Biliary stent migration: why, how, and what?

Background and purpose The frequency, risk factors as well as the sites of biliary stent migration are variable in the literature. This retrospective study investigated the frequency of biliary stent migration, why biliary stents migrated, how the migrated stents affected the patients, and what are the different techniques retrieved the migrated stents. Patients and methods Out of 876 stented patients, 74 patients (8.4%) had their stents migrated. Patients with and without migrated stents were compared regarding endoscopy and stent-related parameters. The sequels of stent migrations were reported. Furthermore, the methods used for stent retrieval were reviewed. Results Proximal and distal stent migration occurred at a rate of 3 and 5.5%, respectively. The independent predictors for stent migration were moderate to marked common bile duct (CBD) dilation, complete sphincterotomy, the use of balloon dilation, and stent insertion for more than 1 month. Cholangitis and stent obstruction was the most commonly reported adverse event ( n = 18, 24.3%). Distal stent migration associated with two cases of bleeding due to duodenal wall injury, and two cases of duodenal perforation. All the retained migrated stents in the current study were retrieved by endoscopy using extraction balloon, Dormia basket, snares, and foreign body forceps. Conclusion Biliary stent migration occurs at a rate of 8.4%. Stents do migrate because of dilated CBD, wide sphincterotomy, and biliary balloon dilation. Furthermore, wide, straight stents inserted for more than 1 month easily migrate. The migrated stents migrated intraluminal in the CBD, duodenum or the colon. All the retained migrated stents were retrieved endoscopically.