A47-36 Chylothorax in the Setting of Walled off Pancreatic Necrosis

Abstract Introduction Chylothorax is a serious, rare complication observed in patients with acute pancreatitis, necrotizing pancreatitis, walled-off pancreatic necrosis (WOPN), and as a complication of endoscopic necrosectomy. The pathophysiology of this disease is thought to be due to chylous ascites tracking through a damaged diaphragm or after damage to lymphatic channels, either from pancreatic inflammation or direct endoscopic damage. Case Presentation A 70-year-old female with prior cholecystectomy complicated by choledocholithiasis and post-endoscopic retrograde cholangiopancreatography pancreatitis with common bile duct stent placement presented with early satiety and abdominal pain. She underwent CT guided drainage of WOPN and subsequent endoscopic creation of posterior duodenal fistula. Endoscopic ultrasound (EUS) was completed with fine-needle aspiration of WOPN and cystogastrostomy stent placement. Large bilateral pleural effusions were found after the second EUS and a left-sided chest tube was placed with exudative pleural fluid studies, undetectable amylase, and triglycerides of 43. One week later, a third EUS was completed. The initial pleural fluid cultures grew E.Coli, leading to the assumption that the effusions were secondary to translocated infected abdominal fluid. However, the pleural effusions persisted and repeat fluid analyses were diagnostic of chylothorax with cream-colored fluid, triglycerides of 570, and cholesterol of 67. Octreotide 50mcg SC q8h was initiated. Pleural fluid studies were collected after a 14-day course of octreotide and again showed cream-colored fluid, triglycerides of 326, cholesterol of 79, and persistently undetectable amylase. Another 14-day course of octreotide was completed, ultimately leading to steady improvement of left-sided chylothorax. Discussion Chylothorax is a rare but recognized complication of necrotizing pancreatitis and WOPN. In this patient, pleural fluid with elevated triglycerides but persistently undetectable amylase excluded a pancreaticopleural fistula and endoscopic evaluation confirmed no pleural communication from drainage tracts, supporting lymphatic disruption as the underlying cause. Two mechanisms have been proposed to explain pancreatitis-associated chylothorax: (1) severe retroperitoneal inflammation or peripancreatic collections may disrupt the cisterna chyli or lymphatics causing chyle leakage and (2) transdiaphragmatic extension of fluid collections creating abnormal lymphatic communication between the abdominal cavity and thorax. In this case, extensive WOPN, or endoscopic necrosectomy itself - through disruption of lymphatic channels communicating with the thoracic duct - likely produced both inflammatory and mechanical disruption of lymphatic pathways, culminating in chylous effusions. Octreotide, which decreases intestinal fat absorption and chyle production, and induces splanchnic vasoconstriction, has been shown to be an effective treatment modality in the setting of chylothorax as it was in this case. This abstract is funded by: None