True about circumcaval ureter ?

Circumcaval (retrocaval) ureter results from altered vasculature rather than ureteral development. Thus, preureteral vena-cava is more appropriate term.This disorder involves right ureter which passes behind IVC winding about and crosses in front of it from medial to lateral direction.The anomaly is divided into two types :?1) Type 1 : It is more common and has hydronephrosis with a typically obstructing pattern demonstrating some degree of fish-hook shaped deformity of ureter.2) Type 2 : It has lesser degree of hydronephrosis or not at all.