BackgroundExtracardiac conduit Fontan procedure (ECFP) employing a Gore-Tex conduit has been widely used for patients with single ventricle physiology; however, the long-term status of the conduit is unknown. We investigated the changes in a Gore-Tex conduit after ECFP and the factors associated with its narrowing. MethodsWe conducted a retrospective analysis of 86 patients who underwent ECFP between January 1995 and December 2008 and had cardiac computed tomography (CT) during the follow-up period. ResultsThe median patient age at ECFP was 2.8 years (range 1.6–9.7), and a cardiac CT was obtained at 13.1 ± 3.4 years later. The minimum conduit area decreased by approximately two-thirds of the original due to calcification, pseudointimal hyperplasia, thrombus, and luminal irregularity. The normalized minimum conduit area was influenced by the time interval from ECFP and normalized original conduit area at ECFP. An oversized conduit was associated with a narrowing of both its sides and a high frequency of pseudointimal hyperplasia or mural thrombus. The ratio of minimum conduit-to-inferior vena cava areas was lower in patients with chronic liver disease than in those with a normal liver. The maximum percent stenosis of the conduit correlated with oxygen pulse and heart rate during peak exercise. ConclusionsUsing a larger conduit at ECFP resulted in a larger minimum conduit area at follow-up. However, oversizing requires careful monitoring for stenosis near anastomotic sites and the occurrence of pseudointimal hyperplasia or thrombus.