Kidney Stones - Prevention

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Ureteroscopy achieves a higher stone removal rate than SWL, but it also has a higher risk of complications. 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.

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Percutaneous Nephrolithotomy

Percutaneous nephrolithotomy (PCNL) may also be used to treat kidney stones when SWL 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). PCNL is also preferred over SWL for stones that have remained in the ureter for more than 4 weeks.

PCNL is more effective than SWL for patients who are severely obese, and it appears to be safe for the very elderly and the very young. Success rates are very high for kidney stones and for ureteral stones; however, success may vary based on 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:

• The surgeon makes a tiny incision in the skin and creates a channel directly into the kidney.
• The surgeon then inserts an instrument called a nephroscope through the channel.
• The stone is located and removed. If it is large, it is destroyed using ultrasound, lasers, or other devices. The surgeon then removes the fragments. An advantage of PCNL over SWL is that the surgeon is able to remove the stone fragments directly, instead of relying on their natural passage from the kidney.
• Generally, patients stay in the hospital for 5 or 6 days and may need a small device called a nephrostomy tube left in the kidney during the healing process.