Urinary Stones

Why Stones Form Most of the time we do not know why stones form in a particular patient. However, we do know that environmental factors play an important role. The majority of urinary stones consist of calcium and a diet rich in calcium such as ikan bilis, milk and milk products, may predispose to stones.

Too much sugar in the diet may also help in the absorption of calcium and stones formation. Certain disease such as gout also predisposes to the formation of uric acid stone. Parathyroid disease raises the blood calcium and can be cause of stones in a small group of patients. Obstruction to the urinary tract giving rise to infection can cause stone to form. one example is bladder stones found in about 10% of our male patients, over the age of 50 years with obstruction of the bladder by the prostate gland.

The most important and the common denominator to stone formation, is inadequate water in-take to dilute the urine. Stones precipitate in concentrated urine. Therefore, for patients with stones problem, it is important to drink at least 3 litres of fluid per day to prevent recurrence of stones, or to prevent the stones from getting larger.

How Do You Suspect You Have Stone
Urinary stones disease is 2 times more common in males than in females. It is uncommon below the age of 20 years, and more common between the ages of 20 to 60 years.

Pain is the commonest complain of stone sufferers. Pain situated in the lower back can be due to kidney stones while severe pain down the side of the tummy can be due to stone coming down the drainage tube of the kidney. Painful and frequent urination especially towards the end can be due to bladder stones.

Blood in the urine can also be due to stones. In patients with blood in the urine and have no pain associated, cancer of the urinary tract needs to be excluded.

Confirming Urinary Stones
Not all back pain is due to stone. To confirm that you stone, your doctor needs to do a special x-ray call IVU - Intravenous Urogram. A special iodine solution is injected into blood stream and this will be excreted by the kidneys and outline the urinary system. This will confirm the stone in the urinary tract. This test will also show the degree of obstruction to the kidneys and give an idea whether the kidney is still working well.

Harmful Effects Of Stones
The most important effect of stones is obstruction to the kidney. If not remove, this will eventually lead to loss of kidney function. If both sides are affected, patient will develop kidney failure. Infections also can occur in patients with stones.

The aim of treating stones disease is to remove this obstruction to the kidney and prevent infections.

Treatment (Management Options)

Traditionally, stones which are causing obstruction and infection to the kidney are removed by open operations. Since the early 1980's, rapid changes had occur in the treatment of urinary stones with the development of new technology such as shockwave machine, (extracorporeal shockwave lithotriptor, ESWL) and the use of ultrasound and laser for the disintegration of urinary stones. The ultrasound or laser probe can be introduced into the urinary system via the skin at the back (percutaneous nephrolithotomy or PCNL) or through the urinary passage from below (ureterorenoscopy or URS). The trend is towards non-invasive or minimally invasive methods of removing the offending stones.

The advantages of these new methods are many, the most important are that there is no painful big operation wound, hospital stay in short. Many patients can be treated as outpatients. Recovery is faster and patient can return to normal activities rapidly.

Extracorporeal Shockwave Lithotripsy (ESWL)
Essentially, the machine consists of a shockwave generator which focus the shockwaves on the urinary stone. The patient will be given an injection to ease any discomfort. The shockwaves will result in fragmentation of the stones into small particulars and the patient will need to drink plenty of fluid to help in the passage of these particles out of the urinary system.

After treatment, patient will have blood stained urine for 24 to 48 hours. In about 10 to 20% of patients they may have severe colicky pain down the side of the tummy due to passage of the fragments. This pain can be controlled by injections of suitable drugs.

Depending on the size and positions of the stones, the success rate of ESWL is about 70 to 90%. Due to hardness of the stone or difficulty in localising the stone, about 10 to 20% of patients may not have any fragmentations and 10 to 40% of patients need repeat treatment.

Because of all these possible failures and complication, patients should be properly selected and advised accordingly. Not all stones are suitable for treatment with the shockwave machine. Patients who are over the age of 65 years with no symptom and stones not obstructing are generally best treated conservatively.

Percutaneous Nephrolithotomy (PCNL) - Removal of stone via a small puncture into the kidney
For stones more than 2 cm in diameter, we prefer to treat patients with ultrasound disintegration of the stones via a small skin puncture at the back to gain access to the kidney. This procedure is done under general anesthesia in the operating room. A small incision is made in the back over the kidney region. The kidney is punctured precisely under x-ray control and the tract is then dilated.

Under direct vision with the kidney-scope, the disintegrated fragments are suck out of the urinary system thus preventing the possible complications of obstruction and infection as seen in ESWL treatment.

Recent series from the Department of Urology, Singapore General Hospital of 130 patients showed a success rate of 97%

Uretero-renoscopy (URS) - Removal of stone via the lower urinary passage
This is done with a special slender ureteroscope introduced via the lower urinary passage (urethra), into the bladder and up the ureter to view the stone. This procedure us ideally indicated for obstructing stone in the lower ureter and for removing fragments which are causing severe obstruction and infection after ESWL.

Urinary Bladder Stones
Currently, lithoclast, using compressed air pressure is used to disintegrate bladder stones. However, for stone less than 2 cm in diameter, mechanical stones crushing forceps, introduced via the urinary passage may be used to crush the stone. The fragments are then wash out. In most patients with bladder stone, there is usually associated obstruction to the bladder outlet and this need to be dealt with at the same time. Currently, the preferred method of dealing with bladder outlet obstruction by the prostate gland is transurethral resection of the prostate (TURP).

Open Operations For Stone
In a well-equipped centre, the open procedure rate for removing urinary stones should be less than 5%. Open procedure is needed for exceptionally large stones in the kidney, ureter or bladder. For large kidney stones, we would attempt to conserve the kidney if it still has good function by just removing the stones and not the kidney.

Dissolving Urinary Stones Without Surgery
There are many drugs on the market which claim to dissolve stones. However, the only conservative method which is effective in dissolving certain type of stones consisting of mainly uric acid, is the use of baking soda (sodium bi-carbonate) orally. About 10% of our patients has uric acid stones. These stones are 40 times more soluble in alkaline than in acid urine. By making the urine alkaline with baking soda or potassium citrate (Urocit K), many of these stones can be successfully treated.

Conclusion
There are now many methods for treating stones. Your doctor will have to advise you on the best method according to the size and position of the stone and whether the stone is causing obstruction to the urinary system.

Not all stones in the urinary system need to be treated either by the non-invasive, minimally invasive or the open methods. In fact, a large proportion of patients with stones which are small (less than 0.5 cm) and not causing obstruction, can be treated conservatively with the cheapest and most effective method - drink plenty of water, to flush out the stone and to prevent the stone growing or recurring.