Surgical site infection after colorectal surgery in a tertiary level cancer center: risk factors, clinical characteristics, and mortality.

Background: Surgical site infections (SSIs) are a common complication in colorectal surgery. In colorectal cancer (CRC), SSIs increase recurrence and mortality. This study aimed to describe the frequency, risk factors, and mortality of patients with SSIs at a cancer center.

Methods: An observational, retrospective study was conducted from 2018 to 2022, including patients with CRC who underwent elective colorectal surgery. Risk factors for SSI were assessed using multivariable logistic regression analysis. A five-year survival analysis was performed using the Kaplan-Meier curves, and hazard ratios were calculated using the Cox proportional hazards method.

Results: We included 712 patients; SSI occurred in 28%. Risk factors included preoperative hemoglobin ≤8.5 g/dL (OR 3.21, p=0.04) and intraoperative mean arterial blood pressure <65 mmHg (OR 5.12, p<0.001). Adequate perioperative antimicrobial prophylaxis (PAP) reduced the SSI risk (OR 0.53, p=0.04). Increased mortality was associated with surgical diversion (HR 2.54, p<0.001), hospital-acquired pneumonia (HR 4.02, p<0.001), and septic shock (HR 14.21, p<0.001). Overall 5-year survival was lower in SSI patients (70% versus 82%; log-rank, p=0.021).

Conclusions: SSIs in CRC were higher compared to other series. Preoperative anemia and intraoperative low perfusion rates were strong predictors of SSI development. An adequate PAP significantly reduced SSIs. Patients with SSIs experienced higher mortality rates.