Review of chylopericardium.

Chylopericardium is a rare pathologic condition consisting of the accumulation of excess amounts of chylous fluid within the pericardial cavity. Most patients are asymptomatic at presentation; however, chest pressure, chest pain and lightheadedness have been reported, and the most common presenting symptom is shortness of breath. Patients are noted to have enlargement of the cardiac silhouette on routine chest radiograph, and evidence of a pericardial effusion on echocardiography. The diagnosis is only definitively confirmed with pericardiocentesis and fluid analysis. The fluid is typically turbid white or milky in appearance, with a triglyceride level in excess of 500 mg/dL. The mechanism by which chyle accumulates within the pericardium is believed to be secondary to abnormal or damaged lymphatics or due to elevated pressure within the thoracic duct that results in chyle reflux into the pericardium. Following drainage with a pericardiocentesis or pericardial drain, attempts at conservative therapy with nothing by mouth and parental nutrition can be made, but have a high rate of failure and subsequent reaccumulation of chyle. Surgical treatment provides the most definitive management and consists of ligation of the thoracic duct just above the level of the diaphragm and creation of a pericardial window. With this treatment, risk of recurrence is incredibly low (<5%).