Anastomotic Leakage in Relation to Type of Mesorectal Excision and Defunctioning Stoma Use in Anterior Resection for Rectal Cancer

BACKGROUND: Anastomotic leakage after anterior resection for rectal cancer is more common after total compared to partial mesorectal excision but might be mitigated by a defunctioning stoma. OBJECTIVE: The aim is to assess how anastomotic leakage is affected by type of mesorectal excision and defunctioning stoma use. DESIGN: This is a retrospective multicenter cohort study evaluating anastomotic leakage after anterior resection. Multivariable Cox regression with hazard ratios and 95% confidence intervals was employed to contrast mesorectal excision types and defunctioning stoma use with respect to anastomotic leakage, with adjustment for confounding. SETTINGS: This multicenter study included patients from 11 Swedish hospitals between 2014 and 2018. PATIENTS: Patients who underwent anterior resection for rectal cancer were included. MAIN OUTCOMES MEASURES: Anastomotic leakage rates within and after 30 days of surgery are described up to one year after surgery. RESULTS: Anastomotic leakage occurred in 24.2% and 9.0% of 1126 patients operated with total and partial mesorectal excision, respectively. Partial compared to total mesorectal excision was associated with a reduction in leakage, with an adjusted HR of 0.46 (95% CI: 0.29-0.74). Early leak rates within 30 days were 14.9% with and 12.5% without a stoma, while late leak rates after 30 days were 7.5% with and 1.9% without a stoma. After adjustment, defunctioning stoma was associated with a lower early leak rate (HR 0.47; 95% CI: 0.28-0.77). However, the late leak rate was non-significantly higher in defunctioned patients (HR 1.69; 95% CI: 0.59-4.85). LIMITATIONS: This study was limited by its retrospective observational study design. CONCLUSIONS: Anastomotic leakage is common up to one year after anterior resection for rectal cancer, where partial mesorectal excision is associated with a lower leak rate. Defunctioning stomas seem to decrease the occurrence of leakage, though partially by only delaying the diagnosis