Comparative Early Postoperative Outcomes in Acute Calculous vs. Acute Acalculous Cholecystitis: A Retrospective Analysis

Background and Objectives: Acute cholecystitis is a common indication for emergency surgery. While acute calculous cholecystitis (ACC) is most common, acute acalculous cholecystitis (AAC) occurs without gallstones and is often associated with severe systemic illness. We compared early postoperative outcomes after cholecystectomy for AAC versus ACC, with emphasis on complication severity and overall morbidity burden. Materials and Methods: We performed a single-center retrospective cohort study of consecutive adults undergoing urgent or emergent cholecystectomy for acute cholecystitis between December 2020 and April 2025. Patients with chronic cholecystitis, duplicate records, missing group assignment, or incomplete 30-day follow-up were excluded. The primary 30-day endpoints were postoperative complications, their severity (assessed with Clavien–Dindo scale), and cumulative morbidity assessed using the Comprehensive Complication Index. Secondary outcomes included operative approach, postoperative length of stay, 30-day readmission, and mortality. Results: A total of 221 patients were analyzed (181 ACC, 40 AAC). Patients with AAC were older and more frequently male. Any complication within 30 days occurred substantially more often in AAC patients than in ACC patients. Morbidity severity also differed markedly, with higher-grade complications occurring more frequently in the AAC group. AAC patients exhibited a substantially greater overall morbidity burden, indicating not only more frequent complications but also a heavier cumulative impact. Thirty-day mortality was considerably higher in AAC. Open surgery was more commonly required in AAC, whereas postoperative length of stay and 30-day readmission rates were similar between groups. Conclusions: In this cohort, AAC was associated with substantially worse early outcomes after cholecystectomy than ACC, characterized by a pronounced increase in clinically significant complications (Clavien–Dindo ≥ IIIa), greater cumulative morbidity (CCI), and markedly higher 30-day mortality. These findings support treating AAC as a high-risk phenotype warranting intensified perioperative optimization and vigilant postoperative monitoring.