Pulmonary complications have long been associated with portal hypertension with or without intrinsic hepatic disease.
- Hepatopulmonary syndrome consists of the triad of liver dysfunction, otherwise unexplained hypoxemia, and intrapulmonary vascular dilation (IPVD) that may be present in up to 20% of patients who present for liver transplantation.
- The natural history of HPS is usually one of progressive hypoxemia.
- Portopulmonary hypertension (PPHTN) is defined as pulmonary hypertension that exists in a patient who has portal hypertension with no other known cause.
- The occurrence of PPHTN is 2% in a population of patients with known portal hypertension compared with 0.13% in an unselected population. Among liver transplant candidates, the prevalence is 4% to 6%.
- The occurrence of PPHTN is unrelated to the severity of the underlying liver disease or portal hypertension.
- The single best screening study for PPHTN is two-dimensional transthoracic echocardiography.
- The role of liver transplantation in the treatment of PPHTN is not well defined. (Some patients have resolution of PPHTN with transplant, some may have no or incomplete resolution and continue to require medical therapy, and some may experience worsening of their PPHTN.)