Pelvo-Ureteric Junction (PUJ) Obstruction

What is the PUJ?

This stands for Pelvo-Ureteric Junction. This is where the renal pelvis joins the upper end of the ureter, the tube through which urine flows from the kidney to the bladder. The renal pelvis is a funnel shape and has cuplike extensions, called Calyces, within the kidney. Under normal conditions, the kidneys filter the blood and remove waste, salts and water to produce urine. This collects in the renal pelvis before it flows on through the ureter into the bladder.

PELVO-URETERIC JUNCTION

What is a PUJ obstruction?

An obstruction of the PUJ is when the kidney makes urine faster than it can be drained through the renal pelvis into the ureter. This causes the urine to pool in the kidney, which leads to kidney swelling (hydronephrosis).

What is the cause of a PUJ obstruction?

  • 1. Primary/congenital
  • due to deficiency of muscle in the PUJ
  • blood vessel crossing the PUJ.
  • 2. Secondary
  • a stricture from a stone,
  • previous surgery
  • tumour

What are the symptoms of a PUJ obstruction?

  • flank pain especially after drinking alcohol
  • recurrent infections
  • blood in urine (haematuria)
  • complications including loss of kidney function and kidney stones.

How is a PUJ obstruction diagnosed?

  • The diagnosis is suspected on imaging (ultrasound and/or CT scan) performed for investigation of symptoms or incidentally. The findings include kidney swelling (hydronephrosis) and a transition point at the PUJ.
  • Obstruction is confirmed with a renogram (MAG3 or DTPA). This also determines the differential renal function (how much function each kidney contributes to the overall kidney function)
  • Sometimes a cystoscopy and retrograde pyelogram (X-Ray and dye study of the ureter and PUJ performed during the cystoscopy) is required to rule out secondary causes of a PUJ obstruction

How is a PUJ obstruction treated?

Treatment is only recommended if the PUJ obstruction is confirmed and is causing symptoms or complications such as:

  • Impaired kidney function
  • Reduced or falling split function of the affected kidney
  • Recurrent UTIs
  • Formation of kidney stones
For symptomatic or significant PUJ obstruction treatment is in the form of a pyeloplasty, which is usually done robotically at GM Urology. Other options, which are less effective and only appropriate in some circumstances include:
  • Endopyelotomy – this is a minimally invasive procedure, in which a fine telescope (ureteroscope) is passed to the PUJ and laser is used to cut the narrow segment. A ureteric stent is left in for 4-6 weeks. It less effective than pyeloplasty for treatment of PUJ obstruction and is thus not our first choice for treatment of a PUJ obstruction. It has a role in cases where a primary pyeloplasty was unsuccessful.
  • Long term ureteric stent – This is an option reserved for those who hace complications from a PUJ obstruction but are unfit to undergo a pyeloplasty (eg. elderly, multiple medical problems). The stent is normally changed every 6-12 months.