Dynamic Changes in Fluid Temperatures during Laser Irradiation Using Various Laser Modes: A Thermography-Based In...

Area of Science:

• Urology
• Medical Engineering
• Laser Medicine

Background:

• Understanding dynamic thermal changes during laser lithotripsy is crucial for preventing thermal injury.
• Previous research has not clearly defined differences in thermal profiles across various laser pulse modes.
• Optimizing laser settings requires detailed knowledge of heat distribution during stone fragmentation.

Purpose of the Study:

• To compare dynamic thermal changes and high-temperature area expansion during laser lithotripsy across different pulse modes.
• To evaluate the impact of short pulse mode (SPM), long pulse mode (LPM), virtual basket mode (VBM), and Moses mode (MM) on thermal profiles.
• To provide data for preventing thermal injuries in retrograde intrarenal surgery.

Main Methods:

• Thermography was employed to monitor temporal changes in high-temperature areas (>43 °C) during laser activation.
• Experiments were conducted using an unroofed artificial kidney model without saline irrigation.
• Laser settings (0.4 J/60 Hz) were applied for 60 seconds across the four pulse modes, with analysis focused on the initial 30 seconds.

Main Results:

• Significant differences in dynamic fluid temperature changes were observed among the laser pulse modes.
• Long pulse mode (LPM) and Moses mode (MM) exhibited larger high-temperature areas compared to SPM and VBM.
• LPM showed anterior expansion of high-temperature areas, while MM demonstrated posterior expansion during early irradiation.

Conclusions:

• Laser pulse mode selection critically influences thermal distribution during lithotripsy.
• LPM and MM present a greater risk of thermal spread compared to SPM and VBM.
• Understanding these distinct thermal patterns is vital for minimizing thermal damage during intrarenal procedures.