[Role of intraoperative neurophysiological monitoring in high-risk endovascular aortic repair for spinal cord ischemia].

Objective: To evaluate the feasibility and efficacy of intraoperative neurophysiological monitoring (IONM) in endovascular repair (EVAR) procedures for aortic pathologies at high risk of spinal cord ischemia (SCI). Methods: This is a retrospective case series study. Clinical data of 19 patients with thoracoabdominal aortic aneurysms or other complex aneurysms involving branches in the aortic arch or visceral branch arteries who underwent elective fenestrated or branched endovascular aortic repair between August 2024 and May 2025 at the Department of Vascular Surgery, Zhongshan Hospital, Fudan University, were retrospectively reviewed. There were 15 male and 4 female patients, with an age of (63.9±13.3) years (range: 30 to 80 years). All patients were identified as at high risk for SCI based on a spinal cord ischemia risk stratification model and related clinical indicators. Multimodal IONM was applied intraoperatively in all patients, including transcranial electrical stimulation motor evoked potentials, somatosensory evoked potentials, and compound motor unit action potentials. Based on monitoring results, one or more managements would be employed accordingly, including increasing mean arterial pressure, reducing cerebrospinal fluid pressure, correcting anemia, temporary aneurysm sac perfusion, or staged surgery. The perioperative and prognostic conditions of 19 patients were observed. Results: Technical success was achieved in 19 patients without any monitoring-related complications. In 4 patients, no IONM alerts occurred and no SCI developed postoperatively. In 15 patients, monitoring alerts were detected; among them, 12 alerts were resolved after intraoperative management. In the remaining 3 patients, alerts persisted, including 1 patient who showed progressive deterioration in monitoring signals and developed postoperative paraplegia (bilateral lower limb motor strength was grade 0), which recovered to grade 5 after 3 months. The last 2 patients exhibited unilateral alarms without progressive deterioration, thus allowing the procedures to be completed. Conclusion: IONM could provide early intraoperative warnings of SCI in EVAR, enabling the surgical team to take timely interventions and minimize the incidence and damage of SCI.