Bosentan Therapy in a Patient with Failed Fontan Procedure: A Case Report

Background: Increased pulmonary vascular resistance index (PVR) leads to several complications in patients after a Fontan operation. This increase is mainly attributed to the overexpression of endothelin-1 for a long duration after the Fontan procedure. Here, we describe the case of a 3-year-old boy with a failed Fontan operation who was treated with bosentan, an endothelin-1 receptor blocker. Case report: Cardiac catheterization was performed, which showed a main pulmonary artery pressure (MPAP) of 19 mmHg and PVRI of 5.6 woods/m2. Oral bosentan regimen at a dose of 31.25 mg was initiated twice a day. The treatment was continued as pleural effusion and ascites persisted. No adverse events were observed, and the treatment was well tolerated. Pleural effusion disappeared, and ascites decreased markedly after 4 weeks, whereas the MPAP was 15 mmHg and the PVRI was 4.3 woods/m2. After 3 months of bosentan therapy, the MPAP was 12 mmHg and the PVRI was 4.1 woods/m2. Conclusion: We observed that bosentan reduces the PVRI and complications such as pleural effusion and ascites after a failed Fontan procedure.