PURPOSE:Topical applications of Mitomycin-C (MMC) following endoscopic dilation of laryngotracheal stenosis delays scarring/re-stenosis of the airways but long-term relapses are common. The effects of repeated MMC applications have not been studied. This study evaluates the hypothesis that two applications of MMC will decrease the rate of re-stenosis when compared to a single application.
METHODS:In this randomized, prospective, double-blind, placebo-controlled clinical trial, patients underwent a series of three endoscopic CO2 laser and dilations over a three month interval. At the first dilational procedure, all patients received topical MMC. At the second dilation performed four weeks later, patients were randomized to topical MMC or placebo. A third dilation was performed eight weeks later with no topical applications. Patients were then followed for up to five years and the relapse rates requiring subsequent interventions were monitored in all patients.
RESULTS:Thirty-two patients with subglottic or cervical tracheal stenosis were randomized to one of the two groups and 26 patients completed the study. The median time to recurrence of symptomatic re-stenosis was 2.4 years in patients receiving two MMC applications and 1.1 years in patients receiving one application. The relapse rates at 1, 3, and 5 years were 7%, 36% and 67% for patients treated with two applications of MMC compared to 33%, 58% and 70% for patients treated with one application of MMC. By four years, the relapse rates converged for the two groups.
CONCLUSION:In the endoscopic management of laryngotracheal stenosis, dilation with MMC application done 4 weeks apart reduces the rate of re-stenosis over the first three years after treatment, when compared to a single application. By four years, the relapse rates were comparable.
CLINICAL IMPLICATIONS:In patients opting for endoscopic dilations rather than definitive surgical therapy for laryngotracheal stenosis, application of MMC delays the recurrence of symptomatic re-stenosis thereby reducing the number of dilations required over a period of time.
DISCLOSURE:Chakravarthy Reddy, No Financial Disclosure Information; No Product/Research Disclosure Information