OBJECTIVETo determine whether there are differences in both the right hepatic vein (RHV) morphology and the size of the angle between the inferior vena cava and the RHV in patients with membranous obstruction of the inferior vena cava (MOVC),in healthy individuals and in patients with cinhosis (HLC), in order to help guide development of an effective interventional treatment program.

METHODSConsecutive patients (n=248) were divided into the following three groups: group A (control; n=94), group B (MOVC patients; n=68), group C (HLC patients; n=86). The angle between the hepatic vein and inferior vena cava was measured and defined as the T value. The morphology of the RHV was classified as N, U, or I. The difference of the constituent ratio was compared among the three groups for the T value and the angle type.Measurement data was calculated as x ± s,and groups were compared using one-way ANOVA; count data was calculated as relative number, and groups were compared using the chi-square test.

RESULTSThe average T value of group B was significantly higher than that of group A (56.1 ± 13.7 vs. 49.3 ± 7.8, P=0.010) and of group C (vs. 51.5 ± 10.0, P < 0.001); the difference was statistically significant (F=8.750, P < 0.001), but there was no significant difference between the groups A and C.N-type proportion of B group was 48.5% (33/68), greater than that of group A(16.0%,15/94) and C (16.3%, 14/86), x² = 20.1, x² =18.6.U-type proportion of B group was 11.8% (8/68), smaller than that of groups A (28.7%,27/94) and C (37.2%, 32/86), 2 2 = 6.70, x² =12.8, and the differences were statistically significant (P < 0.01). For groups A and C, the N and U types were not significantly different.

CONCLUSIONThe angle between the RHV and the inferior vena cava in MOVC patients is morphologically different from that in healthy humans, with the angle value in MOVC patients being slightly larger. However, this difference is irrelevant to cirrhosis.