What factors impact surgical operative time when teaching a resident in the operating room.

Purpose: Resident involvement would likely lead to prolonged operative time of a surgical case performed at academic medical centers. However, little is known about factors beneath this phenomenon. The purpose of this study was to investigate whether factors from case (procedure type, surgical case complexity, and surgical approach), teacher (attending surgeon experience and gender), and learner (resident postgraduate training year and gender) would influence operative time of surgical cases involved teaching a resident (SCT). Methods: A single-institution retrospective analysis of 3 common general surgery procedures, including cholecystectomies, colectomies, and inguinal hernia, with involvement of general surgery residents between 2016 and 2020 was conducted. Surgical operative time was defined as the "cut-to-close" time from incision to completion of wound closure. Analysis of variance for continuous variables and multivariable linear regression were applied. Results: A total of 4,417 eligible SCT were included. The average operative time was 114.8 ± 78.7 min. SCT with male resident involvement showed a significantly longer operative time than those with female residents (117 vs. 112, p = 0.01). Comparable operative time was observed between male and female attending surgeon cases (115.5 vs. 110.8, p = 0.15). SCT operating time decreased with increased resident training level, except for SCT with involvement of Year2 residents. SCT with Year5 residents demonstrated the lowest time to case completion (110.5 min); SCT with major complications took least time to complete (105.7 min). Univariate and multivariate analysis revealed resident training year level, resident gender, and case complexity as factors associated with significant differences in operative time. Attending surgeon experience, surgeon gender, surgical approach, and procedure type did not impact SCT operative time. Conclusion: Our study findings suggest resident training level, resident gender, and case complexity are factors significantly associated with SCT operative time of cholecystectomies, colectomies, and inguinal hernia. Attending surgeons are recommended to factor them into pre-operative planning.