[Hepatopulmonary syndrome]

The hepatopulmonary syndrome (HPS) is a reversible pulmonary insufficiency in association with liver disease, most frequently liver cirrhosis. The pathogenesis of HPS is poorly understood. HPS is characterized by arterial hypoxemia caused by intrapulmonary arteriovenous shunts or marked vasodilatation of the pulmonary vessels and ventilation-perfusion mismatch in the absence of intrinsic heart or lung disease. Typical clinical signs are dyspnea in the upright position which improves in supine position (platypnoe) and decrease of arterial pO2 in the upright position (orthodeoxia). The diagnosis of HPS is based on clinical features, arterial blood gas analyses in supine and upright position, contrast echocardiography and lung perfusion scanning. Arteriovenous fistula can be excluded by pulmonary angiography. There is no established medical treatment of HPS. New medical and noninvasive therapies, such as transjugular intrahepatic Stent-shunt (TIPS), lead to improvement of HPS. These treatment modalities need further elucidation. HPS was shown to be reversible after orthotopic liver transplantation (OLTx) in some cases. Severe HPS, therefore, may be an indication rather than a contraindication for OLTx.