Ablation of teflon granulomas in the canine larynx with the free-electron laser

This study develops a canine model for the treatment of laryngeal Teflon gr anulomas and demonstrates endoscopic ablation using the free-electron laser (FEL) set at a wavelength of 8.5 mu m. Laryngeal Teflon granulomas may cau se dysphonia and airway obstruction, and they are difficult to remove. The infrared absorption spectrum of Teflon reveals a strong absorption peak cen tered at 8.5 mu m. In this study, 12 dogs had the right vocal cord injected with Teflon paste. Two months later, Teflon granuloma formation was confir med histologically. Laser incisions into the granulomas were performed at 3 different wavelengths: 7.4 mu m (FEL), 8.5 mu m (FEL), and 10.6 mu m (carb on dioxide laser). Histopathologic analysis was performed at 1 week and 6 w eeks after the laser incisions. The FEL at the 8.5-mu m wavelength was foun d to optimally ablate the Teflon granulomas, but the granulomas persisted i n the specimens treated with 7.4 mu m (FEL) and 10.6 mu m (carbon dioxide l aser).