Clinical Impact of Staple-Line Oversewing in Totally Mechanical Collard Cervical Anastomosis for Esophageal Cancer

Background: Cervical esophagogastric anastomosis using a gastric conduit is commonly performed after esophagectomy for esophageal cancer, but anastomotic leakage remains a major postoperative complication. Totally mechanical Collard (TMC) anastomosis provides favorable stricture outcomes; however, leakage rates remain variable. The clinical benefit of staple-line oversewing in TMC anastomosis has not been fully clarified. Methods: This retrospective cohort study included consecutive patients who underwent esophagectomy with TMC cervical anastomosis between January 2017 and December 2024. Patients were divided into oversewing and non-oversewing groups according to whether staple-line oversewing was performed. The primary endpoint was anastomotic leakage. Secondary endpoints included leakage severity, timing of leakage onset, healing duration, anastomotic stricture, and postoperative complications. Multivariable logistic regression analysis was used to identify independent risk factors for leakage. Results: A total of 803 patients were included (oversewing: n = 313; non-oversewing: n = 490). Baseline characteristics were well balanced between the two groups. The incidence of anastomotic leakage was significantly lower in the oversewing group than in the non-oversewing group (4.4% vs. 8.1%, p = 0.043). Leakage severity was also reduced, with Grade I leakage occurring more frequently in the oversewing group (78.5% vs. 30%, p = 0.004). Leakage occurred later in the oversewing group (12.7 ± 7.6 vs. 8.9 ± 4.2 days, p = 0.01), whereas healing duration was comparable between groups. The incidence of anastomotic stricture did not differ significantly between the two groups (3.5% vs. 5.3%, p = 0.3). Multivariable analysis identified body mass index ≥25 kg/m2 (OR 2.37, 95% CI 1.08–4.93, p = 0.03) and the absence of staple-line oversewing (OR 2.15, 95% CI 1.03–4.82, p = 0.04) as independent risk factors for leakage. Conclusions: Staple-line oversewing of TMC cervical anastomosis was associated with a reduced incidence and milder severity of anastomotic leakage without increasing anastomotic stricture. This simple and reproducible technique may improve anastomotic stability after esophagectomy for esophageal cancer.