RESUMO
OBJECTIVE: Conventional biological and mechanical prostheses have important limitations with regard to their results concerning thrombosis, hemorrhage and long-term durability. Aortic valve replacement with stentless devices results in superior hemodynamic function because obstructing stents and sewing rims are avoided. In addition, no anticoagulation therapy is needed. METHODS: From 1 June 1991 until 31 May 1996, 235 patients received aortic valve replacement with stentless aortic porcine bioprostheses. Patients' ages ranged from 24 to 88 years (mean 64 years). In 21.3% of all patients, concomitant procedures were performed. Coronary artery bypass graft (CABG) and mitral valve surgical therapy were the most frequent ones (31 and 12 cases, respectively). Implanted valve sizes ranged from 21 to 29 mm in diameter. RESULTS: A total of 122 patients received a subcoronary implantation with the lower row performed with interrupted stitches and the upper row with a continuous suture. In 99 cases we performed the inclusion cylinder technique, also with lower interrupted sutures and running upper sutures after adaptation of the coronary ostia into the graft. In the group with small aortic roots, the total root replacement technique (n = 14) was used. Mortality at 30 days was 4.7% (11/235). Echocardiography at discharge postoperatively revealed a mean gradient across the prosthesis of 6 mm Hg. Color Doppler suggested no or trivial regurgitation in 93% of all examined patients and mild regurgitation without clinical symptoms in 7%. Up to now, 98.2% of all discharged patients have been free of valve-related reoperation. CONCLUSIONS: With implantation of stentless bioprostheses, an improved hemodynamic function will be obtained. Almost every aortic root pathology can be safely treated with any of the techniques described. The short and intermediate results seem to be at least equal to any other prostheses or treatment methods. The long-term performance of these devices is still under investigation.
