Hemodynamic evaluation of a new stentless autologous pericardial mitral valve.

BACKGROUND: There is no satisfactory mitral valve prosthesis. An ideal mitral valve substitute should be biologic, nonantigenic, and anatomically correct. METHODS: We developed a stentless, chordal-supported (including anterior basal stay chords) mitral valve made with glutaraldehyde-treated autologous pericardium. Eight such prostheses were implanted in sheep. RESULTS: Seven animals survived the operation and were studied postoperatively immediately, at 1 week, and at 1 month. Simultaneous left ventricular and left atrial pressures showed peak and mean transvalvular pressure gradients of 6+/-2 mm Hg and 1+/-1 mm Hg, respectively. Echocardiography performed intraoperatively and then 1 week and 1 month postoperatively showed normal valve leaflet movements. Color and pulsed Doppler echocardiography showed no sign of transvalvular stenosis or regurgitation. Effective orifice area was 5.39+/-0.35 cm2 at intraoperative, 5.51+/-0.29 cm2 1 week after operation (n = 5), and 5.51+/-.28 cm2 1 month after operation (n = 3). Three animals were sacrificed at 19 days and at 1 and 3 months. One animal is alive at 10 months. CONCLUSIONS: This new stentless pericardial mitral valve performed satisfactorily with low gradients and no regurgitation. Possible advantages of this pericardial valve are excellent hemodynamics, ease of construction and implantation, lack of immunogenicity, and low cost. Similarly designed valves but with a shorter nonglutaraldehyde treatment time have been used in 3 sheep monitored for more than 3 months.