A Prosthetic Heart Valve

• US 20160067038A1
• Filed: 04/17/2014
• Published: 03/10/2016
• Est. Priority Date: 04/19/2013
• Status: Active Grant

• Current Assignee: Strait Access Technologies Holdings (Pty) Ltd.
• Original Assignee: Strait Access Technologies Holdings (Pty) Ltd.
• Inventors: Bezuidenhout, Deon, Zilla, Peter Paul, Park, Kenneth Stuart, Appa, Harish, Visagie, Claude
• Granted Patent: US 10,631,978 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61F 2/2406 without fixed axis
• CPC Class Codes: A61F 2/2412 with soft flexible valve members, e.g. tissue valves shaped like natural valves check valves with flexible valve members in general F16K15/14
• CPC Class Codes: A61F 2/2415 Manufacturing methods
• CPC Class Codes: A61F 2/2418 Scaffolds therefor, e.g. support stents

Abstract

A prosthetic heart valve (10) which includes a stent (14) having three leaflets (12) attached thereto is provided. The stent (14) is compressible so as to be capable of being introduced into a patient'"'"'s body through a minimally invasive procedure and has a ring-like body (16) defining in its height three arch-shaped elements (18). Each element (18) includes an arc (20) and a pair of haunches (22) extending from opposite sides thereof, with three commissural posts (26) formed by the haunches (22) of adjacent elements (18). The leaflets (12) each have an attachment edge (28) and a free edge (30) with a belly (32) extending therebetween. The leaflets (12) are movable between a coapted condition, in which the free edges (30) abut and prevent fluid flow through the valve (10), and an open condition, in which fluid flow through the valve (10) is permitted. The leaflets (12) are made from a polymeric material and are moulded directly onto the stent (14) so as to provide for continuous attachment thereof.

Claims

1. A prosthetic heart valve which includes a stent having three leaflets attached thereto, the stent being compressible to a compressed condition in which it is capable of being introduced into a patient'"'"'s body through a minimally invasive procedure and further being expandable from the compressed condition to an operative condition during deployment of the valve within the patient'"'"'s body, the stent having a ring-like body with an inlet and an outlet and defining in its height three arch-shaped elements each of which has an arc and a pair of haunches extending from opposite sides thereof, with three commissural posts formed by the haunches of adjacent elements, each leaflet having an attachment edge and a free edge with a belly extending between the free edge and the attachment edge, the leaflets being movable between an open condition, in which fluid flow through the valve is permitted in a direction from the inlet to the outlet, and a coapted condition, in which the free edges abut and prevent fluid flow through the valve in an opposite direction from the outlet to the inlet, wherein the leaflets are made from a polymeric material and are attached to the stent to encapsulate the arch-shaped elements so that the attachment edge of each leaflet is continuously attached along the length of an arch-shaped element.

2. A prosthetic heart valve as claimed in claim 1, wherein the arch-shape is defined by a parametric curve and its mirror image along the z-axis which is wrapped about a cylinder having a diameter of the prosthetic heart valve with the parametric curve being defined by a function A(x)=(1−

x)³P₀+3(1−

x)²xP₁+3(1−

x)x²P₂+x³P₃, with P₀ to P₃ being control points, wherein P₀ and P₃ are selected on the basis of the diameter and height of prosthetic heart valve, and wherein P₁ is selected from the range of 0≦

z≦

H and P₂ is selected from the range 0≦

x≦

π

D/6 where H is the height and D the diameter of the prosthetic heart valve.

3. A prosthetic heart valve as claimed in claim 1, wherein the shape of the free edge of the leaflets is defined by three curves defined by functions y=mx with c_b≦

x≦

−

c_b+x_s, y=K cos(Lx)+t with −

c_b+x_s≦

x<

c_b−

x_s, and y=−

mx with c_b−

x_s≦

x≦

c_b with the constant m being in the range of 0.1 to 1, the constant K being in the range of −

3 to 0, the constant L being in the range of 0.05 to 1.5, and the constant t being in chosen such that the end points of the three curves meet each other.

4. A prosthetic heart valve as claimed in claim 1, wherein the belly is defined by a parametric curve in a two dimensional plane, with the parametric curve being defined by a function B(x)=(1−

x)³P₀+3(1−

x)²xP₁+3(1−

x)x²P₂+x³P₃, with P₀ to P₃ being control points, wherein P₂ and P₃ remain constant, and wherein P₀ is selected from the range of 0.3D≦

P_0x≦

0.5D and 0.5H≦

P_0y≦

0.8H and P₁ is selected from the range 0.4D≦

P_1x≦

0.6D and 0.3H≦

P_1y≦

0.8H where H is the height and D the diameter of the prosthetic heart valve.

