Surgery for the obstruction is done thru an anterior approach and the kidney and pelvis are approached to reveal the site of obstruction. Part of the dilated pelvis and upper part of the narrowed ureter is removed and the remaining pelvis and the ureter is joined together with fine sutures to allow the urine to pass easily into the bladder. The back pressure on the kidney substance is taken away and now the kidney function can start recovering. The time taken for recovery may vary and a follow up of at least 3 years is necessary to determine the recoverability of the renal function.