What are the management options for local complications of acute pancreatitis?

Management of Local Complications of Acute Pancreatitis

Local complications of acute pancreatitis should be managed based on their type, with intervention reserved only for symptomatic or infected collections, while asymptomatic collections should be observed as more than half resolve spontaneously. 1

Types of Local Complications

• Acute fluid collections occur in 30-50% of severe pancreatitis cases and are characterized by lack of a defined wall 1
• Pancreatic necrosis (sterile or infected) involves non-viable pancreatic tissue often with peripancreatic fat necrosis 1
• Acute pseudocysts are collections of pancreatic juice enclosed by fibrous tissue that form at least 4 weeks after onset of pancreatitis 1
• Pancreatic abscess is a circumscribed collection of pus with little or no pancreatic necrosis 1
• Walled-off necrosis (WON) is a mature, encapsulated collection of pancreatic and/or peripancreatic necrosis 2

Diagnostic Approach

• Dynamic CT scanning should be performed on all patients with severe acute pancreatitis between 3-10 days after admission 1
• Follow-up CT scans are recommended only if the patient's clinical status deteriorates or fails to improve 1
• Some experts recommend a single follow-up scan before discharge in patients with apparently uncomplicated recovery to detect asymptomatic complications like pseudocyst or arterial pseudoaneurysm 1
• MRI offers an alternative imaging technique that avoids cumulative radiation exposure 1

Management of Acute Fluid Collections

• More than 50% of acute fluid collections resolve spontaneously and do not require treatment in stable patients 1
• Indications for percutaneous aspiration include:
  • Suspected infection
  • Symptomatic collections causing pain or mechanical obstruction 1
• Asymptomatic fluid collections should not be drained due to risk of introducing infection 1

Management of Infected Collections

• If infection is suspected, the source must be identified through microbiological examination of sputum, urine, blood, and vascular cannulae tips 1
• Suspected intra-abdominal sepsis requires evaluation by radiologically guided fine needle aspiration for microscopy and culture 1
• Fine needle aspiration should be performed cautiously by experienced radiologists as there is risk of introducing infection 1
• Infected necrosis, pancreatic abscess, and infected fluid collections require:
  • Appropriate antibiotics based on culture sensitivities
  • Formal drainage by percutaneous or operative means 1
• For confirmed infected pancreatic necrosis, first-line antibiotics include:
  • Meropenem 1g q6h by extended or continuous infusion
  • Imipenem/cilastatin 500mg q6h by extended or continuous infusion 3
• Antibiotic therapy should be limited to 7 days if source control is adequate 3

Drainage Approaches

• Endoscopic drainage is now the preferred approach for pancreatic fluid collections due to reduced morbidity compared to surgical or percutaneous approaches 2, 4
• Percutaneous drainage may be required in certain cases but carries a higher risk of patients requiring rehabilitation after discharge 5
• Surgical intervention is typically reserved for cases that fail to respond to less invasive approaches 6
• A step-up approach is recommended:
  • Begin with endoscopic or percutaneous catheter drainage
  • Progress to endoscopic or surgical necrosectomy if necessary 2, 4

Special Considerations

• Patients with gallstone pancreatitis should undergo ERCP if they have:
  • Severe gallstone pancreatitis with no response to treatment within 48 hours
  • Ascending cholangitis
  • High suspicion of CBD stones (jaundice, deranged liver function tests, dilated CBD on ultrasound) 1
• For patients at high risk of intra-abdominal candidiasis, consider adding antifungal therapy 3
• Patients with cholangitis complicating pancreatitis require prompt antibiotic therapy and biliary drainage 3

Timing of Intervention

• Early intervention should be avoided when possible to allow collections to mature and wall off 2
• Timing remains controversial - some clinicians use antibiotics to postpone intervention until the stage of walled-off necrosis, while others drain earlier 2
• Referral to a specialist unit is necessary for patients with extensive necrotizing pancreatitis or other complications requiring intensive care and/or interventional procedures 1