A Retrospective Analysis of Cardiac Anatomy in Patients Undergoing the Fontan Operation

Background Hearts suitable for Fontan palliation include those with an anatomically single ventricle (absence of a second ventricular mass), those with a single atrioventricular connection, and those with two ventricles in whom biventricular repair is not feasible due to anatomical or physiological complexity (functionally univentricular physiology). We describe the anatomical spectrum of such hearts over a decade at a single tertiary center. Methodology We encountered 420 patients undergoing the Fontan operation over a decade, between 2010 and 2019. Their detailed medical records were reviewed in this retrospective study, and the information gathered is presented in this article. The cardiac anatomy is presented depending on the information gathered from the medical records. Results A total of 420 patients underwent the Fontan operation during the study period. Only 30 (7.1%) had a true anatomically single ventricle. The remaining 390 had two ventricular chambers, including those with a hypoplastic ventricle. The most common anatomical diagnosis was double-outlet right ventricle (DORV) in 143 (34%) patients, followed by tricuspid atresia in 118 (28%) patients. Major aortopulmonary collateral arteries were present in 250 (59.5%) patients, and left superior vena cava in 61 (14.5%) patients. Completion Fontan operation after bidirectional Glenn shunt was the most common surgical pathway (n = 254, 60.5%), though primary Fontan (n = 15, 3.6%) and other staged approaches were also performed. Conclusions The anatomical spectrum of patients undergoing Fontan operation is wide and includes true anatomically single ventricle, single atrioventricular connection, and functionally univentricular physiology with two ventricular chambers. DORV was the most common diagnosis, followed by tricuspid atresia. The decision for Fontan operation was driven by a combination of anatomical and physiological factors. Early and long-term outcomes were not analyzed in this study.