Ultrasound submucosal inferior nasal turbinate reduction technique: histological study of wound healing in a sheep model.
ABSTRACT AIM OF THE STUDY: To describe histological changes after application of an ultrasound tissue reduction (UTR) technique in a newly introduced sheep model to study inferior nasal turbinate mucosal wound healing. Materials and Methods: An experimental study in a sheep model. Stromal fibrosis, submucosal interstitial space volume (ISV), mucosal epithelial cell necrosis, mucosal inflammation and blood vessels' engorgement in inferior turbinate samples were assessed after application of UTR using hematoxylin/eosin staining in 12 turbinate samples after different time points. Histological grading was performed using a 4-point scale Results: After one week, extensive development of fibrosis (p = 0.006) and significant reduced stromal ISV (p < 0.001) compared to controls were observed. The degree of fibrosis and the stromal ISV remained constant during the 8-week period. The extensive epithelial cell necrosis observed at week 1, diminished later, so that at 8 weeks no significant difference with controls in the necrosis extent was noted. Significant reduction of engorgement of blood vessels in the submucosal layer was noted after 8 weeks (p = 0.008, compared with baseline). Mucosal inflammation, while pronounced at week 1 (p = 0.005, compared with baseline), was normalized at week 8. Conclusion: Due to the rapid induction of extensive fibrosis, to the limited inflammation reaction, to the moderate degree of epithelial necrosis, to the reduction of subepithelial ISV and the persistence of these features till week 8 at least, UTR emerges as an effective minimally invasive technique for inferior nasal turbinate volume reduction.