The Janus‐faced Fontan circulation: unravelling its elusive pathophysiology

Abstract

This article refers to 'Haemodynamic profiles in adultFontan patients: associated haemodynamics and prognosis' by W.R. Miranda et al., published in this issue on pages 803-809.The Fontan procedure is considered the treatment of choice for patients with a univentricular heart defect for whom biventricular repair is not possible. The Fontan procedure entails the surgical rerouting of the systemic venous return directly to the pulmonary arteries and thereby renouncing a subpulmonary ventricle. This results in a restored balance between pulmonary and systemic blood flow, maintaining oxygenation and perfusion. However, due to the absence of a subpulmonary ventricle, the Fontan circulation is characterized by a paradoxal chronically increased systemic venous pressure and non-pulsatile pulmonary blood flow. Furthermore, the single ventricle needs to drive the cardiac output through both the systemic and pulmonary vascular beds.Short-term outcomes of the Fontan procedure have been considered successful. However, long-term outcomes are characterized by an impaired functional clinical status with gradual attrition of the Fontan circulation over time.

The pulmonary vascular bed in patients with functionally univentricular physiology and a Fontan circulation

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