Patients With Hypoplastic Left Heart Syndrome Have a Shorter Superior Vena Cava

The primary treatment for hypoplastic left heart syndrome (HLHS) is the Fontan pathway, which entails performing the Glenn procedure. We hypothesized that the superior vena cava in patients with HLHS was short. As the length of the superior vena cava influences the Glenn procedure, we compared its length between patients with HLHS and those with other congenital heart diseases. Patients with HLHS or its variant, patients with ventricular septal defects (VSD), and patients with pulmonary atresia with intact ventricular septum (PA/IVS)—including critical pulmonary stenosis—were enrolled in this study. The effective superior vena cava ratio (ESCVR), which is defined as the inferior border of the left brachiocephalic vein to the superior surface of the right pulmonary artery/height, was measured. The median ESVCR of the HLHS, VSD, and PA/IVS patients was 12.54 mm/m, 17.96 mm/m, and 18.46 mm/m, respectively. ESVCR of the HLHS group was significantly smaller than that of the other groups (P = .0013 vs VSD group, P = .0002 vs PA/IVS group). Patients with HLHS have a relatively short superior vena cava, which may complicate the Glenn procedure.