The buried stent: a rare complication of endoscopic ultrasound-guided pancreatic necrosectomy using a lumen-apposing metal stent

A 51-year-old man was referred to our facility for endoscopic ultrasound-guided drainage of walled-off pancreatic necrosis. The cyst was first punctured with a 19-gauge needle ([Fig. 1]). A NAGI stent (Taewoong Medical, Seoul, South Korea) was then deployed under ultrasonographic and fluoroscopic guidance without difficulty ([Fig. 2], [Video 1]). A computed tomography (CT) scan 6 weeks later revealed significant reduction in the cyst size with residual necrotic debris. Upper endoscopy showed an orifice in the middle of a small bulge of gastric mucosa and the stent could not be seen. The cystogastrostomy tract was cannulated and dilated with a 15-mm pneumatic balloon ([Fig. 3]). The extremity of the lumen-apposing metal stent (LAMS) embedded in the gastric wall was identified, and the stent was removed using rat-tooth forceps ([Fig. 4]). The endoscope was then passed into the cyst cavity and the residual necrotic debris was irrigated and removed with a snare. A follow-up CT scan after 3 months revealed an almost totally collapsed cyst cavity, consistent with drainage of the collection.

Fig. 1 Endoscopic ultrasound-guided drainage of walled-off pancreatic necrosis in a 51-year-old man: a large, thick-walled pancreatic fluid collection about 15 × 13 cm in size with necrotic debris was punctured with a 19-gauge needle.

Fig. 2 Endoscopic ultrasound-guided pancreatic necrosectomy: NAGI stent after successful deployment.

Video 1: Endoscopic ultrasound-guided pancreatic necrosectomy using a lumen-apposing metal stent, with the rare complication of a “buried” stent.

Fig. 3 The lumen-apposing metal stent cannot be seen. The cystogastrostomy tract is cannulated and dilated with a 15-mm pneumatic balloon.

Fig. 4 Cystogastrostomy tract after removal of the stent with rat-tooth forceps.

Plastic stents were conventionally used for the drainage of pancreatic fluid collections, and although their pigtail feature decreases the risk of migration, premature occlusion usually occurs [1]. Metal stents provide larger diameter lumens for better drainage, but their tubular feature increases the risk of migration [2]. The LAMS attempts to overcome these technical challenges with a “dumbbell” configuration to avoid stent migration and a large diameter allowing necrosectomy in repeated sessions [3]. Fabbri et al. were the first to describe a rare adverse event for the use of the LAMS that resembled the “buried bumper” associated with complicated percutaneous endoscopic gastrostomy, which they called the “buried stent” [4]. The buried stent appears to be a potential problem associated with use of the LAMS. To the best of our knowledge, this is the second reported case of a buried stent and the first reported case of endoscopic ultrasound-guided pancreatic necrosectomy in Egypt.

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• References

• 1 Singhal S, Rotman SR, Gaidhane M. et al. Pancreatic fluid collection drainage by endoscopic ultrasound: an update. Clin Endosc 2013; 46: 506-514
• 2 Walter D, Vleggaar F, Siersema P. Self-expandable metal stents for endoscopic ultrasound-guided drainage of peripancreatic fluid collections. Gastrointest Interv 2013; 2: 24-29
• 3 Yamamoto N, Isayama H, Kawakami H. et al. Preliminary report on a new, fully covered, metal stent designed for the treatment of pancreatic fluid collections. Gastrointest Endosc 2013; 77: 809-814
• 4 Fabbri C, Luigiano C, Marsico M. et al. A rare adverse event resulting from the use of a lumen apposing metal stent for drainage of a pancreatic fluid collection: “the buried stent”. Gastrointest Endosc 2015; 83: 585-587