Outcomes after the palliative arterial switch operation in neonates with single-ventricle anatomy

Background: Newborns with single-ventricle anatomy, transposition of the great arteries, and systemic outflow obstruction are challenging patients most often managed with a Norwood or Damus-Kaye-Stansel (DKS) procedure. The palliative arterial switch operation (pASO) offers the theoretical advantage of avoiding a systemic-to-pulmonary artery shunt physiology and posterior entrapment of the left pulmonary artery while aligning the single left ventricle with the posterior semilunar valve. Limited outcome data exist for the pASO. The purpose of this study was to examine the clinical course of patients after this operation.

Methods: We conducted a retrospective review of all neonates undergoing a pASO at our institution from July 1995 to June 2011.

Results: Fourteen patients underwent pASO at a median age of 7 days (2-16 days). Primary diagnoses included double-inlet left ventricle (6 patients [43%]), tricuspid atresia (TA) (4 patients [29%]), and other (4 patients [29%]). Concomitant procedures at initial operation included aortic arch reconstruction (13 patients [93%]), pulmonary artery banding (6 patients [43%]), and placement of a systemic-to-pulmonary artery shunt (1 patient [7%]). Median intensive care unit stay and hospital length of stay were 11 days (4-60 days) and 21 days (9-84), respectively. There were no deaths. All patients had advanced to a bidirectional cavopulmonary shunt (BCPS). Four patients required intervention between the pASO and BCPS procedures: systemic-to-pulmonary artery shunt (3 patients [21%]) and pulmonary artery banding revision (1 patient [7%]). Eleven patients had Fontan completion; the remaining 3 patients are candidates for this procedure. At the time of the Fontan operation, 7 (64%) patients required pulmonary artery augmentation. All patients were alive at last follow-up (median, 5 years [3 months-14 years]). At last echocardiographic follow-up (median, 5 years [3 months-10 years]), all patients had normal ventricular function, trivial to mild neoaortic insufficiency, and no left ventricular outflow obstruction.

Conclusions: The pASO should be considered in neonates with single ventricle, transposition, and systemic outflow obstruction because it affords a favorable anatomic arrangement for long-term palliation, with excellent survival and preserved ventricular function.