RENAL CALCULI OR KIDNEY STONES

 

Kidney stone facts

  • A kidney stone is a hard, crystalline mineral material formed within the kidney or urinary tract.

  • Nephrolithiasis is the medical term for kidney stones.

  • Symptoms of a kidney stone include flank pain (which can be quite severe) and blood in the urine (hematuria).

  • Kidney stones form when there is a decrease in urine volume and/or an excess of stone-forming substances in the urine.

  • Dehydration is a major risk factor for kidney stone formation.

  • People with certain medical conditions, such as gout, and those who take certain medications or supplements are at risk for kidney stones.

  • Dietary and hereditary factors are also related to stone formation.

  • Diagnosis of kidney stones is best accomplished using a X ray of the KUB region and Ultrasound examination. .

  • Most small kidney stones will pass through the ureter to the bladder on their own with time.

  • Treatment includes pain control medications and, in some cases, medications to facilitate the passage of urine.

  • If needed, lithotripsy or surgical techniques may be used for stones which do not pass through the ureter to the bladder on their own.

Who is at risk for kidney stones?

 

Anyone may develop a kidney stone, but people with certain diseases and conditions (see below) or those who are taking certain medications are more susceptible to their development. Urinary tract stones are more common in men than in women. Most urinary stones develop in people 20-49 years of age, and those who are prone to multiple attacks of kidney stones usually develop their first stones during the second or third decade of life. People who have already had more than one kidney stone are prone to developing further stones.

What causes kidney stones?

Kidney stones form when there is a decrease in urine volume and/or an excess of stone-forming substances in the urine. The most common type of kidney stone contains calcium in combination with either oxalate or phosphate. About 75% of kidney stones are calcium stones. Other chemical compounds that can form stones in the urinary tract include uric acid, magnesium ammonium phosphate (which forms struvite stones; see below), and the amino acid cystine.

Dehydration from reduced fluid intake or strenuous exercise without adequate fluid replacement increases the risk of kidney stones. Obstruction to the flow of urine can also lead to stone formation. In this regard, climate may be a risk factor for kidney stone development, since residents of hot and dry areas are more likely to become dehydrated and susceptible to stone formation.

Kidney stones can also result from infection in the urinary tract; these are known as struvite or infection stones. Metabolic abnormalities, including inherited disorders of metabolism, can alter the composition of the urine and increase an individual's risk of stone formation.

A number of different medical conditions can lead to an increased risk for developing kidney stones:

  • Gout results in chronically increased amount of uric acid in the blood and urine and can lead to the formation of uric acid stones.

  • Hypercalciuria (high calcium in the urine), another inherited condition, causes stones in more than half of cases. In this condition, too much calcium is absorbed from food and excreted into the urine, where it may form calcium phosphate or calcium oxalate stones.

  • Other conditions associated with an increased risk of kidney stones include hyperparathyroidism, kidney diseases such as renal tubular acidosis, and other inherited metabolic conditions, including cystinuriaand hyperoxaluria.

  • Chronic diseases such as diabetes and high blood pressure(hypertension) are also associated with an increased risk of developing kidney stones.

  • People with inflammatory bowel disease are also more likely to develop kidney stones.

  • Those who have undergone intestinal bypass or ostomy surgeryare also at increased risk for kidney stones.

  • Some medications also raise the risk of kidney stones. These medications include some diuretics, calcium-containing antacids, and the protease inhibitor indinavir (Crixivan), a drug used to treat HIV infection.

  • Dietary factors and practices may increase the risk of stone formation in susceptible individuals. In particular, inadequate fluid intake predisposes to dehydration, which is a major risk factor for stone formation. Other dietary practices that may increase an individual's risk of forming kidney stones include a high intake of animal protein, a high-salt diet, excessive sugar consumption, excessive vitamin D supplementation, and possible excessive intake of oxalate-containing foods such as spinach. Interestingly, low levels of dietary calcium intake may alter the calcium-oxalate balance and result in the increased excretion of oxalate and a propensity to form oxalate stones.

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Pictures of kidney and kidney stone

What are kidney stones symptoms and signs?

