Outcomes of the Arterial Switch Operation in Children Less Than 2.5 Kilograms.
Children with body weight less than 2.5 kg who undergo the arterial switch operation (ASO) represent a challenging group. We sought to determine outcomes of patients with weight less than 2.5 kg at ASO at a single institution. All patients who underwent an ASO with biventricular repair and weighed less than 2.5 kg at time of surgery were identified from the hospital database and reviewed retrospectively. From 1983 to 2014, 870 patients underwent an ASO with biventricular repair at our institution. At the time of ASO, 31 patients (3.6%, 31 of 870) weighed less than 2.5 kg (mean 2.1; median 2.1; range, 1.1 to 2.4). Twenty-nine patients underwent an ASO for d-transposition of the great arteries, and 2 patients had an ASO for Taussig-Bing anomaly. Mean age at operation was 16 days (median 11; range, 3 to 66). There were 6 hospital deaths (19%, 6 of 31) among patients weighing less than 2.5 kg compared with a hospital mortality of 1.9% (16 of 839) among patients weighing more than 2.5 kg (p < 0.0001). Mortality for children weighing 2.0 kg or less was 50% (5 of 10) compared with a mortality of 2.8% (1 of 21) for children weighing more than 2.0 kg but less than 2.5 kg. Four patients (13%, 4 of 31) required reoperation during hospital admission. Follow-up was available for 24 survivors (96%, 24 of 25). Mean follow-up was 13.2 years (median 11.9; range, 6 months to 25 years). There were no late deaths. Two patients (8%, 2 of 24) required late reoperation. No patient had more than mild neoaortic valve regurgitation, and all survivors were in New York Heart Association class I at last follow-up. Early mortality for children weighing less than 2.5 kg undergoing the ASO remains high; however, most of the mortality occurred in children weighing 2.0 kg or less. Long-term outcomes for survivors are excellent.