Abstract
The authors have used the potassium titanyl phosphate (KTiOPO_4 : KTP) laser for various craniotomies, and have evaluated its efficacy. The KTP laser has a wavelength of 532 nm, which is half the wavelenght of a neodymium: yttrium-alminum-garnet (Nd : YAG) laser, so that its energy level is very close to that of maximum absorption to hemoglobin and thus is beneficial for hemostatic cutting. Further, as the KTP laser's green light is visible after being delivered through a flexible quartz fiber to the operative field, this light allows the surgeon to set the target precisely. With the light bayonet handpiece, the laser can be introduced even through a minimun opening to deep seated skull base tumors. The laser also can be used in both the contact and non-contact modes by simply cleaving the tip of the fiber whenever polluted. Tissue damage caused by laser irradiation was also investigated when treating brain tumors of the rat cerebrum, and it was found that the thickness of thermal damage was no more than 1.5 mm when the laser mode was set for the usual tumor evacuation. These features of the KTP laser was thus considered to provide powerful advantages for use in microneurosurgery.
