Doppler waveform of the hepatic veins in an obese population.

The objective is to investigate the effect of obesity and hepatosteatosis on the Doppler waveform pattern of the hepatic veins. B-mode and duplex Doppler sonography of the liver and the right hepatic vein was performed in 102 obese subjects and 84 healthy volunteers. The severity of fatty infiltration was graded as mild, moderate and severe. The flow pattern of the right hepatic vein was classified as triphasic, biphasic and monophasic. The Doppler flow pattern in the right hepatic vein was triphasic in 56 (55%), biphasic in 27 (26%) and monophasic in 19 (19%) obese patients, whereas it was triphasic in 83 (99%) and biphasic in 1 (1%) control subject, achieving a statistical significance (Mann-Whitney U-test, P<0.001). There was an inverse correlation between the sonographic grade of the hepatosteatosis and the phasicity of hepatic venous flow (r=-0.67, P<0.001). The hepatic vein pulsatility is significantly dampened in obese patients correlating with the grade of hepatosteatosis. The body habitus itself does not have an independent effect on hepatic venous waveform. The alteration in hepatic vein Doppler flow pattern in an obese population may suggest reduced vascular compliance in the liver because of fatty infiltration.