Operative Time as a Universal Risk Factor for Infectious Complications after Colorectal Cancer Surgery: A Multicenter Stratified Analysis by Surgical Site.

Objectives: Postoperative infectious complications in colorectal cancer prolong hospital stays and increase the risk of recurrence. Given that risk factors may vary depending on the surgical procedure-namely, right-sided colon, left-sided colon, and rectal cancer-we aimed to identify both common and procedure-specific risk factors．. Methods: This retrospective multicenter study included 2,636 patients who underwent elective colorectal cancer surgery between April 2015 and March 2023 at three affiliated institutions. The primary endpoint was the incidence of Clavien-Dindo grade ≥2 infectious complications by surgical site. Multivariate logistic regression analyses were performed to identify common and procedure-specific risk factors across the three anatomical groups．. Results: Infectious complications occurred in 18.5% of patients. The incidence significantly differed by surgical site: 11.7% in right-sided colon, 14.6% in left-sided colon, and 22.0% in rectal cancer (P < 0.001). Operative time was the only risk factor common to all procedures. Right-sided colon cancer was associated with additional risks including advanced age, low BMI, male sex, and open surgery. Rectal cancer, in contrast, showed younger age and male sex as contributing factors. Both male sex and higher BMI correlated significantly with longer operative times in all groups．. Conclusions: Prolonged operative time appears to be a consistent and independent risk factor for postoperative infectious complications across various colorectal cancer procedures. In contrast, other factors such as age, body mass index, sex, and surgical approach showed associations that varied depending on the type of procedure．.