Hemodynamic performance and clinical consequences of aortic valve replacement with 21-mm sized pericardial bioprostheses

Background: Aortic valve replacement (AVR) with a 21-mm sized bioprothesis is still discussed controversially. Since better results have been reported for pericardial valves, the aim of the current study was to analyze the hemodynamic performance as well as clinical parameters in our patients and to compare pericardial and standard porcine valves in particular. Methods: 342 patients underwent AVR with a bioprosthesis between 1987 and 2000. A 21 mm prosthesis was used in 39 patients (group S), while 303 patients received at least a 23-mm sized valve (group Q. Group S was further divided into 19 patients with a pericardial valve (group S1) and 20 patients with a standard porcine valve (group S2). The hemodynamic and clinical parameters were studied in all three groups. Results: The peak and mean transprosthetic gradients were significantly lower in the pericardial group than in the porcine group, particularly between patients with 21 mm valves (peak/mean: S1: 24 +/- 9/20.8 +/- 6.5 mm Hg vs. S2: 38 +/- 15/33 +/- 9 mm Hg, p < 0.05) at discharge. We could also observe that the peak transprosthetic gradient 7 days postoperatively was not significantly higher in patients with a 21 mm pericardial valve compared to group L patients. Comparing clinical parameters, we found significantly more cerebral ischemic events, a prolonged mechanical ventilation, a higher mortality and a longer stay in hospital in the group S2 compared to the group S1. Conclusion: The current study shows that pericardial valves perform well, particularly in patients with small aortic roots. Postoperative hemodynamics and clinical results were better than for comparable standard porcine valves. As the outcome of patients with a 21 mm pericardial valve was no worse than that in patients with bigger valves, enlarging procedures for the aortic root are not necessary in the majority of these patients.