Long-term follow-up of surgically treated phantosmia

Objectives: To determine whether transnasal excision of olfactory epithelium is a safe, effective therapy and to learn more of the pathogenesis of phantosmia by studying the histological features of the excised mucosa. Design: A retrospective study consisting of a medical record review and telephone survey. Follow-up ranged from 1 to 11 years (average, 5.4 years). Excised tissues were histologically processed and descriptively compared with normal and other abnormal olfactory tissues. Setting: Tertiary university medical referral centers. Patients: All patients who presented to the primary an thor (D.A.L.) from 1988 to 1999 with unremitting phantosmia lasting longer than 4 years. Intervention: Olfactory testing and transnasal endoscopic excision of olfactory mucosa. Main Outcome Measures: Tested olfactory function, patients' perception of phantom odor resolution, and histological findings. Results: Of 8 patients, 7 have complete and permanent resolution of their phantosmia. Postoperatively, the single nostril olfactory ability in the operated-on nostril is decreased in 2 nostrils, remains unchanged in 7, and is improved in 1. The excised olfactory mucosa generally shows a decreased number of neurons, a greater ratio of immature to mature neurons, and disordered growth of axons with some intraepithelial neuromas. Conclusions: Surgical excision of olfactory epithelium is an effective and safe method to relieve phantosmia while potentially preserving olfactory ability. The abnormal histological features of the excised olfactory tissue suggest at least some pathological condition in the peripheral olfactory system. This nasal surgery requires intensive olfactory evaluation and follow-up. it is also extremely difficult with significant risks, and therefore should be limited to specialized centers.