An 81-year-old man with advanced pancreatic head cancer was admitted to our hospital due to non-occlusion cholangitis. He had previously received a fully covered self-expandable metal stent (SEMS) for malignant biliary obstruction. We inserted a duodenoscope into the duodenum, but failed to visualize the SEMS endoscopically due to type II duodenal obstruction. We also failed to grasp the SEMS under fluoroscopy using a rat tooth forceps or a bendable type biopsy forceps even after balloon dilation of the duodenal stricture. Therefore, we used the zipline technique to guide the biopsy forceps (Radial Jaw 4 pediatric type) to the SEMS (Fig. 1). As a result, the SEMS was successfully grasped and withdrawn into the duodenum (Fig. 2). We subsequently removed the SEMS using a rat tooth forceps under fluoroscopy. Finally, a 6-Fr pig-tail type naso-biliary tube was inserted to the left bile duct to convert to endoscopic ultrasound (EUS)-guided hepaticogastrostomy (Video S1).

The zipline technique. A loop of thread was attached to the biopsy forceps and the guidewire was passed through it to connect the biopsy forceps and the guidewire.

The biopsy forceps was accurately advanced to the biliary self-expandable metal stent and grasped it under fluoroscopy.

Management of combined malignant biliary and duodenal obstruction is challenging especially in cases with type II obstruction.1, 2 Duodenal obstruction often occurs after biliary SEMS placement (Group 1). When the biliary SEMS remains in the bile duct, it could be very difficult to convert to EUS-guided biliary drainage.3, 4 Therefore, it is desirable to remove the biliary SEMS whenever possible. However, it is sometimes difficult to remove the SEMS under direct visualization or fluoroscopy. In such cases, it is necessary to accurately guide the biopsy forceps to the SEMS. The zipline technique is a method to guide the biopsy forceps to the target site along the guidewire, using a looped thread to connect the biopsy forceps and the guidewire.5 This technique was first reported for biliary mapping biopsy. This technique is also useful to remove the biliary SEMS even when the biliary SEMS is not visible endoscopically.

Authors declare no conflict of interest for this article.