Adem DOĞAN, Gardashkhan KARIMZADA, Demet EVLEKSİZ
Journal of Turkish Spinal Surgery - 2026;37(4):195-201
Objective: Lumbar discectomy and decompression using unilateral biportal endoscopy (UBE) have become increasingly adopted minimally invasive techniques in spine surgery. Nevertheless, intraoperative neural irritation may occur due to procedure-related factors and the technical learning curve. This study aimed to describe intraoperative electrophysiological findings obtained with multimodal neuromonitoring during lumbar surgery performed using UBE, with particular attention to free-running electromyographic activity associated with electrocautery use. Materials and Methods: A retrospective analysis was performed on 78 patients who underwent lumbar discectomy or decompression using UBE between January 2024 and June 2025. The multimodal intraoperative neuromonitoring (IONM) protocol consisted of free-running electromyography (freeEMG), motor evoked potentials (MEP), and somatosensory evoked potentials (SEP). Results: FreeEMG activity temporally associated with electrocautery use was observed in 32 of 78 patients (41.0%). In these cases, the electrocautery power was reduced intraoperatively, after which the freeEMG activity returned to baseline. Among 18 patients with preoperative motor weakness, postoperative improvement was observed in 14. No new postoperative neurological deficits were identified. Conclusion: Multimodal IONM provided real-time electrophysiological information during lumbar surgery performed using UBE. FreeEMG activity was observed in temporal association with electrocautery use and returned to baseline after modification of the electrocautery settings. These findings are descriptive and do not establish a protective effect of IONM. Prospective controlled studies are needed to determine whether such intraoperative feedback translates into improved neurological outcomes.
