Clinical application of cardioplegia in aortic cross-clamping periods longer than 150 minutes.

Out of more than 1000 patients operated upon by means of cardioplegia in profound myocardial hypothermia (15 degrees - 20 degrees C) aortic crossclamping time exceeded 150 min in 26 cases. The average clamping time in this group of patients was 169 +/- 22 min (150 to 227 min). The average duration of the cardioplegic coronary perfusion was 35 +/- 21 min (14 to 99 min). The following procedures were performed. Aneurysmectomy of the ascending thoracic aorta combined with valve replacement (n = 7); valve replacement combined with aorto-coronary bypass procedures (n = 9); multiple valve replacement (n = 3); multiple coronary grafting (n = 6) and one complicated reoperation. Three patients (11.5%) died, none intraoperatively and none as the result of a heart failure connected with the operation.