Chylous ascites is the accumulation of lipid-rich lymph in the peritoneal cavity. The ascitic fluid is characterized by a milky appearance with a triglyceride level greater than 1000 mg/dL. The usual cause in adults is lymphatic obstruction or leakage caused by malignancy, especially lymphoma. Nonmalignant causes include postoperative trauma, cirrhosis, tuberculosis, pancreatitis, and filariasis.
Pancreatic ascites is the intraperitoneal accumulation of massive amounts of pancreatic secretions due either to disruption of the pancreatic duct or to a pancreatic pseudocyst. It is most commonly seen in patients with chronic pancreatitis and complicates up to 3% of cases of acute pancreatitis. Because the pancreatic enzymes are not activated, pain often is absent. The ascitic fluid is characterized by a high protein level (greater than 2.5 g/dL) but a low SAAG. Ascitic fluid amylase levels are in excess of 1000 units/L. In nonsurgical cases, initial treatment consists of bowel rest, total parenteral nutrition (TPN), and octreotide to decrease pancreatic secretion. Persistent leakage requires treatment with either endoscopic placement of stents into the pancreatic duct or surgical drainage.
Bile ascites is caused most commonly by complications of biliary tract surgery, percutaneous liver biopsy, or abdominal trauma. Unless the bile is infected, bile ascites usually does not cause abdominal pain, fever, or leukocytosis. Paracentesis reveals yellow fluid with a ratio of ascites bilirubin to serum bilirubin greater than 1.0. Treatment depends on the location and rate of bile leakage. Postcholecystectomy cystic duct leaks may be treated with endoscopic sphincterotomy or biliary stent placement to facilitate bile flow across the sphincter of Oddi. Other leaks may be treated with percutaneous drainage by interventional radiologists or with surgical closure.