Date Published: December 8, 2012
Publisher: Hindawi Publishing Corporation
Author(s): Edward Gologorsky, Angela Gologorsky, Eliot Rosenkranz.
Fontan and Baudet described in 1971 the separation of the pulmonary and systemic circulations resulting in univentricular physiology. The evolution of the Fontan procedure, most notably the substitution of right atrial-to-pulmonary artery anastomosis with cavopulmonary connections, resulted in significantly improved late outcomes. Many patients survive well into adulthood and are able to lead productive lives. While ideally under medical care at specialized centers for adult congenital cardiac pathology, these patients may present to the outside hospitals for emergency surgery, electrophysiologic interventions, and pregnancy. This presentation presents a “train of thought,” linking the TEE images to the perioperative physiologic considerations faced by an anesthesiologist caring for a patient with Fontan circulation in the perioperative settings. Relevant effects of mechanical ventilation on pulmonary vascular resistance, pulmonary blood flow and cardiac preload, presence of coagulopathy and thromboembolic potential, danger of abrupt changes of systemic vascular resistance and systemic venous return are discussed.
Separation of pulmonary and systemic circulations, initially conceived as a palliation for tricuspid atresia but subsequently expanded to include other causes of univentricular physiology was described forty years ago, in 1971, by Fontan and Baudet. The evolution of the Fontan procedure, most notably the substitution of right atrial-to-pulmonary artery anastomosis with cavopulmonary connections, resulted in significantly improved late outcomes. As the result, many patients survive well into adulthood, fall under NY Heart Association (NYHA) functional classes I and II, and are able to lead productive lives . Therefore, anesthesiologists may occasionally see these patients outside of specialized centers for adult congenital cardiac pathology; examples may include emergency surgery, electrophysiologic interventions, and pregnancy . This presentation illustrates, from a TEE perspective, some of the unique challenges faced by an anesthesiologist caring for a patient with Fontan circulation in the perioperative settings. Consent for this presentation was obtained from the patient.
A 31-year-old patient presented for replacement of a fractured epicardial lead and pacemaker pulse generator. His past surgical history was significant for a number of palliative interventions for a double-outlet right ventricle (DORV) with d-transposition of the great arteries and partial anomalous pulmonary venous return, culminating with a Fontan procedure, as well as a Maze procedure with epicardial pacemaker that leads placement for symptomatic atrial tachyarrhythmias. His medications included Warfarin for venous thromboembolism prophylaxis.
A schematic of the described patient’s circulation at birth is presented in Figure 2. A double outlet right ventricle (DORV) is a type of ventriculoarterial connection in which both great arteries originate entirely or predominantly from the right ventricle; a large nonrestrictive VSD serves as the only left ventricular outlet . Although in the majority of cases the aorta spirals posterior and obliquely to the pulmonary artery, in 30% it is found to course parallel and anterior to the pulmonary artery, resembling transposition of the great arteries. Therefore, the RV contributed to both the pulmonary and systemic circulation (making the patient’s original pulmonary and systemic circuits functionally parallel). Extensive intracardiac mixing of oxygenated and deoxygenated blood at multiple levels (ASD, VSD, and partial anomalous pulmonary venous return) was essential for the patient’s survival, but contributed to significant RV volume overload as well.