Outcome and follow-up of aortic valve replacement with the freestyle stentless bioprosthesis

Background. The aim of this study was to determine the morbidity, mortality , and hemodynamics after implantation of the Freestyle stentless bioprosthe sis in the aortic position. Methods. A total of 280 patients were operated on from June 1993 to July 19 99 as part of a multicenter investigation. Factors influencing hospital mor tality and long-term survival were assessed by logistic regression and Cox proportional hazards analysis. Patients were evaluated postoperatively at d ischarge, at 3 to 6 months, and yearly by clinical examination and color fl ow Doppler echocardiography. Results. Hospital mortality in this group was relatively high (9.6%). Logis tic regression analysis showed that cross-clamp time, age, myocardial infar ction, diabetes, left ventricular hypertrophy, coronary artery disease, New York Heart Association class III or IV and female gender were the independ ent predictive factors. According to the Kaplan-Meier method, the 4-year su rvival for hospital survivors was 94%. In the multivariate Cox proportional hazard analysis, only coronary artery disease proved to be prognostic. Dur ing follow-up, 11 patients developed paravalvular leakage due to prosthetic dehiscence at the side of the noncoronary cusp. Performance of the prosthe sis as assessed by echocardiography was excellent. Mean gradient decreased significantly between discharge and follow-up at 3 to 6 months. At 1-year f ollow-up trivial regurgitation was found in 6 patients (3%) and mild regurg itation in 4 (2%). Regurgitation did not increase with time. The effective orifice area increased significantly from discharge to follow-up at 3 to 6 months. Conclusions. Hospital mortality after implantation of a stentless bioprosth esis was higher compared to conventional prosthesis. A high incidence of pr osthesis dehiscence at the proximal suture line was found, which was probab ly due to technique. Hemodynamic performance up to 3 years showed low trans valvular gradients. There is echocardiographic evidence for reduction of le ft ventricular hypertrophy and improvement of left ventricular function. (C ) 2001 by The Society of Thoracic Surgeons.