Migration of covered expandable metal stents after endoscopic ultrasound-guided hepaticogastrostomy: stent covering versus stent design?

Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) was first described over 20 years ago.1 Techniques for EUS-HGS have not been standardized. Plastic stents and self-expandable metal stents (SEMS) have been used to form the HGS tract. Japanese guidelines recommend that covered SEMS should be preferred over plastic stents to prevent and minimize bile leakage from the stomach and liver into the peritoneum. However, a major concern when placing a covered SEMS is that the coating prevents the stent from embedding into the surrounding tissue, leading to stent migration. Inward (toward the liver) and outward (toward the stomach) stent migration can occur, both of which can lead to life-threatening events, such as perforation and bile leakage, if migration occurs before a fistula can form between the left intrahepatic ducts and the gastric wall (presumed to occur 2 to 4 weeks after placement).