hi yogendra, usually stricture of ureter
occurs after prior surgery (for stone), prior stone passage or rarely due to tuberculosis
of kidney and ureter. often times, stricture seen on ivp may turn out to be small ureteric stone causing obstruction and narrowing. before going for open surgery, a urologist
can do an endoscopy
and push a dye into the ureter to confirm. if there is a stone, it can be removed. if there is complete block, it will need open surgical repair and re-implantation
of ureter into bladder. if partial block, an attempt at dilatation and DJ stenting can be made. results of open surgery for this stricture are better than endoscopic dilatation in most cases. good luck.