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, the patient can stay home during this process, drinking fluids and taking pain medication as needed. The doctor usually asks the patient to save the passed stone(s) for testing. It can be caught in a strainer
A simple and most important lifestyle change to prevent stones is to drink more liquids—water is best. Someone who tends to form stones should try to drink enough liquids throughout the day to produce at least 2 quarts of urine in every 24-hour period.
In the past, people who form calcium stones were told to avoid dairy products and other foods with high calcium content. 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.
Patients may be told to avoid food with added vitamin D and certain types of antacids that have a calcium base. Someone who has highly acidic urine may need to eat less meat, fish, and poultry. These foods increase the amount of acid in the urine.
A doctor may prescribe certain medications to help prevent calcium and uric acid stones. These medicines control the amount of acid or alkali in the urine, key factors in crystal formation. The medicine allopurinol may also be useful in some cases of hyperuricosuria (excessive amounts of uric acid in the urine).
Doctors usually try to control hypercalciuria, and thus prevent calcium stones, by prescribing certain diuretics, such as hydrochlorothiazide. These medicines 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.
People with hyperparathyroidism sometimes develop calcium stones. Treatment in these cases is usually surgery to remove the parathyroid glands, which are 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 kidney stones.
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 an ongoing urinary tract infection
- damages kidney tissue or causes constant bleeding
- has grown larger, as seen on follow-up x rays
Extracorporeal Shock Wave Lithotripsy
Extracorporeal shock wave lithotripsy (ESWL) is the most frequently used procedure for the treatment of kidney stones. In ESWL, shock waves that are created outside the body travel through the skin and body tissues until they hit the denser stones. The stones break down into small particles and are easily passed through the urinary tract in the urine.
Several types of ESWL devices exist. Most devices use either x rays or ultrasound to help the surgeon pinpoint the stone during treatment. For most types of ESWL procedures, anesthesia is needed.
Complications may occur with ESWL. Some patients have blood in their urine for a few days after treatment. Bruising and minor discomfort in the back or abdomen from the shock waves can occur. To reduce the risk of complications, doctors usually tell patients to avoid taking aspirin and other medicines that affect blood clotting for several weeks before treatment.
Sometimes, the shattered stone particles cause minor blockage as they pass through the urinary tract and cause discomfort. In some cases, the doctor will insert a small tube called a stent through the bladder into the ureter to help the fragments pass. Sometimes the stone is not completely shattered with one treatment, and additional treatments may be needed.
As with any interventional, surgical procedure, potential risks and complications should be discussed with the doctor before making a treatment decision.
Sometimes a procedure called percutaneous nephrolithotomy is recommended to remove a stone. This treatment is often used when the stone is quite large or in a location that does not allow effective use of ESWL.
In this procedure, the surgeon makes a tiny incision in the back and creates a tunnel directly into the kidney. Using an instrument called a nephroscope, the surgeon locates and removes the stone. For large stones, some type of energy probe—ultrasonic or electrohydraulic—may be needed to break the stone into small pieces. Often, patients stay in the hospital for several days and may have a small tube called a nephrostomy tube left in the kidney during the healing process.
One advantage of percutaneous nephrolithotomy is that the surgeon can remove some of the stone fragments directly instead of relying solely on their natural passage from the kidney.
Ureteroscopic Stone Removal
Although some stones in the ureters can be treated with ESWL, ureteroscopy may be needed for mid- and lower-ureter stones. No incision is made in this procedure. Instead, the surgeon passes a small fiberoptic instrument called a ureteroscope through the urethra and bladder into the ureter. The surgeon then locates the stone and either removes it with a cage-like device or shatters it with a special instrument that produces a form of shock wave. A small tube or stent may be left in the ureter for a few days to help urine flow. Before fiber optics made ureteroscopy possible, physicians used a similar “blind basket” extraction method. But this technique is rarely used now because of the higher risks of damage to the ureters.