Objective: This study intends to document the presence or absence of triphasic waveforms in hepatic veins in healthy children. Does absence of triphasic hepatic vein flow indicate hepatic abnormality?
Subjects and methods: One hundred children without a known hepatic or intrathoracic abnormality underwent Doppler sonography of their hepatic veins. Fifty girls and 50 boys were divided into five age groups.
Results: Forty-two children had triphasic flow in all three hepatic veins. Veins approaching an angle of 90 degrees with the inferior vena cava could not be assessed or had the least flow modulations despite angle correction. Neonates had the highest percentage of monophasic flow (seven of 21) in all three hepatic veins and none had triphasic flow in all three veins.
Conclusion: Not all healthy children have a triphasic flow pattern in all hepatic veins. Before suspecting hepatic abnormality with abnormal parenchymal compliance (cirrhosis, graft rejection) by virtue of lack of triphasic hepatic vein flow, a normal variant of the flow should be considered. Only the change of a previously documented triphasic flow to monophasic flow in a given vein should be assessed as a sign of possible abnormality.