PUJ (pelviureteric junction) Obstruction

The kidneys filter the blood and remove waste materials, salts and water producing urine. Urine is then drained from the kidneys through a funnel-shaped structure called the renal pelvis and into a tube called the ureter. Urine passes through the ureter into the bladder.

PUJ (pelviureteric junction) obstruction is due to a blockage in the area where the ureter leaves the kidney at the renal pelvis. There are two types of PUJ - a Primary PUJ is when the blockage is the source of the disorder and a Secondary PUJ is where the blockage that occurs is a result of another disorder. The PUJ obstruction may be caused by scar tissue or a congenital defect.

PUJ occurs in around one in 1,500 children and is most commonly caused by a congenital obstruction at the pelviureteric junction (PUJ), which is the point where the ureter joins the renal pelvis. When a PUJ is present there is an accumulation of urine within the kidney because urine is produced faster than it is possible to drain out of the renal pelvis into the ureter.

The use of ultrasound to screen unborn children means that a doctor may easily detect this accumulation of urine (hydronephrosis), which makes it possible to predict the presence of PUJ obstruction before a baby is born. Once a baby is born the symptoms of PUJ obstruction may present as a urinary tract infection with a fever, increased fluid intake, bloody urine with pain in the flank and even stones.

Sufferers of PUJ obstruction may not have an infection but will still experience localised pain. The PUJ obstruction may irregular in nature with sporadic pain as urine may drain normally sometimes and be obstructed at other times.

To correctly diagnose a PUJ obstruction a procedure known as intravenous pyelogram (IVP) is used. During an IVP a dye is injected into the patient's blood stream, which the kidneys will then remove from the blood. The dye then passes into the urine and out through the bladder. The doctor will able to see the shape of the kidneys, renal pelvis and ureters using X-ray examination as the dye is visible under X-rays.

PUJ obstruction is seen much less frequently in adults and may occur as a result of kidney stones, previous surgery or disorders that can cause inflammation of the upper urinary tract.

PUJ in infants and young children less than 18 months of age may be a temporary condition and surgery may not be necessary. If a diagnosis of PUJ obstruction is made and it is believed that there will be no improvement, then surgical treatment will be required.

PUJ obstruction is traditionally treated by pyeloplasty, which is an operation to remove the PUJ and to rejoin the ureter to the pelvis of the kidney giving a wider junction between the two areas. Pyeloplasty eases the symptoms and reduces the risk of infection, because urine produced by the kidney may now be drained faster and more easily.

The latest treatment of PUJ obstruction uses minimally invasive surgery. This type of surgery may be Laparoscopic pyeloplasty or internal incision of the PUJ.

Laparoscopic surgery uses several small instruments passed through the abdominal wall to carry out the surgical procedure. This is normally carried out through the abdominal cavity but may possibly cause slight scarring within the abdomen. But this type of surgery is a less painful technique especially for adults and older children.

The other major option is to cut the tight and narrow PUJ from the inside by inserting a wire through the ureter. A drain in the ureter is left in place for several weeks and then removed. This allows the PUJ to heal in a more open manner in most patients but the treatment may need to be repeated and there is less pain and nausea with this procedure.

After repair of the PUJ obstruction there may be swelling of the ureter and there may continue to be poor drainage of the kidney for a period of time. But this changes when the area heals. After several weeks the doctor will arrange a functional kidney test to check how well the kidney is working after the procedure.