Stents are frequently used to treat stones that have caused blockage to the ureter. A stent can be placed beside the stone to relieve the pain, or after a stone has been removed to stop the ureter getting blocked postoperatively from bruising and swelling.
A stent is nearly always inserted after ureteroscopy / ureteropyeloscopy as otherwise patients will experience severe pain due to blockage in the system. Stents may also be inserted into the ureter to stretch it in cases where the ureter is too narrow to allow the passage of an instrument i.e. stents gradually stretch the ureters.
After a week or two with a stent in the ureter, it is often easier to insert a ureteroscope in order to treat stones in the urinary tract.