Definition

Ureteropelvic junction (UPJ) obstruction is a blockage in the area that connects the renal pelvis (part of the kidney) to one of the tubes (ureters) that move urine to the bladder.

Causes, incidence, and risk factors

UPJ obstruction generally occurs when a baby is still growing in the womb.

The condition can also be caused when a blood vessel is located in the wrong position over the ureter.

Treatment

Surgery to correct the blockage lets urine to flow normally. Open (invasive) surgery is usually performed in infants. Adults may be treated with less-invasive procedures.

Recently, laparoscopy has been used to treat UPJ obstruction in children and adults.