Association Between Body Mass Index, Uterine Size, and Operative Morbidity in Women Undergoing Minimally Invasive Hysterectomy

Abstract

Study objective: Although the selection of an approach to minimally invasive hysterectomy is relatively straightforward in an ideal patient scenario, it is more difficult in patients who pose operative challenges such as high body mass index (BMI) and enlarged uteri. The objective of this study was to explore the association between surgical approach and operative morbidity after minimally invasive hysterectomy and examine whether the association varies based on patient BMI and uterine size.

Design: Retrospective cohort (Canadian Task Force classification II-2).

Setting: Data abstracted from the American College of Surgeons National Safety and Quality Improvement Project registry.

Patients: Thirty-six thousand seven hundred fifty-seven women undergoing vaginal, laparoscopic-assisted vaginal, or total laparoscopic hysterectomy for benign indications between January 2005 and December 2012.

Interventions: Associations between surgical approach, BMI, and operative morbidity were examined, stratifying by uterine size (< or >250 g) and adjusting for covariates. Adjusted means, rate ratios, or odds ratios with 95% confidence intervals (CI) were calculated using linear, Poisson, or logistic regression.

Measurements and main results: Operative times were shortest in women undergoing vaginal hysterectomy regardless of BMI or uterine size (all p < .02). Although operative time increased with BMI, the association varied with uterine size in women undergoing vaginal hysterectomy; increasing BMI had a minimal impact on operative time with small uteri <250 g but lengthened operative time in uteri >250 g. Compared with vaginal hysterectomy, total laparoscopic hysterectomy had lower odds of blood transfusion (all p < .02) and shorter hospitalizations (all p < .03) regardless of uterine size or BMI. Stratifying by uterine size, the association was strongest in morbidly obese women with small uteri; women with uteri <250 g and BMI >40 kg/m² had 76% lower odds of blood transfusion (95% CI, 0.10-0.54) and 18% shorter hospitalization (95% CI, 0.75-0.90) after laparoscopic hysterectomy compared with vaginal hysterectomy.

Conclusion: Major operative morbidity after minimally invasive hysterectomy is rare regardless of the surgical approach. A vaginal approach to hysterectomy is associated with the shortest operative times, but increasing BMI results in a rapid escalation of operative time in women with large uteri. Total laparoscopic hysterectomy is associated with shorter hospitalizations and lower odds of blood transfusion across the BMI spectrum, particularly in women with small uteri. Laparoscopic-assisted vaginal hysterectomy appears to confer no specific advantage over the vaginal or laparoscopic approaches.

Keywords: Body mass index; Complications; Minimally invasive hysterectomy; Morbidity; Uterine size.