Predictive criteria for the need of extracorporeal circulation in single-lung transplantation

Use of extracorporeal circulation is mandatory in heart-lung and en bloc double-lung transplantation. However, no criteria exist to predict the necessity of its application during single-lung transplantation for parenchymal lung diseases. We therefore reviewed our experience in 23 patients undergoing single-lung transplantation for idiopathic pulmonary fibrosis. All patients were evaluated by preoperative right heart catheterization. For intraoperative monitoring, a pulmonary artery thermodilution catheter was placed in the contralateral lung to repeatedly assess pulmonary artery pressure, cardiac output, and pulmonary vascular resistance. Extracorporeal circulation was necessary during graft implantation in 4 patients, whereas 19 patients underwent operation without it. Preoperative demographic patient data, time of ischemia, and hemodynamic values obtained preoperatively and before the clamping of the pulmonary artery showed no significant differences between groups. In contrast, after the clamping of the pulmonary artery, a significant drop in cardiac index of about 1.5 L.min-1.m-2 (p less than 0.01) and a concomitant rise in pulmonary vascular resistance (p less than 0.01) was observed in the group requiring extracorporeal circulation, whereas these variables showed no significant changes in the other 19 patients. Pulmonary artery pressure rose significantly in both groups (p less than 0.05), without significant differences between them. It is concluded that intraoperative assessment of cardiac index and pulmonary vascular resistance is essential for estimation of cardiac performance during single-lung transplantation. A decrease in cardiac index of more than 1.5 L.min-1.m-2 after the clamping of the pulmonary artery rather than the degree of pulmonary hypertension is indicative of the need of extracorporeal circulation.