The hemodynamic superiority of total cavopulmonary anastomosis (TCPA) over atriopulmonary connection as a modification of Fontan-type operation, began to be acknowledged with more applications to clinical cases. The need of adequate resolutions for the investigation and improvement of residual hemodynamic derangements including abnormal distribution of the pulmonary blood flow, is emerging.

We studied 20 patients (M:F=12:8, age:67.9±41.5 months) who have had the TCPA and were followed-up by cardiac catheterization, angiography and lung perfusion scan 24.5±15.7 months after the operation. Pulmonary arterial growth and hemodynamic influences including the pulmonary blood flow distribution were investigated to verify the appropriateness of the conventional TCPA method and to aid in the determination of the consequences and prognosis of the operation.

The mean pulmonary arterial pressure before and after the operation was 15.1±3.2 mmHg and 13.9±4.8 mmHg respectively without significant difference and there was no significant postoperative changes in the cross-sectional area index of pulmonary artery in regard to the variability of body surface area. The pulmonary blood flow was distributed with a greater amount in the ipsilateral side of IVC flow entrance (IVCipsi) than the contralateral side (IVCcontra), with an ipsilateral to contralateral perfusion ratio (i/cPR) of 1.24±0.42. Comparing the subgroups by the type of superior vena caval inflow, unilateral superior cavopulmonary anastomosis (SCPA) group showed significantly higher i/cPR (1.47±0.33) than the bilateral SCPA group (1.07±0.21). Comparing the subgroups by the type of IVC inflow, the i/cPR of the intraatrial tunnel group was higher than the hemiazygous continuation group, but there was no statistical significance.

TCPA does not influence the growth of pulmonary artery, and the type of cavopulmonary anastomosis and the bilaterality of superior vena cava may have major influences on the distribution of the pulmonary blood flow. The details of surgical methods should be evaluated case by case in respect to the associated anomalies in order to achieve adequate postoperative pulmonary blood flow distribution.