Case of Chylous Ascites: A Diagnostic Dilemma

Abstract

We present a case of an 83 year-old male who is status post orthotopic liver transplant in November 2005 for alcoholic cirrhosis, presenting to Henry Ford Hospital with increasing abdominal girth. His symptoms began 2 months prior to presentation following cardiac pacemaker placement for heart block. He was hospitalized shortly after his procedure for shortness of breath and was found to have a pericardial effusion, which was thought to be inflammatory in nature and resolved with steroids. He had been following in the transplant clinic on a regular basis without issues, and was maintained on a stable immunosuppression regimen of mycophenolate and Sirolimus for several years. As part of the work up for his new-onset ascites, a paracentesis was performed. Fluid analysis demonstrated 702 WBCs with 77% lymphocytes, serum-albumin ascites gradient (SAAG) < 1.1 g/dL, total protein < 2.5 g/dL and triglycerides of 2360 mg/dL; consistent with chylous ascites. Lipase and amylase levels were within normal limits. Fungal cultures, acid-fast bacilli stains and cytology were all negative. Echocardiogram showed normal right-sided pressures with preserved ejection fraction and stable pericardial effusion. CT abdomen was unremarkable with no evidence of cirrhosis or portal hypertension. Lymphoscintigraphy study was unremarkable. Liver biopsy was performed without evidence of cirrhosis or rejection. Cardiology was consulted to determine whether the ascites was secondary to venous/lymphatic obstruction as a complication of pacemaker placement or heart failure; this was felt unlikely given preserved cardiac function and normal positioning of pacemaker leads on x-ray. Ultimately, Sirolimus was felt to be the culprit of his chylous ascites. Sirolimus was subsequently discontinued and cyclosporine was initiated with resolution of his ascites. Chylous ascites is a rare finding. It most commonly occurs in the setting of malignancy, lymphatic/vascular obstruction or cirrhosis. Less common etiologies include mycobacterial infection, congenital, inflammatory, post-operative, traumatic and medications such as calcium channel blockers and Sirolimus. Few cases of chylous ascites secondary to Sirolimus have been reported, particularly in renal transplant patients. There are no reported cases of Sirolimus-induced chylous ascites in liver transplant patients. The diagnosis is established by abdominal paracentesis, with fluid studies demonstrating a triglyceride level >200 mg/dL. SAAG and protein levels may vary. Acid-fast bacilli stain and ADA should be performed as well to rule out tuberculous ascites in those at high risk, along with amylase, lipase and standard fluid studies. Abdominal CT should be obtained to rule out pathologic lymph nodes and masses, and lymphoscintigraphy or lymphangiography can aid in detecting leakage from lymphatics and patency of the thoracic duct. Failure to identify a clear etiology following this workup should prompt an investigation into drug etiologies. Treatment is aimed at correction of the underlying etiology (or withholding the offending agent) along with therapeutic paracenteses as needed. A high protein and low fat diet with medium chain triglycerides is recommended. Occasionally, surgery may be performed for obstructive etiologies such as malignancy. Transjugular intrahepatic shunts may be performed for cirrhotic patients. There is also limited evidence for the use of orlistat, somatostatin and octreotride in the mitigation of chylous ascites.