While some kidney stones may not produce symptoms (known as "silent" stones), people who have kidney stones often report the sudden onset of excruciating, cramping pain in their low back and/or side, groin, or abdomen. Changes in body position do not relieve this pain. The abdominal, groin, and/or back pain typically waxes and wanes in severity, characteristic of colicky pain (the pain is sometimes referred to as renal colic). It may be so severe that it is often accompanied by nausea and vomiting. The pain has been described by many as the worst pain of their lives, even worse than the pain of childbirth or broken bones. Kidney stones also characteristically cause blood in the urine. If infection is present in the urinary tract along with the stones, there may be fever and chills. Sometimes, symptoms such as difficulty urinating, urinary urgency, penile pain, or testicular pain may occur due to kidney stones.

How are kidney stones diagnosed?

The diagnosis of kidney stones is suspected when the typical pattern of symptoms is noted and when other possible causes of the abdominal or flank pain are excluded. Imaging tests are usually done to confirm the diagnosis. 

What is the treatment for kidney stones? How long does it take to pass a kidney stone?

Most small kidney stones eventually pass through the urinary tract on their own within 48 hours, with ample fluid intake. Pain killer medication and anti-inflammatory drugs, and narcotics may be used for pain control when over-the-counter pain control medications are not effective. Intravenous pain medications can be given when nausea and vomiting are present.

Although there are no proven home remedies to dissolve kidney stones, home treatment may be considered for patients who have a known history of kidney stones. Since most small kidney stones, given time, will pass through the ureter to the bladder on their own, treatment is directed toward control of symptoms. Home care in this case includes the consumption of plenty of fluids.Ibuprofen (Brufen) may be used as an anti-inflammatory medication if there is no contraindication to its use. If further pain medication is needed, stronger narcotic pain medications may be recommended.

There are several factors which influence the ability to pass a stone. These include the size of the person, prior stone passage, prostate enlargement, pregnancy, and the size of the stone. A 4 mm stone has an 80% chance of passage while a 5 mm stone has a 20% chance. Stones larger than 9 mm-10 mm rarely pass without specific treatment.

Some medications have been used to increase the passage rates of kidney stones. These include calcium channel blockers such as nifedipine  and alpha blockers such as tamsulosin. These drugs may be prescribed to some people who have stones that do not rapidly pass through the urinary tract.

For kidney stones that do not pass on their own, a procedure called lithotripsy is often used. In this procedure, shock waves are used to break up a large stone into smaller pieces that can then pass through the urinary system.

Surgical techniques have also been developed to remove kidney stones when other treatment methods are not effective. This may be done through a small incision in the skin (percutaneous nephrolithotomy) or through an instrument known as an ureteroscope passed through the urethra and bladder up into the ureter.

How can kidney stones be prevented?

Rather than having to undergo treatment, it is best to avoid kidney stones in the first place when possible. It can be especially helpful to drink more water, since low fluid intake and dehydration are major risk factors for kidney stone formation.

Depending on the cause of the kidney stones and an individual's medical history, dietary changes or medications are sometimes recommended to decrease the likelihood of developing further kidney stones. If one has passed a stone, it can be particularly helpful to have it analyzed in a laboratory to determine the precise type of stone so specific prevention measures can be considered.

People who have a tendency to form calcium oxalate kidney stones may be advised to limit their consumption of foods high in oxalate, such as spinach, rhubarb, Swiss chard, beets, wheat germ, and peanuts

SUMMARY OF TREATMENT

The common evaluation of stone disease include

  • Kidney function tests [s. creatinine]

  • Urine microscopy [to look for microscopic hematuria]

  • Metabolic evaluation [s. calcium, s. Phosphorus, s. Uric acid,]

  • Ultrasound examination

  • X ray KUB

  • Special tests if necessary [24 hour urine studies, s. paratharmone, IVU}

Common treatment methods

Kidney stones

ESWL: Expensive, available in few centers, better carried out with good machines

PCNL: Minimally invasive, carried out through small incisions in the back. Needs expensive equipment and is available in few places. Has a certain complications that can be serious

OPEN SURGEIES: For large stones. With certain abnormalities of the Kidney the surgery needs to be carried out by experts as complications are possible. IVU is necessary before surgery

URETERORENOSCOPIC REMOVAL: this was generally carried out for lower and mid ureteric stones. .

CYSTOLITHOLAPAXY: Special instruments are used to break the stones in the bladder

CYSTOLITHOTOMY: Open surgery to remove bladder stones.

NEW AT SEESHA MEDICAL SERVICE

With the large experience gained by treating rural patients in remote locations SEESHA now uses the Ureterorenoscope to remove even Kidney stones by a special technique. The attached PDF file gives the details that were published. Prior DJ stenting allows the ureter to expand and experienced surgeons could use the URS to view and break the ureteric and Kidney stones.