Kidney Stones

Kidney stones are common. 1 in 10 men (less for women) will develop stones sometime in their lives. The commonest age is 25-50, but they can occur at any age. If you have had a previous stone you have a considerably higher risk of having further ones.

The commonest factor leading to stone disease is dehydration. If the urine becomes concentrated crystals start to form and the can grow into stones.

When stones are in the kidney they often produce no symptoms. However, if the stone passes into the ureter (the tube from the kidney to the bladder), patients can develop classic ‘renal colic’ symptoms. This can be severe pain, typically in the side or in the groin, that comes and goes in waves. Not all patients get this classic pain.

To confirm the presence of stones various forms of imaging are used:

• X-rays
• Intravenous urogram (IVU) - a series of X-rays after X-ray dye is injected
• CT scans – with or without injection of X-ray dye
• Ultrasound

Smaller stones < 6mm have a very good chance of passing; the treatment is just pain relief.

Larger stones or smaller ones that don’t pass may need removal. The methods of removing stones in the kidney or ureter are:

• Percutaneous Nephrolithotomy (PCNL)
  This is ideal for large stones in the kidney. It is a major procedure under general anaesthetic. A tube is placed directly into the kidney from the outside. Small instruments are then passed into the kidney to break up the stone.
   
• Ureteroscopy
  Fine telescopes are passed into the bladder and up the ureter to the stone. The latest instruments can even pass up to the small recesses of the kidney. Once the stone is found it is usually broken up with a laser and the fragments removed.
   
• Lithotripsy (ESWL)
  Sound waves are focused from the outside of the body onto the stone and multiple shock waves are fired. This procedure does not require anaesthetic although pain relief is given as it can be uncomfortable. This treatment is good for smaller stones in the kidney of the upper part of the ureter.

As part of the previous treatments a ureteric stent might be required. This is a small plastic tube inserted internally into the ureter. It is also referred to as a “JJ stent” because of its shape. There are a variety of reasons why these may be used. Nowadays urologists only use them when essential. If further treatment is not required these are simply removed under local anaesthetic. A small percentage of patients get ‘stent symptoms’ and find having one unpleasant.

All treatments have pros, cons and side effects. Your surgeon will discuss these and the suitability of the treatments for you.

How can you prevent stones in the first place or reduce you chance of having further ones?

• Drink plenty. You should drink enough to keep your urine a very pale yellow colour.
• Reduce salt intake

Your urologist may advise you on tests to make sure you do not have an obvious underlying condition that is predisposing you to stone formation.