Histopathological outcomes of transanal, robotic, open, and laparoscopic surgery for rectal cancer resection. A Bayesian network meta-analysis of randomized controlled trials.

BACKGROUND

While total mesorectal excision is the gold standard for rectal cancer, the optimal surgical approach to achieve adequate oncological outcomes remains controversial. This network meta-analysis aims to compare the histopathological outcomes of robotic (R-RR), transanal (Ta-RR), laparoscopic (L-RR), and open (O-RR) resections for rectal cancer.

MATERIALS AND METHODS

MEDLINE, Embase, and the Cochrane Library were screened from inception to June 2024. Of the 4186 articles screened, 27 RCTs were selected. Pairwise comparisons and Bayesian network meta-analyses applying random effects models were performed.

RESULTS

The 27 RCTs included a total of 8696 patients. Bayesian pairwise meta-analysis revealed significantly lower odds of non-complete mesorectal excision with Ta-RR (Odds Ratio, OR, 0.60; 95%CI, 0.33, 0.92; P = .02; I:11.7 %) and R-RR (OR, 0.68; 95%CI, 0.46, 0.94; P = .02; I:41.7 %) compared with laparoscopy. Moreover, lower odds of positive CRMs were observed in the Ta-RR group than in the L-RR group (OR, 0.36; 95%CI, 0.13, 0.91; P = .02; I:43.9 %). The R-RR was associated with more lymph nodes harvested compared with L-RR (Mean Difference, MD, 1.24; 95%CI, 0.10, 2.52; P = .03; I:77.3 %). Conversely, Ta-RR was associated with a significantly lower number of lymph nodes harvested compared with all other approaches. SUCRA plots revealed that Ta-RR had the highest probability of being the best approach to achieve a complete mesorectal excision and negative CRM, followed by R-RR, which ranked the best in lymph nodes retrieved.

CONCLUSION

When comparing the effectiveness of the available surgical approaches for rectal cancer resection, Ta-RR and R-RR are associated with better histopathological outcomes than L-RR.