C-Reactive Protein to Albumin Ratio as a Rule Out Predictor For Organ/Space Infections After Ileocolic Resection in Crohn’s Disease

BACKGROUND: Organ/space surgical site infections, including intra-abdominal abscesses and anastomotic leaks, are among the most severe complications after ileocolic resection for Crohn's disease. Biomarker cutoffs validated in oncological colorectal surgery may not translate to Crohn's disease because of modified inflammatory responses due to chronic inflammation and immunosuppressive therapies. OBJECTIVE: To identify early predictors of organ/space surgical site infections after ileocolic resection for Crohn's disease and to evaluate the performance of established biomarkers and specific predictive scores. DESIGN: Single-center retrospective observational study. SETTINGS: Tertiary referral center utilizing enhanced recovery after surgery pathways. PATIENTS: A total of 115 patients with histologically confirmed Crohn's disease. INTERVENTIONS: Ileocolic resection with primary anastomosis between January 2021 and May 2025. MAIN OUTCOME MEASURES: Development of organ/space surgical site infections within 30 days postoperatively, defined according to Centers for Disease Control/National Helathcare Safety Network criteria. RESULTS: Organ/space surgical site infections occurred in 15.7% (18/115) of patients. The C-reactive protein-to-albumin ratio on postoperative day 3 demonstrated excellent diagnostic accuracy (area under the curve = 0.932). At an optimal cutoff of 51.77, C-reactive protein-to-albumin ratio on postoperative day 3 yielded 94.1% sensitivity, 82.1% specificity, and a negative predictive value of 98.6%. C-reactive protein on postoperative day 3 also showed good accuracy (area under the curve = 0.871) with a negative predictive value of 97.1%. Procalcitonin and leucocyte-based indices showed poor-to-limited discrimination. LIMITATIONS: Retrospective, monocentric design without external validation. CONCLUSIONS: In Crohn's disease surgery, C-reactive protein-to-albumin ratio on postoperative Day 3 is a strong early predictor of organ/space surgical site infections. Together with C-reactive protein, its exceptionally high negative predictive value provides high "rule out" utility, supporting postoperative surveillance and safe discharge pathways. (See Video Abstract).