[Bioprosthesis degeneration and reoperation in the aortic and mitral position].
In agreement with our experiences from our first study 15 patients (8 men, 7 women) underwent reoperation because of degeneration of bioprosthetic valves implanted in aortic or mitral position during the last 24 months. At reoperation 4 patients had a more complex cardiac procedure (double valve replacement, double valve replacement with bypass grafting, valve replacement with enlargement of the valvular area). There was no acute operation and only 1 patient was serious symptomatic preoperatively (NYHA IV). We revealed a mean implantation time of 126.4 months +/- 32.2 (median 130) for all bioprostheses without a significant difference in implant time regarding to aortic or mitral position. At reoperation bypass time (p = 0.001) and aortic clamp time (p = 0.011) was significantly longer compared to the first operation. There was no perioperative death, all patients are still alive and in good condition (8 of them NYHA I, 7 NYHA II). The early change of tissue degenerated bioprostheses can be carried out under elective conditions with improved postoperative outcome: mortality and morbidity remains acceptable low. In our group incremental risk factors for early mortality are severely affected patients with low functional status (NYHA IV) and acute operation. Preoperative coronary angiography remains essential for evaluation of concomitant coronary artery disease.