Comparison of Computed Tomography/Magnetic Resonance Imaging Characteristics of Acute Pancreatitis Between Cholecystectomy and Non-cholecystectomy Patients.

Objective: This study aimed to compare computed tomography (CT)/magnetic resonance imaging (MRI) characteristics of acute pancreatitis (AP) between patients with cholecystectomy and non-cholecystectomy and to validate the effect of prior cholecystectomy on the severity of subsequent pancreatitis.

Methods: This retrospective study included 384 inpatients with AP at our hospital from January 1, 2020 to December 31, 2023. Based on their history of cholecystectomy, the patients were split into cholecystectomy and non-cholecystectomy groups. propensity score matching was applied, considering age and sex, in a 1:3 ratio. Demographic, clinical, laboratory, and CT/MRI parameters of each group were analyzed.

Results: There were 200 (52.1%) males and 184 (47.9%) females, with a mean age of 53.55 ± 13.86 years (range: 18-98 y). Ninety-six patients were in the cholecystectomy group that had previously undergone cholecystectomy, and 288 in the non-cholecystectomy group. Creatinine and C-reactive protein levels were lower in the patients with cholecystectomy than in patients with non-cholecystectomy (P1 = 0.001, P2 = 0.049). In the prevalence of biliary pancreatitis, the cholecystectomy patients are 27.1%, whereas the non-cholecystectomy patients are 45.8% (P = 0.005). The non-cholecystectomy patients had a significantly higher mean CT/MRI severity index score (3.57 ± 1.72 points) than the cholecystectomy group (3.00 ± 1.58 points; P < 0.001). Regarding local complications, In the groups that underwent cholecystectomy and those that did not, the prevalence of acute peripancreatic fluid collection was 40.4% and 21.9%, respectively. (P < 0.001).

Conclusions: AP following cholecystectomy exhibits unique imaging characteristics. Cholecystectomy reduces the severity and acute peripancreatic fluid collection rate of subsequent pancreatitis on CT/MRI.