下腔静脉后输尿管指输尿管上 1/ 3位于腔静脉之后 ,在腔静脉与主动脉之间绕到腔静脉之前 ,然后按正常通路进入膀胱 ,是较为少见的输尿管畸形。胚胎时后肾从骨盆上升 ,穿过静脉环达腰部 ,此静脉环称为肾环 ,分为前后两部分 ,输尿管从中经过。下腔静脉由肾环后面组成 ,因此输尿管 Inferior vena cava behind the ureter refers to the ureter 1/3 after the vena cava, between the vena cava and aorta around the vena cava before the normal access to the bladder, is a relatively rare ureteral deformity. When the embryo kidney from the pelvis rise through the venous ring reaching the waist, the venous ring called the kidney ring, divided into two parts before and after the ureter through. The inferior vena cava is made up of the back of the kidney ring, so the ureter