Utility of intra-operative flexible sigmoidoscopy to assess colorectal anastomosis: a systematic review and meta-analysis.

BACKGROUND: Anastomotic leak (AL) after colorectal resection leads to increased oncological and non-oncological, morbidity and mortality. Intra-operative assessment of a colorectal anastomosis with intra-operative flexible sigmoidoscopy (IOFS) has become increasingly prevalent and is an alternative to conventional air leak test. It is thought that intra-operative identification of an AL or anastomotic bleeding (AB) allows for immediate reparative intervention at the time of anastomosis formation itself. We aim to assess the available evidence for the use of IOFS to prevent complications following colorectal resection.

METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, a systematic review of the literature between January 1980 and June 2020 was performed. Comparative studies assessing IOFS versus conventional air leak test were compared, and outcomes were pooled.

RESULTS: A total of 4512 articles were assessed, of which eight were found to meet the inclusion criteria. A total of 1792 patients were compared; 884 in the IOFS arm and 908 in the control arm. IOFS was associated with an increase in the rate of positive leak test (odds ratio (OR) 5.21, P > 0.001), a decrease in AL (OR 0.45, P = 0.006) and a decrease in post-operative AB requiring intervention (OR 0.40, P = 0.037).

CONCLUSION: In a non-randomized meta-analysis, IOFS increases the likelihood of identifying an anastomotic defect or bleeding intra-operatively. This allows for immediate intervention that decreases the rate of AL and AB. This adds impetus for performing routine IOFS after a left-sided colorectal resection with anastomosis and highlights the need for randomized controlled trial to confirm the finding.