title: Does olfactory function improve after endoscopic sinus surgery?
abstract: OBJECTIVE
  To examine the impact of endoscopic sinus surgery (ESS) on olfactory impairment in patients with chronic rhinosinusitis (CRS) over intermediate and long-term follow-up. We hypothesized that patients with mild olfactory dysfunction (hyposmia) would benefit from ESS, whereas patients with severe olfactory dysfunction (anosmia) would not.
  
  
  METHODS
  Prospective, multi-institutional cohort study.
  
  
  METHODS
  A total of 111 patients presenting for ESS for treatment of CRS were examined preoperatively, and at 6 and 12 months postoperatively. Demographic, comorbidity, and Smell Identification Test (SIT) data were collected at each time point. Univariate and multivariate analyses were performed.
  
  
  RESULTS
  The prevalence of gender-adjusted olfactory dysfunction prior to surgery was 67.5 percent. Surprisingly, hyposmic patients did not significantly improve after surgery. In contrast, patients with anosmia significantly improved after ESS (baseline, 6-month SIT scores: 9.7 +/- 2.0, 21.3 +/- 11.2; P = 0.001). Improvement was sustained at 12-month follow-up (21.7 +/- 10.7; P = 0.001). Multivariate linear regression analysis showed that baseline olfactory category and nasal polyposis were significantly associated with improvement in postoperative olfactory function (P = 0.035, P = 0.002).
  
  
  CONCLUSIONS
  Contrary to our hypotheses, patients with severe olfactory dysfunction significantly improved after ESS and sustained improvement over time, whereas patients with mild olfactory dysfunction did not.
authors.affiliation: Division of Rhinology and Sinus Surgery, Oregon Sinus Center, Department of Otolaryngology-Head and Neck Surgery, Oregon Health and Science University, Portland, OR 97239, USA.
authors.forename: Jamie R
authors.initials: JR
authors.lastname: Litvack
authors.forename: Jess
authors.initials: J
authors.lastname: Mace
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Smith
mesh_terms: D000328:Adult; D002908:Chronic Disease; D004724:Endoscopy; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D000857:Olfaction Disorders / Q000209:etiology / Q000601:surgery*; D013517:Otorhinolaryngologic Surgical Procedures; D011446:Prospective Studies; D020127:Recovery of Function; D012220:Rhinitis / Q000503:physiopathology / Q000601:surgery*; D012852:Sinusitis / Q000503:physiopathology / Q000601:surgery*; D012903:Smell / Q000502:physiology*