Walled-off pancreatic fluid collections are often the result of acute pancreatitis. They may also be seen in patients with chronic pancreatitis and in patients who have suffered blunt or penetrating pancreatic trauma. Endoscopic drainage of walled-off pancreatic fluid collections by expert endoscopists is an accepted alternative to surgery when intervention is indicated. Its advantages over percutaneous drainage are the ability to place multiple internal drains through one puncture site and the avoidance of the development of a pancreaticocutaneous fistula for walled-off pancreatic fluid collections that communicate with the pancreatic duct. (See "Walled-off pancreatic fluid collections (including pseudocysts)".)
In the past, many of these lesions were referred to as pseudocysts. However, in 2013, the terminology used to describe pancreatic fluid collections that develop following acute pancreatitis was updated, and the majority of walled-off pancreatic fluid collections now fall into the category of walled-off pancreatic necrosis. (See "Endoscopic management of walled-off pancreatic fluid collections: Techniques", section on 'Definitions'.)
This topic will review the efficacy and complications of endoscopic management of walled-off pancreatic fluid collections. The classification of pancreatic cysts, the diagnosis of walled-off pancreatic fluid collections, and the techniques used in the endoscopic management of walled-off pancreatic fluid collections are discussed separately. (See "Classification of pancreatic cysts" and "Walled-off pancreatic fluid collections (including pseudocysts)" and "Endoscopic management of walled-off pancreatic fluid collections: Techniques".)
In 2013, a revision of the Atlanta classification of acute pancreatitis was published that updated the terminology used to describe inflammatory pancreatic fluid collections to better reflect the underlying pathophysiology . According to the revised Atlanta classification, inflammatory pancreatic fluid collections include acute peripancreatic fluid collections, pseudocysts, acute necrotic collections, and walled-off pancreatic necrosis  (see "Clinical manifestations and diagnosis of acute pancreatitis", section on 'Local complications' and "Classification of pancreatic cysts"):
●Acute peripancreatic fluid collections occur in the setting of acute interstitial pancreatitis within four weeks of the onset of pancreatitis. They are typically extra-pancreatic and do not have a definable wall. The fluid contains no solid material, and there is no pancreatic necrosis present.