Protein-losing enteropathy is a severe complication of Fontan surgery and is associated with anaemia. Few studies have reported on the efficacy of an intravenous iron infusion for treating protein-losing enteropathy and low albuminemia after Fontan surgery. Herein, we present two cases of female patients who suffered from protein-losing enteropathy and low albuminemia following Fontan surgery, both of whom improved after an intravenous iron infusion.

Gastrointestinal bleeding complicated with protein-losing enteropathy after the Fontan procedure has been often reported in recent years, but there is no established therapy for it.

We report the case of an 18-year-old boy who suffered from abdominal pain, melena, and anaemia due to intractable haemorrhagic protein-losing enteropathy after the Fontan procedure. He was successfully treated with octreotide therapy.

Lymphatic vessel dysplasia is associated with Fontan-associated protein-losing enteropathy. Extra nodal non-Hodgkin lymphomas including mucosa-associated lymphoid tissue (MALT lymphoma) are associated with lymphatic vessel dysplasia. Here, we describe the case of a 7-year-old with Fontan-associated protein-losing enteropathy who developed MALT lymphoma with a clinical course indicative of interaction between these pathologies and improvement in protein-losing enteropathy after MALT lymphoma treatment. This case suggests a pathophysiologic overlap which has implications for the management of Fontan-associated protein-losing enteropathy.

We report the case of a 14-year-old boy with severe protein-losing enteropathy after Fontan surgery that led to lymphangiectasia, which caused gastrointestinal haemorrhage and required invasive treatment to stop the bleeding. Through this case and a review of the literature on protein-losing enteropathy after Fontan surgery, we highlight a rare and serious presentation of the disease and the difficulties of diagnosis and management.

We report the case of a young boy with a history of total occlusion of the superior caval vein, diagnosed early after complex neonatal cardiac surgery, who developed severe protein-losing enteropathy. Protein-losing enteropathy was precipitated by a relatively mild stenosis at the junction of the inferior caval vein with the right atrium. Percutaneous stent dilation of the veno-atrial junction definitively relieved the stenosis, and the protein-losing enteropathy subsequently resolved.

In this study, three patients presenting with early or late postoperative Fontan complications were identified to suffer from restriction of the native atrial septum. This caused significant obstruction to pulmonary venous return and elevated systemic venous pressure. Dobutamine stress testing was used in one patient to identify this lesion. Transcatheter stenting was performed in the other two patients. Patients improved after relief of the obstruction.

The Fontan operation, although part of a life-saving surgical strategy, manifests a variety of end-organ complications and unique morbidities that are being recognised with increasing frequency as patients survive into their second and third decades of life and beyond. Liver fibrosis, protein-losing enteropathy and plastic bronchitis are consequences of a complex physiology involving circulatory insufficiency, inflammation and lymphatic derangement. These conditions are manifest in a chronic, indolent state. Management strategies are emerging, which shed some light on the origins of these complications. A better characterisation of the end-organ consequences of the Fontan circulation is necessary, which can then allow for development of specific methods for treatment. Ideally, the goal is to establish systematic strategies that might reduce or eliminate the development of these potentially life-threatening challenges.

A 7-year-old male patient who had abdominal swelling and eyelid oedema was diagnosed with restrictive cardiomyopathy. His serum albumin level was 2.3 g/dl. Protein-losing enteropathy due to restrictive cardiomyopathy was diagnosed and oral budesonide was started. His serum albumin level began to rise and ascites and peripheric oedema disappeared. The patient underwent a successful cardiac transplantation and budesonide was stopped. After the heart transplantation, the albumin level decreased to 2.3 g/dl, and therefore it was restarted. When the serum albumin level increased, the budesonide dose was tapered and stopped in 1 month. Budesonide may be an effective drug in patients with protein-losing enteropathy due to heart failure.

A 12-year-old girl presented with a protein-losing enteropathy. Symptoms started 4 weeks after undergoing the Fontan procedure at the age of 1.5 years for mitral atresia, ventricular septal defect, and double-outlet right ventricle. Upon referral for 3 weeks of rehabilitation after multiple interventional measures and drug treatments, she appeared in a dystrophic state, with decreased plasma protein and electrolyte levels along with occasional tetanic convulsions. Blood glucose levels after a lactose tolerance test were markedly reduced. The introduction of a lactose-free diet was quickly effective, with plasma protein and electrolyte levels raised to normal levels, and the girl's body weight increased without ascites or oedema. Molecular genetic examination revealed a homozygous C/C13910 polymorphism in the LCT gene. Conclusion: Protein-losing enteropathy in the Fontan circulation may be provoked by lactase deficiency and should therefore be ruled out to exclude this rather common condition.

The Fontan operation, originally described for the surgical management of tricuspid atresia, is now the final surgery in the strategy of staged palliation for a number of different forms of congenital cardiac disease with a functionally univentricular heart. Despite the improved technical outcomes of the Fontan operation, staged palliation does not recreate a normal physiology. Without a pumping chamber delivering blood to the lungs, the cardiovascular system is less efficient; cardiac output is generally diminished, and the systemic venous pressure is increased. As a result, patients with “Fontan physiology” may face a number of rare but potentially life-threatening complications including hepatic dysfunction, abnormalities of coagulation, protein-losing enteropathy, and plastic bronchitis. Despite the staged palliation resulting in remarkable survival, the possible complications for this group of patients are complex, involve multiple organ systems, and can be life threatening. Identifying the mechanisms associated with each of the rare complications, and developing strategies to treat them, requires the work of many people at many institutions. Continued collaboration between sub-specialists and between institutions will be required to optimise the care for this group of survivors with functionally univentricular hearts.

An intravascular stent was successfully implanted in a 15-year-old gid with stenosis of the left pulmonary artery subsequent to a modified Fontan correction. Complaints of tiredness, edema, ascites and enlargement of the left breast disappeared. Unfortunately, she died of a rhythm disturbance unrelated to the stent. Autopsy revealed excellent endothelialization of the stent without any thrombosis and with patency of the orifice of the branch to the upper lobe of the lung.

We describe a patient with tricuspid atresia who, after a Fontan operation three years earlier, presented with severe protein-losing enteropathy. After conversion to a cavopulmonary connection, the symptoms regressed and substitution with albumin and immunoglobulin was no longer required.

We describe the development and exacerbation of protein-losing enteropathy after relocating to an environment at an altitude of 3695 feet in El Paso, Texas, in a patient who had undergone a Fontan operation. This report should heighten awareness to the possibility of such patients developing protein-losing enteropathy at high-altitude, with hypoxemia-induced pulmonary vasoconstriction, and subsequent elevation of central venous pressure, the most likely underlying mechanism.

The recent significant reduction in operative mortality associated with surgical completion of the Fontan circulation is clearly multi-factorial. Better understanding of the fundamental physiological and anatomical issues have led to refinements in operative technique, early neutralization of potential risk factors, widespread use of a staged approach, and selective application of the concept of fenestration or incomplete partitioning. While further reduction of operative mortality is important, and may be anticipated in the future, major emphasis now must be placed on optimizing functional outcome, and understanding and managing the late complications associated with the unique physiology produced by the Fontan circulation.