Renal Calculi

Renal Calculi stones form in the kidneys or bladder, and if these become jammed in the narrow canals leading to the next part, particularly the ureters, extreme and agonising pain may occur. Emergency treatment is essential.

Stones may develop in the kidneys. If these become dislodged and pass into the ureter, the tube leading from the kidney to the bladder, and become impacted there, excruciating pain may develop. In fact, it may be among the most severe pains a person is likely to endure, and is similar in nature and intensity to stones becoming jammed in the duct in those with gall-bladder stones.

The stones are commonly made of calcium oxalate or phosphate, or both. Phosphate stones are more probable if infections have been present. Less commonly the stones are formed of uric acid or urates or cystine stones.

Certain medical disorders may predispose to their formation. If the parathyroid glands overact, this leads to excessive quantities of calcium in the blood which is excreted in large amounts. This may be a cause, and must always be investigated. (The parathyroids are the endocrine glands, four in number, located in the back part of the thyroid gland in the neck.) Gout, renal tract infections and various congenital disorders may also play a part.

People living in hot climates where the urine becomes more concentrated (and sweating more profuse), and those lying in bed with chronic disorders also run a higher risk. Some patients have an inborn disorder called congenital oxuluria, in which very large amounts of oxalate are contained in the urine. It is an inborn metabolic error, usually in children. and may be fatal.

Renal Calculi Symptoms

These may vary considerably. Stones not causing obstruction may cause no symptoms. But if they suddenly produce obstruction, symptoms may come on suddenly and be severe. The symptoms are due to obstruction, haem-orrhage and ulceration, or infection. If located in the kidney, loin pain may occur, especially on jolting.

If the stone leaves the kidney and becomes jammed in the ureter, it may cause the acute pain of renal colic. The pain may be agonising, and have a “loin-togroin” distribution, roughly coinciding with the pathway of the ureters. Blood may be present in the urine. If the stones are retained, they may produce obstructive outflow to the urine and symptoms associated with this. However, the intense pain usually brings the patient to the doctor early for investigation and treatment.

Renal Calculi Treatment

Often the patient is seen as an emergency, suffering from acute pain. Plenty of fluids are given, and pain-killers, often morphine, administered.

Investigation is usually necessary to discover the location and extent of the stone. Some are passed spontaneously, Electron micrograph of a kidney stone, a type of urinary stone or calculus. Kidney stones causing infection and obstruction of urine flow require removal by surgery or lithotripsy and this affords instant relief. It is customary to strain all urine passed, in an effort to find the stone, often referred to as “gravel” when small. Sometimes several pieces of solid material may be collected.

An X-ray of the ureters and kidney and bladder (called an IVP, or intravenous pyelogram) may show the stone. It may also indicate if there is any structural impairment of the renal system. They may also be identified with CT, ultrasound, MRI and other forms of high tech investigation.

Some large calculi (stones) called staghorn calculi may almost entirely fill the renal pelvis (the urine-collecting space of the kidney). They may cause serious renal impairment. The degree of treatment will be governed by the investigation results and the opinion of the urologist.

In some instances surgery will be required. For smaller stones a cystoscopic manipulation is frequently successful, the stone being caught in a special net and removed. Others may be crushed and removed. In cases where the stone is large and the kidney severely impaired, removal of the affected kidney may be undertaken. It is a case of the treatment being tailored to suit the needs of the patient in the light of the symptoms and renal involvement. Other high-tech methods are now widely used.

After the initial problem has been overcome, the doctors might investigate the patient to see if there is an underlying reason. This might include tests aimed at checking the parathyroid glands, investigating for gout and other tests. Some of these investigations might extend over a period of time and require repeated examinations of the blood.

Not long ago research carried out in Canberra showed that certain renal stones were amenable to medication that dissolved them, averting the need for surgery. No doubt this was inspired by the successes occurring with chenodeoxycholic acid in dissolving gallstones in suitable subjects.