Endoscopic Endonasal Surgery—Concepts in Treatment of Recurring Rhinosinusitis. Part I. Anatomic and Pathophysiologic Considerations

Histologic examination demonstrates that massive changes of the nasal glands are the reason for permanent mucosal thickening, and retention cysts, highly viscous mucus, mucus extravasations, and metaplastic epithelial changes add to the vicious cycle of blockage of the ostium-meatus unit.