Types of collection
- Pseudocyst: a walled-off pocket of clear fluid.
- Walled-off necrosis (WON): a walled-off pocket containing dead pancreatic tissue as well as fluid.
Both usually take about 4 weeks to develop a firm wall, which is important for safe drainage.
When drainage is needed
- Infection (fever, worsening blood tests)
- Ongoing pain, inability to eat, vomiting
- Pressure on the stomach, bowel or bile duct
A collection that causes no problems can often simply be watched.
How endoscopic drainage works
Using therapeutic EUS, the collection is seen through the stomach wall and a stent, often a wide lumen-apposing metal stent, is placed to connect it to the stomach so it drains. For walled-off necrosis, the dead tissue may need to be cleared through the stent in one or more sessions (endoscopic necrosectomy).