Chapter 344 Pseudocyst of the Pancreas

Pancreatic pseudocyst formation is an uncommon sequela to acute or chronic pancreatitis. Pseudocysts are sacs delineated by a fibrous wall in the lesser peritoneal sac. They can enlarge or extend in almost any direction, thus producing a wide variety of symptoms (see Fig. 343-1C).

A pancreatic pseudocyst is suggested when an episode of pancreatitis fails to resolve or when a mass develops after an episode of pancreatitis. Clinical features usually include pain, nausea, and vomiting, but many patients are asymptomatic. The most common signs are a palpable mass in 50% of patients and jaundice in 10%. Other findings include ascites and pleural effusions (usually left-sided).

Pancreatic pseudocysts can be detected by transabdominal ultrasonography, CT scanning, magnetic resonance cholangiopancreatography (MRCP), endoscopic retrograde cholangiopancreatography (ERCP), and endoscopic ultrasound (EUS). Because of its ease, availability, and reliability, ultrasonography is the 1st choice. Sequential ultrasonography studies have demonstrated that most small pseudocysts (<6 cm) resolve spontaneously. It is recommended that the patient with acute pancreatitis undergo an ultrasonographic evaluation 2-4 wk after resolution of the acute episode for an evaluation of possible pseudocyst formation.

Percutaneous or endoscopic drainage of pseudocysts has replaced open surgical drainage, except for complicated or recurrent pseudocysts. Whereas a pseudocyst must be allowed to mature for 4-6 wk before surgical drainage is attempted, percutaneous or endoscopic drainage can be attempted earlier. In some cases, endoscopic creation of a cyst-gastrostomy is performed. MRCP or ERCP should precede surgical treatment to help the surgeon plan the approach and define anatomic abnormalities. EUS is helpful when an endoscopic approach is chosen.