The kidney excretes urine into a funnel shaped ‘renal pelvis’ which is connected to the ureter at the ‘pelvi-ureteric junction’ (PUJ). Urine then flows down the ureters into the bladder for storage prior to elimination.

PUJ obstruction:

This is an obstruction between the outlet of the kidney (renal pelvis) and the ureter (tube from kidney).

PUJ obstruction may occur as a result of abnormal development of the kidney. It may be due to ‘kinking’ of the ureter over an extra blood vessel supplying the lower part of the kidney in about a third of cases. The obstruction varies in severity, and although it may have been life-long, it may not become symptomatic for many years. For this reason, it can be diagnosed at any age.

Symptoms of PUJ obstruction

Nil (i.e. asymptomatic, diagnosed incidentally)
Abdominal pain, usually worse after drinking large amounts of fluids, or alcohol
Blood in the urine
Urine infection

Complications of PUJ obstruction

Loss of kidney function
Kidney stones
Kidney infection
Recurrent pain
High blood pressure

Treatment of PUJ obstruction

The most effective treatment is surgery to reconstruct the obstructed PUJ, called a ‘pyeloplasty’. Performed laparoscopically (i.e. ‘keyhole’ surgery), this offers a success rate of around 96%* and avoids the prolonged hospital stay (5-7 days) and lengthy recovery (6 weeks) associated with a traditional open pyeloplasty.

Other techniques developed to avoid open surgery include balloon dilatation or telescopic incision of the obstructed PUJ (called endopyelotomy) however these techniques have a lower chance of success (60-80%), and can make subsequent surgery more difficult.

*Figures from the largest world series of laparoscopic pyeloplasty recently published: Moon D, Eden C et al, Laparoscopic pyeloplasty: evolution of a new reference standard. Urology 2006

Laparoscopic pyeloplasty – the operation

Under general anaesthesia four 10-15mm incisions over the kidney (on the back, just below the ribcage) are made to pass a telescope and operating instruments. The kidney along with the obstructed PUJ is located. The obstruction is divided and opened up before re-joining the ureter to the kidney in an unobstructed fashion with stitches. Any stones within the kidney can be removed, and if present, an obstructing blood vessel is placed in a position away from the reconstructed PUJ. The operation generally takes around 2 hours.

Figure 1. Before pyeloplasty Figure 2. After pyeloplasty

Figure 3. Laparoscopic view of completed pyeloplasty

A fine bore tube, called a stent, is placed in the ureter from the kidney to the bladder, to allow urine to drain freely through the reconstructed PUJ while it heals. This sits in place internally, for around a month. It is then easily removed under either local or general anaesthetic, by passing a small telescope through the urethra into the bladder and pulling it out.

If the operation cannot be completed laparoscopically, which occurs in 4-5% of cases, an incision is made over the kidney to convert to a traditional open pyeloplasty.

After the operation

You should expect some discomfort but this should easily be controlled using the pain-killers you will be prescribed. Most patients are able to get out of bed and recommence eating/drinking the day following the operation, and leave hospital after 2-3 days. Be sensible when you are at home – you have had a major operation inside even though the cuts are small and the pain may be minimal. You should therefore not undertake strenuous physical exercise until at least 3 weeks, and not drive until you are capable of braking hard or swerving quickly to avoid an accident (typically around 2 weeks).

While the stent remains inside you, there may be the urge to pass urine more frequently, and it is not uncommon to have some visible blood in the urine from time to time. This should not cause concern, and it is advisable simply to drink more than usual when blood is visible, to flush it out, and the urine will generally clear of its own accord.

Follow-up

Arrangements will be made for your stent to be removed in 4-6 weeks following the surgery. The renogram (radio-isotope test) which initially confirmed your diagnosis will be repeated at 3 months, 1 year, 2 years and 3 years after the operation to confirm success.