Lathyrogenic Agents as Therapy for Subglottic Stenosis—A Pilot Study

The surgical repair of subglottic stenosis (SGS) is often unsuccessful because of recurrence of the scar contracture. Over the past few years, two lathyrogenic agents (compounds that inhibit collagen cross-linking) have been shown effective in prevention of stenosis in animal models that have deep caustic esophageal burns. Since the principles of induced lathyrism have not been applied to the treatment of laryngotracheal stenosis, a pilot study using a canine model was conducted to test the efficacy of penicillamine and N-acetyl-L-cysteine in reduction of the rate of reformation of SGS. In all six animals used, a complete, 10 to 15 mm thick, mature SGS was induced experimentally, then opened with a Co₂ laser. The dogs that were treated with lathyrogenic agents exhibited a lower rate of re-stenosis (one maintained patency throughout the 5 weeks of treatment) when compared to the two control dogs. Histologic sections of the subglottis in each dog revealed severe cricoid collapse, necrosis, and scarring, and thus demonstrated similarities to SGS in human beings. The two lathyrogenic agents used in this study are already approved for human use and may represent a valuable form of adjunctive therapy in the surgical management of SGS.