Aortic prosthetic devices

1. A prosthetic device for use in the treatment of an aortic valve of a patient's heart, said prosthetic device having a compressed state for transarterial delivery and being expandable to an expanded state for implantation, said prosthetic device comprising:

an expandable support constructed so as to be implantable in the expanded state of the prosthetic device in an aortic annulus of the aortic valve;

an inner envelope having an upstream portion that lines the inner surface of the support, and a downstream portion which, when the prosthetic device is in the expanded state, is configured to extend into an aorta and defines a diverging conical section having a diameter that gradually increases from an upstream end of the diverging conical section to a downstream end of the section, which diverging conical section is configured to produce, during systole, a non-turbulent blood flow into the aorta with pressure recovery at the downstream end of the diverging conical section; and

a prosthetic valve coupled to the downstream portion of the envelope at the downstream end of the diverging conical section.

2. The prosthetic device according to claim 1 , wherein, in the expanded state of the prosthetic device, said diverging conical section has an upstream end of 5-20 mm in diameter and a downstream end of 15-30 mm in diameter, and is of 15-45 mm in length.

3. The prosthetic device according to claim 2 , wherein said upstream portion of the inner envelope includes a short straight section of uniform diameter within said aortic annulus effective to avoid flow separation through said upstream portion of the envelope.

4. The prosthetic device according to claim 3 , wherein said short straight section has a length of 2-10 mm.

5. The prosthetic device according to claim 1 , wherein said support includes two annular clamps engageable with the opposite sides of native leaflets of said aortic valve in the native leaflets' open positions for clamping the support to said leaflets.

6. The prosthetic device according to claim 5 , wherein each of said two annular clamps includes an annular array of fingers.

7. The prosthetic device according to claim 6 , wherein said support includes an annular array of bracing elements engageable with an inner surface of the aorta for bracing the prosthetic device within the aorta.

8. The prosthetic device according to claim 7 , wherein said bracing elements are integrally formed at one end with said annular array of fingers of one of said annular clamps.

9. The prosthetic device according to claim 1 , wherein said support, when the prosthetic device is in the expanded state extends to said downstream end of the diverging conical section, such that said inner envelope serves as a liner lining the inner surface of the support from said upstream end to said downstream end of the diverging conical section.

10. The prosthetic device according to claim 1 , wherein said prosthetic valve comprises a plurality of leaflets movable to open and closed positions.

11. The prosthetic device according to claim 10 , wherein said leaflets of the prosthetic valve are integral with said inner envelope.

12. The prosthetic device according to claim 1 , wherein said diverging conical section of said inner envelope comprises a flexible pliable material.

13. The prosthetic device according to claim 1 , wherein said diverging conical section of said inner envelope comprises a plurality of axially-extending reinforcing struts.

14. The prosthetic device according to claim 13 , wherein said reinforcing struts are hingedly connected to said support.

15. The prosthetic device according to claim 1 , wherein the support comprises a metal base.