Comparison of results using "freestyle" stentless porcine aortic root bioprosthesis with cryopreserved aortic allograft.

Aortic valve replacement with natural heart valves offer the advantages of superior hemodynamics, laminar flow patterns, lack of need for anticoagulation, and perhaps improved durability. This study compares 5-year results for two stentless aortic valves. In 1992, two prospective clinical trials using two different stentless aortic valves were initiated at our center. The Freestyle stentless porcine aortic root bioprosthesis (SPB) was placed in 106 patients, and cryopreserved aortic allografts (CAA) were placed in 174 patients using a freestanding total root replacement technique in each series. The mean systolic gradient for the SPB was 7.5+/-4.4 mm Hg at discharge and 5.9+/-3.1 mm Hg at 5 years. The mean systolic gradient for the CAA was 6.4+/-3.3 mm Hg at discharge and 5.0+/-2.2 mm Hg at 5 years. At discharge 92.2% of SPB patients had no aortic insufficiency (AI) and 7.8% had trivial AI. In all, 92.9% of CAA patients had no AI at discharge, and 7.1% had mild AI. At 5-year follow-up, 100% of the SPB had no AI, and only 20% of the allograft patients had no AI. The remainder, 80%, had mild AI. Excellent hemodynamic function was seen with both SPB and CAA. A lower incidence of nonhemodynamically significant AI was observed in the SPB group. Preoperative factors such as chronic renal failure and endocarditis may have adversely affected durability in the allograft group, but long-term follow-up is still required to determine durability.