Phew, It Finally Came Out!! Successful Endoscopic Retrieval of a Buried Lumen-Apposing Metal Stent After Drainage of a Large Pancreatic Fluid Collection

Abstract

Plastic stents, covered metal stents, and, lumen-apposing metal stents (LAMSs) are commonly used for EUS-guided drainage of pancreatic fluid collections (PFCs). Resolution of PFCs is gratifying but adverse events sometimes mar the exuberant success of the procedure. A 55-year-old veteran with history of alcoholic pancreatitis presented with a 17cm symptomatic PFC. He underwent EUS-guided drainage with placement of a 15-mm LAMS (Axios®; Boston Scientific, Natick, MA) (Fig. 1). CT at 2 weeks noted resolution of the PFC. At endoscopy to remove the LAMS, the gastric flange of the stent was not visualized. A bulge was noted at site of prior stent placement. On subsequent EUS, the intracystic flange was in place. Under fluoroscopy, cannulation of the previous stent site was attempted, however guidewire passage was not possible. Using a needle-knife, mucosal incisions were made over the gastric mucosal bulge to expose the stent however stent could not be visualized (Fig. 2). Repeat EGD 4 weeks later noted a small opening at the site of prior stent placement. The opening was dilated using 10 mm biliary balloon over guidewire under fluoroscopy. Then a TTS balloon (12-13.5-15 mm) was used to dilate the area further. The gastric flange of the LAMS was visualized after these dilations. The proximal end of the stent was caught with a rat-tooth forceps and stent was successfully removed (Fig. 3). Post-procedure hemostasis was verified.2142_A Figure 1. CT with pancreatic fluid collection and buried stent2142_B Figure 2. Mucosal bulge with buried stent and post needle-knife2142_C Figure 3. Post dilation and stent retrievalThe potential adverse events that can occur when using LAMSs are occlusion, contact ulceration, hemorrhage and stent migration. PFC drainage with covered metal stents has previously resulted in an adverse event that resembled the “buried bumper” associated with complicated PEG. To prevent such complications, LAMSs were developed consisting of a dumbbell shaped design. There exist very few prior case reports about buried stents with successful endoscopic retrieval. To the best of our knowledge, this is the first case of a “buried stent” resulting from PFC drainage with a LAMS treated with a two-stage retrieval process with needle knife followed by successive dilation. A preventive measure to consider involves placement of 1 or more pigtail stents through the LAMS to maintain stent position. Placement of more than one LAMS for large PFCs may be considered. Finally, it bears exploration if revision of the stent design, such as by increasing the size of the flange, would decrease the risk of similar adverse events.