Kidney Stone Surgery India
What is a kidney stone?
A kidney stone is a hard mass developed from crystals that separate from the urine and build up on the inner surfaces of the kidney. Normally, urine contains chemicals that prevent or inhibit the crystals from forming. These inhibitors do not seem to work for everyone, however, so some people form stones. If the crystals remain tiny enough, they will travel through the urinary tract and pass out of the body in the urine without being noticed.
Kidney stones may contain various combinations of chemicals. The most common type of stone contains calcium in combination with either oxalate or phosphate. These chemicals are part of a person's normal diet and make up important parts of the body, such as bones and muscles.
A less common type of stone is caused by infection in the urinary tract. This type of stone is called a struvite or infection stone. A bit less common is the uric acid stone. Cystine stones are rare.
Urolithiasis is the medical term used to describe stones occurring in the urinary tract. Other frequently used terms are urinary tract stone disease and nephrolithiasis. Doctors also use terms that describe the location of the stone in the urinary tract. For example, a ureteral stone (or ureterolithiasis) is a kidney stone found in the ureter. To keep things simple, however, the term "kidney stones" is used throughout this fact sheet.
Gallstones and kidney stones are not related. They form in different areas of the body. If you have a gallstone, you are not necessarily more likely to develop kidney stones.
What causes kidney stones?
Kidney stones form when there is a decrease in urine volume 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. Other chemical compounds that can form stones in the urinary tract include uric acid and the amino acid cystine.
Dehydration through 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. Kidney stones associated with infection in the urinary tract are known as struvite or infection stones.
Men are especially likely to develop kidney stones, and whites get them more often than African American. The prevalence of kidney stones begins to rise when men reach their 40s and continues to climb into their 70s. People who have already had more than one kidney stone are prone to develop more stones.
A number of different conditions can lead to kidney stones:
Gout results in an increased amount of uric acid in the 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 some inherited metabolic conditions including cystinuria and hyperoxaluria.
People with inflammatory bowel disease or who have had an intestinal bypass or ostomy surgery are also more likely to develop kidney stones.
Some medications also raise the risk of kidney stones. These medications include some diuretics, calcium-containing antacids, and the protease inhibitor Crixivan (indinavir), a drug used to treat HIV infection.
How Do You Know If You Have a Kidney Stone
First we must define a urinary kidney stone as a cluster of crystals which have formed in the urinary tract. Urinary stones can be described by their location as kidney stones, ureteral stones or bladder stones. The location of the stone in the urinary tract may often be determined by the location of the symptoms they are causing. In most cases stones are initially formed in the kidney where they generally don’t cause symptoms. They may be dissolved by the presence of blood or infection in the urine on route to examination. Sometimes they can grow large enough to damage the kidney, which may cause discomfort in the back or flank area. Generally it is not until a kidney stone begins to pass out of the kidney and move down the ureter that we become aware of its presence.
The first symptom of a kidney stone is usually onset of severe, excruciating pain in the flank or mid back area. This pain is often the result of a stone moving in the urinary tract, causing irritation and blockage of urine flow. Nausea and vomiting can accompany this pain, and the pain may spread to the pelvis, groin, and genitals. The passage of large stones can be complicated when trying to squeeze through the narrow ureter. This may result in hematuria, a condition where blood is found in the urine. As the stone passes down the ureter toward the bladder, it can cause an increased urge to urinate, painful or burning urination, excessive urination at night, and urinary hesitancy. Other symptoms may include abnormal urine color or appearance, tenderness in abdomen or back when touched, and loss of appetite. If fever or chills are present with any of these symptoms, an infection may be present, in which cases one should see a doctor immediately.
How Common Are Kidney Stones?
Approximately one person in 200 will form a kidney stone this year, which will total more than 1 million cases in the United States. In these cases, approximately 80% of the stones will pass spontaneously, while the remaining 20% will need treatment. If a person forms a kidney stone, there is a 50% chance of another stone forming in 5-10 years without treatment.
The cause of kidney stone can be determined in 75% of cases by a metabolic evaluation. This evaluation analyzes the stone, blood, and urine chemistry of the patient. If an abnormality is found, the recurrence rate can be reduced with treatment from 50% to 10%. Some of the more common causes of stones are low fluid intake and malfunctions in the way the body absorbs, manufactures, or eliminates urinary products that can form crystals.
Can Kidney Stones Be Prevented?
There are many risk factors leading to the formation of kidney stones. Some of these include a family history of stones, certain variations in kidney anatomy, and the amount of fluid consumed during the day. Some stones are caused by genetic conditions or other medical conditions such as gout, eating disorders, or intestinal disease.
Who gets kidney stones?
For unknown reasons, the number of people in the United States with kidney stones has been increasing over the past 30 years. The prevalence of stone-forming disease rose from 3.8 percent in the late 1970s to 5.2 percent in the late 1980s and early 1990s. White Americans are more prone to develop kidney stones than African Americans. Stones occur more frequently in men. The prevalence of kidney stones rises dramatically as men enter their 40s and continues to rise into their 70s. For women, the prevalence of kidney stones peaks in their 50s. Once a person gets more than one stone, others are likely to develop.
What causes kidney stones?
Doctors do not always know what causes a stone to form. While certain foods may promote stone formation in people who are susceptible, scientists do not believe that eating any specific food causes stones to form in people who are not susceptible.
A person with a family history of kidney stones may be more likely to develop stones. Urinary tract infections, kidney disorders such as cystic kidney diseases, and certain metabolic disorders such as hyperparathyroidism are also linked to stone formation.
