Olfactory and sinonasal outcomes in endoscopic transsphenoidal skull-base surgery

Background: Endoscopic anterior skull-base surgery has been previously suggested to cause a significant deterioration in olfactory function. Given the impact on quality of life, the objective of this study was to determine the effect of a unilateral middle-turbinate-sacrificing approach on olfactory function and sinonasal outcome. Methods: Prospective cohort study comparing olfactory and sinonasal outcomes pre- and post-transsphenoidal skull-base surgery. Olfaction was the primary outcome and was measured prospectively using the University of Pennsylvania Smell Identification Test (SIT). Sinonasal symptoms were assessed subjectively via sinonasal-specific questions from the 22-item Sino-Nasal Outcome Test (SNOT-22), and objectively via the Lund-Kennedy Endoscopic Scoring system (LKES). Results: Twenty-two patients met study inclusion criteria and completed all data acquisition. The mean preoperative SIT score was 34.8 and the mean postoperative SIT value was 35.1 (p = 0.37). The average change in score (delta) was an increase of 0.3, with changes ranging from -3 to +4. When examined categorically, 91% of patients maintained their preoperative olfactory function classification. There was no significant difference in mean pre- and postoperative symptom scores. A small increase in the LKES was noted, from a mean of 0.6 to 2.5 (p = 0.001) in the early postoperative period. Conclusion: Olfactory function, as measured by the SIT test, was preserved with a middle-turbinate-sacrificing skull-base approach. Subjective sinonasal symptom scores were unaffected, but a slight worsening of objective endoscopic appearance was noted.