FAQ on PUJ obstruction

What are alternative names for PUJ obstruction?

Pelviureteric junction obstruction, ureteropelvic junction obstruction, PUJ obstruction, UPJ obstruction

What is PUJ obstruction?

A blockage of the flow of urine from part of the kidney known as the renal pelvis to the ureter, which is the tube that carries urine onwards to the bladder

What causes PUJ obstruction?

There is usually an abnormality in the structure of the wall of the PUJ. This can exist from birth or develop later in life secondary to other causes such as stones or, very rarely, cancer. In about one in three cases to two in three cases, the PUJ passes over a blood vessel known as a ‘crossing vessel’ and this may cause the obstruction sometimes also. Even if PUJ obstruction is present in birth, symptoms may not occur until later in life.

What are the symptoms or features of PUJ obstruction?

In adolescents or adults, PUJ obstruction can cause pain on in the side of the back, and the pain can be worse after drinking. Other symptoms include

  • kidney infection: high fevers, rigors, and pain in the loin
  • stones: pain, blood in the urine and infection

Occasionally, PUJ obstruction is eventually found after tests are made because blood is in the urine. None of these symptoms are specific for PUJ obstruction and the symptoms may be caused by other problems. Therefore, more action will be necessary to make a correct diagnosis.

What findings are made when an examination is made?

Rarely are any specific findings made. Occasionally, there may be swelling felt in the abdomen, or tenderness in the side of the back when the obstruction is significantly worse.

What tests can be done for this problem?

Tests are performed to show the changes characteristic of PUJ obstruction. These changes include an enlarged kidney and a delay in the passage of urine across the PUJ.

  • Ultrasound might show an enlarged kidney (‘hydronephrosis’ or ‘pelvicalyceal dilatation’) and this may also be shown on an
  • Intravenous urogram (IVU, IVP or intravenous pyelogram). An IVU is a special x-ray test in which multiple pictures are taken of the kidney after a dye (‘contrast’) is given through a vein. The contrast demonstrates the narrow region of the PUJ, but the IVU does not always demonstrate PUJ obstruction.
  • Diuretic renogram: This is a kidney scan and is usually necessary to prove PUJ obstruction really is present. There are two main types of diuretic renogram – either MAG3 or DTPA. For these, an injection of a chemical is given into the blood and pictures taken of the kidney.

Why and when is treatment needed?

Reasons for treatment include

  • symptoms associated with obstruction (pain)
  • reduced kidney function
  • development of stones or
  • infection
  • high blood pressure (rarely).

What treatments are available?

The obstruction needs to be removed so that urine can pass freely from the kidney down to the bladder. This can be accomplished by several means:

  • Cutting out the PUJ obstruction and joining the kidney onto the ureter (‘pyeloplasty’).
  • Pyeloplasty i.e. cutting out the obstruction has the best results and lasts for the longest period. This can be achieved through a traditional surgery (‘open pyeloplasty’) or by keyhole surgery (‘laparoscopic pyeloplasty’).
  • Making a cut in the PUJ obstruction so that it splits open and becomes wider that way (‘endopyelotomy’).
  • A cut in the PUJ obstruction (‘endopyelotomy’) is less effective than cutting it out altogether, but is possibly better than bursting it with a balloon. In some situations, it is dangerous because of neighbouring blood vessels.
  • Bursting the obstruction with a balloon (‘balloon dilatation’)
    Bursting the obstruction with a balloon is quick, the least invasive but is less effective and lasts for the shortest period. Furthermore, it produces scarring that can make corrective surgery more difficult. For some patients it is the best option because poor health makes other treatment dangerous.

What is laparoscopic pyeloplasty surgery?

This is a key hole method for correcting the PUJ obstruction that avoids a large incision.