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

@entity1031 @entity505 @entity715 @entity340 @entity1237
On review, all @entity1031 in mechanical heart valves start from a @entity715 lining that covers the suture ring. The @entity715 organizes to a fibrous white sheet over the suture ring, which then can protrude out over the polished surface of the @entity340 . Pieces of the @entity715 can be knocked off by the disc and cause emboli. To diminish @entity1031 , one must either prevent this @entity715 from protruding into the groove between the suture ring and the valve flange or allow the @entity715 to be organized as a thin covering with endothelium-like cells as a continuation from the suture ring over the valve flange. This type of covering was obtained during a short period of anticoagulation by applying a microporous surface to the Bj  rk-Shiley Monostrut mitral valve. These valves were implanted in one set of @entity1237 and the conventional Bj  rk-Shiley Monostrut mitral valve, with a polished surface, in another set of @entity1237 (control group). The two groups were then compared with regard to the incidence of @entity1031 encountered during 1 year's follow-up without anticoagulation. The @entity1237 were put to death and examination revealed the following observations: In the control group, (1) a varying amount of @entity715 formation was found in the groove between the suture ring and the flange in all nine @entity1237 and (2) @entity715 formation did not start on the polished struts or discs in any of the nine @entity1237 . In the group with the microporous Monostrut mitral valve, 19 animals were put to death and examined: (1) The endothelialized covering over the suture ring, thinner when @entity505 coated, continued over the microporous flange, tapering off in the center of the orifice in all 19 valves on the ventricular side and in 14 of the 19 valves on the atrial side; (2) the center of the orifice and the struts were never completely covered by endothelialized tissue because of high flow; (3) there was an increased incidence of small @entity715 formation on the disc-contacting microporous surface of both inflow and outflow struts. Therefore these surfaces should not be coated but left polished.
