• Olfaction;
  • smell;
  • surgery;
  • outcome


Objective/Hypothesis: This prospective study aimed to investigate predictors of nasal surgery in terms of olfactory function.

Study Design: Prospective study.

Methods: A total of 775 patients were included in this prospective study (482 men, 293 women; age range 10–81 years, mean age 41 years, standard deviation = 15.3 y). Prior to surgery, patients received a detailed otorhinolaryngologic examination including nasal endoscopy. Olfactory function was assessed with a standardized odor identification test (“Sniffin' Sticks”). In 356 patients, olfactory function was retested 4 months after surgery (63–339 days after surgery; mean 128 days, standard deviation = 29 days); 206 of these patients received sinus surgery, while 150 received surgery involving the septum.

Results: Using a conservative definition of change of olfactory function, following sinus surgery, improvement of the sense of smell was found in 23%, no change was seen in 68%, and decreased function was seen in 9% of the patients; in patients with septum surgery, improvement was seen in 13%, no change in 81%, and decreased function in 7%. Patients exhibiting a postoperative decrease of olfactory function had significantly higher preoperative olfactory scores than patients who experienced improvement. In terms of the sense of smell, nasal surgery produced the highest success rates in patients with eosinophilia and a high degree of polyposis. Neither age nor sex had a major impact on the outcome of surgery in terms of olfactory function.

Conclusions: These results in a large group of patients confirm previous work. Apart from apparent success in 13 to 23% of patients, there is also a small but significant group of patients (7 to 9%) in whom olfactory function decreases after surgery. Because this decrease was mostly found in patients with relatively good preoperative olfactory function, this group should receive specific attention when counseling patients about the potential risks of nasal surgery.