Prevention of Posterior Glottic Stenosis by Mitomycin-C in a Rabbit Model

Roh, Jong Lyel; Koo, Bon Seok; Yoon, Yeo Hoon; Rha, Ki Sang; Park, Chan Il

Abstract

BACKGROUND AND OBJECTIVES
Posterior glottic stenosis (PGS) is a disabling disease and most commonly induced by trauma from endotracheal intubation. We performed a randomized, controlled study with three animal groups to investigate the preventive effect of mitomycin-C on the posterior glottis undergone laser injury. MATERIALS AND METHOD: Twenty rabbits were available for evaluation. Group 1 (n=7) and 2 (n=6) were treated with topical mitomycin-C of 0.4 and 1.0 mg/ml, respectively, with the group 3 (n=7) used as the control. All animals underwent laser injury of 6 W, continuous mode on the posterior glottis. Group 1 and 2 were treated by a single topical use of cottonoid soaked in mitomycin-C solution on the injured posterior glottis for 5 minutes and the group 3 by saline. The posterior glottis of all groups was evaluated by telescopic examinations under direct laryngoscopy 2 months after the injury and was harvested for histological staining with hematoxylin-eosin and Masson trichrome. RESULTS: The scar, granulation tissue and synechia formation of the posterior glottis was clearly induced by laser injury. Microscopic examinations showed increased collagen content and fibroblast proliferation in the region. Topical use of mitomycin-C significantly decreased the incidence of such gross and microscopic changes of the posterior glottis (p<.05). CONCLUSION: Mitomycin-C prevents PGS via its anti-proliferative effect on fibroblasts. The use of Mitomycin-C is warranted for patients with a history of prolonged intubation or for those who have undergone surgery of the posterior glottis.