5. A prosthetic heart valve as claimed in claim 1, wherein the stent includes reinforcing members which span between both of adjacent arch-shaped elements and the commissural posts.

6. A prosthetic heart valve as claimed in claim 1, wherein the arcs or the haunches of the arch-shaped elements have varying widths along their lengths.

7. A stent for a prosthetic heart valve, the stent configured to house three polymeric leaflets and being compressible to a compressed condition, in which it is capable of being introduced into a patient'"'"'s body through a minimally invasive procedure and further being expandable from the compressed condition to an operative condition during deployment of the valve within the patient'"'"'s body, the stent having a ring-like body defining in its height three arch-shaped elements each of which having an arc and a pair of haunches extending from opposite sides thereof, with three commissural posts formed by the haunches of adjacent elements, wherein each arch-shaped element provides an attachment zone along which an attachment edge of a leaflet can be continuously attached to the stent.

8. A stent as claimed in claim 7, wherein the arch-shape is defined by a parametric curve and its mirror image along the z-axis which is wrapped about a cylinder having a diameter of the prosthetic heart valve, with the parametric curve being defined by a function A(x)=(1−

x)³P₀+3(1−

x)²xP₁+3(1−

x)x²P₂+x³P₃, with P₀ to P₃ being control points, wherein P₀ and P₃ are selected on the basis of the diameter and height of prosthetic heart valve, and wherein P₁ is selected from the range of 0≦

z≦

H and P₂ is selected from the range 0≦

x≦

π

D/6 where H is the height and D the diameter of the prosthetic heart valve.

9. A stent as claimed in claim 7, wherein the stent includes reinforcing members which span between both of adjacent arch-shaped elements and the commissural posts.

10. A stent as claimed in claim 7, wherein the arcs or the haunches of the arch-shaped elements have varying widths along their lengths.

11. A stent as claimed in claim 7, wherein the stent includes biasing members capable of at least partial elastic deformation during compression of the stent and which act on adjacent haunches to bias the haunches from the compressed condition to the operative condition.

12. A stent as claimed in claim 7, wherein the stent includes locating members which extend outwardly from the body of the stent to locate the stent within a natural heart valve of a patient during deployment thereof.

13. A leaflet for a prosthetic heart valve, the leaflet having an attachment edge and a free edge with a belly extending between the free edge and the attachment edge, wherein the leaflet is made from a polymeric material with the attachment edge being generally arch-shaped for continuous attachment to a complementary surface on a stent and the free edge having a length equal to or greater than an arc of radius R between two points on the attachment edge where the free edge intersects the attachment edge, and where R is the radius of the valve.

14. A leaflet as claimed in claim 13, wherein the arch-shape is defined by a parametric curve and its mirror image along the z-axis which is wrapped about a cylinder having a diameter of the prosthetic heart valve, with the parametric curve being defined by a function A(x)=(1−

x)³P₀+3(1−

x)²xP₁+3(1−

x)x²P₂+x³P₃, with P₀ to P₃ being control points, wherein P₀ and P₃ are selected on the basis of the diameter and height of prosthetic heart valve, and wherein P₁ is selected from the range of 0≦

z≦

H and P₂ is selected from the range 0≦

x≦

π

D/6 where H is the height and D the diameter of the prosthetic heart valve.

15. A leaflet as claimed in claim 13, wherein the shape of the free edge of the leaflets is defined by three curves defined by functions y=mx with −

c_b≦

x≦

−

c_b+x_s, y=K cos(Lx)+t with −

c_b+x_s≦

x<

c_b−

x_s, and y=−

mx with c_b−

x_s≦

x≦

c_b with the constant m being in the range of 0.1 to 1, the constant K being in the range of −

3 to 0, the constant L being in the range of 0.05 to 1.5, and the constant t being in chosen such that the end points of the three curves meet each other.

16. A leaflet as claimed in claim 13, wherein the belly is defined by a parametric curve in a two dimensional plane, with the parametric curve being defined by a function B(x)=(1−

x)³P₀+3(1−

x)²xP₁+3(1−

x)x²P₂+x³P₃, with P₀ to P₃ being control points, wherein P₂ and P₃ remain constant, and wherein P₀ is selected from the range of 0.3D≦

P_0x≦

0.5 D and 0.5H≦

P_0y≦

0.8H and P₁ is selected from the range 0.4D≦

P_1x≦

0.6D and 0.3H≦

P_1y≦

0.8H where H is the height and D the diameter of the prosthetic heart valve.

17. A leaflet as claimed in claim 13, wherein the leaflet is manufactured through dip moulding or spray moulding.