Thulium fiber laser: ready to dust all urinary stone composition types?

Area of Science:

• Urology
• Laser Medicine
• Materials Science

Background:

• Urinary stone disease affects a significant portion of the population.
• Effective fragmentation of urinary stones is crucial for successful lithotripsy.
• Different stone compositions pose challenges for current lithotripsy methods.

Purpose of the Study:

• To determine if the thulium fiber laser (TFL) can produce stone dust from all prevalent urinary stone types.
• To analyze the morpho-constitutional characteristics of the generated stone dust.

Main Methods:

• In vitro lithotripsy of human urinary stones using a thulium fiber laser (TFL) generator.
• Laser settings: 0.05 J, 320 Hz, 200 μs, with a total of 2400 J delivered per stone.
• Analysis of stone dust by scanning electron microscopy and Fourier transform infrared spectroscopy.

Main Results:

• Stone dust was successfully retrieved from all tested urinary stone compositions (calcium oxalate monohydrate, calcium oxalate dihydrate, uric acid, carbapatite, struvite, brushite, cystine).
• Most stone dust samples exhibited altered crystalline structures post-TFL lithotripsy.
• Calcium oxalate monohydrate and carbapatite stones retained their original crystalline characteristics.
• The mean maximal width of stone dust particles was less than 254 µm.

Conclusions:

• The thulium fiber laser (TFL) is effective in producing stone dust from all common urinary stone types.
• Observed morpho-constitutional changes in stone dust suggest a photothermal interaction between TFL energy and the stone matrix during lithotripsy.