[Cardiac surgery under extracorporeal circulation in patients with chronic renal insufficiency. Apropos of 4 cases and review of the literature].

Four cases of cardiac valve replacement in patients with chronic renal failure are reported. The problem of surgery under cardiopulmonary bypass in these patients are discussed with respect to 36 other previously reported cases. Of this lot of 40 cases, 33 (82,5 p.100) underwent valve replacement (21 aortic, 9 mitral, 1 mitral and aortic, and 2 unspecified), 26 (79 p.100) for valvular lesions due to infective endocarditis. Coronary revascularisation was performed in 6 cases (15 p.100) and pericardectomy in 1 case. Operative mortality was within acceptable limits (4 deaths) ; the overall mortality was 10 cases. Valvular lesions due to endocarditis were the main cause of death (9 cases). A session of haemodialysis is performed 12 hours preoperatively. Post-operative care is directed to the control of the fluid balance, the neutralisation of metabolic acidosis with alkaline fluids (sodium lactate) and the correction of hyperkalaemia by kayexalate. In addition, dialysis is required between the 24 th post-operative hour and the 3 rd day. The main indications for cardiac surgery under cardiopulmonary bypass in patients with renal failure are valve replacement for infective endocarditis where the operative decision should be made early on, and aorto-coronary bypass grafting, the selection criteria for which should be very strict.