Superior anal function in patients undergoing stoma closure within 6 months after LAR and analysis of factors associated with LARS syndrome: insights from experienced surgeons.

The present study aims to evaluate the impact of stoma closure timing on anal function following low anterior resection (LAR) in rectal cancer patients and to investigate the factors associated with the development of low anterior resection syndrome (LARS). There is currently a lack of clarity regarding this issue, necessitating a comprehensive comparison. Between January 2017 and December 2021, a major public medical center consecutively performed LAR with temporary stoma construction for patients with rectal cancer. The primary objective of this study was to investigate the optimal timing of stoma closure following LAR, with a particular focus on its impact on anal function. To achieve this goal, we compared baseline characteristics, short-term postoperative complications, long-term oncological outcomes, as well as 5-year overall survival (OS) rate and disease-free survival (DFS) rate between two groups of patients: the early stoma closure group (stoma closure time < 6 months) and the late stoma closure group (stoma closure time ≥ 6 months). The secondary objective was to explore factors associated with the development of LARS. A total of 323 patients diagnosed with rectal cancer who underwent LAR were included in this cohort study. Based on the ROC cutoff point, patients were divided into two groups: the early stoma closure group (< 6 months, N = 110) and the late stoma closure group (≥ 6 months, N = 199). No significant differences were observed in baseline patient characteristics between the two groups (p > 0.05). In the comparison of short-term postoperative complications, patients with stoma closure time ≥ 6 months had a higher incidence of anastomotic leakage following LAR (0.9% vs. 6.3%, p = 0.029) and a higher rate of neural invasion (5.5% vs. 13.5%, p = 0.03). Regarding long-term oncological functional outcomes, a significantly higher proportion of patients with stoma closure time ≥ 6 months experienced LARS (35.9% vs. 47.7%, p = 0.045). In terms of long-term oncological outcomes, no differences were observed in OS rate and DFS rate between the two groups (p > 0.05). Logistic regression analysis was performed to identify factors associated with LARS, and the results indicated that stoma closure time (OR = 1.27, 95% CI 0.89-1.43, p = 0.042), gender (OR = 0.50, 95% CI 0.31-0.84, p = 0.008), and tumor distance from the anal verge (OR = 0.86, 95% CI 0.75-0.98, p = 0.029) were independent risk factors of LARS occurrence. We have ascertained that the timepoint for optimal stoma closure following LAR is at 5.5 months postoperatively, at which juncture patients attain the most favorable anal function. Therefore, we advocate performing stoma closure surgery within 6 months after LAR. Moreover, this study results demonstrate that the timing of stoma closure, patient gender, and tumor distance from the anal verge are independent risk factors associated with the development of LARS.