Portopulmonary Hypertension

Physiology

  • Pulmonary HTN probably due to impaired hepatic metabolism of an unknown vasoconstrictor substance (supported by observed plexogenic pulmonary arteriopathy in cases of congenital protal vein agenesis)/ possible role of microemboli from portal circulation

Diagnosis

  • Echo: pulmonary HTN may be severe in these cases (at levels similar to PPH/ CTEPH)

Clinical


Treatment

  • Pulmonary vasodilator trial: NO or Prostacyclin with Swan in place
  • If responsive, may consider Calcium Channel Blockers
  • Liver transplant: anecdotal evidence that this may resolve pulmonary HTN

  • The development of PAH in association with elevated pressure in the portal circulation is known as portopulmonary hypertension (POPH) (39,40).

  • Portal hypertension, rather than the presence of underlying liver disease, is the main determining risk factor for the development of POPH. Prospective hemodynamic studies have shown that 2% to 6% of patients with portal hypertension have PH (41,42).

  • Right heart catheterization is absolutely mandatory for the definitive diagnosis of POPH because several factors may increase pulmonary arterial pressure (PAP) in the setting of ad- vanced liver disease (e.g., high flow associated with the hyperdynamic circulatory state and increased pulmonary capillary wedge pressure owing to fluid overload and/or diastolic dysfunction).

  • Pulmonary vascular resistance (PVR) is usually normal in these cases.

  • Pathologic changes in the small arteries appear identical to those seen in IPAH. A recent multicenter case-control study identified 2 risk fac- tors for the development of POPH: female sex and auto- immune hepatitis (43).

  • Interestingly, hepatitis C infection was associated with a decreased risk. A recent, large cohort study of POPH showed that long-term prognosis was related to the presence and severity of cirrhosis and to cardiac function (44).


References

  • 39 Pulmonary vascular disorders in portal hypertension. Eur Respir J 1998;11:1153– 66.
  • 40 On behalf of the ERS Task Force Pulmonary-Hepatic Vascular Disorders Scien-tific Committee. Pulmonary-hepatic vascular disorders. Eur Respir J 2004;24:861– 80.
  • 41 Pulmonary hypertension complicating portal hypertension: prevalence and rela- tion to splanchnic hemodynamics. Gastroenterology 1991;100: 520–8.
  • 42 Portopulmonary hypertension: results from a 10-year screening algo- rithm. Hepatology 2006;44:1502–10.
  • 43 Clinical risk factors for portopulmonary hypertension. Hepatology 2008;48:196 –203.
  • 44 Portopulmonary hypertension: survival and prognostic factors. Am J Respir Crit Care Med 2008; 178:637– 43