Percutaneously implantable replacement heart valve device and method of making same
A method of making a replacement heart valve device whereby a fragment of biocompatible tissue material is treated and soaked in one or more alcohol solutions and a solution of glutaraldehyde. The dried biocompatible tissue material is folded and rehydrated in such a way that forms a two- or three-leaflet/cusp valve without affixing of separate cusps or leaflets or cutting slits into the biocompatible tissue material to form the cusps or leaflets. After the biocompatible tissue material is folded, it is affixed at one or more points on the outer surface to the inner cavity or a stent.
1. A method of making a percutaneously implantable replacement heart valve, comprising:
(a) forming a transverse linear crease in a sheet of tissue membrane to provide an outer cuff layer and an inner leaflet layer in the sheet of tissue membrane, wherein the transverse linear crease is oriented substantially parallel to a first edge and a second edge of the sheet of tissue membrane;
(b) partitioning the inner leaflet layer by forming two additional linear creases in the sheet of tissue membrane, the two additional linear creases oriented substantially perpendicular to the transverse linear crease to provide three individual valve leaflets, wherein the three individual valve leaflets are bordered in part by the two additional linear creases, the two additional linear creases extending from the transverse linear crease to a free edge of the inner leaflet layer; and
(c) attaching the sheet of tissue membrane with the transverse linear crease and the two additional linear creases to a collapsible and expandable stent member such that the sheet of tissue membrane resides as a single element entirely within an inner channel of the collapsible and expandable stent member, wherein only the inner leaflet layer resides radially inward from the outer cuff layer, and wherein a first lateral edge of the sheet of tissue membrane adjoins a second lateral edge of the sheet of tissue membrane;
wherein the inner leaflet layer contacts the outer cuff layer along each of the two additional linear creases; and
wherein the first edge includes the free edge of the inner leaflet layer, and wherein at least portions of the inner leaflet layer reside substantially radially adjacent and in contact with the outer cuff layer within the collapsible and expandable stent member to form a contiguous double-layer folded construct.
2. The method of making a percutaneously implantable replacement heart valve of claim 1 , further comprising associating a catheter with the collapsible and expandable stent member after attaching the sheet of tissue membrane to the collapsible and expandable stent member.
3. The method of making a percutaneously implantable replacement heart valve of claim 1 , wherein the sheet of tissue membrane comprises one of treated bovine pericardium tissue or treated porcine pericardium tissue.
4. The method of making a percutaneously implantable replacement heart valve of claim 1 , wherein attaching the sheet of tissue membrane to the collapsible and expandable stent member comprises suturing the sheet of tissue membrane to the collapsible and expandable stent member at axially distal and proximal ends of the contiguous double-layer folded construct.
5. The method of making a percutaneously implantable replacement heart valve of claim 1 , wherein each of the two additional linear creases corresponds to a leaflet commissure between adjacent individual valve leaflets.
6. The method of making a percutaneously implantable replacement heart valve of claim 1 , wherein the collapsible and expandable stent member comprises a shape memory alloy.
7. The method of making a percutaneously implantable replacement heart valve of claim 6 , wherein the shape memory alloy comprises nitinol.