In addition, more than 70 percent of people with a rare hereditary disease called renal tubular acidosis develop kidney stones.
Cystinuria and hyperoxaluria are two other rare, inherited metabolic disorders that often cause kidney stones. In cystinuria, too much of the amino acid cystine, which does not dissolve in urine, is voided. This can lead to the formation of stones made of cystine. In patients with hyperoxaluria, the body produces too much of the salt oxalate. When there is more oxalate than can be dissolved in the urine, the crystals settle out and form stones.
Hypercalciuria is inherited. It is the cause of stones in more than half of patients. Calcium is absorbed from food in excess and is lost into the urine. This high level of calcium in the urine causes crystals of calcium oxalate or calcium phosphate to form in the kidneys or urinary tract.
Other causes of kidney stones are hyperuricosuria which is a disorder of uric acid metabolism, gout, and excess intake of vitamin D, urinary tract infections, and blockage of the urinary tract. Certain diuretics which are commonly called water pills or calcium-based antacids may increase the risk of forming kidney stones by increasing the amount of calcium in the urine.
Calcium oxalate stones may also form in people who have a chronic inflammation of the bowel or who have had an intestinal bypass operation, or ostomy surgery. As mentioned above, struvite stones can form in people who have had a urinary tract infection. People who take the protease inhibitor indinavir, a drug used to treat HIV infection, are at risk of developing kidney stones.
How are kidney stones treated?
Fortunately, surgery is not usually necessary. Most kidney stones can pass through the urinary system with plenty of water (2 to 3 quarts a day) to help move the stone along. Often, you can stay home during this process, drinking fluids and taking pain medication as needed. The doctor usually asks you to save the passed stone(s) for testing. (You can catch it in a cup or tea strainer used only for this purpose.)
The First Step: Prevention
If you've had more than one kidney stone, you are likely to form another; so prevention is very important. To prevent stones from forming, your doctor must determine their cause. He or she will order laboratory tests, including urine and blood tests. Your doctor will also ask about your medical history, occupation, and eating habits. If a stone has been removed, or if you've passed a stone and saved it, the laboratory should analyze it because its composition helps in planning treatment.
You may be asked to collect your urine for 24 hours after a stone has passed or been removed. The sample is used to measure urine volume and levels of acidity, calcium, sodium, uric acid, oxalate, citrate, and creatinine (a product of muscle metabolism). Your doctor will use this information to determine the cause of the stone. A second 24-hour urine collection may be needed to determine whether the prescribed treatment is working.
A simple and most important lifestyle change to prevent stones is to drink more liquids—water is best. If you tend to form stones, you should try to drink enough liquids throughout the day to produce at least 2 quarts of urine in every 24-hour period.
People who form calcium stones used to be told to avoid dairy products and other foods with high calcium content. But recent studies have shown that foods high in calcium, including dairy products, may help prevent calcium stones. Taking calcium in pill form, however, may increase the risk of developing stones.
You may be told to avoid food with added vitamin D and certain types of antacids that have a calcium base. If you have very acidic urine, you may need to eat less meat, fish, and poultry. These foods increase the amount of acid in the urine.
To prevent cystine stones, you should drink enough water each day to dilute the concentration of cystine that escapes into the urine, which may be difficult. More than a gallon of water may be needed every 24 hours, and a third of that must be drunk during the night.
Foods and Drinks Containing Oxalate
People prone to forming calcium oxalate stones may be asked by their doctor to cut back on certain foods if their urine contains an excess of oxalate:
People should not give up or avoid eating these foods without talking to their doctor first. In most cases, these foods can be eaten in limited amounts.
The doctor may prescribe certain medications to prevent calcium and uric acid stones. These drugs control the amount of acid or alkali in the urine, key factors in crystal formation. The drug allopurinol may also be useful in some cases of hyperuricosuria.
Doctors usually try to control hypercalciuria, and thus prevent calcium stones, by prescribing certain diuretics, such as hydrochlorothiazide. These drugs decrease the amount of calcium released by the kidneys into the urine by favoring calcium retention in bone. They work best when sodium intake is low.
Very rarely, patients with hypercalciuria may be given the drug sodium cellulose phosphate, which binds calcium in the intestines and prevents it from leaking into the urine.
If cystine stones cannot be controlled by drinking more fluids, your doctor may prescribe drugs such as Thiola and Cuprimine, which help reduce the amount of cystine in the urine.
For struvite stones that have been totally removed, the first line of prevention is to keep the urine free of bacteria that can cause infection. Your urine will be tested regularly to be sure that no bacteria are present.
If struvite stones cannot be removed, your doctor may prescribe a drug called acetohydroxamic acid (AHA). AHA is used with long-term antibiotic drugs to prevent the infection that leads to stone growth.
People with hyperparathyroidism sometimes develop calcium stones. Treatment in these cases is usually surgery to remove the parathyroid glands (located in the neck). In most cases, only one of the glands is enlarged. Removing the glands cures the patient's problem with hyperparathyroidism and with kidney stones as well.
Surgery should be reserved as an option for cases where other approaches have failed. Surgery may be needed to remove a kidney stone if it
Does not pass after a reasonable period of time and causes constant pain
Is too large to pass on its own or is caught in a difficult place
Blocks the flow of urine
Causes ongoing urinary tract infection
Damages kidney tissue or causes constant bleeding
Has grown larger (as seen on followup x ray studies).