Dual-frequency setting for urinary stone fragmentation during shock wave lithotripsy: an in vitro study

Area of Science:

• Biomedical Engineering
• Urology
• Medical Physics

Background:

• Extracorporeal shock wave lithotripsy (SWL) is a minimally invasive treatment for kidney stones.
• Improving SWL efficacy and reducing procedure time are clinical goals.
• Investigating novel SWL parameters, such as dual frequency, can enhance treatment outcomes.

Purpose of the Study:

• To evaluate the effectiveness of a dual-frequency (DF) setting in SWL for kidney stone fragmentation.
• To compare stone fragmentation efficacy and treatment duration between single and dual-frequency SWL.
• To determine if DF SWL can improve stone comminution while minimizing procedure time.

Main Methods:

• In vitro fragmentation of 10 mm phantom kidney stones using an electromagnetic lithotripter.
• Comparison of 60 Hz, 120 Hz, and a DF (60-120 Hz) setting, with 3000 shocks per setting.
• Measurement of total weight of significant fragments (>3 mm and >2 mm) and total number of significant fragments (>3 mm and >2 mm).

Main Results:

• The DF 60-120 Hz setting showed significantly lower total weight of fragments >3 mm compared to 120 Hz (p=0.02).
• There was an increasing trend in fragment weight and number for DF, 60 Hz, and 120 Hz settings (p<0.05).
• Treatment time was significantly reduced with 120 Hz (25 min) and DF (34 min) compared to 60 Hz (50 min).

Conclusions:

• Dual-frequency SWL demonstrates effective stone fragmentation comparable to 60 Hz but with a reduced treatment time.
• The DF setting offers a potential optimization for SWL, balancing fragmentation efficiency and procedure duration.
• Further clinical evaluation is warranted to validate the benefits of DF SWL for kidney stone treatment.