[M-mode and two-dimensional echocardiographic features of porcine xenograft valve dysfunction]

Clinical survey was made on the porcine xenograft valve replacements in 76 patients who underwent the replacement for the past five years at Hyogo College of Medicine Hospital. The follow-up period was from 3 to 84 months after implantation. Seventy-one patients had mitral valve replacements, 1 aortic, 2 mitral and tricuspid and 2 tricuspid. Seven patients were diagnosed as porcine valve dysfunction echocardiographically, and in four of these the dysfunction (two with bacterial endocarditis, one with perivalvular leak and one with ruptured porcine aortic valve) was confirmed at operation, and the echocardiographic features were correlated with surgical findings. M-mode and two-dimensional echocardiograms of one patient with fungal endocarditis demonstrated vegetations on the mitral and tricuspid valves. In another patient with endocarditis, the echocardiographic finding of valve thickening associated with the flail and torn cusp was observed. The two-dimensional echocardiographic study was particularly useful in detecting the dislocation of the stent echo in one patient with paravalvular regurgitation. In one patient with the ruptured and flail porcine aortic valve, the two-dimensional echocardiogram was characterized by rapid diastolic motion of the involved leaflet into the left ventricular outflow tract beyond the line of valve closure. Three patients were not confirmed at operation. In one patient, the two-dimensional echocardiogram demonstrated a systolic prolapse of the porcine mitral valve. In another two patients the M-mode echocardiographic finding included a coarse fluttering of the porcine mitral cusp in diastole. The major M-mode features of prosthetic regurgitation were fuzzy echoes with fluttering of the cusp in systole or diastole or both. In one patient with fluttering, the two-dimensional echocardiogram also demonstrated the thickening of the cusp. But in another patient with fluttering, the two-dimensional echocardiogram revealed no abnormality, and prosthetic regurgitation was not confirmed at cardiac catheterization. It was postulated that this patient had a false positive echocardiogram. Two-dimensional echocardiography complemented the M-mode echocardiographic findings and both techniques were very useful in identifying porcine valve dysfunction. Moreover, we considered that the comparison of the echocardiographic features in the course of individual case was very important in detecting porcine valve dysfunction.