The Use of Intraoperative Neuromonitoring in Routine Percutaneous Spinal Cord Stimulator Surgery is Not Associated With Improved Placement, Patient Safety, or Pain Severity Outcomes.

Abstract

The placement of spinal cord stimulators (SCSs) relies on midline placement to provide bilateral coverage. Implantation under general anesthesia using intraoperative neuromonitoring (IOM) has been shown to be a valid alternative to awake placement to confirm positioning. It has been suggested that placement should be confirmed with awake testing or IOM for reasons of efficacy and safety. No study has compared operative outcomes in percutaneous SCS surgery with our without the use of IOM. A single-center retrospective chart review was performed, identifying 228 patients who underwent percutaneous SCS implantation between 2021 and 2023 by a single surgeon. Surgery was performed with IOM (n = 55) or without IOM (n = 173). The primary outcome measures were laterality of coverage, revision and explant rates, and incidence of intraoperative complications. Secondary outcomes included pain severity scores (Numerical Rating Scale) and operative duration. All patients had bilateral stimulation coverage regardless of IOM, and no revisions for laterality occurred. Revision rates for fracture of migration did not significantly vary between cohorts (IOM 3.6%, non-IOM 4.0%; P > .999). Explantation rates were also not significantly different (IOM 9.1%, non-IOM 5.2%; P = .334). Patients in both cohorts demonstrated a lower Numerical Rating Scale at last follow-up compared with baseline; however, this change did not significantly vary between cohorts (IOM 4.7 vs non-IOM 4.4; mean difference: 0.26; P = .713) nor did the proportion of responders (IOM 52.6% vs non-IOM 48.9%; P = .684). Operative duration was significantly longer in the IOM cohort (65.3 vs 48.6 minutes; mean difference: 16.5 minutes; P < .001), as was "room-to-incision" time (41.0 vs 33.3 minutes; mean difference 7.66 minutes; P < .001). No intraoperative complications were encountered in either cohort, including no nerve irritation or neurological injury. Percutaneous SCS placement can safely and accurately be performed without the use of IOM. IOM does not improve placement accuracy or laterality of coverage, as long as leads are placed anatomically in the midline.