Can topical mitomycin prevent laryngotracheal stenosis?

Abstract

Early topical application of mitomycin to a laryngotracheal lesion may prevent or reduce laryngotracheal stenosis (LTS). Prospective controlled animal study. LTS was induced in 60 dogs randomly assigned to four groups. Controls received an immediate topical application of normal saline. The suction-control group received an immediate application of normal saline followed by suction of secretions on day 2. The mitomycin group received immediate application of 0.7 mL mitomycin (0.2 mg/mL). The repeat-mitomycin group received an immediate application of mitomycin and a second application on day 2, after secretions were suctioned. The laryngeal lumens were measured endoscopically at baseline, day 12, and day 21. Animals were euthanatized if stenosis approximated 95% or at day 21. All dogs in the mitomycin groups survived to day 21, compared with 12 in the suction group and only 2 controls. No side effects of mitomycin were observed. At day 21, surviving controls had 85% and 95% stenosis. In the mitomycin group, median stenosis was 27% (interquartile range, 29% to 42%); in the repeat-mitomycin group, 30% (22% to 40%); and in the suction-control group, 84.5% (72.5% to 93.5%). The mitomycin group differed significantly from controls on day 12 (median difference = 85%, 95% CI = 80%-94%, P < .0001) and day 21 (difference = 63.9%, 95% CI = 58%-85%, P = .031). A single topical application of mitomycin significantly reduces the severity of LTS in dogs. Reapplication after 2 days does not improve results. Prospective clinical studies are warranted to assess the efficacy in humans.