Pericholecystic Fat Stranding as a Predictive Factor of Length of Stays of Patients with Acute Cholecystitis: A Novel Scoring Model

<b>Background:</b> The 2018 Tokyo Guidelines (TG18) are used to classify the severity of acute cholecystitis (AC) but insufficient to predict the length of hospital stay (LOS). <b>Methods:</b> For patients with AC, clinical factors and computed tomography features, including our proposed grading system of pericholecystic fat stranding were used for predicting an LOS of ≥7 days in the logistic regression models. <b>Results:</b> Our multivariable model showed age ≥ 65 years (OR: 2.56, <i>p</i> < 0.001), C-reactive protein (CRP) ≥ 2 mg/dL (OR: 1.97, <i>p</i> = 0.013), gamma-glutamyltransferase levels (OR: 2.460, <i>p</i> = 0.001), TG18 grade (OR: 2.89 per grade, <i>p</i> < 0.001), and moderate to severe pericholecystic fat stranding (OR: 2.14, <i>p</i> = 0.012) exhibited prolonged LOS ≥ 7 days. <b>Conclusions:</b> We developed a scoring model, including TG18 grades (score of 1-3 per grade), our grading system of fat stranding (score of 1), CRP (score of 1), and gamma-glutamyltransferase (score of 1), and a cutoff of >3 had highest diagnostic performance.