Effect of Middle Turbinate Partial Resection in Olfactory Function in Endoscopic Transsphenoidal Approach: A Retrospective Study

Background: There are controversies on whether endoscopic transsphenoidal approach (TSA) affects postoperative olfaction. This study aimed to compare olfactory function in regard of partial resection status of middle turbinate (MT) and analyze the amount of resection in images. Materials and Methods: This study retrospectively reviewed 46 patients who had undergone endoscopic TSA due to pituitary adenoma or Rathke’s cleft cyst from 2015 to 2019. MT preserva-tion (MTP) group was defined as the group of patients whose MTs were preserved. MT resection (MTR) group was defined as the group of patients whose MTs were partially resected unilaterally or bilaterally. Olfactory function was compared with pre- and postoperative 3-month Korean version of sniffing sticks test-II which was composed of threshold, discrimination, identification (TDI) scores each making 16 with correct answers. Pre- and postoperative images including paranasal computed tomography and sellar magnetic resonance imaging were analyzed using Picture Archiving and Communication System. Results: There were 41 pituitary adenomas and 5 Rathke’s cleft cysts. Male patients were 39.1% (n = 18) and mean age was 42.6. About 1/3 (31%) of MT was resected in MTR group (n = 13), which had the effect of increasing the cross-sectional area of the nasal cavity by 19%. Post-septectomy area was 6% of total septum. Preoperative TDI score was 27.34 and postoperative TDI score was 25.42. There were no significant differences of olfactory score in total, MTR and MTP groups 3 months after endoscopic TSA. Conclusions: Resection of lower third of MT may produce low morbidity in respect of olfactory function after endoscopic TSA.