The Evaluation of Medulla Spinalis Perfusion at Moderate Hypothermia With Patients Who Undergo Antegrade Selective Cerebral Perfusion in Ascending and Arcus Aortic Surgery

Aim: Antegrade Selective Cerebral Perfusion (ASCP) with lower body circulatory arrest (LBCA) used in aortic arch surgery can lead to postoperative ischemic organ dysfunctions if it lasts long enough. We aimed to evaluate methods that can provide early detection of spinal cord ischemia during aortic arch surgery. Methods: Thirty consecutive patients were prospectively enrolled and Near infrared spectrometry (NIRS) data obtained from the 5 th and 10 th thoracic vertebral region, S100β protein, lactate blood levels during various operative phases and postoperative neurological outcomes were evaluated. Results: A total of 30 patients underwent elective hemi arch (73.29%) or total arch (23.31%) replacement and with a mean ASCP period of 25.1 ± 19.0 (limits 10-90) minutes. In-hospital mortality was 6.66% (two patients). Paraparesis developed in one patient (3,33%). Thoracic T5 and T10 NIRS values were lowest during the ASCP period (p<0.001) with a good correlation between them (r=0.853, p<0.001). However, a significant difference between the T5 and T10 levels was observed during the same period (55.40 vs 51.07 respectively, p=0.001). A moderately negative correlation between the lactate levels in descending aorta and NIRS values at the T10 level was found during ASCP (r =-0.514, p = 0.004). Conclusion: Thoracic 5 th and 10 th level NIRS monitoring for spinal cord oxygenation were significantly lower during ASCP period compared to the other periods of aortic arch surgery with T10 values being lower than T5 values during the same period indicating a more significant flow disturbance at this level. Measuring lactate levels with thoracic NIRS monitoring seems promising for future studies with larger volumes and longer ASCP periods.