Gil Wernovsky

James S. Tweddell

In the late 1960s, two surgical teams (one led by François Fontan in Bordeaux, France, the other by Guillermo Kreutzer in São Paolo, Brazil) concurrently introduced what is perhaps the most “disruptive” surgical innovation in congenital cardiac surgery—a procedure that simultaneously eliminated volume load and cyanosis among patients with a functionally univentricular heart. These operations were initially applied to patients with right heart obstructive lesions (tricuspid atresia in particular) and were termed “right heart bypass” procedures. The success of these pioneering operations has been followed by multiple surgical modifications of the original concept. With a long-term palliative option now available for the patient with a functionally univentricular heart, additional ingenious and equally disruptive operations were created, including the Norwood and hybrid procedures, the superior cavopulmonary connection (the “bidirectional Glenn”), and others. These newer procedures have continued to undergo modifications to better allow survival in infancy and minimize risk factors for the eventual modified Fontan (or perhaps more correctly Fontan-Kreutzer) procedure. In combination, these complex surgical procedures can be considered staged reconstruction . Along with medical management and monitoring, they have come to be known colloquially as the Fontan pathway.

In this text and elsewhere, congenital cardiac anomalies are typically described morphologically, followed by a description of the physiology, surgical and perioperative management, and finally, outcomes for these conditions. This type of approach is impossible and inadequate for the myriad of anatomic conditions that require an approach of staged reconstruction. In addition, the perioperative care and short- and long-term outcomes are quite similar irrespective of the cardiac malformations necessitating this management strategy. Therefore the following chapters approach the management of patients with a functionally univentricular heart in a somewhat unorthodox fashion ( Fig. 68.1 ), emphasizing what is necessary for a child to undergo the “Fontan pathway” with the highest likelihood of survival, along with both a good duration and quality of life.

The Fontan pathway is a term used colloquially to denote the combination of surgical procedures (orange) and medical monitoring/management (blue) for children and adults born with a functionally univentricular heart. Monitoring and management during interstage I is becoming more standardized, whereas medical management, surveillance for consequences of the Fontan circulation, and guidelines for cardiac transplantation remain highly variable and center specific.

In Chapter 69 , the multiple anatomic malformations that do not allow for a biventricular repair are described and illustrated. This is followed in Chapter 70 by an in-depth discussion of the anatomic and physiologic principles that maximize the survival rate as well as the ultimate success of the final planned surgical procedure in this approach, which for the purposes of these chapters is simply called the Fontan procedure, as it is most widely known. In the past 3 decades, recognition of these important principles has led to a better understanding of the timing and techniques required for the initial and subsequent surgical procedures as well as the physiologic changes during and after staged reconstruction.

The physiologic indications for the type, timing, and number of surgical procedures are determined by the unique anatomy of each patient with a functionally univentricular heart. These various surgical procedures are described in detail in Chapter 71 . Irrespective of the anatomic substrate and types of surgical approaches necessary, the perioperative physiology and management following each of these procedures is surprisingly similar; these are also discussed in Chapter 71 . Likewise, the principles of interstage monitoring (discussed in Chapter 72 ) as long-term consequences (discussed in Chapter 73 ) are quite similar irrespective of the underlying anatomy.

The Fontan procedure has been one of the most remarkable achievements in the fields of pediatric cardiology and cardiac surgery. The past 5 decades have seen an exponential increase in the number of patients who have survived into adolescence and adulthood with a “Fontan circulation,” including gratifying examples of survival into the fourth and fifth decades of life, successful pregnancies, career satisfaction, and an acceptable quality of life. However, along with this success has come an increased understanding of the long-term consequences of the Fontan circulation, including effects on the heart itself; the impact on multiple organ systems, particularly the gut, liver, and brain; the psychosocial impact of a chronic medical condition; the need for additional interventional (see Chapter 19 ) and surgical procedures; as well as the physiologic state known as “Fontan failure,” the surgical options for which are extremely limited and that may ultimately lead to cardiac transplantation (see also Chapter 67 ).

The future directions and outcomes for children born with a functionally univentricular heart remain both optimistic and unknown. Despite the longer-term consequences now being described for children undergoing staged reconstruction, there can be a sense of optimism. In virtually all congenital cardiac malformations, increased survival rates and ongoing research have led to an increased understanding of the long-term consequences of surgical interventions, followed by changes in surgical, medical, and interventional approaches, leading to subsequent improvements in survival and quality of life seen over time. The Fontan pathway is no exception. Innovations in medical, catheter, and technologic interventions as well as the standardization of follow-up are under way. We believe that although the lifelong outcomes for our current and future patients are unknown, experience tells us that those will improve incrementally over time.

“We can’t solve problems by using the same kind of thinking we used when we created them.” –ALBERT EINSTEIN