Fig. 2

The traced waveform of the inferior vena cava pressure. A–B: The normal IVC pressure was approximately 10 mmHg. B–C: When the veno-venous bypass was open, the IVC pressure decreased to 8 cmH₂O. C–E: When the azygos vein was temporarily blocked, the IVC pressure quickly increased to 52 cmH₂O. When the azygos vein was opened, the IVC pressure gradually decreased to 8 cmH₂O