Kidney stones- Could they be the cause of that back pain?

Mar 01, 2009

IN 2003, while at university in Mbale, Hassan Matovu was suddenly overcome with agonising pain in the abdomen and rushed to the university’s dispensary.<br>“It felt like someone was piercing my back with a wire,” Matovu, 28, says. “It was the kin

BY Frederick Womakuyu

IN 2003, while at university in Mbale, Hassan Matovu was suddenly overcome with agonising pain in the abdomen and rushed to the university’s dispensary.
“It felt like someone was piercing my back with a wire,” Matovu, 28, says. “It was the kind of pain that would make you feel like cutting off that part of the body.”

After two scans tests, one misdiagnosed as appendicitis, doctors discovered the problem: A large kidney stone was wedged in Matovu’s ureters (tubes that carry urine to the bladder), requiring prompt intervention.

Kidney stones are a serious health problem in Uganda. According to a study carried out by World Relief Health Services (WRHS) on chronic illnesses in the country, every year, about 3,000 people, most between the ages of 20 and 40, are treated for kidney stones.

Three out of five cases are men and experts say men who have had one episode are likely to have another.

“One in 10 men will have a kidney stone at some point in their life,” says Dr. Andrew Magode, a surgeon with WRHS. “Once they have had one, about 50% of men will have another attack within seven years.”

What are kidney stones?
They are chemical deposits in urine that turn into hard crystals and affect the urinary tract. The urinary tract comprises two kidneys, which filter the blood and produce the urine as waste; two ureters, the bladder, which stores urine; and the urethra, which carries urine out of the body.

The stones, which can be as tiny as a grain of sand or as big as a golf ball, can remain in the kidney and grow, or begin to pass down the ureter.

Most small stones pass through the urine spontaneously. But larger stones can get lodged in the urinary tract.

“Only the small stones go down, because they can fit through the ureter,” says Dr. Musa Mwambu, a urologist at WHRS.

“The ureter is about four millimetres in diameter, so when a five-millimetre object is put through it, you have a problem.”

What causes kidney stones?
Experts say there are many causes, including dehydration, which makes the urine concentrated with stone-forming substances; metabolic and genetic disorders; diet and certain medications and urinary tract infections.

Mwambu says about 80% of stones are made up of calcium oxalate, caused by an excess of calcium or oxalate in the urine. “Oxalate is a substance found in foods like spinach, chocolate and tea.”

Dr. Martin Were of the Mulago School of Medicine says less common types of kidney stones are linked to urinary infections. They can also be caused by too much uric acid in the urine and by an excess of the amino acid cystine, associated with a genetic defect.

Symptoms
“Kidney stone symptoms include sharp pains in the back and on the sides that radiate to the abdomen and the groin; blood in the urine; difficult urination; fever or chills and nausea and vomiting,” Were says.

Contrary to what most people think, the pain is not caused by the stone. “What causes the pain is when the stone blocks the urine flow,” Mwambu says.

“The backup pressure into the kidney causes it to swell and stretch and when it gets stretched the nerve fibres become irritated, and cause pain.”

Diagnosis and treatment
The common methods of diagnosing the stones are urine and blood tests and imaging techniques like scans and X-rays.

“If you pass a stone, try to catch it in a strainer and give it to the doctor for analysis. Treatment will depend on the type of stone you have,” Mwambu explains.

The majority of stones are treated by modifying the diet and some with medication.

Though most stones pass through urine on their own — a process that can take three to six weeks — some will need intervention.

Mwambu says invasive surgery may be an option, but there are minimal techniques available and these are:

Extracorporeal shock wave lithotripsy; a device is used to transmit shock waves to break the stone

Ureteroscopy; a telescopic instrument is inserted into the urethra, through the bladder and to the ureter, where the doctor can pull out the stone or crush it with a laser.

Percutaneous nephrolithotomy; a tube is inserted into the kidney, through which a small telescopic device removes the stone or breaks it up.

Prevention
Magode advises that changing the diet is a crucial part of treatment, particularly with calcium stones. “The factors that contribute most to stone formation are dehydration, over consumption of animal protein and salt and excess calcium and oxalate,” he says.

In matovu’s case, diet was the likely cause of the problem. “Most students eat a lot of junk food because they are always looking for cheap food,” Mwambu says.And many who suffer from stones revert to their old diets, experts say.

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