In soft-tissue laser surgery, a highly focused laser beam vaporizes the soft tissue with the high water content. The laser makes small incisions when the beam is focused on the tissue: the focal spot size can be as small as 100 µm, but the most widely used in practice is 400 µm (0.4 mm). When the beam is defocused, the intensity of the laser light on the tissue diminishes, and it can be used for cauterization of small blood vessels and lymphatics, therefore decreases post-operative swelling.
Soft-tissue laser surgery is used in a variety of applications in human (general surgery, neurosurgery, ENT, dentistry,and oral and maxillofacial surgery) as well as veterinary surgical fields.
A laser beam has a natural sterilization effect: it evaporates bacteria, viruses and fungi, which leads to a decrease in local infections. Probably most important, the laser decreases post-operative pain by sealing nerve endings.
Soft-tissue laser surgery is differentiated from hard-tissue laser surgery (bones and teeth in dentistry ) and laser eye surgery (eyesight corrective surgeries ) by the type of lasers used in a particular type of laser surgery.
Hard tissue surgical lasers are dominated by Er:YAG lasers operating at the wavelengths of 2.94 µm. Laser eye surgery utilizes excimer lasers in the UV range of wavelengths. Unlike many solid-state and diode lasers in the visible and near infrared wavelength range (600-2,000 nm), the carbon dioxide laser wavelength (10.6 µm) is highly absorbed by in-vivo soft tissues containing water. Furthermore, modern CO2 laser technology makes these lasers far more affordable than solid-state Er:YAG lasers, which also feature a wavelength that is highly absorbed by water. Because of their wavelength and precision, CO2 lasers remain the dominant soft-tissue surgical lasers.