Optimal microporous surface for endothelialization of metal heart valves in the blood stream.

Optimum surface porosity of a prosthetic heart valve was obtained with use of microspheres less than 40 microns in diameter. A thin and translucent neointima then forms on the valve surface, so thin that its nutrition is supplied by diffusion and thickening will not take place, thereby avoiding interference with the functioning disc. Larger microspheres tend to promote clotting and buildup of fibromyxoid soft tissue, which may cause such interference.

Modified porous metal-surfaced Björk-Shiley monostrut heart valve. Long-term study in goats without anticoagulation.

To diminish the risk of thrombosis on a mechanical heart valve without anticoagulation, specific areas of the valve ring should be polished, as thrombosis has not been found to start there. By limiting the porous-surfaced area to the groove and the adjacent part of the flange, the thin endothelialized covering of the carbonized suture ring will continue over the groove and top of the flange to the high-flow area. As the high-flow areas that are not completely covered with the neointima, i.

Development of mechanical heart valves: past, present and future.

Aortic valve replacement with Bjork-Shiley tilting disc valves in 1753 patients gave a 15 year actuarial survival of 54%. Better results were obtained in narrow aortic roots and in pure aortic stenosis than in pure aortic insufficiency. Anti-coagulation was necessary.

Rewarming and cardiac surgery: a review.

Patients undergoing cardiac surgery are mildly hypothermic by the completion of the surgical procedure. They need to return to a normothermic state if enzymatic functions are to proceed in their normal manner. The body can produce heat by elevating metabolic rate or by activating the shivering mechanism.

The porous metal-surfaced heart valve. Long-term study without long-term anticoagulation in mitral position in goats.

On review, all thromboembolic complications in mechanical heart valves start from a thrombus lining that covers the suture ring. The thrombus organizes to a fibrous white sheet over the suture ring, which then can protrude out over the polished surface of the valve ring flange. Pieces of the thrombus can be knocked off by the disc and cause emboli.