Kidney Stones - Prevention

Other Treatments

Surgery is usually needed if the stone is too large to pass on its own, if there are signs that the stone is growing, or if the stone is blocking the urine flow and causing a urinary tract infection or kidney damage.

Until recently, the procedure to remove a stone was a very painful, major surgery that required a 4- to 6-week recovery period. Today, treatments for stones are much less invasive. Major surgery is performed in less than 2% of patients.

Stone removal procedures:

• Extracorporeal shock wave lithotripsy (ESWL) is used for small stones (less than one centimeter, or slightly less than half an inch) that occur in the upper part of the ureter and do not pass on their own. One study indicated lithotripsy might even be safe and effective for patients whose stones are associated with malformed kidneys, although such patients are at higher risk for stone recurrence and should be carefully monitored.
• Percutaneous nephrolithotomy (PNL). PNL can be used for very large stones in the upper tract, when ESWL fails, for kidney transplant patients, or when there are structural abnormalities in the kidney or surrounding area. PNL is the preferred procedure for drug-resistant cystine stones, which are usually resistant to shock wave therapy.
• Ureteroscopy. For stones in the lower tract, ureteroscopy is generally the best procedure, although lithotripsy is also usually feasible and patients ordinarily prefer it.
• Standard open surgery (nephrolithotomy) may be required if any of these procedures fail or are not appropriate, or in special cases, such as when the patient is very obese.

Most procedures are more effective for calcium and uric acid stones and less effective for struvite and cystine stones, although new techniques may be improving their effects on all stones.

Extracorporeal Shock Wave Lithotripsy

Extracorporeal shock wave lithotripsy (ESWL) is a technique that uses sound waves (ultrasound) to break up simple stones in the kidney or upper urinary tract. ("Extracorporeal" means "outside the body," and "lithotripsy" means stone-breaking.) ESWL is not used for cystine stones. The procedure generally does not work for stones larger than three centimeters in diameter (which is slightly over an inch). There are several variations. The following is a typical procedure:

• Most ESWL procedures use some anesthesia, although they are often done on an outpatient basis.
• The patient is positioned in a water bath. (In some procedures the patient lies on a soft cushion.)
• The procedure uses ultrasound to generate shock waves that travel through the skin and body tissues until they hit the dense stones. (X-rays or ultrasound are used to help the surgeon pinpoint the stone during treatment.)
• The stones are crushed into tiny sand-like pieces that usually pass easily through the urinary tract.
• The shattered stone fragments may cause discomfort as they pass through the urinary tract. In such cases, the doctor may insert a small tube called a stent through the bladder into the ureter to help the fragments pass. This practice, however, has not proved to speed up passage of the stones in most cases and is not used routinely.