexible membranes each include an arcuate cusp edge and a free edge the arcuate cusp edges of the leaflets being attached around one of the sinus apertures; positioning the rolled prosthetic heart valve at a heart valve annulus; and unfurling the prosthetic heart valve in a controlled manner from the spirally-wound contracted, first configuration to the unwound expanded, second configuration within the heart valve annulus to ensure that the prosthetic heart valve retains a tubular shape rather than a frustoconical shape throughout the step of unfurling. 19. The method of claim 18, further including anchoring the prosthetic heart valve in its expanded configuration to the heart valve annulus. 20. The method of claim 18, wherein native heart valve leaflets of the heart valve annulus are left in place and the step of unfurling causes the prosthetic heart valve to contact and outwardly compress the native leaflets. 21. The method of claim 18, wherein the step of unfurling further includes ensuring that the prosthetic heart valve remains generally tubular. 22. The method of claim 18, further including the step of locking the prosthetic heart valve in its expanded configuration. 23. The method of claim 18, further including at least one guide to ensure the stent body retains its tubular shape throughout the step of unfurling. 24. The method of claim 23, wherein the stent body defines a pair of opposed side edges that generally mate in the expanded, second configuration, and a pair of opposed end edges that extend between the side edges, and the at least one guide comprises a guide tab extending generally radially along each one of the end edges. 25. The method of claim 18, further including at least one anchoring element extending radially outward from the stent body for preventing axial migration of the heart valve after implantation in the annulus. 26. The method of claim 18, wherein the flexible membranes are formed of bioprosthetic tissue. 27. A method of prosthetic heart valve implantation, comprising: positioning a rolled prosthetic heart valve at a heart valve annulus, the prosthetic head valve including a stent body having a spirally-wound contracted, first configuration with a first diameter configured for advancement to the heart valve annulus and an unwound expanded, second configuration with a maximum second diameter, and wherein the stent body defines a pair of opposed side edges that generally mate in the expanded, second configuration, and a pair of opposed end edges that extend between the side edges, and at least one tab extending generally radially along each one of the end edges to ensure the stent body expands evenly along an axis when unfurling from the contracted, first configuration to the expanded, second configuration; and unfurling the prosthetic heart valve from the spirally-wound contracted, first configuration to the unwound expanded, second configuration at the heart valve annulus. 28. A method of prosthetic heart valve implantation, comprising: providing a rolled prosthetic heart valve having a sheet-like stent body with lockout tabs and slots, the stent body having a spirally-wound contracted, first configuration with a first diameter for delivery to a heart valve annulus and an unwound expanded, second configuration wherein the tabs engage the slots to prevent contraction as well as further expansion, wherein the stent body defines a pair of opposed side edges that generally mate in the expanded, second configuration, and a pair of opposed end edges that extend between the side edges, and at least one guide tab extending generally radially along each one of the end edges to ensure the stent body expands evenly along an axis when unfurling from the contracted, first configuration to the expanded, second configuration; positioning the rolled prosthetic heart valve at a heart valve annulus; and unfurling the prosthetic heart valve from the spirally-wound contracted, first configuration to the unwound expanded, second configuration within the heart valve annulus. 29. A method of prosthetic heart valve implantation, comprising: positioning a rolled prosthetic heart valve at a heart valve annulus, the prosthetic heart valve including a stent body having a spirally-wound contracted, first configuration with a first diameter configured for advancement to the heart valve annulus and an unwound expanded, second configuration with a maximum second diameter, the prosthetic heart valve further including a plurality of flexible, bioprosthetic tissue membranes attached to the stent body that form heart valve leaflets in the expanded configuration, wherein the stent body defines a pair of opposed side edges that generally mate in the expanded, second configuration, and a pair of opposed end edges that extend between the side edges, and further including at least one tab extending generally radially along each one of the end edges to ensure the stent body expands evenly along an axis when unfurling from the contracted, first configuration to the expanded, second configuration; and unfurling the prosthetic heart valve from the spirally-wound contracted, first configuration to the unwound expanded, second configuration at the heart valve annulus. 30. The method of claim 29, further including the step of locking the prosthetic heart valve in its expanded configuration. 31. The method of claim 29, wherein the stent body has an annulus section on an inflow end, a sinus section, and an outflow section, the sinus section being between the annulus section and outflow section and having a plurality of sinus apertures. 32. The method of claim 29, wherein the flexible membranes each include an arcuate cusp edge and a free edge, and each arcuate cusp edge attaches to the stent body such that the leaflets billow inward upon blood flow in one direction to coapt along an axis of the valve and form fluid occluding surfaces. 33. A method of prosthetic heart valve implantation, comprising: providing a rolled prosthetic heart valve having a sheet-like stent body with lockout tabs and slots, the stent body having a spirally-wound contracted, first configuration with a first diameter for delivery to a heart valve annulus and an unwound expanded, second configuration wherein the tabs engage the slots to prevent contraction as well as further expansion, wherein the stent body defines a pair of opposed side edges that generally mate in the expanded, second configuration, and a pair of opposed end edges that extend between the side edges, and at least one guide tab extends generally radially along each one of the end edges to ensure the stent body retains its tubular shape throughout the step of unfurling; positioning the rolled prosthetic heart valve at a heart valve annulus; and unfurling the prosthetic heart valve in a controlled manner from the spirally-wound contracted, first configuration to the unwound expanded, second configuration within the heart valve annulus to ensure that the prosthetic heart valve retains a tubular shape rather than a frustoconical shape throughout the step of unfurling.