Results of Use of the Pyrolytic Carbon Tilting Disc Bjork-Shiley Aortic Prosthesis

Replacement of the aortic valve with a new BjorkShiley prosthesis was performed in 110 patients during the period from November, 1971 to July, 1973. The previously reported Delrin-disc Bjork-Shiley valve had a built-in valvular leak of up to 10 percent due to .003“ clearance. The new pyrolite-disc prosthesis is machined to a clearance of .001“. Excellent clinical results have been achieved in 99 of the survivors (90 percent), with followup from 3 to 20 months. There was no systolic ejection gradient across the prosthesis in 16 patients studied. There were three early and five late deaths. None of the early deaths (2.7 percent) was related to the prosthesis. However, one late death was due to a thrombotic prosthesis. A significant fact was the low incidence of thromboembolic phenomenon and hemolysis. Three paravalvular leaks occurred. Treadmill exercise tests demonstrated significant improvement. A new technique of insertion with continuous suture was used in selected patients. This technique reduces the bypass time and eliminates the need for coronary perfusion.