Long-Term Results of the Cardiac Valve Replacement-Experiences in Seoul National University Hospital(1968-1994)

ABSTRACT

A total of 3,119 cardiac valves were replaced in 2,471 patients with acquired valvular heart diseases at Seoul National University Hospital during a period of 26 years from 1968 to 1994. Mechanical valves including St. Jude, Carbomedics, Bjork-Shiley and Duromedics were used in 1,609 cases(52%) and bioprosthetic valves including Lonescu-Shiley, Hancock and Angell Shiley were implanted for the rest of the patients(1,510 cases, 48%). A total of 308(12.5%) redo valve replacement was performed during the same period, and 10 of 308 patients underwent second redo valve replacements. The single valve replacement was done in 1,846 cases, double valve replacement in 602 cases and triple valve replacement in 23 cases. Among the single valve replacement, the mitral valve replacement was performed most frequently(1,377 cases). The male to female ratio was almost equal(1.223 : 1,248) and the mean age was 37.9+/-10.5 years old. But the mean age has been increasing year by year and it reached to 44.8 years old in the 1990's. The overall hospital mortality was 5.3%, and 6.8% in redo valve replacement. However, the hospital mortality for the recent 10 years dropped to 1 to 4%. The number of redo valve surgery has been increasing since the mid-1980's because of structural deterioration of bioprostheses that were replaced during the late-1970's and early 1980's. Redo valve surgery comprised 34% for all valve replacement in 1994. The causes of the redo valve operation were structural deterioration(81.5%), prosthetic valve endocarditis(11.7%), paravalvular leakage(5.6%), and valve thrombosis(0.9%). The actuarial freedom from overall valve failure in Ionescu-Shiley were 81.0+/-7.1%(5 year) in mitral position, 89.1+/-1.8%(7 year) in aortic position and 88.9+/-7.6% in double valve replacement. The 5 year actuarial freedom from all complications in Carbomedics were 90.1+/-3.1% in mitral position, 84.9+/-4.2% in aortic position and 81.7+/-5.1% in double valve replacement. The 10 year actuarial freedom from all complications in St. Jude were 80.9+/-3.8%, 81.4+/-6.1%, 72.4+/-10.7% in each positions. In conclusion, the mean age of patients was younger than that of western countries, but it showed increasing tendency year by year. Bioprosthetic valves were used during the initial period until mid-1980's when mechanical valves were used instead of bioprosthetic valves, mainly because of the structural deterioration of the bioprostheses. In terms of thromboembolism, both bioprostheses and mechanical valves seems to be almost comparable although the comparison of both valves was impossible because of the different period of operation, various surgeon and level of the prothrombin time and so on. Recently the number of valve replacement has been decreased since the 1990's and the number of redo valve surgery and valve repair has been increased.