Robotic versus laparoscopic TME for rectal cancer: meta-analysis of pathological quality indicators

BACKGROUND: Total mesorectal excision (TME) quality is a key determinant of oncological outcomes in rectal cancer. While robotic surgery offers technical advantages over laparoscopy in the confined pelvis, its superiority regarding pathological outcomes remains debated. We conducted a meta-analysis comparing robotic and laparoscopic TME focusing on quality indicators of TME and risk factors for incomplete TME. METHODS: A PROSPERO-registered systematic search of PubMed and EMBASE up to May 2025. Comparative studies reporting pathological outcomes of robotic versus laparoscopic TME were included. Primary endpoints were TME completeness, circumferential resection margin (CRM) positivity and distal resection margin (DRM) positivity. Secondary analysis included baseline characteristics (male gender, BMI, bulky tumours, distance to anal verge, neoadjuvant radiotherapy) and local recurrence rate. RESULTS: Fifty-six studies (27,648 patients; robotic 10,629, laparoscopic 17,019) were included. Robotic surgery was associated with significantly more complete TME specimens (OR 1.50, 95% CI 1.23-1.82, p < 0.001) and fewer positive DRMs (OR 0.68, 95% CI 0.48-0.97, p = 0.031). CRM positivity was comparable between groups (OR 0.93, 95% CI 0.77-1.12, p = 0.44). In random-effects analysis, there was a non-significant trend towards fewer local recurrences after robotic TME (OR 0.75, 95% CI 0.54-1.05, p = 0.09). Robotic cohorts more frequently included male patients, distal tumours and neoadjuvant chemoradiotherapy, suggesting preferential selection of technically challenging cases. CONCLUSIONS: Robotic TME is associated with higher specimen completeness and lower DRM positivity compared with laparoscopic TME, while CRM positivity and local recurrence rates appear broadly similar. These data support the use of robotics as a primary minimally invasive option for mid-low rectal cancer; however, as a result of low certainty of evidence, these findings should be interpreted cautiously. SYNOPSIS: This meta-analysis provides the most up-to-date synthesis of pathological outcomes comparing robotic and laparoscopic TME for rectal cancer, incorporating data from 56 studies including the recent REAL and COLRAR randomized trials. Unlike previous reviews, it exclusively analyses total mesorectal excision procedures, excluding partial or high anterior resections, thereby eliminating a major source of heterogeneity. The findings demonstrate that robotic TME is associated with higher specimen completeness and fewer positive distal margins, even in technically demanding mid- and low-rectal cancers, supporting the role of robotics as the preferred minimally invasive approach in mid-low, difficult tumours.