Abstract
Objectives The aim of this study was to determine the clinical characteristics and cephalometric risk factors associated with decreased postoperative olfaction in patients in whom the transplanum and transtuberculum expanded endonasal approach (EEA) was performed. Methods A retrospective cohort of 41 patients treated with the transplanum and transtuberculum EEA was divided into two groups based on the maximum change in the postoperative 22-item Sino-Nasal Outcome Test (SNOT22) olfaction score: prolonged olfactory loss group ( n = 5) with a ΔSNOT22 olfaction score of ≥ 4 without a return to baseline and a preserved olfaction group ( n = 36) with a ΔSNOT22 olfaction score ≤ 3 with return to baseline on follow-up of at least 3 months. Demographics, operative details, and cephalometric measurements were compared between the two groups. Results There were no differences in terms of the type of surgical approach (transplanum and transtuberculum), resection of turbinates (middle and superior), use of reconstructive flap (nasoseptal flap and reverse flap), or tumor pathology between the two groups. In the prolonged olfactory loss group, there was a smaller angle between the planum and the face of the sella (89.75 ± 9.18 vs. 107.17 ± 16.57 degrees, p = 0.05) and a smaller angle between the anterior nasal spine and the sphenoid sinus face (21.20 ± 2.49 vs. 25.89 ± 4.90 degrees, p = 0.047) compared with the preserved olfaction group. Conclusion Patients with a narrow angle between the planum and the face of the sella or that between the anterior nasal spine and the sphenoid sinus face are at a higher risk of prolonged olfactory dysfunction with the transplanum and transtuberculum approaches. Level of Evidence IV.