An Isolated Posterior Spinal Aneurysm Resection in Which Intraoperative Electrophysiological Monitoring Was Successfully Used to Locate the Lesion and to Detect the Possibility of Ischemic Complications

Study Design.A case report.Objective.To report the successful use of electrophysiological monitoring in the surgical resection of a ruptured spinal artery (SA) aneurysm to locate the lesion, and to predict ischemic complications.Summary of Background Data.Isolated aneurysm of the posterior SA is an extremely rare event without established treatment and diagnosis procedures. Reports describing the surgical intervention of aneurysm of the posterior SA using electrophysiological monitoring are scant.Methods.We performed the surgical resection of a dissected posterior SA aneurysm in an older patient who presented with spinal subarachnoid hemorrhage using intraoperative electrophysiological monitoring.Results.Intraoperatively, motor evoked potentials decreased over 50% when a distal site of the lesion was clipped, indicating that site was the posterior SA. This lead to further investigation of the vascular anatomy around the lesion, which revealed the descending part of the posterior SA buried deeply in a thick thrombus. Clipping and resection were successful, and ischemia of the posterior SA was avoided. The postoperative clinical course was good, and there was no recurrence or long-term squeal.Conclusion.Electrophysiological monitoring might be useful when intraoperative anatomical findings of the hemodynamic structure are inadequate. Moreover, in our case, intraoperative changes in motor evoked potentials indicated the risk to occlude one of posterior SAs, although it is said that posterior circulation of spinal cord has ischemic tolerance.Level of Evidence: N/A