eP461 - Unveiling Hidden Threats:Precise Localization of Anastomotic Leakage in Low Anterior Resection with Double-Stapled Anastomosis and the Impact of Prospective Management

Purpose/Background: Anastomotic leakage (AL) is a severe complication following low anterior resection (LAR) for the treatment of rectal cancer. However, identifying predisposing factors for AL can be challenging, particularly when masked by protective stomas, which often lack symptoms and offer limited site-specific data. In this study, we systematically investigated risk factors associated with AL and precisely identified the leak sites through routine checkups following LAR. Furthermore, we evaluated the effectiveness of our institutional postoperative management strategy in protecting anastomosis.Methods/Interventions: We prospectively collected clinical characteristics, detailed operative findings related to anastomosis, and perioperative outcomes in patients scheduled for LAR. Institutional recommendations for postoperative anastomosis protection were tailored to the presence of specific risk factors, including male, preoperative chemoradiotherapy, lower location of anastomosis, and the use of ≥ 3 linear staplers. For patients with 0 risk factors, no treatment was advised; for those with 1 or 2 risk factors, a rectal tube was recommended; and for those with ≥ 3 risk factors, a protective stoma was considered. Anastomosis checks on postoperative day 5 involved digital rectal examination, sigmoidoscopy, or loopogram.Results/Outcomes: Of 150 patients who underwent LAR with double-stapled anastomosis (DST), AL occurred in 12 patients (8.0%), including 10 clinical and two subclinical cases. Nine of 92 patients with 1 or 2 risk factors and three of 54 patients with ≥ 3 risk factors developed AL. A rectal tube was placed in 52 patients, and a protective stoma was created for 62 patients (41.3%), including 60 (96.8%) having ≥ 2 risk factors. Ninety-one patients (61.0%) received the planned treatment following the institutional strategy. Vertical transection of the linear stapler showed a higher AL incidence (18.2%) compared to a horizontal approach (6.7%). In most patients, the ‘dog ear’ was the main part of the leak site, except for two patients having rectovaginal fistula and proximal colon ischemia. The univariate analysis highlighted a notably higher incidence of younger age and preoperative chemotherapy in the AL group.Conclusion/

Discussion: This prospective study highlights that ‘dog ears’ predominantly serve as the main site of AL in most patients. Although our institutional postoperative management strategy effectively reduces predisposing risk factors through interventions such as rectal tubes and protective stomas, this study underscores the significant influence of younger age and preoperative chemotherapy on postoperative management. Further prospective treatment strategies supplementing these two factors might be recommended for patients with ≥ 2 risk factors following LAR with DST.Figure 1. Institutional postoperative management strategy and comprehensive assessment of anastomotic leakFigure 1. A. Institutional postoperative management strategy B. Actual practice for protecting anastomosis C. Anastomotic leak site