Operative Time Heterogeneity in Laparoscopic Cholecystectomy at High Altitude: Surgeon Variability as a Modifiable Factor under Hypoxic Stress

Objective: To quantify inter-surgeon heterogeneity in operative efficiency of laparoscopic cholecystectomy (LC) at high altitude and identify independent determinants of operative time. Methods: A single-center retrospective cohort study at Qinghai Red Cross Hospital (2,260 m altitude) included 591 elective LC cases by 7 surgeons (2020-2023). One-way ANOVA, multivariate regression with log-transformed operative time, nested model comparison, and ICC quantified surgeon versus baseline factor contributions. Results: Inter-surgeon operative time differed significantly (F = 7.16, P < 0.001, eta squared = 0.069), with 12.64 min (24.0%) gap between fastest and slowest surgeons. Regression (Adj R2 = 0.075, P < 0.001) identified age (beta = 0.0029/yr, P = 0.009), male sex (beta = 0.063, P = 0.019), and surgeon identity as independent predictors. Nested comparison showed surgeon factors explained 2.02-fold more variance than all baseline factors combined (Delta R2 = 0.063 vs R2 = 0.031; ICC = 0.074). Conclusion: Surgeon variability is the dominant modifiable determinant of operative time heterogeneity in high-altitude LC.