Impact of Body Mass Index on Operative Time in Women Undergoing Benign Hysterectomy.

Background: Optimization of surgical scheduling represents an opportunity to improve resource utilization and increase patient access. Increasing body mass index (BMI) has been associated with increased operating time and may provide an opportunity to more accurately predict operating time.

Objective: To investigate the relationship between BMI and operative time for benign hysterectomy and develop a predictive model for hysterectomy operating time based on patient BMI.

Methods: A secondary analysis of women undergoing benign laparoscopic, abdominal, or vaginal hysterectomy between 2014 and 2019 was performed using the American College of Surgeons National Surgical Quality Improvement Program database, N = 117,691. Our primary outcome was log₁₀ transformation of operative time. Multivariable linear regression was used to analyze the relationship between operative time and BMI. A model to predict operating time was created using variables that could be reliably obtained preoperatively.

Results: From our cohort, 22% of benign hysterectomies were performed abdominally, 16% were vaginal, and 62% were laparoscopic, and mean operative times were 144, 133, and 158 minutes, respectively. For every 10-unit increase in BMI, estimated mean operation time (OT) increased by 12.8%, 8.1%, and 6.5% for abdominal, vaginal, and laparoscopic hysterectomy, respectively. Neither an expanded nor a concise model was able to account for the variability in log₁₀(OT).

Conclusion: Increasing BMI differentially impacts the operative time in abdominal greater than laparoscopic and vaginal hysterectomy. However, operative time for hysterectomy is highly variable, and its estimation is difficult to reliably predict using common preoperative variables.