You are in: eMedicine Specialties > Gastroenterology > Liver Chylous AscitesArticle Last Updated: Feb 8, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 10
  Author: Unnithan V Raghuraman, MD, FRCP, FACG, FACP, Consulting Staff, Department of Gastroenterology, St John Medical Center Unnithan V Raghuraman is a member of the following medical societies: American College of Gastroenterology, American College of Physicians, American Gastroenterological Association, and American Society of Gastrointestinal Endoscopy Coauthor(s): David C Wolf, MD, FACP, FACG, AGAF, Medical Director of Liver Transplantation, Westchester Medical Center, Professor of Clinical Medicine, Division of Gastroenterology and Hepatobiliary Diseases, Department of Medicine, New York Medical College Editors: Mounzer Al Al Samman, MD, Department of Internal Medicine, Division of Gastroenterology, Assistant Professor, Texas Tech University School of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; BS Anand, MD, Department of Internal Medicine, Division of Gastroenterology, Professor, Baylor University College of Medicine; Alex J Mechaber, MD, FACP, Assistant Dean for Medical Curriculum, Associate Professor of Medicine, Division of General Internal Medicine, University of Miami Miller School of Medicine; Julian Katz, MD, Clinical Professor of Medicine, Drexel University College of Medicine; Consulting Staff, Department of Medicine, Section of Gastroenterology and Hepatology, Hospital of the Medical College of Pennsylvania Author and Editor Disclosure Synonyms and related keywords: chyloperitoneum, milky ascites, abdominal lymphatics, chyliform ascites, pseudochylous ascites, lymphomas, disseminated carcinomas, tuberculosis, lymphangiectasia, mesenteric cyst, high portal pressures, polycythemia vera, portal vein thrombosis, hepatic vein thrombosis, abdominal distension, peritoneocentesis, paracentesis INTRODUCTIONSection 2 of 10
  Chylous ascites is the extravasation of milky chyle into the peritoneal cavity. This can occur de novo as a result of trauma or obstruction of the lymphatic system. Moreover, an existing clear ascitic fluid can turn chylous as a secondary event. True chylous ascites is defined as the presence of ascitic fluid with high fat (triglyceride) content, usually higher than 110 mg/dL. PATHOPHYSIOLOGYSection 3 of 10
Chylous ascites is a rare clinical condition that occurs as a result of disruption of the abdominal lymphatics. Multiple causes have been described, including the following:
CLASSIFICATIONSection 4 of 10
Milky ascites is subdivided into 3 groups as follows:
This classification is not clinically useful and has been discarded by some. FREQUENCY AND AGE AND SEX DISTRIBUTIONSection 5 of 10
Frequency The rarity of chylous ascites in clinical practice can be judged by the fact that only 28 cases were identified at Massachusetts General Hospital over a period of 20 years. Of these 28 patients, 4 were children. The mean age at detection in adults was 54.3 years. An earlier study (1957) reported the incidence of chylous ascites as approximately 1 case per 187,000 hospital admissions. In subsequent years, due to more aggressive retroperitoneal and cardiothoracic surgical techniques and longer survival of cancer patients, the incidence of chylous ascites has increased to 1 case in 11,584 hospital admissions (1982). Age and sex distribution No differences in sex distribution have been cited, but, of the 28 patients with chylous ascites from Massachusetts General Hospital, 75% were women. Chylous ascites can occur in adult and pediatric populations. In adults, it commonly is observed in individuals aged 50-65 years. CLINICAL DISEASE ASSOCIATIONS AND PATHOLOGYSection 6 of 10
Clinical disease associations In adults, chylous ascites is associated most frequently with malignant conditions. These conditions particularly include lymphomas and disseminated carcinomas from primaries in the pancreas, breast, colon, prostate, ovary, testes, and kidney. Inflammatory disorders, such as tuberculosis, can infrequently be associated with chylous ascites. In children, the most common causes are congenital abnormalities, such as lymphangiectasia, mesenteric cyst, and idiopathic "leaky lymphatics." Neoplasia is an uncommon cause of pediatric chylous ascites. Recently, chylous ascites has been reported in adults in association with hepatoma, small bowel angiosarcoma, retroperitoneal lymphoma, and jejunal carcinoid. The incidence of spontaneous chylous ascites in patients with chronic liver diseases is estimated to be 0.5%. The lymphatics rupture spontaneously as a result of high portal pressures. Chylous ascites has been reported in patients with polycythemia vera due to portal and hepatic vein thrombosis. Abdominal surgery is a common cause of chylous ascites. The surgical procedures most frequently associated with chylous ascites are resection of abdominal aortic aneurysm and retroperitoneal lymph node dissection. In one series of 329 patients with testicular cancer who underwent postchemotherapy retroperitoneal lymph node dissection, 7% of patients developed chylous ascites. Chylous ascites is also described after splenorenal shunt surgery. Pathology Dietary chylomicrons are absorbed in the small intestines and gradually pass along larger omental lymphatics to the cisterna chyli located anterior to the second lumbar vertebra. The cisterna is joined by the descending thoracic, right and left lumbar, and liver lymphatic trunks, and, collectively, these form the thoracic duct, which passes through the aortic hiatus and courses through the right posterior mediastinum and eventually enters the venous system. The thoracic duct carries lymphatic drainage from the entire body, except for the right side of the head and neck, right arm, and right side of thorax. Chylous effusions develop when these channels are injured or obstructed. Based on animal experiments, Blalock concluded that obstruction of the thoracic duct alone is not sufficient to cause chylous ascites. Patients with a limited reserve of anastomotic channels are at greater risk of developing persistent ascites when obstruction or injury of the lymphatic channels occurs. CLINICAL FEATURES AND COMPLICATIONSSection 7 of 10
