Predictive Value of the Cally Score in Determining Surgical Strategy for Complicated Left-Sided Colonic Diverticulitis: A Retrospective Cohort Study.

: Complicated left-sided colonic diverticulitis is one of the important causes of hospital admissions and emergency surgery in industrialized societies and requires serious clinical decision-making processes for patient management. This study aims to evaluate the predictive role of albumin-based nutritional indices in deciding on surgical strategy (primary anastomosis vs. Hartmann procedure) in patients treated operatively for complicated left-sided colonic diverticulitis. : This retrospective single-center study included 57 patients who were operatively treated for Hinchey stage III-IV diverticulitis between 2021 and 2024. Patients were divided into two groups according to surgical method: Hartmann procedure (n = 40) and primary anastomosis (n = 17). Prognostic Nutritional Index (PNI), Hemoglobin-Albumin-Lymphocyte-Platelet Score (HALP), CRP-Albumin-Lymphocyte (CALLY) Index, and Modified Glasgow Prognostic Score (mGPS) were evaluated as albumin-based nutritional indices in the preoperative period. Predictive parameters were determined using ROC analysis and multivariate logistic regression. : Albumin level, PNI, HALP, and CALLY scores were found to be significantly lower in the Hartmann procedure group. Additionally, the proportion of patients with mGPS score 2 was significantly higher in the Hartmann procedure group (57.5% vs. 5.9%; < 0.001). In the ROC analysis, the cut-off value for the CALLY index was determined as 0.45 (AUC: 0.826). In multivariate analysis, albumin < 38.5 g/L (OR: 16.53), CALLY index < 0.45 (OR: 6.40), and systemic inflammatory response syndrome (SIRS) detection (OR: 12.98) were determined as independent factors predicting the Hartmann procedure. : A low CALLY index was found to be independent predictors for the Hartmann procedure. The CALLY index, which reflects the inflammatory response, immune capacity and nutritional status, can assist surgeons in making objective, and individualized decisions by holistically evaluating the patient's physiological status. Multicenter prospective studies are required to confirm the clinical validity of the findings.