Mucosal Remodeling in Chronic Rhinosinusitis Without Nasal Polyposis - an Ultrastructural Evaluation

Objective: Because of recurrent scarring of the ostiomeatal complex after paranasal sinus surgery the therapy of chronic rhinosinusitis without nasal polyps (CRSsNP) seems to be difficult. The aim of this study was to evaluate ultrastructural changes of nasal mucosa in patients with CRSsNP. Material and Methods: In case of revision sinus surgery we took specimens of altered mucosa from 21 patients. All subjects suffered from recurrent CRSsNP. Twelve patients without signs of chronic rhinosinusitis dealed as control group. To prepare for electron microscopy the samples were immersed in 3% phosphate-buffered glutaraldehyde and refixed in 1% osmium acid. After dehydration and heat polymerization ultrathin cuts were prepared. After double-contrasting ultrastructures were evaluated by transmission electron microscopy. Results: Typical changes evaluated by electron microscopy were loss of cilia, an increase of microvilli, collagen fibres, fibrocytes, fibroblasts and myofibroblasts as well as perivascular alterations and endothelial changes. Conclusion: The study revealed the presence of evident ultrastructural changes in the mucosa of patients with chronic rhinosinusitis without nasal polyps. Mucosal remodeling seems to be not reversible by conservative treatment.