Could sterile water match chemotherapy in preventing bladder cancer return?

This trial tests whether rinsing the bladder with sterile water during surgery works as well as a chemotherapy drug (gemcitabine) placed directly into the bladder to prevent cancer from coming back. People with upper tract urothelial carcinoma who are having surgery to remove the affected kidney or ureter may join. The goal is to see which approach better reduces the chance of bladder cancer recurrence after surgery.