The effect of a dissolvable hyaluronic acid-based pack on the healing of the nasal mucosa of sheep

Introduction: There is a paucity of knowledge about the healing of the nasal respiratory mucosa after endoscopic sinus surgery (ESS). Nasal packs often are placed after ESS in an attempt to reduce adhesions but the effect of these packs on the healing of the nasal mucosa is not known. Methods: A standardized normal animal model (the sheep) was used to examine the healing of the nasal epithelium after ESS. A full-thickness wound was created in the nasal mucosa and either packed with a dissolvable hyaluronic acid-based pack, or left unpacked to serve as control. The wounded areas were biopsied at 28, 56, 84, and 112 days postinjury and epithelialization, and cilial regeneration was assessed by light microscopy and scanning electron microscopy. Results: The wounds with the dissolvable hyaluronic acid-based packs showed no differences in reepithelialization up to 84 days postwounding. However, a significant increase in reepithelialization was observed on day 84 in packed wounds compared with unpacked controls, indicating an increased rate of healing at that time point. In addition, there Alas a significant increase in the epithelial height in the packed wounds on day 28, indicating that packing was affecting the epithelial maturity of the mucosa. No significant difference was observed in cilial regeneration between the packed and control wounds. Conclusions: Application of the hyaluronic acid-based nasal packs to wounds after ESS may improve reepithelialization of the nasal mucosa but appears to have minimal effect on reciliation at the time points studied in normal-healing wounds.