Preoperative C-reactive protein-to-albumin ratio for perioperative risk stratification in penetrating crohn's disease: identification of a candidate rule-out threshold (a propensity score-matched cohort study).

purposeDetermining the optimal timing of surgery for Crohn disease (CD) is challenging. The C-reactive protein-to-albumin ratio (CAR) is inexpensive and widely available; however, its utility in determining surgical timing remains unclear.

methodsWe retrospectively analyzed 112 cases of penetrating-type CD resection (screened 2010-2024). Preoperative CAR was measured within 7 days of surgery. A receiver operating characteristic analysis defined the CAR threshold to maximize the negative predictive value (NPV) for 30-day complications. Patients were categorized as having a low or high CAR and were matched 1:1 using propensity scores. The early morbidity and 5-year re-operation-free survival rates were compared.

resultsA CAR cutoff value of 0.102 yielded the highest NPV. A high CAR was associated with increased overall morbidity (55% vs. 20%) and increased wound infection (21% vs. 5%). After matching (25 pairs), a high CAR was correlated with more complications (52% vs. 24%; P = 0.04) and prolonged stay (median 17 vs. 11 days; P = 0.02). The five-year reoperation risk was higher with a high CAR (14.6% vs. 4.0%; P = 0.03).

conclusionsPreoperative CAR < 0.102 indicates a candidate rule-out threshold for elective CD surgery, predicting fewer early complications and a lower 5-year re-operation rate. Because CAR is rapidly available and treatment-agnostic, serial monitoring could support a testable preoperative timing framework. Further prospective validation is required.