Results At 1, 10, and 20 years, survival for the entire cohort was 95%, 88%, and 76%, respectively, with no deaths in the last 6 years of the study. Hazard modeling showed a 1.3% risk of death per year 24 years after the Fontan procedure, with no late increasing hazard phase. Freedom from reoperations was greater than 90% at 20 years and freedom from thrombotic complications was 98% at 20 years (with greater than 80% of patients on aspirin alone). Survival curves were superimposable for 16- to 20-mm conduits, and the freedom from any reoperation including transplantation was greater than 90% after 20 years. Multivariable risk factor analysis identified only earlier date of operation as a predictor of early and late mortality. By era of surgery, the 10-year predicated survival is 89% for patients undergoing surgery in 2000 and 94% for patients in 2010.Conclusions Early and late survival after a Fontan operation with a PTFE conduit is excellent, with no late phase of increasing death risk after 20 years. Late functional status is good, the need for late reoperation is rare, and thrombotic complications are uncommon on a standard medical regimen including aspirin as the only anticoagulation medication.Objective Dating back to the first published report of the Fontan circulation in 1971, multiple studies have examined the long-term results of this standard procedure for palliation of single-ventricle heart disease in children. Although the technique has evolved over the last 4 decades to include a polytetrafluorethylene (PTFE) conduit for a large percentage of patients, the long-term outcome has not yet been established. The aim of the current study was to investigate the possibility of a late increasing risk for death after 15 years among patients with a modern Fontan operation and to evaluate late morbidity.© 2014 The American Association for Thoracic Surgery Methods Between January 1, 1988, and December 31, 2011, 207 patients underwent the Fontan procedure using an internal or external PTFE conduit plus a bidirectional cavopulmonary connection. Survival and late adverse events were analyzed. Risk factors for early and late mortality were examined using hazard function methodology.