Background: Extended endoscopic transsphenoidal (EET) approaches can include complete resection of both superior turbinate (ST) for wider exposure. Moreover, ST resection has been associated with postoperative olfactory impairment.
Objective: We sought to determine the impact of bilateral ST resection on olfaction during a transsphenoidal approach.
Method: A prospective observational study was conducted on 29 patients undergoing endoscopic skull base surgery sparing the olfactory tracts at a tertiary academic center. Olfactory function was measured with Sniffin' Sticks at the preoperative visit, 2-weeks and 6 to 8 weeks postoperatively. All components: odor threshold (OT), odor discrimination (OD), odor identification (OI) and composite scores (TDI = OT+OD+OI) were evaluated.
Result: Study was completed in 15 patients with 14 excluded due to a variety of reasons. At 2 weeks, a significant decrease was noted in composite scores (32.3 ± 5.4 vs. 23.8 ± 5.8, P < .05) and OT (7.7 vs. 3.2, P < .05). There was a significant increase in olfactory scores between post-op weeks 2 and 6 to 8 weeks in TDI (23.8 vs. 31.4, P < .05) as well as in OT (3.2 vs. 7.6, P < .05), OD (9.4 vs. 11.1, P < .05), and OI (11.1 vs. 12.7, P < .05). No significant difference was found between TDI (32.3 ± 5.4 vs. 31.4 ± 5.1), OT (7.7 vs. 7.6), OD (11.4 vs. 11.1) and OI (13.2 vs. 12.7) from preoperative and 6-8 weeks postoperative visits.
Conclusion: Patients undergoing bilateral ST resection during EET procedures experience transient hyposmia postoperatively. However, the olfactory function normalizes to preoperative levels at 6 to 8 weeks. The resection of the bilateral superior turbinate does not appear to decrease olfactory function.
Keywords: endoscopic pituitary surgery; endoscopic sinus surgery; endoscopic skull base surgery; hyposmia; miscellaneous; nasal turbinate; olfaction test; olfactory function test.