Supplementary Material for: Cost Variability in Stereotactic Technique for Deep Brain Stimulation: A Single Institution Retrospective Study

Introduction Deep brain stimulation (DBS) is a well-defined therapeutic intervention for various neurological and psychiatric disorders; however, there are limited data comparing the costs associated with the various advanced stereotactic techniques employed in DBS surgery. In this study, we assessed the specific factors driving the variability in costs at a single institution across stereotactic approaches for DBS and aimed to highlight potential areas for cost optimization. Methods Inflation-adjusted cost data for patients undergoing DBS from 2012 to 2023 were retrospectively accessed using the University of Utah’s Value Driven Outcomes (VDO) tool. Patients who underwent bilateral DBS surgery with and without same-stage internal pulse generator implantation were included. Surgical approaches to DBS implantation were separated into four techniques by the type or lack of frame and intraoperative imaging used: 1) frame with C-arm fluoroscopy; 2) frame with intraoperative computed tomography (iCT); 3) robotic stereotaxy with iCT; and 4) frameless with intraoperative magnetic resonance imaging (iMRI [ClearPoint™]). Total reported costs for each technique were also split into four subcategories (imaging, facility, supply, services) and expressed as a percentage relative to the total cost for the staged frame with C-arm method. Results Our study included 256 patients who underwent surgical procedures for DBS. The median (interquartile range) cost percentages were 171.0% (±29.0%) for frameless with iMRI, 121.7% (±14.9%) for frame with iCT, and 117.5% (±14.0%) for robotic stereotaxy with iCT procedures. Only the iMRI-based method demonstrated a significantly increased cost (p<0.05) when compared with all other methods. Similarly, the iMRI-based method demonstrated notably higher costs than all other methods across imaging and supply subcategories. Conclusion The iMRI method’s imaging likely costs significantly more because iMRI procedure times are longer than other methods. Supply costs for the iMRI-based method were not statistically correlated with procedure length, highlighting a potential area for cost-saving measures. Future inclusion of technical accuracy, revision and readmission rates, perioperative complications, and other postoperative outcomes may more fully evaluate the most cost-effective approach.