Evaluation of medulla spinalis perfusion during aortic arch surgery with antegrade selective cerebral perfusion

Aim: Lower body circulatory arrest with antegrade selective cerebral perfusion (ASCP) during aortic arch surgery can lead to postoperative ischemic spinal cord injury due to the disturbance of blood supply to the cord. Methods that might provide early detection such as near-infrared spectrometry (NIRS) and biomarkers have been evaluated throughout the perioperative phase. Material and Methods: Thirty consecutive patients were prospectively enrolled in the study. NIRS data were obtained from the cerebral and thoracic spine region. Additionally, S100β protein levels, lactate blood levels and postoperative neurological outcomes were evaluated at various surgery phases. Results: A total of 30 patients underwent elective hemiarch (73.29%) or total arch (23.31%) replacement with a mean ASCP period of 25.1±19.0 (limits 10-90) minutes. Paraparesis developed in one patient (3.33%). During ASCP period, a significant difference between thoracic T5 and T10 NIRS values was observed (55.40 vs 51.07 respectively, p=0.001). Conclusion: Thoracic 5th and 10th level NIRS monitoring for spinal cord oxygenation was 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.