What is the recommended treatment for walled-off pancreatic necrosis?

Treatment of Walled-Off Pancreatic Necrosis

The recommended treatment for walled-off pancreatic necrosis (WON) is a step-up approach starting with endoscopic transluminal drainage using lumen-apposing metal stents, followed by endoscopic necrosectomy if necessary, with surgical intervention reserved only for cases that fail minimally invasive approaches. 1, 2

Initial Assessment and Management

• WON typically develops in the late phase of necrotizing pancreatitis (usually 4+ weeks after onset)
• Initial management should include:
  • Intensive monitoring of vital signs in severe cases requiring ICU/HDU care 3
  • Early enteral nutrition to decrease risk of infected necrosis 3, 1
  • Targeted antibiotic therapy only for culture-proven infection or strong suspicion of infection 1
  • Avoidance of prophylactic antibiotics for sterile necrosis 1, 4

Indications for Intervention

Drainage and/or debridement of WON is indicated in:

1. Infected necrosis (primary indication)
2. Symptomatic sterile necrosis with:
   • Persistent abdominal pain
   • Nausea and vomiting
   • Nutritional failure
   • Associated complications (GI obstruction, biliary obstruction, fistulas) 1

Step-Up Approach for WON

Timing of Intervention

• Critical timing consideration: Debridement should be delayed for approximately 4 weeks to allow for proper "walling-off" of the necrosis 1, 5
• Early intervention (<2 weeks) is associated with increased morbidity and mortality 1

First-Line Treatment

1. Endoscopic transluminal drainage:

   • Preferred first-line approach for accessible WON 1, 2
   • Lumen-apposing metal stents (LAMS) are superior to plastic stents 1
   • Early removal of LAMS at 3 weeks post-intervention if WON is resolved 2

2. Percutaneous catheter drainage alternatives:

   • For patients too ill for endoscopic intervention
   • When WON is inaccessible endoscopically
   • As adjunct to endoscopic drainage for WON extending into paracolic gutters/pelvis 1
   • Note: Percutaneous approach carries risk of pancreaticocutaneous fistula formation 2, 1

Second-Line Treatment

If inadequate response to drainage alone:

1. Direct endoscopic necrosectomy:

   • Reserved for patients who don't respond to transluminal drainage 1
   • Particularly effective for limited necrosis or large amounts of infected necrosis
   • Should be performed at referral centers with necessary expertise 1

2. Minimally invasive surgical approaches:

   • Videoscopic-assisted retroperitoneal debridement
   • Laparoscopic transgastric debridement
   • Open transgastric debridement 1

Third-Line Treatment

• Open surgical necrosectomy:
  • Reserved for cases not amenable to less invasive procedures
  • Associated with higher morbidity and mortality 1, 5
  • Only 4% of patients typically require this approach 6

Outcomes and Complications

• Success rates with endoscopic approaches range from 83.9-92.9% 7
• Procedure-related complications occur in approximately 13-26% of cases 6, 7
• Mortality rates with modern step-up approaches are approximately 4-7% 6
• Recurrence of pancreatic fluid collections occurs in about 19.6% of patients 7

Special Considerations

• Multidisciplinary approach involving gastroenterologists, surgeons, interventional radiologists, and critical care specialists is essential 1
• Patients with significant pancreatic necrosis should be considered for transfer to tertiary-care centers with appropriate expertise 1
• For disconnected left pancreatic remnant after mid-body necrosis, definitive surgical management with distal pancreatectomy should be considered in appropriate candidates 1

Common Pitfalls to Avoid

• Intervening too early (<2-4 weeks) before adequate "walling-off" occurs
• Mistaking WON for a simple pseudocyst (internal consistency best determined by EUS or MRI) 4
• Using prophylactic antibiotics for sterile necrosis
• Delaying enteral nutrition
• Failing to recognize when to escalate care to a tertiary center with appropriate expertise