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 1 10 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 ln 16 patients studied. There were three early and five