INTRODUCTION
The Fontan operation is a palliative procedure carried out in univentricular congenital heart disease where biventricular repair is not possible. The concept involves directing systemic blood flow to the pulmonary circulation without active ventricular propulsion. The surgery has evolved since Francis Fontan described his initial series [1], and this has led to increasing survivorship through adolescence to adulthood. Whilst life-prolonging, Fontan surgery has consequences leading to late cardiac and extra-cardiac morbidity, which physicians caring for these patients need to detect and manage.
Complications of a Fontan Circulation
An effective Fontan relies on low pulmonary vascular resistance (PVR) and elevated systemic venous pressure to drive transpulmonary blood flow. Systemic venous hypertension, however, can lead to direct effects on the liver, with a degree of fibrosis seen in all Fontan survivors [2] and abnormalities of the peripheral venous and lymphatic circulation. However, whichever organ is studied, there is evidence of an impact due to the effect of the Fontan circulation and the multiple surgeries performed in early life (Table 1). In our experience, educational outcomes have been largely good, and adult employment is typical, however, there is a risk of long-term learning deficit with consequences in later life, and there is frequently a psychological impact. A consistent long-term surveillance strategy for complications is necessary through adolescent and adult life.
|
Organ involvement |
Late complications |
|
Bone |
Osteopenia Osteoporosis |
|
Brain |
Cerebral abscess Cerebrovascular events Neurodevelopmental delay White matter changes |
|
General |
Cyanosis Delayed puberty Exercise intolerance Fertility issues Issues related to genetic syndromes Growth issues Psychological trauma |
|
Heart |
Arrhythmia – tachycardia & bradycardia Fontan pathway obstruction Outflow tract obstruction Pulmonary venous pathway obstruction Valvular heart disease Ventricular dysfunction |
|
Immune system |
Reduced immunoglobulins |
|
Kidney |
Reduced glomerular filtration rate |
|
Liver |
Cirrhosis Hepatocellular carcinoma (HCC) Liver fibrosis Portal hypertension |
|
Lungs |
Bronchial casts Hemoptysis Restrictive lung physiology |
|
Lymphatics |
Chylous effusions Plastic bronchitis Protein losing enteropathy |
|
Pregnancy |
Cardiac complications Fetal congenital heart disease Fetal loss Prematurity Hemorrhage |
|
Vascular |
Arterial and venous collaterals Dilatation of Damus Endothelial dysfunction Paradoxical embolus Venous thromboembolism |
Warchoł-Celińska et al. [3] carried out a multicenter study to assess the management of Fontan patients in Poland. They surveyed 8 centers caring for a total of 398 adolescent and adult patients with a Fontan circulation. Data were collected on follow-up, cardiovascular examination, and surveillance investigations. They applied a novel scoring system to create a standardized method of comparing centers. They demonstrated differences in the care and follow-up of adolescent and adult patients; with centers that provided care for pediatric patients (up until 18 years) achieving a better score.
Adolescents were more frequently followed up whilst adults were more likely to be hospitalized. The frequency of basic investigations such as electrocardiogram (ECG), echocardiogram, NT-proBNP, and chest X-ray (CXR) was satisfactory in both groups. There were, however, deficiencies in functional assessment and surveillance of long-term complications, with many patients not undergoing appropriate exercise assessment, liver monitoring, or cardiac evaluation with cardiac MRI.
The authors highlighted the need for a standardized approach to the long-term care of patients with Fontan palliation. European Society of Cardiology (ESC) guidelines for management of adult congenital heart disease (ACHD) recommend a follow-up strategy for these patients and others with complex congenital heart defects, in whom similar principles of care apply [4]. Using ESC guidance as a basis for clinical practice, we have developed a standarized approach to the transition of care from pediatric to adult care and lifelong follow-up of patients living with a Fontan circulation (Table 2).
|
Timing |
Assessment |
|
Age 12–16 |
Transitional process begins with introduction to adult service:
Possible formal evaluation with cardiac catheterisation and optimization as necessary |
|
16–18 years |
Transition of care to adult services Full baseline assessment as below |
|
All ages — annual |
Clinic review and examination 12 lead ECG Blood investigations:
Liver investigations:
Echocardiography |
|
All ages at routine interval |
Cardiac MRI Cardiopulmonary exercise testing |
|
As required |
Cardiac catheterization — pressures, pathway assessment, collaterals ± intervention as necessary Liver imaging — contrast enhanced MRI or Triple phase CT Lung function testing Prolonged ECG monitoring if symptomatic |
Transitional care is vitally important to ensure long-term compliance with surveillance strategies, optimize approaches to healthy living, and assist in making realistic life choices. Whilst many pediatric cardiologists are experienced in managing adult patients, the setting of care should be within the adult hospital to facilitate routine care and the management of emergency presentations and adult events such as pregnancy and routine inpatient care.
The nature of follow-up investigations is dependent on local facilities, but routine assessments of cardiac function and end-organ involvement are necessary in all patients. We follow a strategy as described in Table 2. Using a holistic approach, we recommend all patients undergo dental checks twice per year, for mitigation of infective endocarditis risk. We discuss with women of childbearing age contraception and pregnancy routinely.
We also recommend follow-up in a patient-initiated approach and utilize a dedicated team of clinical nursing specialists, who are available for patient advice by email and telephone.
In the UK, specialist centers offer outreach services to local hospitals in a network approach, to share experiences and expand care in the hospitals local to our patients. We recommend a collaborative working pattern with these centers and utilize a hub-and-spoke approach to routine and emergency care, with the hub being responsible for surgery and catheter-based interventions and supervising the care of pregnant women with a Fontan circulation. All specialized centers will have a relationship with a cardiac transplant center, with the ability to assess patients for possible cardiac transplantation.
ESC guidelines discuss minimal staffing levels required in a congenital heart disease center, including at least two consultant physicians each with a special interest in ACHD, ACHD structural intervention, and imaging. In addition, the regular presence of at least two congenital surgeons and two specialized cardiac anesthetists is recommended. The holistic care of these complex patients and families should be supported by dedicated clinical psychology services. National health systems have a responsibility to provide such safe levels of care for all complex congenital heart disease patients, including those with a Fontan circulation.
Article information
Conflict of interest: None declared.
Funding: None.
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