Migration of Epidural Leads During Spinal Cord Stimulator Trials.

Objective: Lead migration is the most commonly reported complication of spinal cord stimulation (SCS) procedures and lead migration during trials of SCS can compromise both the success of the trial as well as the efficacy of subsequent implantation. Our objective was to examine the incidence and degree of intra-trial SCS lead migration and our hypothesis was that there would be a higher rate of significant radiographic lead migration during SCS trial than what has been previously published for permanently implanted leads. Materials and Methods: We retrospectively assessed the radiographic location of SCS leads on final fluoroscopic imaging at the time of trial lead placement compared to thoracic radiographs obtained at the end of the SCS trial to quantify the rate and degree of migration during the trial. Thirty-five patients were included in the study with 69 leads assessed for radiographic degree of migration. The majority of patients were trialed utilizing paresthesia-free systems (57%) and the most common indication was for post-laminectomy syndrome (57%). Results: In our series of 35 patients, on average there was 28 mm or 1.17 vertebral body levels of migration. No statistically significant correlation was found between fixation technique, physician experience, device manufacturer, patient age, sex, height or BMI and likelihood of significant radiographic migration. Conclusion: In our study, lead migration appears to be a more significant occurrence during SCS trial than previously reported. Intra-trial migration presents a significant challenge for clinical care and examination of risk factors for migration and techniques for prevention are warranted.