Experiences with various types of mitral valve prostheses

Long-term results of cardiac valve replacement with the Delrin-disc model of the Björk-Shiley valve prosthesis

One hundred two Björk-Shiley valve prostheses with the Delrin-disc occluder were implanted in 83 patients between January, 1971, and July, 1972. Fifty-eight were in the mitral position, 42 in the aortic, and 2 in the tricuspid. Complete follow-up until 1981 was obtained in 93% of the patients (mean follow-up, 66.8 months). Hospital mortality was 18% and late mortality, 19%. Survival according to actuarial methods was 84.8% at 5 years and 78.1% at 9 years after operation. Thromboembolism was detected in 8.8% of patients but caused no deaths. The incidence was 1.2% and 1.5% per year in those patients treated with Coumadin and antiplatelet agents, respectively. Reoperation was necessary in 13% of the patients. Most survivors (72%) are in New York Heart Association Functional Class I, despite a preoperative status of Class III or IV in 57% of the patients. Hospital mortality may be due to poorer understanding of patient management and less refined techniques of myocardial protection. Long-term survival with this prosthesis is similar to that in more recent studies, and rates of thromboembolism and malfunction compare favorably with other prosthetic valves.

Haemodynamic findings after insertion of the Lillehei-Kaster valve in the mitral ostium

Clinical deterioration after insertion of prosthetic mitral valves may be caused by myocardial failure or valve dysfunction or a combination of both. The need for a method to decide which is predominantly causative is obvious. This study describes the haemodynamic findings with special reference to prosthesis rheology among 13 patients with lillehei-Kaster valves in the mitral ostium. Three patients were re-operated on because clinical signs of valvular dysfunction. Our investigation indicates that stroke volumes of less than 35 ml were useful in predicting valve dysfunction and that pulmonary wedge and mean arterial pressure at rest were significantly increased in this group of patients. It is advocated that such haemodynamic findings should lead to further evaluation of valve gradient and valve flow.