Clinical effects of major aortopulmonary collateral arteries in term neonates diagnosed with transposition of the great arteries

Background: Transposition of the great arteries is a severe CHD that affects term neonates. The presence of major aortopulmonary collateral arteries in neonatal transposition of the great arteries patients is rare. This study investigated the clinical and haemodynamic implications of the presence of major aortopulmonary collateral arteries in neonatal transposition of the great arteries patients who underwent an arterial switch operation.

Materials and methods: The study was a retrospective analysis conducted on neonates diagnosed with transposition of the great arteries who underwent arterial switch operation within the period from 1 May 2020 to 1 January 2023 at two high-patient-volume paediatric cardiac surgery centres in Turkey. The patients' demographic characteristics, echocardiographic features, and clinical data were analysed. Additionally, the possible clinical effects of the presence of major aortopulmonary collateral arteries were statistically evaluated.

Results: Two hundred cases of neonatal transposition of the great arteries were included in this study, with 55% of the cases male. All the patients underwent arterial switch operation. The median age at the time of arterial switch operation was 5 days (interquartile range 3-7), with a median weight of 3,100 g (interquartile range 2,900-3,400). The median pre-operative saturation level was 76% (interquartile range 70-82%). Prior to arterial switch operation, 32 patients underwent balloon atrial septostomy.In all the patients, the interatrial septum was checked to determine if the atrial septum was intact. A patent foramen ovale (≤ 3 mm) was found in 112 patients, and a non-restrictive atrial septal defect (> 3 mm) was found in 88. Forty-eight patients had ventricular septal defects, and 72 had coronary anomalies. Major aortopulmonary collateral arteries were found in 4 patients pre-operatively and in 12 patients after arterial switch operation (echocardiography, n = 8; angiography, n = 4). Of the patients with post-operative detection of cumulative number of major aortopulmonary collateral arteries were on post-operative day 1 in 2 patients, on post-operative day 3 in 5 patients, on post-operative day 7 in 6 patients, and on post-operative day 14 in 11 patients.Transcatheter closure was performed in 3 cases due to recurrent extubation failure. Major aortopulmonary collateral artery shrinkage was observed in one case under medical treatment. The length of paediatric cardiac intensive care unit stay (10 days versus 8 days; p < 0.005), mechanical ventilator time (4 days versus 2 days; p = 0.02), and inotrope use time (5 days versus 3 days; p = 0.04) were higher in the major aortopulmonary collateral artery cases than patients without major aortopulmonary collateral artery.

Conclusion: Major aortopulmonary collateral arteries are frequent in transposition of the great arteries patients and may have clinical effects. The presence of major aortopulmonary collateral arteries should be investigated in patients who do not have a favourable post-operative course after arterial switch operation.