Hepatopulmonary syndrome: update on pathogenesis and clinical features

Abstract

Hepatopulmonary syndrome (HPS) is a serious vascular complication of liver disease that occurs in 5-32% of patients with cirrhosis. The presence of HPS markedly increases mortality. No effective medical therapies are currently available and liver transplantation is the only established treatment option for HPS. The definition and diagnosis of HPS are established by the presence of a triad of liver disease with intrapulmonary vascular dilation that causes abnormal arterial gas exchange. Experimental biliary cirrhosis induced by common bile duct ligation in the rat reproduces the pulmonary vascular and gas exchange abnormalities of human HPS and serves as a pertinent animal model. Pulmonary microvascular dilation and angiogenesis are two central pathogenic features that drive abnormal pulmonary gas exchange in experimental HPS, and thus might underlie HPS in humans. Defining the mechanisms involved in the microvascular alterations of HPS has the potential to lead to effective medical therapies. This Review focuses on the current understanding of the pathogenesis, clinical features and management of HPS.

◆ Hepatopulmonary Syndrome

“…It has been reported that HPS can increase the mortality of patients with liver cirrhosis, especially in those with severe hypoxemia 6,11,14,19 .…”

“…It was also seen in both genders in middle-aged patients 17 . HPS pathogenesis is not well defined, but it is speculated that a combination of factors, such as an imbalance in the response of vascular endothelin receptors, pulmonary microvascular remodeling and genetic predisposition, leads to intrapulmonary vascular dilatation and bacterial translocation 1,10,12,14,17,19 .…”

Molecular mechanisms of hepatopulmonary syndrome

“…Today the term "hepatopulmonary syndrome" (HPS) describes deficiency of arterial oxygenation caused by dilatation of intrapulmonary vessels associated with liver disease [2][3][4][5]. A classification of the severity of HPS based on oxygenation abnormalities has been proposed [4] (table 1).…”

Hepatopulmonary Syndrome: A Brief Review

“…This event could occur in portal hypertension, which will eventually result in intestines perfusion disturbance and increased rate of gram-negative bacteria and enteral endotoxin translocation. Moreover, it also induced the release of vasoactive mediators including NO [1,6,8,9].…”