Arterial calcification burden predicts anastomotic leakage after colorectal cancer surgery: a retrospective cohort study

Anastomotic leakage remains a major source of morbidity after colorectal cancer surgery, despite advances in surgical technique and perioperative care. Impaired tissue perfusion is a key determinant of anastomotic healing, yet preoperative markers of vascular compromise are insufficiently defined. Arterial calcification reflects chronic atherosclerotic burden and may serve as a surrogate marker of compromised perfusion relevant to anastomotic integrity. In this retrospective cohort study, patients who underwent colorectal cancer surgery with primary anastomosis between 2019 and 2025 were evaluated. Preoperative computed tomography was used to assess arterial calcification within perfusion-relevant vascular territories. Calcification severity was represented by an ordinal composite score (0–3). The primary outcome was anastomotic leakage. Univariable and multivariable logistic regression analyses were performed, and ordinal trend and receiver operating characteristic analyses were used to assess the association and discriminative performance. A total of 605 patients were included, and anastomotic leakage occurred in 33 patients (5.45%). Leakage rates increased across ordered calcification categories. After adjustment for age, diabetes mellitus, and hypertension, the composite calcification score remained associated with anastomotic leakage (adjusted OR 1.75 per 1-point increase, 95% CI 1.11–2.75; p = 0.016). Ordinal trend analysis was significant (p for trend = 0.027). The score showed poor standalone discrimination (AUC 0.59), supporting interpretation as an adjunctive rather than standalone risk marker. Preoperative arterial calcification burden was associated with an increased risk of anastomotic leakage after colorectal cancer surgery. Although the composite CT-based calcification score demonstrated poor standalone discriminative performance, it may serve as an exploratory adjunctive marker for perioperative risk stratification. Further prospective and externally validated studies are required before clinical application can be recommended. - Anastomotic leakage occurred in 5.45% of patients after colorectal cancer surgery with primary anastomosis. - Arterial calcification burden, assessed on routine preoperative CT, showed a significant monotonic ordinal trend with leakage risk. - A composite calcification score combining longitudinal extent and circumferential involvement independently predicted anastomotic leakage. - Arterial calcification may serve as a practical preoperative risk stratification marker to support surgical planning.