Association of Preoperative Mixed Venous Oxygen Saturation with Postoperative Segmental Pulmonary Hypertension in Pulmonary Atresia with Ventricular Septal Defect and Major Aortopulmonary Collaterals

In patients with pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (PA/VSD/MAPCAs), segmental pulmonary hypertension is common; however, its pathophysiology remains to be elucidated. This study aimed to identify preoperative hemodynamic factors associated with segmental pulmonary hypertension after intracardiac repair in patients with PA/VSD/MAPCAs. This study included 12 patients with PA/VSD/MAPCAs who underwent unifocalization and intracardiac repair from 2009 at our institution. Hemodynamic measurements of preoperative and postoperative cardiac catheterization were collected. Patients were considered to have pulmonary hypertension if the mean pulmonary pressure measured postoperatively at any peripheral pulmonary artery was >= 20 mmHg. The data were compared between patients with and without postoperative segmental pulmonary hypertension;pvalue < 0.05 was considered statistically significant. Intracardiac repair was performed at the age of 2.1 years (range 0.5-28.2 years). Unifocalization was performed separately prior to intracardiac repair in two patients and concomitantly in 10 patients. Postoperative cardiac catheterization, performed 1.2 years (range 0.2-8.7 years) after intracardiac repair, revealed that five patients had segmental pulmonary hypertension. Patients with postoperative pulmonary hypertension had significantly lower preoperative mixed venous oxygen saturation than those without pulmonary hypertension (57% [55-63%] vs. 65% [53-75%],p < 0.05). No significant differences were found between the groups in terms of age at intracardiac repair, preoperative arterial oxygen saturation, and preoperative peripheral pulmonary arterial mean pressure. Lower preoperative mixed venous oxygen saturation was associated with segmental pulmonary hypertension after intracardiac repair in patients with PA/VSD/MAPCAs.