[Hemodynamics of the St. Jude Medical aortic prosthesis in comparison to the Björk-Shiley and Lillehei-Kaster prostheses].

Pre- and postoperative hemodynamic data in 10 patients in whom the aortic valve was replaced by a St. Jude Medical (SJM) prosthesis are compared with those in 29 patients who received a Lillehei-Kaster tilting disk (LK) valve prosthesis and 11 patients with a Björk-Shiley tilting disk (BS) valve prosthesis. The SJM aortic prosthesis of the small size (A 21) has advantages over the LK and BS types, and it is therefore particularly suited to use in a small aorta. There are also good hemodynamic results for the larger sizes of the SJM prosthesis. As a result of the 85-degree opening angle and the favorable ratio between the inner and outer diameters of the valve (suture ring), there is only minor impedance of blood flow. The SJM aortic prosthesis thus involves a lesser degree of hemolysis than the BS and the LK. In spite of the promising hemodynamic data, however, long-term findings on the durability of the SJM prosthesis in vivo have not yet been published. It therefore seems to us justifiable, especially where the aorta is large, to continue to use BS prostheses.