Figure 5. Representative sections from larynx of sheep intubated with either the new ETT or the standard ETT, for 1 or 3 days; hematoxylin and eosin stain. Original magnification x160. (A) One-day intubation, new ETT (arytenoid). The Figure 5shows mild epithelial injury and a small area of erosion. There is mild inflammation in the submucosal layer. (B) One-day intubation, standard ETT (arytenoid). There is epithelial erosion; and moderate inflammation involved the submucosa. Moderate hemorrhage is present. (C) Three-day intubation, new ETT (arytenoid). There are moderate to severe epithelial changes and a small area of epithelial erosion. Submucosa shows moderate neutrophilic infiltration and mild hemorrhage. (D) Three-day intubation, standard ETT (arytenoid). Transition zone between severe damage and epithelial erosion. The left side shows severely injured epithelium; the right, epithelial erosion along the tract of insertion of the tube. There is mild hemorrhage.