From May/1990 to March/1992, 81 "Stentless" porcine bioprosthesis were implanted in the aortic position in three Centers: Biocor Institute (34 patients), University of Torino (31 patients) and Karolinska Hospital (16 patients). The age ranged from 14 to 85 years, with a mean age of 51. There were 48 male patients and 33 femele; the post operative follow-up ranged from 1 to 22 months (mean = 7 months). The main indication was aortic stenosis. There were 5 patients with acute endocarditis of the native aortic valve, with significant hemodynamic impairment, and presence of annular abscesses in 3 of them. All patients were operated on under moderate hypothermia and myocardial protection, with cristalloid cardioplegia. The "Stentless" bioprosthesis was inserted using two layers of a 4-0 Prolene running suture. All patients survived the operation; there were 4 early deaths (4.93%) and one late death secundary to pulmonary embolism (16 th months post. op.). The major hospital complication was complete AV block in 7 patients. All patients are in regular clinical follow-up, including hemodynamic assessment by echodopplercardiography. The preliminary data show an excellent hemodynamic performance of the "Stentless" bioprosthesis.
próteses cardíacas artificiais; próteses cardíacas artificiais; heart valves prosthesis; heart valves prosthesis