LAUSR

Objective: We aimed to better understand the longitudinal course of low anterior resection syndrome (LARS) to guide patient expectations and identify those at risk of persisting dysfunction. Summary Background Data: LARS describes disordered bowel function after rectal resection that significantly impacts quality of life. Methods: MEDLINE, EMBASE, CENTRAL, and CINAHL databases were systematically searched for studies that enrolled adults undergoing anterior resection for rectal cancer and used the LARS score to assess bowel function at ≥2 postoperative time points. Regression analyses were performed on deidentified patient-level data to identify predictors of change in LARS score from baseline (3–6months) to 12-months and 18–24 months. Results: Eight studies with a total of 701 eligible patients were included. The mean LARS score improved over time, from 29.4 (95% confidence interval 28.6–30.1) at baseline to 16.6 at 36 months (95% confidence interval 14.2%–18.9%). On multivariable analysis, a greater improvement in mean LARS score between baseline and 12 months was associated with no ileostomy formation [mean difference (MD) –1.7 vs 1.7, P < 0.001], and presence of LARS (major vs minor vs no LARS) at baseline (MD –3.8 vs –1.7 vs 5.4, P < 0.001). Greater improvement in mean LARS score between baseline and 18–24 months was associated with partial mesorectal excision vs total mesorectal excision (MD–8.6 vs 1.5, P < 0.001) and presence of LARS (major vs minor vs no LARS) at baseline (MD –8.8 vs –5.3 vs 3.4, P < 0.001). Conclusions: LARS improves by 18 months postoperatively then remains stable for up to 3 years. Total mesorectal excision, neoadjuvant radiotherapy, and ileostomy formation negatively impact upon bowel function recovery.