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Algorithm for chylous ascites
Evaluation — Chyle typically has a cloudy and turbid appearance. Triglycerides are > 110 mg/dL. CT can be helpful diagnostically. Lymphangiography and lymphoscintigraphy helps assess retroperitoneal nodes, leakage from dilated lymphatics, fistulization, and thoracic duct patency. -Chylous ascites is a milky-appearing peritoneal fluid that is rich in triglycerides. It is due to the presence of thoracic or intestinal lymph in the abdominal cavity. Incidence of <1 per 20,000 admissions. Aetiology
Malignancy — Malignancy is a common cause Lymphoma accounts for 50% of malignant chylous ascites Cirrhosis — Chylous in 1% of cirrhotic ascites Infectious — Peritoneal tuberculosis and filariasis (Wuchereria bancrofti) are the common infectious causes of chylous ascites. Infection with Mycobacterium avium intracellulare has been described as a cause of chylous ascites in patients with AIDS. Congenital — More common in kids a) Primary lymphatic hypoplasia- characterized by lymphedema, chylothorax, and/or chylous ascites. b) Primary lymphatic hyperplasia. Two forms have been described: "bilateral hyperplasia," in which the lymphatics are not severely dilated and contain valves, and lymphan - giectasia (megalymphatics), in which the lymphat - ics are very dilated and lack valves. c) The Klippel-Trenaunay syndrome (AD) - in which venous and lymphatic hypoplastic malformations cause hypertrophy of the tissues of an involved limb and is associated with chylous ascites. d) The yellow-nail syndrome -hypoplastic lymphatics leading to chylous effusions. The characteristic triad consists of lymphedema, pleural effusion, and/or chylous ascites and a yellow discoloration together with dystrophy of the nails. Chylous Ascites
3. Obstruction of the lymph flow due to malignancy cau - ing leakage from dilated subserosal lymphatics into the peritoneal cavity. 1. Exudation of lymph through the walls of dilated retroperitoneal vessels lacking valves, which leak fluid through a fistula into the peritoneal cavity (ie, congenital lymphangiectasia).
2. Acquired thoracic duct obstruc - tion from trauma causing direct leakage of chyle through a lympho - peritoneal fistula.
Inflammatory — a) Radiation therapy to the abdomen, causing fibrosis and obstruction of the lymphatic vessels in the small bowel and mesentery. b) Acute or chronic pancreatitis, which can cause compression of adjacent lymphatic channels resulting in chylous ascites and pleural effusions. c) Constrictive pericarditis (as described above), which can cause chylous ascites by increasing hepatic venous pressure, thereby increasing lymph production d) Other rare inflammatory disorders, such as idiopathic retroperitoneal fibrosis or Ormond's disease, sarcoidosis, retractile mesenteritis, and Whipple's disease. Postoperative and traumatic — Any disruption of thoracic duct In children, the Battered Child Syndrome, which accounts for 10 % of cases of chylous ascites in the pediatric population, should be excluded. Other causes — Right heart failure and dilated cardiomyopathy can cause impaired drainage of lymph, with an increase in lymphatic pressure producing stasis, dilation, and chylous ascites. The nephrotic syndrome has been reported to cause chylous ascites and chylothorax. Lymphangioleiomyomatosis (LAM), is a rare disorder of unclear etiology characterized by smooth muscle proliferation in the lung, lymphatics, and lymph nodes in the mediastinum, abdomen and lower cervical region. It affects almost exclusively women of childbearing age. The disorder can be associated with a variety of clinical manifestations including chylous ascites. Radiological studies —
Management — If no cause found and no response: high protein and low fat diet with medium-chain triglycerides (MCT)- these are absorbed directly into intestinal cells and transported as FFA and glycerol directly to the liver via the portal vein therefore bypass lymphatic system. -Orlistat, a reversible inhibitor of gastric and pancreatic lipases, was reported to minimize ascites and triglyceride levels in ascitic fluid in a patient with chylous ascites due to cirrhosis. -Somatostatin and octreotide (can inhibit intestinal wall lymph vessel fluid secretion have been used successfully to treat chylous effusions in patients with the yellow nail syndrome and lymphatic leakage due to abdominal and thoracic surgery. -TPN if not responding to above. -If cirrhotic, can consider a shunt, but high rates of shunt blockage due to viscous chyle. Surgery may be beneficial depending on the cause. Medium- chain fatty acid, low fat diet TPN
Consider adding somatostatin or analog Consider therapeutic paracentesis for symptom palliation Failure
Lymphangiography
Lymphoscintigraphy
Maintenance medium- chain fatty acid, low fat diet Recovery
Success
Conservative measures Invasive measures Imaging to localize leak Image guided sclerotherapy Surgical exploration and repair Peritoneovenous shunting
Failure
Failure
Failure
OR
Success
Success
Written by Dr Sebastian Zeki
