Ureteropelvic Junction (UPJ) Obstruction

What is ureteropelvic junction (UPJ) obstruction?

The ureteropelvic junction is the area where the kidney joins to the drainage tube that empties urine into the bladder. A blockage, or obstruction, can occur at this location.

What are signs and symptoms of a UPJ obstruction?

Many times in newborns, this obstruction is first recognized on prenatal ultrasound. The baby may show extra urine sitting within one of the kidneys. When this extra urine is severe, a blockage may be present.  Babies may also present with recurrent urinary tract infections.

In older children, signs and symptoms may be different then younger children. Older children may complain of abdominal or flank pain. They may also have this pain with vomiting. The pain and vomiting may come and go or be cyclical in nature. Older children may also present with kidney stones or urinary tract infections.

What causes a UPJ obstruction?

An obstruction in the tube can occur because that section of the ureter is narrowed or from compression of a nearby blood vessel.

What tests are done?

Renal bladder ultrasound can be used to look for back up of urine in the kidney, which is also called hydronephrosis. Ultrasound is a non-invasive test that uses sound waves to visualize the kidneys and bladder.

A MAG-3 test is usually done to determine how well the kidneys function and see if the kidney drains slowly from a blockage. During this test your child will have an IV placed and a catheter in the bladder. The IV is used to inject the isotope that allow the kidneys to be visualized.

How is UPJ obstruction treated?

The treatment for a UPJ obstruction is usually surgical.  However, in some children the blockage is mild and the kidney functions well. In these children, the blockage may be watched very closely with repeat imaging.

During surgery the narrowed area is fixed and a drain may be left inside to help the area heal better.  This surgery is called a pyeloplasty. The surgery may be done through a very small incision up by the kidney. In bigger and older children, this procedure can sometimes be performed via very small incisions either laparoscopically or robotically. Your surgeon will discuss these options with you.

UPJ obstruction can be treated in our Robotic Surgery Program.