Endoscopic Staged Management of Large Pancreatic Walled-Off Necrosis in a Pediatric Patient

Walled-off pancreatic necrosis (WON) is an encapsulated collection that develops as a late sequela of acute necrotizing pancreatitis, typically after four to six weeks. In children, large WON is rare but can be life-threatening due to secondary infection, multiorgan involvement, or compression of adjacent structures. Traditional surgical necrosectomy carries significant morbidity; however, minimally invasive endoscopic ultrasound (EUS)-guided interventions have emerged as a safe and effective alternative. We report a 12-year-old boy with a history of obesity and fatty liver disease who developed severe acute pancreatitis complicated by ascites and pleural effusion. After initial recovery, he presented with persistent abdominal pain and was found to have a large multiloculated pancreatic collection measuring approximately 14 × 14 × 15 cm consistent with walled-off necrosis. EUS-guided cystogastrostomy was performed using a 15 mm lumen-apposing metal stent (LAMS), draining purulent material that cultured <i>Staphylococcus aureus</i> and <i>Streptococcus mitis/oralis</i>. Staged endoscopic therapy included repeated endoscopic necrosectomies, intravenous antibiotics, and total parenteral nutrition. The patient achieved near-complete resolution of the necrotic cavity following two sessions of necrosectomy and subsequent stent removal at six weeks, without surgical intervention. This case highlights the role of the endoscopic staged approach in managing large pediatric WON, demonstrating effective drainage and necrosectomy with low morbidity and excellent clinical recovery.