When is lithotripsy (extracorporeal shock wave lithotripsy) recommended for patients with kidney stones (nephrolithiasis)?

From the Guidelines

Lithotripsy is recommended for patients with kidney stones smaller than 2 cm, particularly those located in the kidney or upper ureter, as it is a non-invasive procedure with the least morbidity and lowest complication rate 1.

Key Considerations

• The success rate of lithotripsy varies based on stone composition, size, and location, with lower effectiveness for very hard stones (like calcium oxalate monohydrate or cystine stones) or those in the lower pole of the kidney where gravity makes fragment clearance difficult.
• Lithotripsy is not recommended for pregnant women, patients with bleeding disorders, active urinary tract infections, or certain anatomical abnormalities.
• Patients should expect some discomfort during passage of fragments and may require pain medication such as NSAIDs or, in some cases, narcotic analgesics for 1-2 weeks following the procedure.

Treatment Guidelines

• For patients with mid or distal ureteral stones who require intervention, ureteroscopy (URS) is recommended as first-line therapy, with lithotripsy offered as an alternative for those who decline URS 1.
• Routine stenting should not be performed in patients undergoing lithotripsy, and placement of a ureteral stent prior to URS should not be performed routinely 1.

Stone Size and Location

• Lithotripsy is most effective for stones that are not too dense and when patients have normal anatomy without obstruction below the stone.
• The procedure is generally preferred for patients who are poor surgical candidates, those with solitary kidneys, or when other approaches are contraindicated.

Evidence-Based Recommendations

• The American Urological Association (AUA) recommends lithotripsy as a treatment option for patients with kidney stones, with a strong recommendation for its use in patients with small to medium-sized stones 1.
• The AUA also recommends URS as first-line therapy for patients with mid or distal ureteral stones who require intervention, with lithotripsy offered as an alternative for those who decline URS 1.

From the Research

Indications for Lithotripsy

Lithotripsy, also known as extracorporeal shock wave lithotripsy (ESWL), is a non-invasive treatment for kidney stones (nephrolithiasis) that uses shock waves to break up stones into smaller pieces that can then pass out of the body in the urine. The following are indications for lithotripsy:

• Small to medium-sized stones (less than 2 cm in diameter) in the kidney or ureter 2, 3
• Stones that are causing severe pain or obstruction, but are not suitable for other treatments such as ureteroscopy or percutaneous nephrolithotomy (PCNL) 4, 3
• Patients who are not good candidates for more invasive procedures, such as those with bleeding disorders or severe medical conditions 5, 6
• Stones in the lower pole of the kidney, although the effectiveness of lithotripsy for these stones is lower compared to other locations 4, 3

Contraindications and Considerations

While lithotripsy is generally a safe and effective treatment, there are some contraindications and considerations to keep in mind:

• Large stones (greater than 2 cm in diameter) may not be suitable for lithotripsy, as they may not be fully broken up by the shock waves 2, 3
• Stones in the lower pole of the kidney may have a lower success rate with lithotripsy, and other treatments such as PCNL or ureteroscopy may be more effective 4, 3
• Patients with certain medical conditions, such as bleeding disorders or severe kidney disease, may not be good candidates for lithotripsy 5, 6
• The long-term effects of lithotripsy on the kidney are not fully understood, and patients should be monitored for potential complications such as new onset hypertension 2, 5

Comparison with Other Treatments

Lithotripsy is one of several treatment options for kidney stones, and the choice of treatment depends on the size, location, and type of stone, as well as the patient's overall health. The following are some comparisons with other treatments:

• PCNL: Lithotripsy may have a lower success rate compared to PCNL, especially for larger stones or stones in the lower pole of the kidney 4, 3
• Ureteroscopy: Lithotripsy may have a lower success rate compared to ureteroscopy, especially for stones in the ureter 4, 3
• Mini PCNL: Lithotripsy may have a similar success rate compared to mini PCNL, but may have fewer complications and shorter hospital stays 6