“…However, the study also demonstrated that nine patients experienced technical failure due to long-segment obstruction or diffused stenosis of the HV (2). The difficulty and challenge of HV recanalization in patients with long-segment obstruction of the HV may be attributed to the following factors: first, it is extremely difficult to cut through the long-segment of obstruction (1,2). Second, long-segment obstruction of the HV occasionally results in narrowing of the HV stem, which will impede its drainage function (2).…”