Low anterior resection syndrome following rectal cancer surgery: are incidence and severity lower with long-term follow-up?

Background: Low anterior resection syndrome (LARS) is a functional disorder that may follow restorative proctectomy. The aim of this study was to evaluate the long-term incidence and risk factors for LARS following surgery for rectal cancer. Methods: A retrospective study was performed on patients from a prospectively maintained database, who underwent a restorative proctectomy between January 2014 and December 2019 at Hadassah Hebrew University Medical Center. The study cohort was divided into two groups: patients following partial proctectomy with a partial mesorectal excision and a colorectal anastomosis (PME group) and patients following total proctectomy with total mesorectal excision and a coloanal anastomosis (TME group). The incidence and severity of LARS were evaluated using the LARS questionnaire. Risk factors for LARS were also evaluated. Results: A total of 240 patients (male: female ratio 134:106, median age 64 years [interquartile range 55–71 years]) were included in the analysis. There were 160 patients in the PME group and 80 patients in the TME group. The overall incidence of LARS was 37.4% (26.5% major LARS and 10.9% minor LARS). Major LARS was observed in 53.8% of patients who underwent TME and in 12.7% of patients who underwent PME (p < 0.001). On multivariate analysis, distance of the anastomosis from the anal verge, TME, and neoadjuvant radiotherapy were independent prognostic factors for LARS. The incidence and severity of LARS were significantly lower in patients with longer follow-up (p = 0.05). Conclusions: Significant improvement in LARS can be expected with longer follow-up. Distance of the anastomosis from the anal verge, TME and neoadjuvant radiotherapy are independent risk factors for LARS.