Postoperative C-Reactive Protein-to-Albumin Ratio as a Predictor of 90-Day Morbidity After Hartmann’s Reversal

Abstract Background Hartmann’s reversal is a technically demanding colorectal procedure with substantial postoperative morbidity. The C-reactive protein-to-albumin ratio (CAR) combines inflammatory burden with albumin status and may aid postoperative risk stratification. Methods This retrospective cohort included 86 adults undergoing Hartmann’s reversal with colorectal anastomosis between April 2019 and March 2025. The primary outcome was Clavien-Dindo grade ≥ II morbidity within 90 days. CAR was calculated as postoperative C-reactive protein (mg/L) divided by preoperative albumin (g/dL) and evaluated on postoperative days (POD) 3 and 5. ROC analysis and logistic regression assessed discrimination and association with morbidity. Results Twenty-three patients (26.7%) developed 90-day morbidity. POD5 CAR was higher with morbidity than without morbidity (32.82 [IQR 20.82–50.95] vs 19.98 [12.74–26.32]; p = 0.016); POD3 CAR was not significantly different (p = 0.103). POD5 CAR showed an AUC of 0.715 (95% CI 0.528–0.877). A cutoff of 28.77 yielded 66.7% sensitivity, 76.9% specificity, and 85.7% negative predictive value. Each 10-unit increase in POD5 CAR was associated with higher odds of morbidity (OR 1.65, 95% CI 1.13–2.41; p = 0.009), remaining significant after adjustment for operative time. Conclusions POD5 CAR was associated with 90-day morbidity after Hartmann’s reversal and showed moderate discriminatory ability. External validation is required before clinical implementation.