Cerebral regional oxygen saturation: a useful monitor during a surgical procedure involving the right-sided aortic arch in an infant.

A right aortic arch with an aberrant left subclavian artery and a Kommerell's diverticulum represents a rare anatomic variant carrying the risk of dissection or rupture. Resection of the diverticulum and re-implantation of the left subclavian artery during childhood have been recommended. Because of the risk of cerebral blood flow reduction during the aberrant subclavian artery re-implantation to the common carotid artery, monitoring and prompt measures to curb blood flow reduction are required. A 5-month-old boy was scheduled to undergo resection surgery. During the translocation of the aberrant subclavian artery to the common carotid artery, his regional oxygen saturation (rSO2) in the left cerebrum began to decrease. We increased the end-tidal CO2 (EtCO2), mean arterial pressure, and a fraction of inspired oxygen, successfully restoring the rSO2 to the initial level. No postoperative neurological complications were observed. Our experience with this patient suggests that rSO2 monitoring is a useful, and intervention protocol including hypercapnia, elevated mean arterial pressure, and hyperoxia to counter the decreased cerebral blood flow is effective in infant patients undergoing right-sided aortic arch surgery.