Intraoperative ultrasonographic troubleshooting after the arterial switch operation

Less than perfect coronary artery translocation accounts for the majority of perioperative deaths after the arterial switch procedure for transposition of the great arteries. Some types of coronary arterial anatomy are associated with a higher risk of death.

Prospective epicardial ultrasound examination of all neonates with failing left ventricle or difficulty in weaning off cardiopulmonary bypass was performed after completion of the arterial switch operation during a 2-year period from March 1994 to February 1996. The aim was to identify any mechanical, and potentially remediable, factors accounting for ventricular failure.

Four neonates fulfilling the above criteria were identified during a 2-year period when epicardial echocardiography was routinely applied. In 2 patients coronary arterial problems in the form of kinking of the proximal left coronary artery (1 patient) and extrinsic compression of the artery by the neo-pulmonary trunk (1 patient) were identified and successfully corrected. In 2 other patients, supravalvar aortic stenosis was recognized, leading to prompt revision.

Epicardial echocardiography has an important "troubleshooting" role in the subgroup of patients with a suboptimal hemodynamic result after the arterial switch operation. Patients with unusual coronary anatomy should routinely be candidates for such studies.