Key points
INTRODUCTION
Currently, the olfactory dysfunction rate associated with pituitary surgery has been decreasing with improved approaches to access the pituitary region. The rate after a sub-microscopic transsphenoidal approach is approximately 39.7%,2–9 whereas those associated with the use of a nasoseptal flap (NSF) under endoscopy and bilateral rescue flaps are approximately 14.4%1, 10-13 and 0−12%,4, 6, 7, 14, 15 respectively. However, even with the use of bilateral rescue flaps, olfactory dysfunction after the endoscopic endonasal transsphenoidal approach (EETSA) remains a risk, attributed to the mechanical irritation to the nasal septal mucosa and superior turbinate that occurs when securing the corridor creation and visual field.6 Therefore, a less stressful approach to the nasal septal mucosa and turbinates is needed.
There are also concerns about the olfactory testing methods used after EETSA. Since most olfactory testing in the literature relies on bilateral nasal olfactory tests, the test results may depend on the results of the good side. Therefore, after EETSA surgery, it is unclear whether the olfactory sense is preserved on one or both side(s). Therefore, the assessment of olfactory function needs to be performed on a unilateral basis because unilateral olfactory impairment influences the ability to identify and discriminate olfaction16and is more likely to result in overall olfactory impairment associated with increasing age.17
In our institution, we use the endoscopic modified transseptal bi-nostril approach to minimize turbinate and olfactory mucosal invasion and ensure every turbinate’s and bilateral olfaction’s preservation. Herein, we investigated the results of olfactory function and changes in the right and left nostrils before and after surgery for cases using this approach, and reported them with statistical analysis.
MATERIALS AND METHODS