Doctors use ureteral stents to treat kidney stones, according to WebMD. Ureteral stents are thin, hollow tubes that help drain urine and kidney stones by keeping the ureter open for a short period.
Doctors place ureteral stents in the ureter when something, such as kidney stones, infections, tumors and scar tissue, blocks the passage and restricts the flow of urine, states WebMD. The physician inserts the ureteral stent in the urethra through the bladder, past the ureter and into the kidney. The stent may be in place for several months. The risk of side effects associated with having a stent increases with time.