Children are at a higher risk of incurring damage to the kidneys due to a UVJ blockage.
The area where the tube that carries urine from the kidney to the bladder and the actual bladder itself converge is the ureterovesical junction. When there is a blockage of some kind in this junction, it is called a ureterovesical junction obstruction or UVJ obstruction.
The blockage causes the ureters to stretch out and expand due to urine back up, and the kidneys begin to swell as a result of excess urine. In more simple terms, the urine simply has nowhere to go since the entrance to the bladder is obstructed and drains slowly. UVJ obstruction is most often detected by routine prenatal ultrasounds.
Ureterovesical Junction Obstruction Causes
- An obstruction of the ureterovesical junction happens during the development of the child in utero. The UVJ obstruction can be a direct result from a malformation that occurs when the ureters grow into the bladder during urinary tract development. It also can occur when there is a narrowing of the connection between the bladder and ureter.
- On occasion, older children will develop a blockage in the UVJ as the result of a severe untreated infection or a lodged kidney stone.
The quickest way to diagnose a UVJ blockage is by doing an ultrasound on the kidneys and bladder area to see how swollen the ureters and kidneys appear to be. A voiding cystourethrogram, or VCUG, can confirm an obstruction with reflux because the x-ray contrast material injected into the bladder via a catheter will allow the physician to see any urine back up to the kidneys. There may also be a role for a renal scan, used to evaluate function and the drainage pattern of the kidney and ureter.
- When a UVJ obstruction is detected before the child is born, there are no symptoms present aside from mild enlargement of the baby’s kidney(s) or ureter(s) on a prenatal ultrasound. In those cases, the baby is closely monitored until he/she is born, at which point the blockage can be treated, if needed.
- UVJ obstruction symptoms can include pain in the abdominal area, back pain, bloody urine, especially in the presence of infection, fever, frequent urinary tract infections, nausea, and vomiting.
- In some cases, the presence of kidney stones can be a sign that one of them is causing a UVJ blockage.
Ureterovesical Junction Obstruction Treatment Options
Preserving the function of the renal system is the main objective of UVJ obstruction treatment. Surgery is the only way to permanently resolve the UVJ blockage, and because most cases are in newborn babies, a temporary fix has to be put into place until the child is able to undergo the permanent resolution surgery.
- A ureterostomy is where the bladder and the ureter are separated and the ureter is connected to the skin for an external drainage of urine in order to bypass the bladder.
- Temporary ureteral or kidney tube drainage may also allow drainage of the blocked kidney until a permanent removal of the blockage can be done.
- When the child is older, usually after a few months of life, they are usually strong enough and big enough to undergo the full ureteral correction of UVJ obstruction which will resolve the blockage.