Ureteropelvic Junction (UPJ) Obstruction

What is UPJ obstruction?

This condition involves a blockage of the ureter. This can be congenital (something one is born with) or acquired. The ureter, which is the drainage tube from the kidney to the bladder, is 10 inches (25 cm) long and has three constrictions along its course: where the pelvis of the ureter joins the ureter, where it is kinked as it crosses the pelvic brim, or where it pierces the bladder wall.

Congenital causes include malformation of the ureteral muscle, which cannot function to help push urine down to the bladder. This is more common in children. In adults, an extra artery or vein to the lower portion of the kidney can cross over the ureter as it exits the kidney causing a slow, progressing kinking that leads to obstruction. Both of these congenital entities are known as ureteropelvic junction (UPJ) obstruction. UPJ obstruction usually has symptoms of back pain, multiple kidney infections, and/or kidney stone formation.

When blockage is above the level of the bladder, dilatation (widening) of the ureter and renal collecting system occurs. UPJ obstruction pain is relatively steady and continuous, with little fluctuation in intensity, and often radiates to the lower abdomen, testes, or labia. Other symptoms include excessive urination and frequent nighttime urination.

How is UPJ obstruction diagnosed?

Confirming the diagnosis is straightforward. Either an X-ray study or a CT scan will show a sluggish, stretched-out kidney pelvis with very little draining from the kidney to the ureter.

Next, a renal scan will look at the kidney function and measure the time it takes the injected dye to travel from the kidney to the bladder. This time period normally is under 10 minutes, but it can be as long as several hours in a blocked kidney.

Treatment options

Endopyelotomy: Endoscopic techniques, which use an instrument that is threaded through the urethra and bladder, can look into the ureter and cut the blockage. This procedure, called an endopyelotomy, can be performed as long as no crossing blood vessel is found on the CT. These relatively quick procedures have a success rates of 40 to 60 percent. Future laparoscopic reconstruction of the ureter can be challenging after endopyelotomy.

Pyeloplasty: This surgical reconstruction or revision of the renal pelvis drains and decompresses the kidney. Most commonly, it is performed to treat a UPJ obstruction if residual renal function is adequate. This revision of the renal pelvis treats the obstruction by cutting out the stenotic (abnormally narrow) area of the renal pelvis or UPJ and creaties a roomier channel using the tissue of the remaining ureter and renal pelvis.

  • Laparoscopic pyeloplasty is a minimally invasive alternative to the standard open pyeloplasty. The surgery involves cystoscopy (looking in the bladder), stent placement (drainage tube in the ureter), and reconstruction and reconnection of the ureter through three small puncture holes. The procedure has a 95 percent success rate.
  • Another technique for cutting the obstruction involves abdominal surgery, called an open pyeloplasty. This surgery requires full anesthesia and a long hospital stay because it is requires opening the abdomen to access the ureter and kidney.

Da Vinci pyeloplasty: If your doctor recommends surgery for UPJ obstruction, you may be a candidate for a minimally invasive robotic-assisted procedure. Pyeloplasty performed with da Vinci incorporates the best techniques of open surgery into a robotic-assisted, minimally invasive approach and offers numerous potential benefits over a conventional open surgery, including:

  • Significantly less pain
  • Less blood loss
  • Fewer transfusions
  • Lower risk of infection
  • Less scarring
  • Shorter hospital stay
  • Shorter recovery time

Using the da Vinci Surgical System, our surgeons are able to perform reconstructive surgery with high precision through four incisions that are only a half-inch or less. And a patient's typical hospital stay is decreased from three days to one.

All surgical procedures are both patient- and procedure-specific. While pyeloplasty performed using the da Vinci Surgical System is considered safe and effective, this procedure may not be appropriate for every individual. Always ask your doctor about all treatment options, as well as the risks and benefits.