S1703 Circumferential Pancreatic Pseudocyst Encasing the Duodenum Causing Gastric Outlet Obstruction

Abstract

Introduction: Pancreatic pseudocysts are common findings that form from inflammation and fluid accumulation. Paraduodenal Pancreatitis is a form of chronic pancreatitis where inflammation is limited to the pancreatic head for unknown reasons, though chronic alcohol abuse and strictures of the distal common bile duct and pancreatic duct are commonly reported. Approximately 40% of these patients will have a pseudocyst in the pancreatic head and the presence of cysts in adjacent structures may occur in up to half of patients. Pseudocysts may cause obstructive symptoms in both the biliary and GI tracts, usually due to mass effect and not encasement. We present the case of a patient with a pseudocyst circumferentially enveloping the duodenum causing gastric outlet obstruction (GOO). Case Description/Methods: A 35-year-old man with chronic pancreatitis and alcohol abuse presented after syncopizing. Upon arrival he was unresponsive, tachycardic, and had a distended abdomen with a left upper quadrant mass. The patient was profoundly hypoglycemic which was treated with continuous dextrose-containing fluids. A CT scan identified a donut shaped torus, with communication to a pancreatic duct, causing duodenal and GOO (Figure). Attempts to relieve this obstruction via nasogastric tube placement were unsuccessful. Endoscopy with intraoperative ultrasound (EUS) was performed, biopsies were taken, and 10 milliliters of fluid were aspirated. The biopsy was benign and the fluid had elevated concentrations of amylase and lipase confirming the diagnosis of pancreatic pseudocyst and a cystoduodenostomy was performed on a second EUS. Despite initial improvement the patient had continued difficulty eating with a follow up endoscopy revealing severe esophagitis and persistent GOO. Laparoscopic gastrojejunostomy with conversion to an open procedure due to adhesions was performed to bypass the lesion. His postoperative period was uneventful and had an uncomplicated discharge. Discussion: The anatomy of this pseudocyst is rare and no guidelines exist regarding management. Prior to EUS many patients underwent invasive procedures, and patients have benefited from the availability of less invasive options. The anatomic characteristics of our patient’s pseudocyst are rare and may represent a type of pseudocyst that requires more invasive management. Anatomic features of pseudocysts may be a reasonable way to stratify patients into noninvasive or invasive management options.Figure 1.: Abdominal CT of the patient with key findings. Red arrow- "Donut-Shaped" pancreatic pseudocyst enveloping the duodenum. Green arrow- Patient's stomach which is markedly distended and full of gastric contents. Yellow arrow- Head of the pancreas.