Multiple hidden vessels in walled-off necrosis with high-risk bleeding: Report of two cases.

Background: Walled-off necrosis (WON), as a local complication of acute necrotizing pancreatitis, is difficult to differentiate from pancreatic pseudocysts (PPC). Imaging modalities such as computed tomography show a lower accuracy than endoscopic ultrasound (EUS) in confirming the diagnosis. EUS-guided cystogastrostomy following direct endoscopic necrosectomy has achieved excellent results and has been regarded as a preferred alternative to traditional surgery. However, high-risk bleeding is one of the greatest concerns.

Case Summary: Two patients with symptomatic pancreatic fluid collections (PFCs) were admitted to our hospital for EUS-guided lumen-apposing metal stent therapy. The female patient suffered from intermittent abdominal pain and underwent two perioperative CT examinations. The male patient had recurrent pancreatitis and showed a growing PFC. The initial diagnosis was a PPC according to contrast-enhanced CT. However, the evidence of solid contents on EUS prompted revision of the diagnosis to WON. An endoscope was inserted into the cavity, and some necrotic debris and multiple hidden vascular structures were observed. Owing to conservative treatment by irrigation with sterile water instead of direct necrosectomy, we successfully avoided damaging hidden vessels and reduced the risk of intraoperative bleeding.

Conclusion: The application of EUS is helpful for the identification of PFCs. Careful intervention should be conducted for WON with multiple vessels to prevent bleeding.