Management of Walled-Off Necrosis (WON)

Definition and Recognition

Walled-off necrosis is a mature, encapsulated collection of pancreatic and/or peripancreatic necrosis with a well-defined inflammatory wall that develops more than 4 weeks after the onset of necrotizing pancreatitis 2
The American Gastroenterological Association recommends using EUS or MRI to differentiate WON from simple pseudocysts, as the presence of solid debris fundamentally changes management strategy 2
Do not mistake WON for a simple pseudocyst - the internal consistency contains solid necrotic debris requiring more aggressive management than fluid-only pseudocysts 3, 2

Intervene for WON when infected necrosis is confirmed or strongly suspected, or when symptomatic collections cause persistent abdominal pain, gastric outlet obstruction, biliary obstruction, or persistent systemic inflammatory response syndrome 2
The American College of Gastroenterology recommends intervention for WON when there is persistent organ failure without infection after 4 weeks, or when there is progressive enlargement of collections or disconnected pancreatic duct syndrome 2

Delay all interventions for at least 4 weeks after disease onset whenever possible, as early intervention significantly increases mortality 1
The only exceptions for early intervention are abdominal compartment syndrome unresponsive to medical management, acute ongoing bleeding when endovascular approach fails, or bowel ischemia/acute necrotizing cholecystitis 1

The American College of Gastroenterology recommends a step-up approach starting with drainage, followed by minimally invasive debridement only if drainage alone fails 1, 4
Complete debridement of all necrotic material is essential during any intervention 1, 4
The American College of Gastroenterology recommends using broad-spectrum agents with good pancreatic penetration, such as carbapenems, quinolones, or metronidazole, when antibiotics are necessary 3, 1

Do not use prophylactic antibiotics routinely, as they do not prevent infection of sterile necrosis 1
The American College of Gastroenterology recommends using antibiotics when there is confirmed infected necrosis or strong clinical suspicion of infection 3, 2

Initiate early enteral nutrition to decrease the risk of infected necrosis 1
The American Gastroenterological Association recommends starting oral feeding immediately if the patient has no nausea, vomiting, or severe ileus, and using nasogastric or nasojejunal tube feeding if oral feeding is not feasible 1

Manage all patients with extensive WON in an HDU/ICU setting with continuous monitoring of vital signs, oxygen saturation, urine output, and temperature 1
The American College of Critical Care Medicine recommends transferring patients to specialized centers with multidisciplinary teams, including gastroenterology, surgery, interventional radiology, critical care, infectious disease, and nutrition expertise 1