Calcium stones; Nephrolithiasis
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.
Today, treatments for stones are much less invasive than in the past. Major surgery is performed in less than 2% of patients.
Stone removal procedures:
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 effectiveness on all stones.
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 3 centimeters in diameter (which is slightly over an inch). There are several variations of ESWL. The following is a typical procedure:
The shattered stone fragments may cause discomfort as they pass through the urinary tract. If so, the doctor may insert a small tube called a stent through the bladder into the ureter to help the fragments pass. This practice, however, does not usually speed up passage of the stones and is not used routinely.
ESWL has a 50 - 90% success rate, depending on the location of the stone and the surgeon's technique and experience. Recovery time is short. Most people can resume normal activities in a few days.
Complications. Complications may include:
ESWL appears to be safe for children. Experts recommend using the least amount of shocks and impact possible in young people. If more than one treatment is needed, the patient should wait at least 15 days before the next treatment.
Percutaneous nephrolithotomy may also be used for treatment of kidney stones when ESWL is not available or the patient is not a candidate for it (such as if the stone is very large, in an inaccessible location, or is a cystine stone). It is also preferred over ESWL for stones that have remained in the ureter for more than 4 weeks.
It is more effective than ESWL for patients with severe obesity, and appears to be safe for the very elderly and the very young. Success rates are nearly 98% for kidney stones and 88% for ureteral stones. They may vary by the technique used and the specific patients. For example, success rates are slightly lower in children, although the procedure can be done safely in young patients. Long-term effects are unknown.
A typical procedure is as follows:
Devices Used to Destroy Stones. For large stones, some type of energy-delivering device may be needed to break the stone into small pieces. They are referred to as intracorporeal lithotripsy devices (meaning stone breakers within the body). The device may be one of the following:
Complications. Complication rates are about 3%. Major complications occur in about 1% of patients. These complications may include scarring of the tissue, but studies indicate that this scarring does not impair kidney function, even if the patient needs repeat surgery. There is also a risk for blood loss during and after the procedure, which sometimes can be significant.
Because the procedure uses large volumes of fluid, fluid overload is a potential problem, particularly in children or patients with heart disease.
Infection may result in some patients. Other complications may include a collapsed lung and injuries to areas outside the kidney (but within the operative area), such as the abdomen or chest.
Ureteroscopy may be used for stones in the middle and lower ureter. With the arrival of smaller instruments, this procedure can be done successfully in children as well. The procedure involves the following:
Complication rates range from 10 - 20%, with major problems occurring in up to 6% of patients. In some cases, large stones are not broken up into small enough pieces. This can result in a blockage of the urinary tract and possible kidney damage.
Imaging tests, such as ultrasound or spiral CT, are useful within 3 months to check for residual stones, and a second procedure may be required. The risk of complications is highest when the procedure is performed by less experienced surgeons, or if stones are found in the kidney. The risk for perforation of the ureter increases the longer the procedure takes.
Open surgery involves incisions through the patient's flank and into the kidney. The surgeon will cool the kidneys using ice. X-rays during the procedure help locate the stone. At the beginning of the surgery, the surgeon will isolate the arteries supplying the kidneys, ensuring they are not harmed during the surgery. The surgeon will then locate and remove the stone. The surgeon will also correct any blockage in the affected area. The surgery, called nephrolithotomy, is very invasive and is restricted to the following:
Some centers report success with extracorporeal shock wave lithotripsy in patients who would normally be nephrolithotomy candidates. Therefore, even these patients should discuss other options with their surgeon.
The procedure is not appropriate for patients with:
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