Implications of anomalous right subclavian artery in the repair of neonatal aortic coarctation

Background Spinal cord perfusion is predominantly from the anterior spinal artery, which arises from the vertebral arteries by way of the subclavian arteries. Anomalous origin of the right subclavian artery and coarctation of the aorta is considered to be an increased risk factor for spinal cord damage, possibly because of the minimal collateral circulation during aortic clamping. The aim of this study is to review 5 consecutive cases of neonatal aortic coarctation with ARSA. Methods Five neonates (0.8 to 4.6 kg) underwent operation between July 1999 and December 2000 with resection of the coarctation and end-to-end anastomosis. Both subclavian arteries (n = 5) and left carotid artery (n = 4) were clamped, leaving the right carotid artery as the sole provider of perfusion for the spinal cord. Results Despite clamping of both subclavian arteries, right radial artery pressure was measurable in 4 of the 5 cases. Aortic cross-clamp times varied from 12 to 26 minutes at a core temperature of 34° to 35°C. There was no operative mortality. None of the neonates developed any major neurologic sequelae. Conclusions When clamping the two subclavian arteries during coarctation repair, the spinal artery is left with collateral blood flow that can theoretically originate from the carotid arteries through the circle of Willis and retrogradely down the vertebral arteries. The presence of such collateral circulation was documented as recordable blood pressure in the right radial artery during surgical repair.