This study evaluates the role of continuous monitoring of venous drainage flow and oxygen extraction (ERiO2) using near-infrared spectroscopy (NIRS) in cerebral perfusion during aortic arch surgery. A retrospective review of 10 patients undergoing selective antegrade cerebral perfusion (SACP) found a strong correlation (r = 0.91, p < 0.01) between ERiO2 and NIRS-derived regional oxygen saturation (rSO2). The study suggests that integrated monitoring improves perfusion management and neurological outcomes.