Pancreatic Pseudocysts

Pseudocysts complicate about 5% of patients after an episode of acute pancreatitis. A pseudocyst is a localized pancreatic fluid collection that is present 4-6 weeks after an episode of acute pancreatitis. A pseudocyst is different from a collection of a mixture of both fluid and solid components (debris), as it often occurs in patients with necrotizing pancreatitis (i.e.: in cases where part of the pancreas has died and is in various stages of decomposition, thus the mixture of solid and liquid material). It is not uncommon for a pseudocyst to get smaller with time and eventually resolve on its own without specific treatment. In patients where pseudocyst persist, get progressively larger and cause symptoms, there are two questions that should be definitively answered before the appropriate, individualized treatment strategy is designed.

1. Is there any communication between the pseudocyst and the pancreatic duct?

2. Is there any stenosis (narrowing) or occlusion (obstruction) of the segment of the pancreatic duct between the pseudocyst and the ampulla of Vater?

Endoscopic Retrograde Cholangio-Pancreatography (ERCP) is the diagnostic modality of choice to give the answers and provide the base for treatment planning. Depending on the various combinations of conditions that are present after precise delineation of the anatomy of the pseudocyst and the pancreatic duct, one of the following treatment modalities should be implemented:

1. Percutaneous Drainage. It is very easy to perform when guided by simultaneous ultrasonography and should be performed when no communication between the pseudocyst and the pancreatic duct is present.

2. Endoscopic Trans-sphincteric Drainage. A small tube (“stent”) is placed inside the opening of the pancreatic duct to the duodenum, or as a bridge between two segments of the pancreatic duct with a narrowing between them. This way, a low-pressure system is created, so the pseudocyst can preferentially drain (and eventually empty its content) into the duodenum. This modality is very demanding technically and very advanced technology is necessary for it to be performed.

3. Endoscopic Intragastric Drainage. Two or more tubes are endoscopically positioned between the stomach and the pseudocyst, so free communication is established between them. This way, the fluid of the pseudocyst finds an easy way to drain into the stomach and eventually the cyst is evacuated. Placement of these tubes is facilitated by simultaneous endoscopic ultrasound guidance.

4. Operative Drainage. It is considered, even today, the gold-standard in pseudocyst treatment, especially after the modern evolution of laparoscopic techniques. An operation is preferred in patients with very large (over 15cm) pseudocysts, or when other nonoperative, endoscopic methods have been applied and proved not definitive (i.e.: pseudocysts did not resolve or came back).