[Mid-term results of stentless bioprosthesis for aortic valve replacement. Experience in a series of 97 patients].

Stentless bioprostheses have been described as valve substitutes of interest for aortic valvular replacement. We studied 97 consecutive patients with a mean age of 72.2 years (40-84) who underwent aortic valvular replacement with 80 Toronto SPV and 17 Freestyle prostheses. Operative mortality was 6.2. With a mean follow-up of 19 +/- 10 months (1-46), 87.2% of the surviving 86 patients underwent an echocardiography performed by the same operator. Mean gradient was 10.9 +/- 3.6 mmHg (4.2-22.6) and effective orifice area was 1.8 +/- 0.5 cm2 (0.8-3.0) for the 75 controlled stentless valves. The best haemodynamic data were obtained with the 25 mm diameter prostheses. One asymptomatic partial dehiscence was observed during monitoring. None of the 15 detected aortic leaks was significant. We observed a significant reduction of the ventricular mass in 41 patients who had undergone pre- and postoperative evaluation (p < 0.0014). Overall survival was 86.8 +/- 4.4% at 2 years. Stentless bioprostheses offered satisfactory haemodynamic results in our series. They however require an implantation technique learning curve as well as a thorough knowledge of the aortic root anatomy and physiology.