Urter are mildly dilated aftr ston oprtn

I was diagnosed kidney stone of 2 stones of 15- 15mm in ureter and 1 of 3mm in kidney.after operation of ureter one stone of 15 mm stent is placed and after 1 month it is removed.After removal of stent infection and high grade fever and shievering is started.and again put the doctor stent but stent is not placed propely due to obstruction of stone.after some time infection is again started. then we change the hospital doctor and new hospital doctor placed it properly and some relief in fever is done.he do the operation after 10 days and when after Operation catheter is removed again infection started.He give highly antibiotics For 10 days in hospital then it become settle down. now after one month i have done ultrasound and "pelvic calceal system and ureter are mildly dilated with mildly thickened ureter wall approx 1.8 mm. non obstructing calculi of 3 mm are noted in upper right ureter are diagnosed. then what should do in this.