1.Double-J (D-J) or percutaneous nephrostomy tube is usually placed for urinary internal or external drainage. The J-shaped catheter is self-retaining at both the ends – the renal pelvis and the bladder. The method of internal drainage of D-J insertion is less invasive without external wound and may provide a better quality of life and body figure than external percutaneous nephrostomy drainage.More than four decades since the first description of an indwelling ureteral stent by Zimskind et al. in 1967,D-J insertion is now the accepted procedure of choice for maintaining a patent ureter. It can be placed in a retrograde or antegrade method.

2.The ureters carry urine from the kidneys to the bladder. (Each kidney is connected to one ureter.) In rare cases, both ureters may be blocked, in which case bilateral ureteral stents are placed, one in each ureter.