Trends and consequences of surgical conversion in the United States

Background: The aim of this study was to identify national utilization trends of robotic surgery for elective colectomy, conversion rates over time, and the specific impact of conversion on postoperative morbidity. Conversion to open represents a hard endpoint for minimally invasive surgery (MIS) and is associated with worse outcomes when compared to MIS or even traditional open procedures. Methods: All adult patients who underwent either laparoscopic or robotic elective colectomy from 2013 to 2018 as reported in the American College of Surgeons Quality Improvement Program (ACS-NSQIP) database were included. National trends of both robotic utilization and conversion rates were analyzed, overall and according to underlying disease (benign disease, inflammatory bowel disease (IBD), cancer), or the presence of obesity (body mass index (BMI) ≥ 30 kg/m²). Demographic and surgical risk factors for surgical conversion to open were identified through multivariable regression analysis. Further assessed were overall and specific postoperative 30-day complications, which were risk adjusted and compared between converted patients and the remaining cohort. Results: Of 66,652 included procedures, 5353 (8.0%) were converted to open. Conversion rates were 8.5% for laparoscopic and 4.9% for robotic surgery (p < 0.0001). A decline in conversion rates over the 6-year inclusion period was observed overall and for patients with obesity. This trend paralleled an increased utilization of the robotic platform. Several surrogates for advanced disease stages for cancer, diverticulitis, and IBD and prolonged surgical duration were identified as independent risk factors for unplanned conversion, while robotic approach was an independent protective factor (OR 0.44, p < 0.0001). Patients who had unplanned conversion were more likely to experience postoperative complications (OR 2.36; 95% CI [2.21–2.51]), length of hospital stay ≥ 6 days (OR 2.86; 95% CI [2.67–3.05], and 30-day mortality (OR 2.28; 95% CI [1.72–3.02]). Conclusion: This nationwide study identified a decreasing trend in conversion rates over the 6-year inclusion period, both overall and in patients with obesity, paralleling increased utilization of the robotic platform. Unplanned conversion to open was associated with a higher risk of postoperative complications.