Clinical experience with porcine xenografts in the mitral position

In a 7-year period, 120 porcine xenografts, 16 of Hancock and 104 of Carpentier-Edwards type, were implanted in the mitral position in patients with isolated mitral valve disease. The operative mortality was 4.2%. The actuarial survival after 5 years was 93%. Death during the observation period was valve-related in two cases. Three valves had to be exchanged, one because of calcification and two because of prosthetic endocarditis. The risk of contracting prosthetic endocarditis was 0.38% per patient year. All the patients received peroral anticoagulant medication indefinitely. Two minor embolic episodes occurred, both in the first 6 post-operative months. The probability of freedom from thromboembolism was thus 98.2% after 7 years. In functional evaluation of 92 patients observed for at least 6 months, more than 90% were in NYHA class I or II. Porcine xenograft is a good valve substitute in the mitral position with a low incidence of complications, especially of thromboembolism, in patients on maintenance anticoagulant therapy. Long-term observations of this type of valve substitute are not yet available, however.