Course of olfaction after sinus surgery for chronic rhinosinusitis.

Background: The influence of surgery on olfaction in patients who suffer from chronic rhinosinusitis (CRS) is still not fully understood. Most particularly, the time course of the recovery is poorly studied. Methods: The prospective study describes the results of the Sniffin' Sticks identification test in 41 subjects before (V1), 2 weeks after (V2), and 6 months after (V3) endonasal sinus surgery (ESS). Influencing factors (gender, revision surgery, nasal polyposis, and initial olfactory score) on the changes of the smell testing were evaluated. Results: The whole cohort showed a significant improvement in Identification scores, from 8.63 to 10.24 after 2 weeks and to 10.68 after 6 months. Patients with nasal polyps revealed a similar increase in the identification test at V3 (+2.17 compared to +1.89 in those without polyps) but not at V2 (+1.30 compared to 2.00). The initial classification of olfaction was the only significant influencing factor. Patients who showed initially anosmic results improved (+4.87 at V2 and +4.73 at V3), as did patients in the hyposmic group (+0.58 resp. +1.42). Forty-four percent of the patients reached an improvement with regard to their diagnostic group. Conclusions: This study of the evaluation of the sense of smell after ESS exhibits an improvement of olfaction already 2 weeks after surgery, which is stable for 6 months. CRSwNP and CRSsNP patients showed similar improvements of olfaction, although the recovery was slower in CRSwNP patients. Level of Evidence: 2b.