# Feasibility and outcomes of robotic colorectal cancer surgery in patients with high body mass index

## TL;DR

Robotic surgery for colorectal cancer is feasible and safe for obese patients, with low conversion rates and manageable complications.

## Contribution

This study provides outcome data on robotic colorectal surgery in high BMI patients from a single-centre case series.

## Key findings

- Conversion to open surgery occurred in only 1.3% of cases.
- Prolonged Trendelenburg positioning did not increase anaesthetic risk significantly.
- The 30- and 90-day mortality rate was 1.3%.

## Abstract

Minimally invasive techniques are the standard of care in colorectal surgery. However, high body mass index (BMI) presents technical and anaesthetic challenges. Robotic-assisted surgery offers potential advantages in this population; however, given its relatively recent adoption, outcome data remain limited. This article presents a single-centre case series evaluating the short-term surgical and anaesthetic outcomes of obese patients undergoing robotic colorectal resections.

A retrospective review was performed of patients with BMI > 30 kg/m2 who underwent robotic colorectal cancer resection at Liverpool University Hospital NHS Trust between July 2019 and April 2024. Demographic, surgical, anaesthetic, and clinical outcome data were collected from a prospectively maintained database. Key measures included operative time, Trendelenburg positioning, critical care admissions, complications, and mortality.

Seventy-five patients [mean BMI 35.8 (range 30.0–66.1) kg/m2] underwent robotic resection. Conversion to open surgery occurred in one case (1.3%). Mean operative time was 380 min for rectal and 289 min for colonic resections. The average Trendelenburg tilt was 20o (range 15–22), with an average lateral tilt of 15o (range 10–20), and mean head down duration was 225 (range 120–320) min. Fifty-six (74.7%) patients had primary anastomosis; the anastomotic leak rate was 9.3%. Thirty-two per cent of patients were electively admitted to the critical care as part of our institutional pathway for high BMI-cases. Of these, three patients (4.0%) required overnight mechanical ventilation and were both extubated the following morning without further organ support. One case of postoperative visual disturbance, attributed to positioning, resolved fully. The 30- and 90-day mortality rate was 1.3%.

Robotic colorectal surgery is a feasible and safe option in elevated BMI patients, with low conversion rates and acceptable morbidity. Importantly, prolonged Trendelenburg position did not appear to increase anaesthetic risk, with only one reversible positioning-related complication observed.