Clinical features Abdominal distension is the most common symptom in patients with chylous ascites. Other clinical features include abdominal pain, anorexia, weight loss, edema, weakness, nausea, dyspnea, weight gain, lymphadenopathy, early satiety, fever, and night sweats. Fever, night sweats, and lymphadenopathy usually are observed in patients with lymphoma. Often, features of the primary illness, such as cirrhosis or of an associated malignancy, dominate the clinical picture. Rarely, it can present as acute peritonitis. Complications Sepsis is the most common complication, and sudden death has been reported in patients with chylous ascites. The prognosis in adult patients with chylous ascites is poor due to its association with malignancy and severe liver disease. However, pediatric patients and those with postsurgical and posttraumatic chylous ascites have a favorable prognosis. LABORATORY STUDIES, ASCITIC FLUID STUDY, AND OTHER DIAGNOSTIC TESTSSection 8 of 10
Laboratory Studies Routine laboratory tests may show hypoalbuminemia, lymphocytopenia, anemia, hyperuricemia, elevated alkaline phosphatase and liver enzymes, and hyponatremia. Usually, serum cholesterol and triglyceride levels are normal. Abnormal liver enzymes are more common in patients with disseminated carcinoma than in patients with lymphoma or nonmalignant disorders. Anemia is common in patients with neoplasia. The diagnosis of chylous ascites is made by peritoneocentesis and analysis of the ascitic fluid. Ascitic fluid study
Other diagnostic tests
CT scan, lymph node biopsy, and laparotomy carry the highest yield of diagnostic information. The role of MRI is not well defined. Lymphangiography can transiently worsen chylous ascites due to the oily contrast medium used for the test. TREATMENTSection 9 of 10
Because chylous ascites is a manifestation rather than a disease by itself, the prognosis depends on the treatment of the underlying disease or cause. Supportive measures can relieve the symptoms. These measures include repeated peritoneocentesis, diuretic therapy, salt and water restriction, elevation of legs with use of supportive stockings, and dietary measures. A low-fat diet with medium-chain triglyceride supplementation can reduce the flow of chyle into the lymphatics. Typically, medium-chain triglyceride oil is administered orally at a dose of 15 mL 3 times per day at meals. However, this approach is frequently not successful. One recent case report described the successful use of orlistat (Xenical) in a patient who had difficulty complying with a low-fat diet. If chylous ascites persists despite dietary management, the next step may involve bowel rest and the institution of total parenteral nutrition. Bowel rest and total parenteral nutrition are postulated to be beneficial in patients with posttraumatic or postsurgical chylous ascites. Paracentesis can result in immediate symptom relief; however, reaccumulation of fluid usually follows, and patients may require repeated paracentesis. Some authorities have advocated large-volume paracentesis. Morbidity from a single tap usually is low, but complications, such as peritonitis and hemorrhage, can occur. Transfusion of albumin and/or RBCs during paracentesis may help prevent hypovolemia in patients with hypoalbuminemia or anemia. Peritoneovenous shunting has been used successfully in small numbers of patients with chylous ascites. However, shunt failure is common. Surgical revision of the shunt may be necessary. Postsurgical chylous ascites usually resolves with supportive therapy. Early reoperation is indicated when the site of leakage is apparent and if the patient is a good operative candidate. Case reports now describe the laparoscopic treatment of chylous leaks, using suture ligation and fibrin glue to control the leak. Use of TIPS to successfully treat chylous ascites related to cirrhosis has been reported. Spontaneous healing of a chylous leak has been noted after lymphangiography performed to identify a lymph leak prior to a planned surgical therapy. Multiple case reports describe the use of octreotide, a somatostatin analog, in the management of chylous ascites, typically at a dose of 100 mcg administered subcutaneously 3 times per day. Somatostatin receptors have been described in the lymphatic vessels of the intestine. In 1999, one group postulated that octreotide was effective in managing chylous ascites because it helped to decrease lymph flow through these vessels. Malignant chylous ascites requires specific therapy directed at the primary cause and also supportive therapy. These therapies may include chemotherapy, radiation, and surgery. Laparotomy and ligation of the leaking lymphatics, resection of the leaking small bowel segment, and removal of an obstructing tumor all have been attempted with varying degrees of success. Transient success also has been achieved with peritoneovenous shunts. Laparotomy should not be used in pediatric patients with chylous ascites unless the condition is unresponsive to conservative therapy and a lesion that can be corrected by surgery is apparent. REFERENCESSection 10 of 10
Article Last Updated: Feb 8, 2007 |
