The impact of obesity class on perioperative outcomes in minimally invasive surgery for endometrial cancer (594)

Abstract

<b>Objectives:</b> Minimally invasive surgeries (MIS) have been shown to reduce complication rates and length of hospital stays in patients with obesity. However, there is limited data analyzing outcomes for specific obesity classes (Class I [30-34.9 kg/m2], Class II [35-39.9 kg/ m2], and Class III [≥40.0 kg/m2]). This study aimed to evaluate differences in perioperative outcomes, stratified by obesity class, in obese patients undergoing minimally invasive surgery for endometrial cancer. <b>Methods:</b> This is an IRB-exempt retrospective cohort study investigating women who underwent MIS for treatment and staging of endometrial cancer. Inclusion criteria were age 18 years or older, MIS performed for endometrial cancer, and BMI of 30 kg/m² or greater. We excluded those who underwent neoadjuvant chemotherapy or radiation therapy. Data were collected from the de-identified National Surgical Quality Improvement Program (NSQIP) between 2012-2018. The primary outcome was intraoperative complications, such as bowel injury, urologic injury, and conversion to laparotomy. Secondary outcomes were unplanned re-admission, unplanned reoperation, and postoperative infection. Chi-square and Kruskal- Wallis rank-sum tests were used as appropriate for categorical and continuous variables, respectively. P-values of < 0.05 were considered significant. Statistical analysis was performed using SAS 9.4v (SAS Institute Inc., Cary, NC, USA). <b>Results:</b> We identified 12,956 patients who met the inclusion criteria within NSQIP. Of these, 29.3% (<i>n</i> = 3,801) patients were Class I (avg. BMI 32.5 kg/m²), 26.7% (<i>n</i>= 3,467) were Class II (avg. BMI 37.4 kg/m²), and 43.9% (<i>n</i> = 5,688) were Class III (avg. BMI 47.5 kg/m²) (see Table 1). The average ages were 64.1, 62.7, and 59.2 years old for Class I, II, and III, respectively. Intraoperatively, there were no statistically significant differences among the three classes for bowel injury, urologic injury, or conversion to laparotomy (p= 0.575). Re-admission rates were higher for Class III patients (4.1%) than Class I and II (3.1%, p=0.005). There was a higher rate of superficial surgical site infection in Class III obese patients versus Class I and II (0.6% vs 1.1% vs 1.3%, respectively; p=0.005). There were no significant differences among Class I, Class II, and Class III obesity for deep wound (0.1%, 0.1%, and 0.3%, respectively, p=0.052) and organ space (0.9%, 1.2%, 1.4%, respectively, p=0.101) surgical site infections. <b>Conclusions:</b> In conclusion, among obese women undergoing MIS for endometrial cancer, there were no statistical differences between the risks of intraoperative complications, such as bowel injury, urologic injury, and conversion to laparotomy, when assessing the different obesity classes. However, postoperatively, patients with Class III obesity had higher re-admission rates and superficial surgical site infections when compared to Class I and Class II obese patients.