Carefully selected adolescents and young adults can safely undergo the primary FO. However, persistent pleural effusions, arrhythmias, thromboembolic events, and the need for reoperation mandate regular follow-up in such patients. Preoperative NYHA functional class III, mean PA pressure ≧ 15 mm Hg, hematocrit ≥ 60%, ventricular dysfunction, and AVVR were associated with early mortality, suggesting that primary FO should be avoided in such patients.