Risk factors and treatment strategies for cholecystitis after metallic stent placement due to malignant biliary obstruction: a multicenter retrospective study

Cholecystitis can occur after self-expandable metallic stent (SEMS) placement for malignant biliary obstructions (MBO). Furthermore, the best treatment option for cholecystitis has not been determined. Here, we aimed to identify the risk factors of cholecystitis after SEMS placement and determine the best treatment option.Incidence, treatments, and predictive factors of cholecystitis were retrospectively evaluated in 1,084 patients with distal MBO (DMBO) and 353 patients with hilar MBO (HMBO) who underwent SEMS placement at the 12 institutions from January 2012 to March 2021.Cholecystitis occurred in 7.5% of patients with DMBO and 5.9% of patients with HMBO. The recurrence rate was significantly lower (p=0.043), and the recurrence-free period was significantly longer (p=0.039) in endoscopic procedures than in percutaneous procedures for cholecystitis treatment. Endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) was better in terms of technical success, procedure time, and recurrence-free period than endoscopic transpapillary gallbladder drainage. The cases with obstruction across the cystic duct orifice by tumor (p=0.015) and those with obstruction by stent (p=0.037) were the independent risk factors for cholecystitis in DMBO. The cases with multiple SEMS placements (OR 11, 95% CI 0.68-190, p=0.091) and those with gallbladder stones (OR 2.3, 95% CI 0.92-5.6, p=0.075) had a higher risk for cholecystitis in HMBO.The incidences of cholecystitis after SEMS placement for DMBO and HMBO were comparable. EUS-GBD is the optimal treatment option for patients with cholecystitis after SEMS placement for MBO.