Kidney Stones

A large "staghorn" kidney stone.

What are kidney stones?
Stones can form in the kidney from the crystals in the urine that build up and stick together. The function of the kidneys is to filter chemical waste products from the blood and remove them in the urine. The crystals in the urine tend to form stone when you do not drink enough water especially living in a hot climate country like Malaysia.

Pain from kidney stones
When the kidney stones block the flow of urine, it will cause severe pain. In some patients the stones are discovered incidentally, as they may not cause pain. The excruciating pain of kidney stones usually begins in your lower back and later, moves to your side or groin. You may feel nauseous, pass bloody urine or burning sensation on urination. The initial treatment would be painkiller and also antibiotics if you have fever.

What tests will your doctor perform?
Once your doctor suspects that you may have kidney stones, he will perform a series of tests to confirm the diagnosis:

Microscopic analysis of your urine Urine culture for bacteria Intravenous urogram (IVU) – An injection of contrast will be given to you followed by a series of X-rays. Your doctor should be informed if you are an asthmatic and have a history of drug and food allergy. Ultrasound of your kidneys

Figure 1 : An X-ray shows of a patient with large kidney stones in both kidneys

What treatment will be given for your kidney stones?
A number of treatment options are available to treat your kidney stones.

A. Expectant Therapy :
If you have "small" kidney stones, your doctor may suggest that you try to pass the stone naturally by drinking lots of water. Water helps to flush out the stone. You will be asked to strain all of your urine to catch the stone.

B. Medications:
If you have uric acid or cystine stones your doctor may prescribe you some medicine to dissolve the stone. Allopurinol ( zyloric) reduces uric acid. Polycitrate or bicarbonate helps dissolves uric acid and cystine stones.

C. Extracorporeal Shock Wave Lithotripsy (ESWL) :
If you fail to pass the kidney stone naturally, it can be crushed by ESWL. Shock wave is transmitted through your body and targeted at the kidney stone. The stone will crumble into sandlike particles which then pass easily through your urinary tract. The noninvasive procedure is performed on an outpatient basis with minimal pain.

Figure 2:Patient lying on the ESWL table undergoing
extracorporeal shock wave treatment to her kidney stone.

D. Endoscopic lithotripsy:

ESWL may not be able to crush the kidney stones in some patients. Such patients may have to undergo endoscopic treatment to directly fragment and remove the stones. In this procedure the stone is crushed using probes introduced by endoscopic means while they are still inside the body. The probes are connected to a machine that produces the energy to crush the stone. The types of energy used include ultrasonic, ballistic and laser. ESWL may not be able to crush "hard" and "large" kidney stones. Stones in the ureter and bladder also need endoscopic treatment for fragmentation.

Figure 3 showing fragmentation of a kidney stone by flexible ureterorenoscope using laser

How to prevent formation of future stones?
After the successful treatment of your kidney stones, the following advice must be followed to prevent formation of future stones. Once you have had kidney stones, you are at risk of having them again.

• drink plenty of fluids, about a glass of water for every waking hour
• follow your prescribed diet
• take your medications
• see your doctor regularly