SP 3.01 Abdominal Fat Ratio as a Predictor of Conversion and Post-Operative Outcomes in Laparoscopic Versus Robotic Colorectal Cancer Surgery

Abstract

Abdominal fat ratio (AFR) is a validated CT-derived measure of visceral fat distribution and an independent predictor of conversion in obese patients (BMI≥30) undergoing laparoscopic colorectal cancer surgery, with a cut-off of >4 predicting conversion with ∼75% accuracy. Robotic colorectal surgery is associated with lower conversion rates in obese patients. This study examines AFR as a predictor of conversion across minimally invasive approaches and its association with post-operative outcomes. Records of patients undergoing elective, minimally invasive colorectal cancer surgery at a single centre between April 2022 and February 2025 were retrospectively reviewed. AFR was calculated from pre-operative CT scans in obese patients. Patients were stratified by operative approach. Conversion rates and post-operative outcomes were analysed. 348 operations were performed (144 laparoscopic, 204 robotic). 51 laparoscopic (35.4%) and 78 robotic (38.2%) patients were obese. For obese patients with AFR >4, conversion occurred in 15.4% of laparoscopic patients compared with 0% of robotic patients (0/36) (p=0.027). Among obese robotic patients, length of hospital stay was shorter in patients with AFR <4 compared with AFR >4: median 4 days (range 2-11) versus 6 days (range 3-64), respectively (p=0.0003). Post-operative complication rates were also lower in patients with AFR <4 (19.0% versus 41.7%) (p=0.045). In obese patients with AFR >4, laparoscopic colorectal surgery carries a higher risk of conversion, whereas a robotic approach appears to eliminate this risk. In robotic approaches, AFR >4 predicts worse post-operative outcomes. AFR is a simple pre-operative metric to aid risk stratification and optimal surgical approach selection.