Assess whether fully-immersive simulation training with structured debriefing of a standardized emergency thoracic endovascular aortic repair (TEVAR) scenario improves team-work performance of the lead surgeon. Secondary aims: assess whether technical skills (TS) and radiation safety behaviors (RSB) improved concurrently.Pre-post study.UK-based training days.General and vascular surgical trainees (n = 16).Fully-immersive simulation training with structured debriefing of a standardized emergency TEVAR scenario. Following standardized emergency TEVAR technical training, trainees led 2 standardized fully-immersive endovascular surgery simulations, with scripted support from a passive surgical team. A non-TS (NTS) structured debrief was delivered following simulations. NTS were assessed using the validated observational teamwork assessment for surgery tool post hoc using video recordings of simulations. TS were assessed through time taken to complete each step of the procedure, as defined during technical training. RSB were assessed through checking for presence of pre-defined actions and the length of time fluoroscopy was used during each simulation.Total observational teamwork assessment for surgery scores improved following structured debrief (p = 0.005, median 52.55/90 vs 73.0/90), alongside all constituent domains - communication (p0.001, median 11.7/20 vs 16.6/20), coordination (p0.001, median 8.6/15 vs 13.4/15), cooperation (p0.001, median 13.15/20 vs 16.35/20), leadership (p0.001, median 8.70/15 vs 11.30/15) and monitoring (p0.001, median 9.85/20 vs 14.85/20). TS improved; time to complete 12 of 13 procedural steps improved (p0.027). Fluoroscopy time (seconds) decreased (p = 0.339, 543.6 vs 495.5), frequency lead surgeons checked the team were wearing leads increased (p = 0.125, 3 vs 7) and asked the team to step back before screening increased (p = 0.003, frequency team asked to step back/total angiography runs before = 2/36 vs after = 14/44).fully-immersive endovascular simulation with structured debrief is a robust tool to improve NTS and TS. Incorporation into surgical training may reduce operating theatres errors, increase efficiency, and improve RSB. However effective translation into the clinical workplace must be demonstrated to see these benefits.