Intraoperative neurophysiological monitoring and spinal cord stimulator implantation

Spinal cord injury (SCI) is one of the most dreaded complications after spinal cord stimulation (SCS) implantation surgery. As a result, intraoperative neurophysiological monitoring (IONM) has been proposed to avoid accidental damage to nervous structures under anesthesia and confirm positioning for optimal stimulation. Our study uses a large administrative claims database to determine the 30-day risk of SCI after SCS implantation.

This retrospective cohort study used the IBM MarketScan Commercial and Medicare Supplemental Databases from 2016 to 2019. Adult patients undergoing SCS surgical procedures with at least 90 days of follow-up, IONM use, the type of sedation used during the procedure, and subsequent SCI were identified using administrative codes. In addition, logistic regression was used to examine the relationship between various risk factors and subsequent SCI.

A total of 9676 patients underwent SCS surgery (64.7% percutaneous implants) during the study period. Nine hundred and forty-four (9.75%) patients underwent SCS implantation with IONM. Conscious sedation, Monitored Anesthesia Care anesthesia, and general anesthesia were used in patients with 0.9%, 60.2%, and 28.6%, respectively. Eighty-one (0.8%) patients developed SCI within 30 days after SCS implant surgery. The SCI rate was higher in the group that underwent IONM (2% vs 0.7%, p value <0.001) during the implantation procedure, reflecting the underlying risk. After adjustment for other factors, the OR of SCI is 2.39 (95% CI: 1.33 to 4.14, p value=0.002) times higher for those with IONM than those without IONM.

Increased SCI risk among patients with IONM likely reflects higher baseline risk, and further research is needed for risk mitigation.