Clinical Implications of Preoperative Thoracic Spine Magnetic Resonance Imaging for Percutaneous Spinal Cord Stimulation Procedures: A Large Retrospective Cohort Study

ABSTRACT Introduction Spinal cord stimulation (SCS) is an effective method for pain relief in patients with Persistent Spinal Pain Syndrome (PSPS) type II. International guidelines recommend preoperative imaging to assess spinal anatomy for placement of thoracic SCS leads. This study examines the clinical implications of routine preoperative imaging in patients scheduled for thoracic percutaneous SCS lead placement. Methods A single‐center retrospective study of MRIs was performed in patients who were planned for SCS lead placement in a period from January 2020 to March 2023. The study excluded lead revisions and cervical or dorsal root lead placements. We examined the impact of imaging findings on procedural planning and execution, categorizing the clinical impact as minor (additional imaging or consultation) or major (cancellation or technical modification of the procedure). We also evaluated the correlation between abnormalities in the epidural space and periprocedural (but not postprocedural) complications such as dural puncture or improper lead positioning at Th7. Results Of the 167 patients who underwent MR imaging, 129 continued with SCS lead placement. The major reason for not proceeding with lead placement was patient and/or physician preference for conservative treatment. MRI revealed abnormalities in 58 patients—22 in the relevant epidural space and 36 incidental findings. In 29 of the patients (17.4% of total) these abnormalities had no clinical consequences. There were minor consequences in 23 patients (13.8% of total) and major consequences in 6 patients (3.6% of total). Major consequences included the decision to perform a primary surgical implantation in one patient, changes in epidural entry level in two patients, surgical decompression in two patients, and cancellation of the procedure in one patient. Of all MRI findings with clinical implications, 14 of 29 (48.2%) (and 3 of 6 for major consequences) were visible on prior imaging. Although not specifically powered for this correlation, statistical analysis using a Fisher exact test found no significant association between epidural abnormalities on MRI and the occurrence of dural puncture, the inability to place the lead at the desired position, or perioperative neurological sequelae. Conclusion Routine preoperative MRI before thoracic SCS lead placement often detects abnormalities with major consequences in 3.6% of cases. In half of these cases, the abnormalities could not be identified on previous imaging, all of which were in the thoracic region. There was no association between epidural abnormalities and periprocedural complications in our data.