Usefulness of half‐covered metallic stent placement in preventing acute cholecystitis complication in pancreatic cancer‐induced distal biliary stricture

BACKGROUND AND AIM: A self‐expandable metallic stent (SEMS) is commonly used for biliary stricture caused by pancreatic cancer. Covered SEMS may obstruct the cystic duct, causing acute cholecystitis. This study aimed to determine the outcomes of using a half‐covered SEMS with an offset covered portion for preventing cystic duct obstruction. METHODS: Among 80 patients with half‐covered SEMS placement for the treatment of pancreatic cancer‐induced distal biliary stricture, 74 were followed up. The half‐covered SEMS has a total length of 6 or 7 cm, and the offset covered part was 0.5–4.5 or 0.5–5.5 cm, respectively. Intraductal ultrasonography (IDUS) and endoscopic nasobiliary drainage (ENBD) were performed during the initial endoscopic retrograde cholangiopancreatography (ERCP). IDUS findings and ENBD tube cholangiogram confirmed the cystic duct confluence. SEMS placement was performed on the second ERCP or several weeks after the initial tube stent placement. RESULTS: Half‐covered SEMS placement was successful in all patients. However, four (5.4%) patients exhibited early complications, including acute cholecystitis in one patient and stent displacement in another. Over 30 days, cholangitis, tumor growth, and stent displacement occurred in nine (11.3%), five (6.3%), and two (2.5%) patients, respectively. The median stent patency was 71.1 weeks, and the median overall survival in patients with and without chemotherapy was 31.8 and 12.2 weeks, respectively. CONCLUSIONS: With confirmation of the cystic duct confluence, half‐covered SEMS placement may become a treatment option for distal biliary stricture caused by pancreatic cancer to prevent acute cholecystitis. Half‐covered SEMS patency was comparable with that of covered SEMS.