Protein-Losing Enteropathy Following Fontan Palliation

Protein-losing enteropathy (PLE) is a chronic condition involving multiple organ systems that may develop any time following Fontan completion. The pathogenesis of PLE is complex and multifactorial. Chronic venous hypertension, low cardiac output, and abnormal lymphatics may all play a role in the pathogenesis of PLE. Common signs and symptoms include chronic diarrhea, abdominal pain, and ascites. Diagnosis is based on the presence of signs and symptoms in addition to hypoalbuminemia and elevated stool alpha 1 antitrypsin. Early identification and a comprehensive approach to evaluation and treatment are important, as they may affect survival. The initial evaluation should include cardiac catheterization for hemodynamic assessment. Although an evidence base for treatment is lacking, various medical, interventional, and surgical approaches have been described with variable degrees of success. Commonly used therapies include nutritional support, diuretics, subcutaneous unfractionated heparin, budesonide, and sildenafil. Limited data exist for Fontan conversion or takedown. Assessment for heart transplantation should be considered. PLE mortality is high-approximately 50%-but may be mitigated by aggressive investigation and management. The evolving understanding of the role of lymphatics in the pathophysiology of PLE and the emerging role of interventional lymphatic procedures may further improve outcomes in this patient population.