Surgical Site Infections in Simultaneous Colorectal and Liver Resections for Metastatic Colorectal Adenocarcinoma.

Background: Surgical site infections (SSIs) are a major driver of morbidity after combined liver and colorectal surgery for metastatic colorectal cancer. Available literature is inadequate to characterize risk factors and benchmarks for quality improvement.

Methods: Consecutive cases of simultaneous liver and colorectal surgery for colorectal adenocarcinoma from November 2013 through September 2022 were reviewed for SSIs per National Surgical Quality Improvement Program (NSQIP) and National Healthcare Safety Network (NHSN) criteria. Univariable and multivariable logistic regression evaluated associations with NSQIP 30-day organ-space SSIs.

Results: In 580 procedures, the rate of 30-day organ-space SSIs was 16% (n = 94) using NSQIP criteria and 11% (n = 64) using NHSN criteria; 4% (n = 24) had incisional SSIs by both criteria. Most organ-space SSIs were perihepatic, and a minority were associated with bile (26%) or anastomotic (15%) leak. Independent risk factors for organ-space SSIs included major liver resection, upper abdominal (compared with lower abdominal/pelvic) colorectal procedure, and ostomy reversal. Organ-space SSI rates increased over time by approximately 16% per calendar year (p = 0.02) despite a declining rate of major liver resection; incisional SSI rates remained low. Overall, major morbidity was 22%, with 7-day median length of stay (interquartile range 6-9) and 0.3% 90-day mortality.

Conclusion: Organ-space SSIs are a significant driver of postoperative morbidity in simultaneous liver and colorectal resections for metastatic colorectal adenocarcinoma. Our findings confirm simultaneous resection remains safe and interventions to mitigate the risk of perihepatic organ-space SSIs in high-risk patients are warranted.