Kidney Stones

Kidney stones are very common in Australia with approximately 1 in 10 people developing a kidney stone in their lifetime.  Once one has formed a kidney stone they are at increased risk of forming more.

Cause:

It is often difficult to find a specific cause for an individual kidney stone and there may be several factors contributing.  Most stones are made up of the combination of calcium with oxalate or phosphates. Stones can also form from uric acid, which forms when the body metabolises protein. Subtle metabolic changes in the body or situations that may lead to an increased concentration of these substances in the urine such as dehydration are often causes, however urinary infection and structural abnormalities associated with impaired drainage of the kidney may also be factors.

Symptoms

The most common symptom of kidney stones is sudden pain in the loin or upper abdomen. The pain is often so severe the sufferer will require urgent medical attention and will attend a doctor or present to a hospital emergency department for pain relief. The patient may also notice blood in the urine. 

Diagnosis

X-rays confirm the diagnosis. Whilst a majority of kidney stones will be detected on a plain abdominal X-ray, significant number may be missed. An abdominal CT scan is the best way to diagnose kidney stones.

Management

The initial treatment is adequate pain relief. Usually this requires the administration of strong painkillers by injection in hospital. Once pain control has been achieved a plan of management can be decided.

Conservative Management

Some small stones may pass and can be managed conservatively. When stones do not pass after a period of conservative management or they are considered too large to pass, surgical intervention is considered

Ureteroscopy

This is where a long thin telescope called a ureteroscope is inserted through the urethra and bladder into the ureter to visualise the stone. The stone is then fragmented into small pieces using a laser.  This treatment is most suitable for stones in the lower ureter. Stones in the upper ureter and kidney are best treated by flexible ureteropyeloscopy.

Ureteropyeloscopy

Stones in the kidney can be treated by ureteropyeloscopy and laser fragmentation. This is done by passing a long thin flexible fiber optic telescope called a flexible ureteroscope into the ureter, up to the kidney. On reaching the kidney it can be maneuvered into all the calyces (pockets) inside the kidney.  Once the stone is visualised it can be fragmented using a Holmium laser. A stone or a fragment of stone considered small enough that it can be safely removed through the ureter can be grasped in a tiny wire cage called a Dormia basket and removed.  Once the stone has been adequately fragmented tiny fragments are left to pass spontaneously.  On completion it is my practice to insert a temporary ureteric stent in the ureter to prevent obstruction of the kidney caused by the passage of the fragments or swelling associated with the instrumentation.  For more information on ureteric stents please click here

Extracorporeal Shock Wave Lithotripsy (ESWL)

This involves using X-rays to pinpoint where the stone is. A machine then sends shock waves of energy to the stone to break it up into small pieces so they can be passed in the urine. Passing the fragments can be very painful and it is common to require more than one treatment to treat the stone.

Percutaneous Nephrolithotomy (PCNL)

A percutaneous nephrolithotomy is an operation where a thin telescope (nephroscope) is inserted directly into the kidney through a small incision in the loin. An oscillating probe called a lithoclast is inserted through a channel in the nephroscope and is used to break the stone into small fragments that can be removed from the kidney. This technique is best suited for larger stones and staghorn stones in the kidney. At the completion of this procedure a tube called a nephrostomy tube is inserted through the track into the kidney to assist in drainage of the kidney.  It is usually left in for approximately two days. Once this tube is removed the small hole in the kidney usually seals itself without complication.

Open Surgery

Nowadays it is rare to perform open surgery for kidney stones. It is sometimes required for very large complicated stones or cases where there is abnormal renal anatomy.

Prevention Of Kidney Stones

Preventing kidney stones means preventing the conditions that support their formation. Some helpful measures may include to;

  • Increase fluid intake
  • Take in enough dietary calcium to support bone health but do not take calcium supplements
  • Reduce sodium intake
  • Reduce foods that are rich in oxalates, including: beetroot, asparagus, rhubarb, chocolate, berries, leeks, parsley, celery, nuts, and soy products
  • Limit red meat. The breakdown of protein increases the uric acid levels.