Principles of Laser Microlaryngoscopy

Abstract

■ The key components that determine a laser’s interaction with tissue are wavelength, intensity, spotsize and pulse duration.

■ The CO₂ laser is the workhorse laser for laryngotracheal work, and the ideal indications include:

- Glottic/posterior glottic stenosis

- Subglottic/tracheal stenosis

- Bilateral vocal fold paralysis (arytenoidectomy, transverse cordotomy)

- Teflon granuloma of the larynx

- Squamous cell carcinoma of the glottis (T1–select T2)

- Papillomatosis (especially with extensive disease)

- Vocal fold varix (select cases)

- Saccular cyst of the larynx

■ The CO₂ laser is generally not a good choice for the removal of benign lesions of the vocal fold, such as polyps, or cysts, or nodules, due to decreased precision, and unintended collateral heat damage, which can result in scarring and dysphonia.

■ CO₂ laser settings generally employ low-wattage settings (4–8 W) in an intermittent or superpulse mode to minimize collateral damage to the tissues. The continuous-beam setting should be used sparingly, and is most appropriate for cartilage ablation.

■ A laser safety protocol should be employed in all cases where the CO₂ laser is used. The key concepts are protection of the patient (moist towels), protection of the endotracheal tube (laser safe, with O₂ concentration of 35% or less), and protection of operating room personnel (safety glasses).