INTRODUCTION: a hybrid valve was developed for improving a durable mechanic disc valve with good biocompatibility, by promoting easy healing around the ring valve and making the maximum isolation of the synthetic material in the blood stream. Lining the mechanical valve with porcine biologic tissue (pericardium and vein) is a tentative to reduce the morbidity and mortality on respect of thrombosis, thromboembolism, reoperations and minor use of anticoagulants to reduce the hemorrhagic events. Some principles were established on hybrid valve: durable mechanical system, points of contact without biologic material, use of biological material with minor organic reaction, movable parts without biologic material outside its perimeter, preferential closing system with superposition on a track seat and loose joints for accept biologic material limited growth. MATERIAL AND METHOD: the valve is the type of perforated tilting disc and all made of Carbolite (hardened polymeric carbon). The prosthesis is all covered except the central pivot, the disc and the internal part of the minor orifice, with 65% amount of surface recovered. The disc extends over thetnajor orifice with a track seat. The valve is processed in glycerol and sterilized in ETO and preserved in glycerol preferentially. There are seven mitral patients in observation with a mean time of 7,8 months (4 to 13 months) with oral anticoagulation. INITIAL RESULTS: in the first three months the mean Prothrombin Value (PV) was 60% and a case of valvular thrombosis occurred after two months with a PV of 70%, history of tachycardia and dyspnea. The patient was reoperated and was seen a good healing on Polyester ring and diffuse fibrin deposit. The fibrin was removed and the valve is going well after ten months. Two majors of hemorrhagic episodes occurred in two patients with a PV of 10% and 20% with good evolution. After three months the group has the mean PV of 51 % with no cases of hemolysis, thromboembolism, dysfunction or hemorrhagic events. CONCLUSIONS: the mechanical tests of the valve and the initial clinical aspects are favorables. It is necessary to augment the number of cases with more effective and uniform anticoagulant protection in the first three months to avoid thrombosis and hemorrhagic events. After three months the biolization of the valve with low anticoagulant doses seems to be efficient.
Heart valves prostheses