Prolonged aortic cross-clamping in early infancy and method of myocardial preservation

A cardioplegic solution containing blood with a low level of ionic calcium was prepared independent of pump-oxygenator perfusate blood, so as to contain a constant concentration of each component at any given time. Using this solution, Jatene's anatomic repair under prolonged periods of aortic cross-clamping ranging from 117 to 184 minutes (mean: 149 min) was performed on seven young infants with simple complete transposition. The ages of the patients ranged from 34 days to 3 months, with a median age of 2 months. Four patients, aged 39 days, 41 days, 2 months and 3 months, survived and showed uneventful postoperative hemodynamics. Two of the three non-survivors were considered retrospectively to have been unsuitable candidates for Jatene's anatomic repair due to their low left ventricular pressure (LV/RV pressure ratio less than 0.60 in both). The remaining infant who died had TGA with a large ventricular septal defect of the muscular type and developed a postoperative residual shunt. It was considered unreasonable to attribute the cause of death in this case to inadequate myocardial protection. Judging from our experience with these four survivors who underwent prolonged aortic clamping ranging from 117 to 160 minutes, our cardioplegic solution and the technique of its administration were considered to be effective and promising for heart surgery in young infants and neonates.