Preoperative vascular status, left colic artery management, and clinically relevant anastomotic leakage after anterior resection for rectal cancer: a retrospective cohort study

Clinically relevant anastomotic leakage after rectal cancer surgery is multifactorial, and baseline vascular status may contribute to anastomotic perfusion risk. This study evaluated the associations of patient-level vascular comorbidity, preoperative CT/CTA-derived vascular status, and intraoperative left colic artery (LCA) management with clinically relevant anastomotic leakage after anterior resection-based surgery for rectal cancer. This single-center retrospective cohort study included adults who underwent elective anterior resection-based surgery for rectal cancer with primary colorectal or coloanal anastomosis between October 2018 and February 2026. Preoperative contrast-enhanced CT or CT angiography was reviewed for superior and inferior mesenteric artery stenosis and aorto-mesenteric atherosclerotic/calcification burden. An exploratory CT/CTA-derived vascular burden indicator was defined from these imaging features. The primary outcome was clinically relevant anastomotic leakage within 30 days. Associations were evaluated using logistic regression with a prespecified parsimonious model. Among 194 patients, clinically relevant anastomotic leakage occurred in 28 patients (14.4%). Patients with leakage were more often male, had lower albumin levels, and more frequently had diabetes mellitus, vascular comorbidity burden ≥ 2, and low anastomotic level. The exploratory CT/CTA-derived vascular burden indicator was more frequent in patients with leakage than in those without leakage (57.1% vs. 31.3%, P = 0.008). In the multivariable model, the exploratory CT/CTA-derived vascular burden indicator was associated with clinically relevant leakage (adjusted OR = 2.46, 95% CI 1.04–5.81, P = 0.041), as was low anastomotic level (adjusted OR = 2.38, 95% CI 1.03–5.52, P = 0.043). LCA preservation was not independently associated with leakage (adjusted OR = 0.58, 95% CI 0.23–1.48, P = 0.257). In this rectal cancer cohort, an exploratory CT/CTA-derived vascular burden indicator and low anastomotic level were associated with clinically relevant anastomotic leakage, whereas an independent protective association of LCA preservation was not confirmed. Prospective validation is required. Not applicable.