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Properties of
Laser Light

How Laser
Energy is Generated

Laser Tissue Interaction

Holmium Laser
in Endourology

Anatomy of a Laser Pulse

Understanding Energy Density

Safety Precautions

Ocular Hazards

Skin Hazards

Other Hazards

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Holmium Laser in Lithotripsy

The holmium laser, being a long-pulsed laser, creates thermal interactions with tissue. In the case of urinary lithotripsy, the laser heats up and vaporizes water on the surface and within the calculus, the water expands and the expansion causes the calculus to disintegrate.

Holmium lasers range in pulse duration between 250 to 350 microseconds. It is not very useful to compare these values as each manufacturer measures pulse duration differently. Clinically for lithotripsy, there is very little difference between a 250 and 350 microsecond holmium laser.

The Odyssey contains a special feature that allows it to change its pulse duration intraoperatively. For soft tissue applications, the clinician may want the laser to create more coagulative tissue effects, to decrease bleeding for instance. By increasing the laser exposure time to tissue, the same amount of laser energy can be delivered using a much lower peak power. The peak power still remains above the ablation threshold of water, yet the tissue has more time to absorb the laser energy.