Portosystemic shunt with hyperammonemia and high cardiac output as a complication after Fontan surgery

Area of Science:

• Cardiology
• Hepatology
• Interventional Radiology

Background:

• Fontan surgery is a palliative procedure for complex congenital heart disease.
• Late Fontan-associated circulatory dysfunction is often linked to elevated central venous pressure (CVP).
• Organ dysfunction, particularly liver issues, is a significant concern in the late phase post-Fontan surgery.

Observation:

• Two patients developed portosystemic shunts post-Fontan surgery, presenting with hyperammonemia and high cardiac output.
• Peripheral vasodilatation was noted in conjunction with high cardiac output.
• Elevated CVP post-Fontan surgery is hypothesized to induce portosystemic shunt formation, irrespective of underlying liver disease.

Findings:

• Portosystemic shunts were successfully treated using transcatheter coil embolization and balloon-occluded retrograde transvenous obliteration.
• Clinical improvement was observed following shunt closure.
• The study highlights the potential for portosystemic shunts as a complication of Fontan surgery.

Implications:

• Portosystemic shunts should be considered in patients with unexplained hyperammonemia and high cardiac output after Fontan surgery.
• Early diagnosis and intervention are crucial for managing Fontan-associated complications.
• Transcatheter shunt closure offers a viable therapeutic option to improve clinical status and potentially delay liver disease progression.