Some patients are born with a narrowing of the ureter where it leaves the kidney or where it enters the bladder. Scar tissue from previous surgery or stones in the ureter can also cause narrowing of the ureter with blockage of the flow of urine from the kidney. These abnormalities can be treated using the ureteroscope to examine the area of narrowing and use a device through the ureteroscope to incise, or cut, the area of stricture or scar tissue. A fter this procedure, a stent (a small tube that passes from the kidney, down the ureter to the bladder) is left inside the body for several weeks. This stent helps to keep the kidney drained, and can usually be easily removed in the office.