The obstructive positions were found 9 at the upper ureter (26- 5% ), 25 at the lower ureter (73. 5% ),and among the later group, 7 (20. 6% )at the intramural portion of ureter.

• 梗阻部位在输尿管上段9例（26.；5%25），输尿管下段25例（73