A ventricular septal defect was repaired in a 3 1/2-year-old child on cardiopulmonary bypass. Because of excessive pulmonary venous return, a period of circulatory arrest under deep hypothermia was used. A large volume of air was found in the arterial line and the ascending aorta before perfusion was reinstituted. The air probably entered the arterial system through a large aortopulmonary collateral artery during circulatory arrest. This artery was not visualized on angiocardiography and could have caused excessive pulmonary venous return during perfusion. Air was successfully expelled by reversed perfusion. There were no neurological sequelae.
Aortic Diseases Cardiopulmonary Bypass