Bosentan is a kind of dual endothelin receptor antagonist.The purpose of this study is to investigate if Bosentan therapy can modify the outcome of children with functional single ventricle.

Increased pulmonary vascular resistance (PVR) is a serous issues in children with functional single ventricle during the staged operative period. The purpose of this study is to investigate if Bosentan therapy can improve the survival and life quality after staged Fontan procedure in the children with high risk of increased PVR.

Inclusion Criteria:

• Signed informed consent obtained from patient's legally acceptable representative.

• Pediatric patients waiting for staged Fontan procedure with high risk of increased PVR after bidirectional cavopulmonary connection (BCPC)

  • Transpulmonary pressure gradiant (TPG) > 10mmHg when the obstruction of anastomosis and lung problem were excluded.
  • With the diagnosis of high risk of increased PVR, such as associated with TAPVC, after pulmonary artery banding, after systemic to pulmonary shunt more than 6 months, and et al.
  • Diagnosed as increased PVR with catheterization.

Exclusion Criteria:

• PAH associated with conditions other than those mentioned above, e.g., iPAH, PAH secondary to portal hypertension, HIV patient with opportunistic infection
• Psychotic, addictive or other disorder limiting the ability to provide informed consent or to comply with study requirements
• AST and/or ALT > 3 times the upper limit of normal ranges.
• Hemoglobin concentration < 75% the lower limit of normal ranges
• Treatment or planned treatment with another investigational drug within 3 months of screening
• Treatment with calcineurin-inhibitors (e.g., cyclosporine A and tacrolimus), fluconazole, glibenclamide (glyburide) within 1 week of enrollment of this study
• Known hypersensitivity to bosentan or any of the excipients