Postoperative infectious complications are associated with diminished overall survival of patients undergoing resection for colorectal liver metastases.

Introduction: Postoperative infectious complications (PIC) remain one of the most common complications after surgery. The influence of PIC on long-term survival for patients after liver surgery for colorectal liver metastases (CRLM) needs further investigation.

Methods: Data of patients who underwent liver resection for CRLM between 2012 and 2017 at the Department of Surgery, Campus Charité Mitte and Campus Virchow-Klinikum, Charité - Universitätsmedizin Berlin were evaluated. Overall survival (OS) was stratified according to the development of PIC. Independent predictors of PIC and diminished survival were identified using regression models.

Results: Of 270 patients, eighty-four (31%) patients developed PIC including intraabdominal infections (n = 51, 61%), cholangitis (n = 5, 6%), pneumonia (n = 12, 14%), wound infections (n = 28, 33%), urinary tract infections (n = 5, 6%), or central line-associated bloodstream infections (n = 4, 5%). PIC were associated with a significantly diminished five-year OS (30% vs. 43%, p = 0.008). Age >65 years (p = 0.016, hazard ratio [HR] = 2.2, 95% confidence interval [CI] = 1.2-4.0), comorbidity (p = 0.019, HR [95% CI] = 2.4 [1.2-4.9]), simultaneous resection of primary tumor (p = 0.005, HR [95% CI] = 4.3 [1.6-11.9]), biliary drainage (p < 0.001, HR [95% CI] = 4.1 [2.0-8.5]), and length of procedure ≥272 min (p = 0.012, HR [95% CI] = 2.2 [1.2-4.1]) were independent predictors for the development of PIC. Body-mass index (BMI) > 30 kg/m (p = 0.002, HR [95% CI] = 2.4 [1.4-4.0]), postoperative major complications (p = 0.003, HR [95% CI] = 2.2 [1.3-3.8]), and 3- or 4-MRGN bacteria (p = 0.001, HR [95% CI] = 7.7 [2.2-27.3]) were independently associated with diminished OS.

Conclusions: PIC are associated with diminished OS after resection for CRLM. Age >65 years, comorbidities, simultaneous resection of the primary tumor, and biliary drainages were identified as independent risk factors for the development of PIC. High BMI, postoperative major morbidity and 3-/4-MRGN bacteria were independently predictive of worse OS. These factors need to be considered in perioperative management for patients with CRLM.