Olfaction after endoscopic sinus surgery: long-term results

Loss of olfactory function is one of the main symptoms in patients with chronic rhinosinusitis. This prospective, non-randomized interventional study reports five years results of olfaction of patients with chronic rhinosinusitis who underwent endoscopic sinus surgery in conjunction with topical medical treatment. Forty-five patients with chronic rhinosinusitis who underwent endoscopic sinus surgery were evaluated preoperatively, after three months and 34 (76%) of them after five years. Olfactory function was assessed by a subjective visual analogue scale, by a screening test of olfaction with Smell Diskettes and by measuring the N-Butanol threshold. Patient`s subjective sense of olfaction using a visual analogue scale was improved in 79% at 5 years. Objective measurements by Smell Diskettes improved in 53% at 5 years whilst the quantitative measurement by the N-Butanol threshold improved in 85% at 5 years. The high percentage of patients with improvement of olfaction five years after surgery indicates that endoscopic sinus surgery in conjunction with continued topical treatment leads to a long term improvement of the sense of smell. However, it was found that - measured by the sensitive N-Butanol threshold - up to 9% had no improvement and 6% had deterioration in their olfaction at 5 years after endoscopic sinus surgery. This fact has to be considered in the preoperative counselling of patients.