S tones can occur in any part of the urinary tract: kidneys, kidney pipes (ureters) and the bladder.
People living in countries with warm climates are more prone to developing kidney stones. Although having a stone in your urinary tract is often very painful, some may go unnoticed for months or even years and not cause any symptoms. Men develop stones more often than women and the age group most affected is 20-40 years. Kidney stones usually need to be removed - if left untreated, they could be dangerous and cause complications such as kidney damage, infection, and even death. About half of people who get a kidney stone will develop another one within 10 years.
The following factors can increase a person’s risk of kidney stone formation:
- Living in a country with a warm climate
- Inadequate water intake
- Diet – eating too much red meat
- Recurrent urinary tract infection
- Structural abnormalities of the urinary tract
- Obstruction of the urinary tract
- Previous surgery on the urinary tract
- Inborn metabolic abnormalities (the body doesn’t handle salts correctly: calcium, magnesium, phosphate) – this is relatively rare
- Some medication – this is also uncommon
A patient with a stone in the urinary tract may have the following complaints:
- Severe pain in the flank / back - the severity of the pain has been compared to that of childbirth... The pain typically comes and goes – this is called “renal colic”. The pain may spread from the back to the lower abdomen, to the bladder, and even to the genitals.
- Blood in the urine
- Some patients with kidney stones are asymptomatic, ie they have no pain or other complaints
Stones are mostly classified according to their main mineral component:
- Calcium stones: The most common type - 75% of all stones consist mainly of calcium. These stones are rarely pure calcium and more often a mix of calcium phosphate or calcium oxalate. These stones are hard and do not break easily.
- Struvite stones: Caused by recurrent infection. These stones consist of calcium, ammonium, magnesium, and phosphate. They often become very big and can even fill the entire kidney if left untreated. This is a relatively soft type of stone that is easily fragmented (broken up into smaller pieces). The stone is often filled with bacteria - antibiotics are not very effective in eradicating these organisms that “hide” inside the stone.
- Uric acid stones: These stones are often associated with a diet rich in red meat. Some bowel diseases (chronic diarrhea), as well as gout, may also contribute to uric acid stone formation. These stones are not visible on plain X-rays – a CT scan is necessary to identify them.
- Cysteine stones: These are very rare and are found only in people who have a specific inborn metabolic abnormality. Cysteine stones usually occur in young people and even small children. These stones are very hard and do not fragment easily.
1. General measures:
Drink plenty of water and reduce the intake of salt and red meat. These measures can prevent existing stones from getting bigger and may also prevent the formation of new stones.
2. Medical treatment:
Strong pain medication is often needed for patients who experience severe pain associated with kidney stones. Small stones situated low down in the kidney pipe (ureter) can sometimes pass on their own – there is also medication available that can assist with the passage of these small stones. Medication that decreases the acidity of urine is often used in the treatment and prevention of uric acid stones.
3. Surgical treatment:
There are many surgical options available for removing stones from the urinary tract. The choice of surgical method depends on several factors:
- Type of stone
- Size and number of stones
- Location of the stone
- The patients general health condition and previous operations
Surgical options include:
Shockwave treatment (ESWL):
This is also called Extracorporeal Shockwave Lithotripsy (ESWL). It is useful for the treatment of small stones located in the kidney and ureter. A general anaesthetic is usually needed but no surgical incisions are made. ESWL treatment is given with a large machine that produces shockwaves. The shockwaves are directed into the body and concentrated on the stone – sending repeated shockwaves into the stone will eventually cause it to break up into smaller pieces, which can then pass on their own. Typically, about 5000 shockwaves are given per treatment and the entire procedure lasts about 45 minutes. ESWL causes minimal pain and the recovery is usually very quick. Stones that are very hard may be resistant to ESWL treatment and will not break into smaller pieces.
Percutaneous nephrolithotomy (PCNL):
This procedure involves “keyhole surgery” and enables the urologist to remove very large stones through one or two 1,5cm skin incisions. This is a fairly long operation (anything from 1 to 4 hours, depending on the size and location of the stone) and patients usually spend a few nights in hospital. Through a small skin incision, a camera is placed into the kidney and the stone located. A very thin drill or laser is then passed alongside the camera and the large kidney stone broken into smaller pieces, which are then removed with special instruments.
Endoscopic stone removal:
Specialized small cameras and tiny instruments are used to remove stones from any part of the urinary tract, without making surgical incisions on the skin. Small lasers or drills can also be used to break up large stones – the fragments can then be easily removed using entrapment baskets or grasping forceps.
Nowadays it is hardly ever necessary to make big surgical incisions in order to remove kidney stones because most stones can be removed using the other (less invasive) methods.