Wound Healing of True Vocal Cord Squamous Epithelium after CO 2 Laser Ablation and Cup Forceps Stripping

A study was conducted on the effect of deepithelization of the true vocal cords; microcup forceps were used, as opposed to CO₂ laser ablation. A CO₂ laser, coupled to an operating microscope, was used to ablate the surface epithelium of the right true vocal cords in eight canines, while conventional microlaryngeal stripping was performed on the left true cords in the same animals. Photographs were taken immediately after injury and again before the animals were killed. Histologically, the series of true vocal cords ablated by the CO₂ laser revealed granulation formation at day 5, whereas those treated with conventional stripping developed granulation at day 3, thus indicating delayed healing. Charred carbonaceous debris of CO₂ laser ablation was found to cause a giant cell reaction that persisted after reepithelization. Despite the precise control offered by the laser, many of the laser-injured true vocal cords revealed vocalis muscle edema and muscle destruction. After healing occurred, dense fibrosis was found in the vocal muscle injured during CO₂ laser ablation of the overlying squamous epithelium.