Ethmoid histopathology does not predict olfactory outcomes after endoscopic sinus surgery.

Area of Science:

• Otolaryngology
• Pathology
• Rhinology

Background:

• Olfactory dysfunction is common in chronic rhinosinusitis (CRS).
• Histological inflammation correlates with baseline smell loss in CRS patients.
• Predictors of olfactory improvement after endoscopic sinus surgery (ESS) are not well understood.

Purpose of the Study:

• To compare histopathological findings in CRS patients with olfactory loss.
• To determine if inflammatory markers predict long-term olfactory improvement after ESS.

Main Methods:

• Prospective enrollment of adult CRS patients undergoing ESS.
• Blinded histopathological review of mucosal tissue specimens.
• Preoperative and postoperative Smell Identification Test (SIT) administration (minimum 6 months follow-up).
• Multivariate logistic regression to identify histological predictors of SIT score improvement.

Main Results:

• 101 patients completed follow-up (mean 16.7 months).
• Higher mucosal eosinophil counts in patients with hyposmia/anosmia (p < 0.001).
• Anosmia associated with greater basement membrane (BM) thickening (p = 0.021).
• 54.7% of patients with olfactory dysfunction improved by at least 4 SIT points post-surgery.
• Histological variables did not predict olfactory improvement after controlling for nasal polyposis.

Conclusions:

• Severe olfactory dysfunction in CRS is linked to mucosal eosinophilia and BM thickening.
• Specific histopathological findings do not reliably predict olfactory recovery after ESS.