A ureteral (say "you-REE-ter-ul") stent is a thin, hollow tube that is put in the ureter to help urine pass from the kidney into the bladder. Ureters are the tubes that connect the kidneys to the bladder.
A ureteral stent is put in when something is blocking the ureter. A blocked ureter can cause urine to back up into the kidneys. This can hurt the kidneys. It can also cause an infection. The blockage can be caused by problems such as a kidney stone, scar tissue, a tumor, or an infection. A stent may be needed after surgery on the ureter or kidney.