Monday, July 11, 2011
One of my long time patients came to see me a while back with a complaint of abdominal distention, pain, and early satiety. A few years prior to this visit I had taken care of him during a prolonged bout of severe necrotizing gallstone pancreatitis. The scan above shows a giant pancreatic pseudocyst. A pseudocyst lacks a true epitheliazed wall. After an episode of severe pancreatitis involving parenchymal destruction and damage to branches of the pancreatic duct, pancreatic juices leak out into the surrounding retroperitoneal tissues. Once the flow of pancreatic secretions is tamponaded off (the ultimate size of the cyst is a function of the degree of ductal damage or obstruction) it will organize itself into a discrete cystic collection. Symptoms generally arise due to the mass effect of the cyst. Pseudocysts can also become superinfected leading to sepsis. Pseudocyst rupture is another rare complication.
We usually adopt a stance of watchful waiting with regards to pancreatic pseudocysts. Most will spontaneously regress as the duct/parenchymal injuries heal. Those cysts that persist past 6-12 months are unlikely to ever go away. Furthermore, cyst size is predictive of regression--- those greater than 6cm are less likely spontaneously resolve.
This cyst was over 20 cm. I watched it for a while but it never got smaller and his symptoms persisted. Treatment options include endoscopic vs. percutaneous vs. surgical decompression. Percutaneous drains are generally a poor choice because you simply convert a contained internal pancreatic fistula into an uncontained external fistula with all the attendant fluid/electrolyte sequelae. Endoscopic drainage of pseudocysts into the stomach utilizing endoscopic ultrasonography is an exciting new option but it isn't universally available and long term results are lacking.
The standard treatment has long been surgical decompression of the cyst into either the stomach or small intestine. I performed a cystogastrostomy on this patient. It's a nifty little procedure. By the time you operate the cyst wall has densely adhered to the posterior wall of the stomach. So all you do is open up the stomach anteriorly, palpate the bulging cyst through the posterior wall and excise a wedge of the gastric/pseudocyst confluence. Classic teaching is to send off that specimen to the path lab to rule out a neoplastic process. The image below represents the 3 month follow-up appearance of the upper abdomen.