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Ureteropelvic Junction Obstruction

The Children's Hospital Department of Pediatric Urologic Surgery


The urinary system includes the kidneys, ureters, bladder and urethra. The kidneys produce urine which is drained into the bladder via small tubes called ureters. Ureteropelvic Junction (UPJ) Obstruction is a condition where there is an abnormality in the ureter obstructing the normal flow of urine. When urine cannot properly drain into the bladder it will pool in the kidney, causing the kidney to swell. This condition is referred to as hydronephrosis. A UPJ obstruction can occur in one, or both, ureters.

Urine that is unable to drain adequately can make a child quite ill. Typically, a kidney infection will occur, secondary to the urine’s inability to drain correctly. Once an infection of the kidneys is diagnosed, x-rays will be needed to determine if there are structural abnormalities.


         An illustration depicting an
          abnormality in the ureter

A kidney/bladder ultrasound (RUS) will be obtained to evaluate for the presence of hydronephrosis. Your child will also have a renal lasix scan (MAG III with lasix) to evaluate the kidneys’ ability to drain and to evaluate if there is an obstruction in the tubes.

Surgical Treatment

The surgical procedure used to correct this problem is called a pyeloplasty. This involves a small incision made on the side that has the obstruction. The abnormal part of the ureter is removed and the remaining part of the ureter is reconnected to the kidney. After surgery your child will have a small tube (penrose drain) coming from the incision. This tube is to keep drainage away from the incision as it heals. It will be left in for 7-10 days at which time you will return to the Urology Clinic to have it removed. In addition your child may have a tube (stent) left in the ureter, which will allow the kidney to drain and give the ureter time to heal. This will be removed 6-8 weeks after surgery. Stent removal is a very simple procedure requiring approximately 30 minutes and will be performed in Day Surgery. Follow-up is a clinic appointment with a renal ultrasound and a MAG III with lasix scan several months after surgery.