TIME-RELATED HEMODYNAMIC-CHANGES AFTER AORTIC REPLACEMENT WITH THE FREESTYLE STENTLESS XENOGRAFT

Background. The Freestyle valve is a porcine aortic root fixed with ne t zero pressure across the cusps and treated with the anticalcificatio n agent alpha-aminooleic acid. We evaluated the hemodynamic function o f this stentless valve. Methods. We implanted the valve into 80 consec utive patients scheduled to receive a bioprosthesis. Sixty-nine patien ts were more than 70 years old and 14 had calcified aortic sinuses. Th e ''cylinder within a cylinder'' implantation technique was used. Twen ty-seven patients received coronary grafts, and 3 had mitral repair. A ll patients were studied echocardiographically during week 1 and 41 we re studied at 6 months. Results. Median ischemic time for isolated aor tic valve replacement was 44 minutes. There were four hospital deaths, none valve related. No patient had more than trivial aortic regurgita tion. Mean systolic gradients for valve sizes 21 to 25 mm fell signifi cantly with time (p less than or equal to 0.05) due to remodeling of t he porcine root and early regression of left ventricular hypertrophy. Late hemodynamic function was equivalent to an aortic homograft. Concl usions. The Freestyle valve is easily implanted and has excellent hemo dynamics. Transvalvular gradients decrease progressively.