title: The unnatural history of valvular heart disease: late results with silastic ball valve prostheses.
abstract: The development of prosthetic heart valves successfully arrested the dismal natural history of valvular heart disease for thousands of patients. The experiences of numerous investigators provided a setting wherein the design and implantation of the silastic ball valves led to improved survival with both aortic and mitral valve replacement. Refinement of the caged-ball design was based on clinical and laboratory findings. In the mitral position, valve related thromboembolism was reduced from 38% to 3%. With the aortic prostheses the problem of ball variance was overcome by reducing trauma to the poppet and altering its heat curing process. In 1967 a completely cloth covered valve was introduced to reduce further the thromboembolic rate. Significant improvement in the embolus-free rate was ultimately found to be dependent on the year of operation with introduction of the time-frame concept. The current mitral silastic ball valve, Model 6120, yields an actuarial survival of 72 (+/- 3%), 54 (+/- 5%), and 37 (+/- 5%) for five, ten and fifteen years respectively. For aortic valve replacement, current Model 1260, the actuarial survival is 71 (+/- 2%), 58 (+/- 3%) and 48 (+/- 4%) for five, ten and fifteen years respectively. Late results are compared to other valvular prostheses.
mesh_terms: D001021:Aortic Valve; D005260:Female; D005500:Follow-Up Studies; D006349:Heart Valve Diseases / Q000601:surgery*; D006350:Heart Valve Prosthesis / Q000009:adverse effects / Q000266:history* / Q000401:mortality; D049673:History, 20th Century; D006801:Humans; D008297:Male; D008943:Mitral Valve; D009922:Oregon; D012826:Silicone Elastomers; D013923:Thromboembolism / Q000209:etiology
chemical_list: D012826:Silicone Elastomers