[Mitral replacement using a ball-valve prosthesis under hypothermic protection of the myocardium. 230 cases].
A series of 230 mitral valve replacements using exclusively the Starr-Edwards ball valve prosthesis is presented. These 230 patients underwent surgery over a 4 year period, a uniform operative technique being used. Its essential feature was the use of a standardised technique for protection of the myocardium based upon continous clamping of the aorta and deep hypothermia at around 15 degrees. The technique of myocardial hypothermia, already reported, is briefly reviewed. The results are analysed, in the short and long term. Overall hospital mortality was 6.9 per cent, including multiple valve replacements and combined coronary surgery. The total number of thrombo-embolic complications was 8, including 1 early thrombosis out of 230 patients - i.e. 0.4 per cent and 7 late thrombo-embolic episodes out of 180 patients followed up for 1 month to 4 years - i.e. 3.8 per cent. Secondary and late mortality was 11 cases out of 180 patients. The survival rate at 4 years was 78 per cent by actuarial calculation, including operative mortality. These results justify the continued use of ball prosthesis, the long term thrombo-embolic risks of which are equal to or less than those of disc prosthesis, and the resistance of which to wear and tear is shown by the long postoperative survivals.