# Anastomotic leakage increases the risk of major low anterior resection syndrome 3 years after rectal cancer surgery

## TL;DR

Anastomotic leakage after rectal cancer surgery increases the risk of long-term bowel dysfunction three years later.

## Contribution

This study shows a significant long-term link between anastomotic leakage and major LARS in rectal cancer survivors.

## Key findings

- Anastomotic leakage was associated with a 2.09 times higher risk of major LARS.
- Reintervention after leakage further increased the risk of major LARS.
- Including permanent stoma in the outcome showed a 3.90 times higher risk with leakage.

## Abstract

Anastomotic leakage is a serious complication following anterior resection for rectal cancer and may increase the risk of long‐term bowel dysfunction. This study aimed to assess the long‐term impact of anastomotic leakage on major low anterior resection syndrome (major LARS) at a uniform follow‐up time.

We conducted a nationwide cohort study using the Swedish Colorectal Cancer Registry. Patients who underwent anterior resection for rectal cancer between 2015 and 2017 received the validated LARS questionnaire by mail 3 years after surgery. The primary outcome was major LARS among patients without a permanent stoma. Propensity score weighting was used to adjust for confounding, with covariates chosen using a directed acyclic graph. Sensitivity analyses included a dose–response analysis based on reoperation and an evaluation of a composite outcome of major LARS or permanent stoma.

Of 1778 patients contacted, 1178 responded (66.2%). Among 1033 stoma‐free patients, 52 (5.0%) had experienced a symptomatic anastomotic leak. Major LARS was reported in 69.2% and 52.9% of patients with and without leakage, respectively. Symptomatic anastomotic leakage increased the risk of major LARS (OR 2.09; 95% CI: 1.13–3.87) and this risk was higher in patients requiring reintervention (OR 2.78; 95% CI: 0.87–8.91) and when including permanent stoma in the outcome (OR 3.90; 95% CI: 2.20–6.91).

Anastomotic leakage significantly increased the risk of major LARS 3 years after anterior resection for rectal cancer. These findings underscore the importance of preventing anastomotic leakage to reduce long‐term functional morbidity in patients who survive rectal cancer.