Budd-Chiari syndrome (BCS) is a vascular disorder characterized by obstruction of hepatic venous outflow from the hepatic venules to the entrance of the inferior vena cava (IVC) into the right atrium.1,2 In contrast to Western countries, IVC obstruction is a common cause of BCS in China. This disorder is classified into membranous obstruction of IVC (MOVC; obstructed segment of IVC is ≤1.0 cm) and segmental obstruction of IVC (SOVC; obstructed segment of IVC is >1.0 cm). [3][4][5][6] Treatments for this disorder include medical management, surgical operation, and endovascular intervention. Medical management alone has a limited ability to arrest progression of the disease, as reported in a study of 237 patients, where 72% failed to show a significant survival benefit.7 Surgery has been associated with high mortality rates (≤50%) and complicated by dysfunction rates as high as 32%. 8,9 Endovascular intervention has proven more effective than medical management and is associated with lower rates of mortality than open surgical procedures. [10][11][12] It has become the primary treatment of choice for BCS management in China because of its minimal invasiveness and good efficacy.Although several studies reported the safety and efficacy of endovascular intervention for the management of primary BCS caused by IVC obstruction, [13][14][15][16] few studies compared long-term outcomes of endovascular management between MOVC and SOVC patients. Moreover, there are still controversies about the optimal endovascular strategy for these conditions according to previous reports. 5,[13][14][15][16] Two previous studies showed that balloon dilation alone was sufficient in most BCS patients with MOVC and SOVC, and <3% had recurrence in 3 to 8 years of follow-up.5,13 However, otherBackground-Endovascular management is important for the treatment of primary Budd-Chiari syndrome, which is caused by inferior vena cava (IVC) obstruction. The aims of this study were to compare long-term outcomes of endovascular management for primary Budd-Chiari syndrome patients with membranous obstruction of IVC (MOVC) and segmental obstruction of IVC (SOVC) and explore the optimal endovascular strategy for these conditions. Methods and Results-Clinical data of 265 patients with Budd-Chiari syndrome who received endovascular management (MOVC group, n=136; SOVC group, n = 129) were retrospectively reviewed. Cumulative IVC patency rates were generated by the Kaplan-Meier method and compared by log-rank test. In total, 245 patients were followed up from 3 to 72 months after treatment. The difference of long-term outcomes of balloon dilation alone versus stent placement was not significant in each group. The overall cumulative 1-, 3-, and 5-year primary IVC patency rates were 98.3%, 90.7%, and 83.8% in the MOVC group and 88.3%, 79.1%, and 67.9% in the SOVC group (P=0.007), respectively. The long-term IVC patency rates were lower in the SOVC group than in the MOVC group for patients who underwent balloon dilation alone (P=0.001) and did not significantly d...