Method of manufacturing a prosthetic valve
A prosthetic valve for implantation in a stenosed aortic valve. The prosthetic valve includes a metallic frame formed with intersecting bars having diameters in the range of 0.1 to 0.6 mm. The frame is radially collapsible for advancement into a native aortic valve using a catheterization technique. The frame is radially expandable for embedding the frame within the native aortic valve. The frame has sufficient radial strength to resist the recoil forces of the native aortic valve after implantation. The prosthetic valve includes a collapsible valvular structure made with pericardium. The prosthetic valve also includes an internal cover which forms a substantially impermeable tubular sleeve. The internal cover preferably extends between a lower extremity of the frame and the valvular structure. The internal cover is preferably sutured to the valvular structure. The valvular structure and internal cover are sutured to the bars of the frame.
1. A method of manufacturing a prosthetic heart valve assembly for implantation in a stenosed aortic valve, comprising:
forming a metallic frame having upper and lower extremities, the frame comprising intersecting bars having diameters in the range of 0.1 to 0.6 mm, the frame being collapsible to a compressed external diameter suitable for advancement through a patient's vasculature and into a stenosed aortic valve using a catheterization technique, the frame being expandable for embedding the frame within the stenosed aortic valve, the frame being capable of resisting the recoil forces of the stenosed aortic valve, the frame forming zig-zag lines along the upper and lower extremities;
constructing a valvular structure from pericardial tissue, the valvular structure adapted for permitting blood flow in one direction;
constructing an internal cover from pericardial tissue, the internal cover forming a sleeve;
suturing an upper end of the internal cover to the valvular structure;
suturing the valvular structure to the intersecting bars of the frame while the frame is in an expanded state, the valvular structure sutured to the frame with stitches extending around the bars of the frame between the upper and lower extremities;
suturing a lower portion of the internal cover to the lower extremity of the frame along the zig-zag line; and
reinforcing the fastening of the internal cover to the frame by suturing the internal cover to the intersecting bars of the frame at various points along an internal surface of the frame, the internal cover positioned between the lower extremity of the frame and the valvular structure such that the internal cover covers the internal surface only along an inferior portion of the frame;
wherein the internal cover is configured to prevent the passage of blood through spaces between the intersecting bars of the frame below the valvular structure.
2. The method of manufacture of claim 1 , wherein the frame is collapsible to an external diameter suitable for introduction through an 18 French arterial introducer.
3. The method of manufacture of claim 1 , wherein the frame has a compressed external diameter suitable for introduction through a 16 French arterial introducer.
4. The method of manufacture of claim 1 , wherein the frame has a compressed external diameter suitable for introduction through a 14 French arterial introducer.
5. The method of manufacture of claim 1 , wherein the frame has an expanded diameter of about 20 to 25 mm.
6. The method of manufacture of claim 1 , further comprising the step of securing strips of stiff material to the valvular structure, the strips extending substantially along a longitudinal axis for inducing a patterned movement of the valvular structure.
7. The method of manufacture of claim 1 , wherein the frame is formed with a generally concave profile.
8. The method of manufacture of claim 1 , wherein a wall of the frame is constructed to have a grate structure adapted for supporting the valvular structure and behaving as a scaffold for pushing against the native aortic valve.
9. The method of manufacture of claim 1 , wherein the internal cover is wrapped around the lower extremity of the frame and secured to an external wall of the frame to form an external cover.
10. The method of manufacture of claim 1 , wherein the internal cover strengthens securement of the valvular structure to the frame.
11. The method of manufacture of claim 1 , further comprising coating the valvular structure with a substance having anti-thrombotic properties.