IMMEDIATE HISTOLOGICAL-CHANGES IN SOFT PALATE AFTER UVULOPALATOPHARYNGOPLASTY WITH CO2, CONTACT ND-YAG OR COMBINED CO2 AND ND-YAG LASER-BEAMS

CO2, contact Nd:YAG and Combolaser (combined, simultaneous and coaxial CO2 + Nd:YAG laser beam) were used for uvulopalatopharyngoplasty (UPP P). It has been proposed that the combined beam geometry diminishes th ermal damage to surrounding tissues when compared with single laser ra diation. To study the extent of thermal tissue damage produced by the lasers, tissue samples for light (LM) and transmission electron micros copy (TEM) were taken from the surface of the resected area and 2 and 4 mm below the resection plane. The depth of tissue damage and coagula tion was measured. The results showed no consistent differences in the inflammatory reactions or the amount and depth of tissue coagulation observed in samples taken immediately after the operation. The CO2 las er typically produced a carbonized and coagulated wound edge. Combolas er and contact Nd:YAG lasers generated slightly less charring but othe rwise resembled each other with coagulated and vacuolized resecate mar gins. These results indicate that the beam geometry in Combolaser does not diminish thermal damage to surrounding tissues.