['Ultrasound is increasingly used to facilitate right internal jugular vein (RIJV) cannulation in children. In children without cardiac disease, position changes and enhancement maneuvers increase RIJV cross-sectional area (CSA) and further facilitate cannulation. We investigated the effect of these maneuvers on RIJV CSA in children with a bidirectional Glenn (BDG) shunt presenting for a Fontan procedure.', 'The CSA (cm(2)) of the RIJV in 21 children with a BDG shunt presenting for a Fontan procedure was assessed by ultrasonic planimetry (SonoSite). Two positions, supine (S) and 15 degrees Trendelenburg (T); and two enhancements maneuvers, manual liver compression (L) and a simulated Valsalva maneuver (V) were utilized in combination. Eight separate measurements (S, S + L, S + V, S + L + V, T, T + L, T + V, T + L + V) were made in each patient. Data were analyzed using one-way analysis of variance with repeated measures and with Tukey post hoc pairwise comparison analysis.', 'No significant change in the RIJV CSA or % change in CSA from baseline (S) was observed.'] Do trendelenburg position , simulated Valsalva maneuver , and liver compression alter the size of the right internal jugular vein in patients with a bidirectional Glenn shunt?