Abstract
Around 3-4 children born with congenital heart diseases have univentricular hearts, where the prognosis of univentricular hearts is poor in the past, with a survival rate of less than 50% during the first year and 10% during the first ten years of life. Based on a literature search, current advances in perioperative management of neonates with complex congenital heart diseases have increased their survival rate by 85%. To aid cardiothoracic surgeons worldwide, this comprehensive literature review will focus on the perioperative management of staged palliation surgery for functional univentricular hearts, considering current trends as well as how we do it in our centre. Our review article specifially discusses perioperative strategies regarding surgical considerations, current techniques, to deal with overshunting and undershunting during the first stage of palliation surgery. This article also gives an overview on when a patient is suitable to go through with the next stage of the procedure, which is the implementation of a bidirectional cavopulmonary shunt or the Hemi-Fontan procedure. Lastly, this article gives a comprehensive approach regarding perioperative strategies of the Fontan procedure, which include patient criteria, current surgical techniques, postoperative management, as well as the use of anticoagulants after the Fontan procedure.
Keywords: fontan procedure, perioperative management, staged palliation, univentricular hearts
Introduction
Congenital heart diseases (CHD) are the most frequent congenital defect found in neonates, accounting for nearly one-third of major congenital anomalies.1 CHD that cannot be surgically reconstructed to achieve normal anatomic conditions of biventricular circulation are often described as functional univentricular hearts (UVH). It is reported that the incidence of functional UVH is 3 to 4 per 100 children born with CHD.2 The natural history of functional UVH is poor in the past, with a reported survival rate of less than 50% at one year and 10% at ten years. Advances in perioperative management for neonates with complex CHD have increased survival rates by more than 85%.3, 4
The functional univentricular heart can result from a variety of anatomic lesions. Regardless of the etiology, newborns with these lesions mix systemic and pulmonary venous blood. Perioperative management is becoming as important in patients with UVHs as preoperative patient management focuses on the balance of competing circulations, where systemic and pulmonary circulations exist in parallel rather than in series, as in normal circulation. Thus, most patients will require surgical intervention to provide unobstructed systemic blood flow (Qs) and restrictive pulmonary blood flow (Qp).5 Intraoperative management focuses on selecting ideal candidates for each staged palliation surgical procedure such as pulmonary artery size and pulmonary artery resistance index, while postoperative patient management focuses on optimizing systemic output, respiratory status, and mitigating the effects of cardiopulmonary bypass.5