451 Validation of a 3-D Printed Model for Spinal CSF Leak Repair and the Rochester OSATS CSF Leak Repair Criteria

INTRODUCTION: Iatrogenic spinal durotomies occur at a rate of 3%–16%. Surgical simulation for durotomy repair is needed to provide affordable, accessible, and validated practice in resident education. METHODS: A digitally designed spinal model was modeled to mimic a lumbar laminectomy with the L3-5 lamina removed and 3D printed using Vero polymers. The model was paired with a porcine collagen casing-based “dura” that was pressurized using IV saline and overlayed with gel-molded fascial, muscle, and skin layers with an opening. Participants were provided a training model with a 1.5 cm midline durotomy, surgical micro-instrument set, surgical microscope, and 6-0 Prolene suture. The 25-point Rochester Objective structured assessment of technical skills for CSF Leak (ROCL) repair criteria was adapted from the original objective structured assessment of technical skills principles and used to assess proficiency in surgical repair by two neurosurgeons not participating in the trials in a blinded fashion. Post-simulation survey data regarding model realism was collected. RESULTS: 6 residents and 4 attendings participated. Median operative time in minutes was 13 minutes amongst residents and 7 minutes amongst attendings. Moreover, ROCL score was median 19/25 for attendings and 15/25 for residents, a larger sample would be needed to assess significance. Suture angle was statistically more consistent among senior residents and attendings compared to junior residents. Participants agreed the model was realistic (median 4/5), useful for improving operative technique (median 5/5), and would increase comfort in spinal CSF leak repair procedures (median 5/5). Each re-usable model costs $19.99 when printed with polylactic acid (PLA) and each replacement dura costs <3¢. CONCLUSIONS: This study presents an affordable, realistic and educational spinal CSF Leak Repair model and introduces the ROCL for assessment.