Surgical lasers and soft tissue interactions.

The different physical and biological qualities of the carbon dioxide, argon, and neodymium-YAG lasers provide the otolaryngologist and head and neck surgeon with a surgical tool with specific qualities and applications. The specific wave lengths of laser energy produce a varied soft tissue action. The carbon dioxide laser energy is absorbed by all biological tissues, whereas argon laser energy is an effective photocoagulator and penetrates into the subepithelial plane; the Nd-YAG laser creates a coagulation effect, which penetrates deep into the tissues. Each laser has specific physical qualities. The argon laser and the Nd-YAG laser can be transmitted through a flexible fiberoptic delivery system, whereas the carbon dioxide laser currently requires a rigid optical delivery system. The Nd-YAG and carbon dioxide lasers both require a second coincident aiming beam because of the invisibility of their laser energy, whereas the argon laser does not have such a requirement. The spot size of the laser beam can be much smaller for the argon laser than for the carbon dioxide laser. Protective lenses are necessary for the argon, carbon dioxide, and Nd-YAG lasers. The carbon dioxide laser energy is not transmitted through glass; thus most media (glass, plastic) are suitable to prevent any ocular injury. The argon laser requires a special yellowish protective mechanism, and the Nd-YAG laser requires a green protective lens mechanism. With further technical advances and improvements in the fiberoptic delivery system, smaller laser spot sizes, and changes in operating laser modes and color specifications of lasers, the advantages of laser surgery over conventional surgical techniques will become increasingly more apparent.