Ho: YAG Laser-Application to Laryngeal Microsurgery

Objectives: The Holmium:YAG (Ho:YAG) laser can perform evaporation, incision, and coagulation simultaneously. It enables the treatment of target tissue only, making surgery less thermally damaging to surrounding tissue. It provides a different range and depth of evaporation depending on the distance between the laser fiber tip and the mucosa. Clinical cases are presented, and the potential for treatment of laryngeal diseases is discussed. Methods: We designed the following three ways of irradiation. 1) Non-contact irradiation: Evaporation occurs only at the mucosal surface. 2) Contact irradiation: When irradiated with light contact with the mucosa, the area of evaporation on the mucosal surface is smaller than in 1. 3) Shooting irradiation: When irradiated with pressing the tip of the fiber on the mucosa, only spots of evaporation are left on the mucosal surface. On the other hand, evaporation can be up to a depth of approximately 2 cm with irradiation for approximately 3 seconds. Results: Cases of hemorrhagic vocal cord polyp, laryngeal papillomatosis, and vocal cord cancer were presented. For evaporation of a narrow area and point evaporation, contact irradiation was suitable. Irradiation experiments on chickens showed that shooting irradiation can evaporate up to a depth of 2 to 3 cm despite the narrow area of evaporation at the shooting site. It is believed to have been proven by the experiences of treating patients with recurrent laryngeal cancer. Conclusions: Application of this technique to laryngeal surgery is expected.