Near-Infrared Spectroscopy Does Not Reliably Detect the Cerebral Status in Adults During Aortic Arch Surgery - A Retrospective Trial

Introduction: To investigate relationship between intraoperative regional oxygen cerebral desaturation (rScO_2) and the incidence of neurological deficit after aortic arch surgery in adult patients. Methods: This study was conducted in a retrospective fashion. 53 patients undergoing aortic arch surgery with antegrade selective cerebral perfusion during deep hypothermic circulatory arrest between 2010 and 2012 were included. ln all patients cerebral monitoring was performed using the near-infrared spectroscopy (NIRS) and a bispectral index electroencephalography (BIS). Cumulative values of rScO_2 decrease ＞ 20% of the baseline level (min%) captured as the area under the curve (rScO_2 AUC) were calculated. Patients were divided in two groups: patients with (N-group) and without (Non-N group) a nonreversible neurological deficit, and patients with (D-group) and without (Non-D group) a reversible neurological deficit. Results: Of 53 patients, 49 (93%) suffered an aortic dissection Stanford Type A/De Bakey Type I and 4 (8%) patients a De Bakey Type II. Six (11%) patients died. Eleven (21%) patients developed a nonreversible (stroke, hemorrhage) and 23 (43%) patients a reversible neurological deficit (postoperative delirium). Postoperative delirium was significantly more frequent in the N-group (91%) compared to the Non-N group (33%). No significant difference was found for absolute rScO_2 values ＜ 50% and for the rScO_2 AUC in both hemispheres between all groups. Conclusion: Regional oxygen cerebral desaturation measured by NIRS appears to be a poor indicator for neurological outcome after aortic arch surgery in adults.