New-Generation Pulsed Carbon Dioxide Laser: Comparative Effects on Vocal Fold Wound Healing

Abstract

We investigated wound healing of vocal fold mucosal excisions using a canine model, comparing cold steel, the continuous wave (CW) carbon dioxide (CO₂) laser, and a new, microsecond-pulsed CO₂ laser. The thermal injury to the surrounding normal tissues produced by the laser increases the risk for scar formation and poor functional voice outcome. This injury may be reduced with a pulsed CO₂ laser. Acute, 2-week, and 6-week studies of 15 dogs were made with blinded observers and nonparametric statistical analyses. Histologic comparison showed less thermal injury and scar formation in the vocal folds treated with the pulsed CO₂ laser than with the CW CO₂ laser. Functional outcomes as studied with laryngeal videostroboscopy revealed better vibratory characteristics with the pulsed CO₂ laser as compared with the CW CO₂ laser. No differences were seen on these measures between the pulsed laser and cold techniques. Pulsed CO₂ lasers may offer the ease of laser laryngology and the superior wound healing of cold steel.