Assessing the role of robotic proctectomy in obese patients: a contemporary NSQIP analysis

Robotic proctectomy has become increasingly popular for both benign and malignant indications. The purpose of this study was to determine if the robotic approach has a distinct advantage over laparoscopy in obese patients, which has been suggested by previous subgroup analyses. We performed a retrospective review of 2016-2018 National Surgery Quality Improvement Program (NSQIP) data to compare outcomes between patients who underwent robotic versus laparoscopic proctectomy, stratified by Body Mass Index (BMI) subgroups. We also compared outcomes of converted minimally invasive proctectomy to planned open operations. Four thousand four hundred eighteen (69.3%) patients underwent laparoscopic proctectomy, and 1956 (30.7%) patients underwent robotic proctectomy. Robotic proctectomy was associated with a significantly lower conversion rate compared to laparoscopic proctectomy (5.1% vs 12.3%; p = 0.002), and this relationship was maintained on an adjusted model. Obese (BMI > 30) patients were more likely to require conversion in both laparoscopic and robotic groups with the greatest difference in the conversion rate in the obese subgroup. Patients who underwent conversion had higher composite morbidity compared to patients who underwent planned open operations (50.8% vs 41.3%; p < 0.001). And among patients with rectal cancer, robotic proctectomy was associated with a greater incidence of positive radial tumor margins compared to laparoscopic proctectomy (8.0% vs 6.4%; p = 0.039), driven primarily by the obese subgroup. Our study demonstrates that robotic proctectomy is associated with a 7% lower conversion rate compared to laparoscopy and that obese patients are more likely to require conversion than non-obese patients. Among obese patients with rectal cancer, we identified an increased risk of positive radial margins with robotic compared to laparoscopic proctectomy.