Ureteropelvic Junction Obstruction (UPJO)
What is it?
An ureteropelvic junction obstruction (UPJO) is a blockage where the ureter and renal pelvis meet. The ureter is a tube that drains urine from the kidney to the bladder. The renal pelvis is the collecting area of the kidney. A blockage at this place can lead to urine backing up, causing the kidney to enlarge (hydronephrosis).
How common is it?
UPJO is one of the most common birth defects of the ureter. It is more common in males and affects the left kidney more than the right. A blockage in both kidneys occurs in about 10-15% of the cases.
What causes it?
This defect occurs while the kidney is developing in the unborn infant. The cause of UPJO is not well known. The result is a narrow segment of the ureter that causes a blockage. It can often be found on prenatal ultrasounds.
Signs and Symptoms
UPJO may cause flank or back pain, blood in the urine, and repeated urinary tract infections. But most often there are no symptoms.
How is it diagnosed?
Special tests are done to look for UPJO. A renal ultrasound can help find out if the kidney is enlarged. A renal scan is needed to confirm blockage and assess how well the kidney is working. It is done by putting a dye into a vein and taking pictures as it travels into the kidney and down the ureter to the bladder.
How is it treated?
If the UPJO is severe, an operation called a pyeloplasty is done. The blockage is removed and the ureter is re-attached to the kidney. This is done in the operating room under general anesthesia. In some cases, a stent may be placed in the ureter to help drain the kidney. The stent will remain in place for about six weeks. Risks linked with a pyeloplasty include return of the blockage and infection. The success rate is greater than 95%.
How do I get more information?
Call the Urology Clinic, Monday-Friday 8:00 - 4:30 at (608) 263-4757.
If you live out of the area, call 1-800-323-8942 and ask for the urology clinic.
The information provided should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Any duplication or distribution of the information contained herein is strictly prohibited.
Last Updated: 05/06/2010
Copyright © 05/06/2010 University of Wisconsin Hospitals and Clinics Authority. All rights reserved. Produced by the Department of Nursing. HF#5963
Print Health Fact For You