Can Surgeons Predict the Olfactory Outcomes After Endoscopic Surgery for Nasal Polyposis?

Objectives/Hypothesis: The aim of this study is to identify predictors for olfactory outcomes in patients with nasal polyposis (NP) after surgery on the ethmoidal labyrinths, either with or without resection of the polyps of the olfactory cleft (OC). Study Design: Prospective study. Methods: Ninety-six patients endoscopically operated on for NP were enrolled in this study. Olfactory measurements were performed 1 day prior to surgery and 6 weeks after surgery, using odor thresholds and identification tests of the Sniffin' Sticks kit and a 0- to 10-point visual analog scale. The multivariate logistic regression model was also used to assess independent predictors for olfactory outcomes after surgery. Results: Twenty-seven patients with preoperative normosmia demonstrated normal olfactory function 6 weeks after surgery. Out of 69 patients with preoperative hypo-anosmia, 33 patients (47.83%) improved their olfactory function after surgery on the basis of the Sniffin' Sticks results. History of previous sinus surgery was reported by 77.78% of patients without olfactory improvement and by 51.52% with olfactory improvement (P=.022). By multivariate analysis, history of previous sinus surgery for NP remained a strong predictor of poor olfactory outcomes after surgery (adjusted odds ratio=4.14, 95% confidence interval: 1.29-13.32, P=.017). Histopathological types of lesions inside the OC as well as the resection of moderate/big lesions in the OC were not predictors of olfactory outcomes. Conclusions: The more previous sinus surgeries, the smaller the chance for patients to recover their olfactory function after each surgical revision.