8553 The Effect of Obesity on the Accuracy of Uterine Weight Estimation and Impact on Hysterectomy Outcomes

Abstract

<h3>Study Objective</h3> Determine the effect of obesity on the accuracy of uterine weight estimation by bimanual exam (BME) and transvaginal ultrasonography and evaluate the impact on hysterectomy outcomes including surgical route and operative complications. <h3>Design</h3> Retrospective cohort study. <h3>Setting</h3> Large academic medical center. <h3>Patients or Participants</h3> 1297 patients who underwent hysterectomy for benign indications at Parkland Hospital by generalists and Minimally Invasive Gynecologic Surgery (MIGS) fellowship-trained gynecologists between 01/2016 to 06/2018. <h3>Interventions</h3> Data was collected from electronic medical records up to 6months after hysterectomy. Surgeon type and mode of hysterectomy were compared. Resident physicians performed preoperative BME to determine estimated uterine size by gestational age, which was then converted to clinical uterine weight (grams) using mean weights for uteri between 6-26 weeks. For ultrasound weight, the equation: weight (g) = 50.0 + 0.71 x volume (cc) was used. Actual uterine weight was collected from surgical pathology data. <h3>Measurements and Main Results</h3> There was a significant correlation between both ultrasound-converted weight and pathology weight (r=0.81, p<0.001), and BME clinical weight and pathology weight (r=0.70, p<0.001). The correlation between ultrasound estimation and actual weight did not statistically differ between obese and non-obese populations (p=0.06). The correlation between BME estimation and actual weight did statistically differ between obese and non-obese populations (p<0.001). Most hysterectomies performed by MIGS surgeons were laparoscopic (59%) and generalists were open (50%). With uteri up to 22 weeks, MIGS surgeons performed significantly more laparoscopic hysterectomies than generalist surgeons regardless of obesity class (p<0.05). Complication rates did not statistically differ in obese versus non-obese populations (p>0.05). <h3>Conclusion</h3> BME estimation was affected by obesity and had a stronger correlation with actual weight in obese patients. Regardless of obesity class or uterine size, more MIGS surgeons chose a laparoscopic route while generalist surgeons chose open. Despite MIGS surgeons performing minimally invasive hysterectomies in more surgically complex cases, there were no differences in complication rates.