Applying Lean principles to pediatric neurosurgery: quantifying residents' perception of complexity of common...

Enhancing operating room efficiency while preserving resident surgical education remains a priority for teaching hospitals. Applying Lean principles to pair residents' step-level risk and comfort perceptions with step-level time may reveal training targets that reduce operative duration and improve safety. This study quantified the relationship between residents' step-level perceived risk or comfort and operative time during filum terminale lysis (FTL) and primary vagus nerve stimulator (VNS) placement.

Attending pediatric neurosurgeons defined 11 FTL and 10 VNS placement steps. A 2-part survey captured step-specific comfort and perceived risk from junior residents, senior residents, and faculty members (for VNS placement, 11 junior residents, 10 senior residents, and 3 faculty members were surveyed; for FTL, 11 junior residents, 9 senior residents, and 4 faculty members). Responses were mapped to a risk matrix with a "danger zone" (high-risk score of 3-5 and low-comfort score of 1-3) and a "safe zone" (low-risk score of 1-2 and high-comfort score of 4-5). Step-level times were prospectively recorded across FTL (n = 16) and VNS (n = 24) cases. Analyses included the Fisher's exact test, Spearman correlations, and linear-by-linear tests for training-level trends.

Risk-matrix analysis showed significant junior resident-faculty member differences for both procedures, with no senior resident-faculty member differences. In FTL, significant junior resident-faculty member differences were observed for dural closure (p = 0.004). In VNS placement, junior residents more often labeled carotid sheath exposure, vagus nerve exposure, and lead placement as the danger zone (all p = 0.0027). Excluding closure, VNS placement demonstrated positive associations between perceived danger and both step time and share of cases (for junior residents, ρ = 0.73, p = 0.025; senior residents, ρ = 0.75, p = 0.020; faculty members, ρ = 0.58, p = 0.10). In FTL, no association was observed. Training-level trends showed increasing high comfort (≥ 4) with seniority across most steps (10/11 steps for FTL; 7/10 steps for VNS placement). Step timing highlighted skin closure for VNS placement (median [IQR] 1769 [1447-2304] seconds) and dorsal bony exposure (700 [427-1037] seconds), dural closure (932 [336-1387] seconds), and fascial closure (695 [563-828] seconds) for FTL as the most time-consuming phases.

Combining step-level risk-comfort matrices with timing can yield procedure-specific teaching targets. In FTL, danger perception aligns with time burden, supporting focused coaching on dural closure and exposure; in VNS placement, the main time-intensive step is low-risk closure, which may yield areas for improvement via workflow and team-based interventions, while danger-labeled exposure/lead steps merit targeted supervision for safety. This Lean principle-based framework enables training level-specific interventions to improve both efficiency and safety.