A ureteropelvic junction obstruction (UPJO) is a congenital narrowing or blockage where the ureter meets the kidney. These develop prenatally (before birth) as the kidney forms. Studies suggest that it is more common in males and on the left side. Sometimes both kidneys are involved.

This narrowing prevents normal draining of urine (pee) from the kidney. This causes hydronephrosis (kidney swelling). With prenatal ultrasounds, hydronephrosis is often diagnosed as early as 15-20 weeks of fetal development. Early detection allows for evaluation and treatment soon after birth.

Signs and Symptoms

Symptoms of a UPJO may be an abdominal mass (felt on a routine exam by the primary care provider) or a urinary tract infection with fever, belly pain or back (flank) pain. The flank pain may worse with increased fluid intake. Other symptoms may include blood in the urine and vomiting. Symptoms of a UPJO may not occur until the obstruction has progressed. High-grade obstruction (blockage) of the kidney can lead to increasing kidney damage and loss of kidney function. Sometimes a UPJO can be found by chance, after an injury to the back or abdomen occurs and imaging shows a swollen kidney.

Treatment

UPJO can be diagnosed with different imaging methods. The method used depends on the age of the baby or child. Common radiology tests include: renal / bladder ultrasound, voiding cystourethrogram and Lasix renal scan.

1. If a prenatal ultrasound shows hydronephrosis, a renal / bladder ultrasound will be done in the first few weeks after birth. A renal / bladder ultrasound will show kidney size and the degree of swelling. This may be repeated later.
2. A voiding cystourethrogram (VCUG), will often be done at the same time as the renal ultrasound or soon after. This test will show if there is back flow of urine from the bladder up the ureter and to the kidney. This back flow of urine is called vesicoureteral reflux.
3. A Lasix renal scan is a nuclear medicine study that is done to look at the function and drainage of the kidney. With this test, a dye is injected into the child's vein along with Lasix, a diuretic. The drainage of the dye from the kidney is then "timed." Drainage times from both kidneys show the amount of blockage. They also show how much work each kidney is doing.

Your child's urologist will study the test results to see if the kidney is blocked. Sometimes, further follow-up testing is needed to make this decision. There are times when the swollen kidney improves on its own and no surgery is needed. Your doctor will talk to you about this.

Surgery for UPJO is recommended in some cases to protect kidney function. Surgery right after birth is most often not necessary but may be done as soon as 1-2 months of age. Close monitoring and testing will be done by your urologist.

Pyeloplasty is the surgical repair of the kidney to drain and decompress the swollen kidney. During the surgery, the narrowed segment is removed. The ureter is then re-connected to the kidney. Your child may have a temporary drainage tube in the kidney. The surgery usually takes 3-4 hours. Your child may stay in the hospital for 1-3 days.

Follow-up testing will include a renal ultrasound 1-3 months after the surgery. Your child may be placed on a low dose of antibiotics, taken by mouth, to help prevent urinary tract infections. Your doctor will decide when the medicine can be stopped.

Call Your Child's Doctor If:

1. Temperature greater than 101 degrees
2. Bleeding from the incision (cut)
3. Bright, red blood in the urine
4. Extreme irritability / pain not controlled with pain medicine
5. Difficulty peeing
6. Lack of drainage out of the kidney drainage tube