Ureteropelvic Junction Obstruction (UPJO)

What is a ureteropelvic junction obstruction (UPJO)?

Under normal conditions, the kidneys filter the blood and remove waste in the form of urine. The urine then drains from the kidneys down through the ureters into the bladder. A UPJO is an obstruction or blockage at the junction of the kidney and ureter. When a UPJO occurs, the amount of urine produced is more than the amount that can be drained through the ureter causing a ‘backup’ of urine. This in turn creates a collection of urine in the kidney, also called hydronephrosis.

There are multiple causes of a UPJO including abnormal tethering of the ureter or a narrowing of the ureter during fetal development. The most common cause of an obstruction or blockage occurs while the child is in utero and is considered a congenital obstruction.

Why come to The Children’s Hospital for treatment of this condition?

The professionals at The Children’s Hospital in Aurora, Colorado are dedicated to caring for kids. The members of the urology team are experts in pediatric urologic conditions and our surgeons are specialized in both pediatrics and urology. We strive to help patients and families feel educated about their condition, prepared for treatment and fully cared for by our urology team. 

What are the signs and symptoms?

Usually, a ureteropelvic junction obstruction has no symptoms; however patients suffering from urinary tract infections caused by an obstruction can experience flank pain, painful urination, irritability, fussiness, fever and/or foul-smelling urine.

How do you diagnose it?

A ureteropelvic junction obstruction is a congenital abnormality which can often be detected during pregnancy. It can be diagnosed during a prenatal ultrasound, however it may not show up until the child is older.

How is it treated?

Treatment of a ureteropelvic junction obstruction usually requires an operation called a pyeloplasty. During a pyeloplasty surgery the obstruction is removed and the ureter is reconnected to the kidney. This allows normal drainage to occur, however it can take some time for the kidney to fully drain. Sometimes a stent will be left in the ureter which allows the repair to heal. This helps the ureter to continue to function correctly. Removal of the stent takes place in the operating room and usually occurs 4 to 6 weeks later. Radiology testing is done after the surgery to ensure that the operation has worked.

Who gets it, and can it be prevented?

The cause of a UPJO is unknown, and therefore there is no known prevention for this condition.

When should I seek medical attention?

If your child is diagnosed prenatally, you may contact The Children’s Hospital Urology Department prior to or immediately after your child’s birth. If your child is not diagnosed at birth contact Children’s Urology for further evaluation at the recommendation of your primary care physician.