Fontan Circulation of the Next Generation: Why It's Necessary, What it Might Look Like

N ot many decades ago, it was the rare patient with a functionally univentricular heart who survived to adulthood. While this grim prognosis has gradually improved over the years, the diagnosis of single ventricle in a fetus or an infant is still the initiating event in what will become a cascade of clinical transitions and events demanding difficult management decisions. Care in the current era is directed toward the objective of achieving successful separation of the systemic and pulmonary circulations, using the functionally single ventricle to support the systemic arterial circulation while relying on surgically created direct systemic venous-topulmonary arterial connections to deliver blood flow to the lungs. Proof of concept for this approach was demonstrated in patients with tricuspid atresia by Francis Fontan in the late 1960s, and amplified almost contemporaneously by the work of Guillermo Kreutzer. Accepted indications for the evolving types and styles of “modified Fontan operation” have liberalized considerably since then, as surgical techniques have changed, facilitating the application of “total cavopulmonary connection (TCPC)” to an extremely broad spectrum of anomalies that are not amenable to biventricular repair.