Neonatal arterial switch operation: coronary artery patterns and coronary events.

Objective: To determine the incidence of coronary events following neonatal arterial switch and to identify potential risk factors for death and coronary events.

Methods: The total experience (236 consecutive arterial switch operations) of one surgeon was studied. Associated procedures included ventricular septal defect closure in 37 patients (16%) and aortic arch repair in 14 patients (6%)). The influence of various patient, procedural, support technique and experience variables was analyzed.

Results: There were 19 deaths (8-70% confidence limits = 6-10%). Survival at 1 month, 1 year and 5 years was 93, 92 and 92%, respectively. Risk factors for death included small birth weight (P = 0.0015), hypoplasia of right ventricle (P < 0.0001), aortic arch obstruction (P < 0.0001) and coronary patterns with coronary arteries coursing between the great arteries (P = 0.0066). Coronary events occurred in 26 patients (11-70% confidence limits = 9-13%) and involved coronary deaths (11 patients), non fatal myocardial infarctions (8 patients) and coronary stenoses or occlusions (7 patients). Freedom from coronary events at 1 month, 1 year and 5 years was 94, 91 and 88%, respectively. Risk factors for coronary events included coronary patterns with retropulmonary course of the left main or left circumflex coronary artery (P = 0.0122), coronary patterns with coronary arteries coursing between the great arteries (P < 0.0001), all variations of intramural coronary arteries (P = 0.0010) and commissural origin of coronary ostia (P = 0.0171).

Conclusions: (1) In most neonates, arterial switch operation carries a low operative risk and provides excellent mid-term results; (2) The operative risk remains increased in some subsets; and (3) Some coronary patterns increase the risk of coronary events. Further surgical experience may improve the results.