CO2 laser management of laryngeal stenosis.

The introduction of the carbon dioxide laser as an endoscopic surgical instrument has stimulated interest in its application for removal of stenotic lesions of the larynx. Clinical reports have indicated mixed results in the efficacy of this treatment modality. Nineteen large dogs received acute subglottic injuries from a high-speed electric drill and electrocautery. All animals developed obstructing lesions from 7 to 21 days after injury. With at least weekly removal of granulation tissue and dilations, all animals developed mature subglottic and/or posterior commissure scars. Two animals required tracheostomy. The 15 animals in the experimental group underwent 16 laser procedures. Three animals had vaporization of one third of the scar, three of one half of the scar, and three had total circumferential vaporization. Five animals underwent microtrapdoor flap procedures. Of these, four had a single flap and one had three separate flaps created. In the remaining animal in the experimental group a glottic web developed, which was totally ablated. In one animal treated with a microtrapdoor flap procedure a posterior sinus tract also developed and was treated with laser ablation. The animals undergoing segmental resection of scar demonstrated no improvement in airway size. Those undergoing total resection experienced a worsening of the condition. Those undergoing microtrapdoor flap repair demonstrated moderate improvement in airway size. It can be concluded that large areas of scar removal in the larynx by the CO2 laser will result in prompt recurrence and possible worsening of the scar and smaller submucosal resection of the scar, with preservation of mucosa by the microtrapdoor flap technique, may be helpful in improving the airway.