Prosthetic heart value
A tubular prosthetic semilunar or atrioventricular heart valve is formed by cutting flat, flexible leaflets according to a pattern. The valve is constructed by aligning the side edges of adjacent leaflets so that the leaflet inner faces engage each other, and then suturing the leaflets together with successive stitches along a fold line adjacent the side edges. The stitches are placed successively from a proximal in-flow end of each leaflet toward a distal out-flow end. During operation, when the leaflets open and close, the leaflets fold along the fold line. Distal tabs extend beyond the distal end of each leaflet. The successive stitches terminate proximal of the distal tab portion so that no locked stitches are placed along the distal portion of the fold line. The tab portions of adjacent leaflets are folded over each other and sewn together to form commissural attachment tabs. The commissural tabs provide commissural attachment points to accommodate sutures and the like in order to secure the tab to a vessel wall, if a semilunar valve, and papillary muscles and/or chordae tendineae if an atrioventricular valve.
1. A stentless prosthetic heart valve, comprising:
a first thin, flexible leaflet and a second thin, flexible leaflet, each of the leaflets having an inner face, an outer face, an in-flow edge, an out-flow edge, and side edges, the plurality of leaflets being sewn directly together along at least a portion of their side edges so as to form a substantially tubular valve structure having an in-flow end and an out-flow end, adjacent leaflets being arranged so that their side edges are substantially aligned and the inner faces of the leaflets engage each other adjacent the side edges, and a width of the in-flow edge of the first leaflet is greater than a width of the out-flow edge of the second leaflet,
wherein the valve structure is movable between a closed position in which the out-flow edges of adjacent leaflets engage each other, and an open position in which the out-flow edges of adjacent leaflets are separated from each other except along the side edges, the sewn portions of the side edges of the leaflets biasing the leaflets toward a partially closed position.
2. A heart valve as in claim 1 , wherein the aligned leaflet side edges extend generally outwardly from the substantially tubular valve structure.
3. A heart valve as in claim 1 , wherein each of the leaflets comprises a tab portion adjacent the leaflet out-flow edge.
4. A heart valve as in claim 3 , wherein each tab portion extends beyond the out-flow edge of the corresponding leaflet.
5. A heart valve as in claim 3 , wherein the tab portions are disposed adjacent at least one of the leaflet side edges.
6. A heart valve as in claim 5 , wherein a tab portion is formed adjacent each leaflet side edge.
7. A heart valve as in claim 6 , wherein the tab portions of adjacent leaflets are connected to each other to form commissural attachment tabs.
8. A method for making a stentless tubular prosthetic hear valve, comprising:
providing a section of substantially flat, flexible material;
cutting a plurality of leaflets out of the flat material, each of the leaflets having an inner face, an outer face, a proximal end, a distal end, side edges, and tab portions adjacent the distal end and tending from the side edges, wherein a width of the in-flow edge of the first leaflet is greater than a width of the out-flow edge of the second leaflet;
aligning the side edges of adjacent leaflets together so that the inner faces of adjacent leaflets engage each other adjacent the side edges; and
sewing aligned side edges together so as to form a substantially tubular valve structure having an in-flow and an out-flow end.
9. The method of claim 8 , wherein providing a section of substantially flat, flexible material involves providing a section of pericardium and fixing the pericardium.
10. The method of claim 9 , wherein the material is equine pericardium.
11. The method of claim 8 , wherein cutting a plurality of leaflets is accomplished using a non-contact cutting apparatus.
12. The method of claim 11 , wherein cutting a plurality of leaflets is accomplished using a laser.