Fatigue-induced failure of the Ionescu-Shiley pericardial xenograft in the mitral position: In vivo and in vitro correlation and a proposed classification

摘要: Four patients had signs of primary bioprosthetic dysfunction within the fourth postoperative year after mitral valve replacement with an Ionescu-Shiley pericardial xenograft; they represent approximately 9% xenograft valves followed up for more than 3 years at our institution. Pathological investigation showed severe incompetence all explanted due to cusp tears and lacerations. Histologic study tissue disclosed mild moderate collagen degeneration, without infection or calcification. Neoendothelial formation on Dacron cloth sewing ring was either absent minimal. The high incidence valvular prompted us try establish a correlation between in vivo vitro modes failure xenograft. For this purpose, 10 unimplanted were tested fatigue test system. Severe fatigue-induced lesions occurred group average 29.09 ± 17.26 × 106 cycles; initial could be recognized six them 16.94 20.12 cycles. Valves system lacerations similar those noted xenografts obtained from four (which assumed have functioned 100 cycles each case). Correlation results testing clinical experience enabled recognize types which may occur following: (1) Primary suddenly. (2) A classification occurring is useful since presentation differ according type location lesion. (3) In manufacture valves, particular care must observed selection frame design. (4) Improvement quality control one clues enhance durability