Short-Term Olfactory Changes after Endoscopic Transsphenoidal Pituitary Surgeries: Identification, Discrimination, and Threshold Results

Background: It has been shown that endoscopic transsphenoidal pituitary surgery (ETPS) preserves olfaction better than microscopic techniques. Nevertheless, even if ETPS is utilized, olfaction can be affected. The aim of this study is to assess short-term changes in olfactory functions and the quality of life in the postoperative second month in patients having ETPS.

Materials and Methods: Patients who underwent ETPS between June 2017 and December 2018 were evaluated with preoperative and postoperative 2nd month olfaction tests including identification, discrimination, and threshold scores as well as SNOT-22 questionnaire.

Results: From 73 patients included, 48 (65.8%) were female and 25 (34.2%) were male; the mean age was 44.8 (8 – 76 ± 16.4). 29 patients (39.7%) were asymptomatic and 20 patients (27.4%) described headaches as their primary symptoms. There were intraoperative cerebrospinal fluid (CSF) leakage during surgery in 41 (56.2%) patients, and nasoseptal pedicled flaps were used in 47 (64.4%) patients for watertight closure. The mean score for SNOT-22 was 23.46 preoperatively and 27.86 postoperatively. The preoperative and postoperative mean scores for odor identification, discrimination, and threshold tests were 7.29 to 5.43, 6.99 to 5.00, and 6.58 to 3.70, respectively, showing worsening of scores in all components of olfactory tests postoperatively at second month.

Conclusion: Even though previous studies showed that olfactory functions are better preserved in ETPS, our data indicate that a worsening in olfaction is to be expected at postoperative second month. Patients should be informed on this fact preoperatively. Larger series with longer follow-up periods are needed to better assess olfactory function in the long run.