Artificial valved conduits for cardiac reconstructive procedures and methods for their production
Artificial heart valve structures and methods of their fabrication are disclosed. The heart valve structures may be fabricated from a biocompatible polymer and include one or more heart valve leaflet structures incorporated within a conduit. The valve structures may incorporate one or more conduit sinuses, as well as a gap between the lower margin of the valve leaflets and the interior of the conduit. In addition, the valve structures may include one or more valve sinuses created in a space between the valve leaflets and the conduit inner surface. Computational fluid dynamics and mechanical modeling may be used to design the valve leaflets with optimal characteristics. A heart valve structure may also incorporate a biodegradable component to which cells may adhere The incorporated cells may arise from patient cells migrating to the biodegradable component, or the component may be pre-seeded with cells prior to implantation in a patient.
1. A valve structure comprising:
a conduit comprising an inner conduit surface; and
a multi-leaflet structure having an open state and a closed state comprising:
a first valve leaflet, comprising a first sinus structure having a first sinus edge and a first fan structure having a first fan edge, wherein at least a portion of the first sinus edge is affixed to the inner conduit surface;
a second valve leaflet, comprising a second sinus structure having a second sinus edge and a second fan structure having a second fan edge, wherein at least a portion of the second sinus edge is affixed to the inner conduit surface; and
a commissure disposed between the first valve leaflet and the second valve leaflet,
wherein at least a portion of the first fan edge, at least a portion of the second fan edge, and at least a portion of the inner conduit surface are mutually disposed to form a valve gap in the closed state of the multi-leaflet structure.
2. The valve structure of claim 1 , wherein the first sinus edge comprises a plurality of first sinus edge components and the second sinus edge comprises a plurality of second sinus components.
3. The valve structure of claim 1 , further comprising:
a first sinus structure height edge comprising a first inner edge component and a first outer edge component;
a second sinus structure height edge comprising a second inner edge component and a second outer edge component;
the first inner edge component, the first outer edge component, the second inner edge component, and the second outer edge component are essentially linear;
the first inner edge component and the first outer edge component intersect to form a first sinus intersection having a first height as measured from the a first leaflet baseline width; and
the second inner edge component and the second outer edge component intersect to form a second sinus intersection having a second height as measured from the a second leaflet baseline width;
a first fan height; and
a second fan height.
4. The valve structure of claim 3 , wherein a ratio of the first leaflet baseline width to a diameter of the conduit is about 0.054 to about 0.17 and a ratio of the second leaflet baseline width to a diameter of the conduit is about 0.054 to about 0.17.
5. The valve structure of claim 3 , wherein a ratio of a length of the commissure to the first leaflet baseline width is about 0.18 to about 0.38.
6. The valve structure of claim 1 , wherein:
the first fan edge comprises a first fan edge steep portion proximate to the first sinus edge, and a first fan edge gradual portion; and
the second fan edge comprises a second fan edge steep portion proximate to the second sinus edge, and a second fan edge gradual portion.
7. The valve structure of claim 1 , further comprising a first valve sinus bounded by the inner conduit surface and the first sinus structure and a second valve sinus bounded by the inner conduit surface and the second sinus structure.
8. The valve structure of claim 1 , further comprising a third valve leaflet and a second commissure disposed between the second valve leaflet and the third valve leaflet,
wherein the third valve leaflet comprises a third sinus structure having a third sinus edge and a third fan structure having a third fan edge and at least a portion of the third sinus edge is affixed to the inner conduit surface.
9. A method of fabricating a heart valve structure, the method comprising:
providing a flexible conduit comprising a wall, an inner surface, and an outer surface;
providing a heart valve multi-leaflet structure;
everting the flexible conduit;
affixing the heart valve multi-leaflet structure to the inner surface; and
reverting the conduit, thereby forming a multi-leaflet valve within an interior of the conduit,
wherein the heart valve multi-leaflet structure comprises
a first heart valve leaflet, comprising a first sinus edge and a first fan edge, and
a second heart valve leaflet, comprising a second sinus edge and a second fan edge,
wherein the first fan edge intersects the second fan edge at an outer commissure point, and the first sinus edge intersects the second sinus edge at an inner commissure point, thereby forming a commissure extending from the outer commissure point to the inner commissure point,
wherein the first fan edge intersects the first sinus edge at a first outer leaflet point, thereby forming a first baseline extending from the first outer leaflet point to the commissure, the first baseline further having a first width as measured from the first outer leaflet point to the commissure,
wherein the second fan edge intersects the second sinus edge at a second outer leaflet point, thereby forming a second baseline extending from the second outer leaflet point to the commissure, the second baseline further having a second width as measured from the second outer leaflet point to the commissure,
wherein the second baseline is essentially collinear with the first baseline,
wherein the first sinus edge extends from and is not coextensive with the first baseline, thereby forming a first sinus structure bounded by the first sinus edge, the commissure, and the first baseline,
wherein the second sinus edge extends from and is not coextensive with the second baseline, thereby forming a second sinus structure bounded by the second sinus edge, the commissure, and the second baseline,
wherein the first fan edge extends from and is not coextensive with the first baseline, thereby forming a first fan structure bounded by the first fan edge, the commissure, and the first baseline, and
wherein the second fan edge extends from and is not coextensive with the second baseline, thereby forming a second fan structure bounded by the second fan edge, the commissure, and the second baseline, and
wherein at least a portion of the first fan edge, at least a portion of the second fan edge, and at least a portion of the inner conduit surface are mutually disposed to form a valve gap,
wherein at least a portion of the first sinus structure and a portion of the inner conduit surface are nonadjacent, thereby forming a first valve sinus bounded at least in part by at least a portion of the inner conduit surface and at least a portion of the first sinus structure, and
wherein at least a portion of the second sinus structure and a portion of the inner conduit surface are nonadjacent, thereby forming a second valve sinus bounded at least in part by at least a portion of the inner conduit surface and at least a portion of the second sinus structure.
10. The method of claim 9 , wherein affixing the heart valve multi-leaflet structure to the inner surface comprises affixing the first sinus edge, the second sinus edge, and the commissure to the inner surface.
11. The method of claim 9 , further comprising:
providing a sinus stencil; and
marking the inner surface with a shape substantially the same as the sinus stencil.
12. The method of claim 11 , wherein affixing the heart valve multi-leaflet structure to the inner surface comprises affixing the first sinus edge, the second sinus edge, and the commissure along the shape marked on the inner surface.
13. A valve structure comprising:
a conduit comprising an inner conduit surface; and
a leaflet structure having an open and a closed state comprising:
a valve leaflet, comprising a sinus structure having a sinus edge and a fan structure having a fan edge,
wherein at least a portion of the sinus edge is affixed to a portion of the inner conduit surface,
wherein at least a portion of the fan edge and at least a portion of the inner conduit surface are mutually disposed to form a valve gap in the closed state of the leaflet structure.