Hepatic Hydrothorax

This specific condition can be related to cirrhosis with ascites in which ascitic fluid leaks into the pleural cavity. Hepatic hydrothorax is often difficult to manage in end-stage liver failure and often fails to respond to therapy.

Per Dr. Rechien @ http://www.ikp.unibe.ch/lab2/hydrothorax.htm,
Prevalence: In prospective studies, a prevalence of 5 - 6 % of hepatic hydrothorax has been described (1,2). Of particular note is that this can occur in the absence of manifest ascites (3,4-7). Personally, we have seen this entity most frequently in patients with previous abdminal surgery, in particular if it involves the liver hilus. Conversely, about 1 - 2 % of all pleural effusions are of hepatic origin (8).

Clinical presentation: Most (65 %) of effusions are right sided only, 15 % left-sided and 15 - 30 % are bilateral (8). The effusion is transsudative but the protein content of the pleural effusion is usually slighty higher than that of ascitic fluid since the pleura has a higher absorptive capacity (8). It is of note that the usual criteria for differentiation between ex- and transsudate cannot be applied to hepatic hydrothorax (9). Transmission of spontaneous bacterial peritonitis to the pleural cavity has also been described further complicating the analysis of the fluid (9). Rarely, a chylothorax of cirrhotic origin can be diagnosed by the usual criteria (10). In a prospective study, spontaneous empyema was found in 15 % (20).

Pathogenesis: Three causes of hepatic hydrothorax have been proposed, namely leakage from the thoracic duct, leakage through lymphatic channels in the diaphragm and leakage through defects in the diaphragm. The evidence for and against is superbly discussed in the review of Alberts and colleagues (8). The overwhelming evidence points to diaphragmatic defects as the source of hepatic hydrothorax (11-13).