Impairment of Olfaction and Mucociliary Clearance After Expanded Endonasal Approach Using Vascularized Septal Flap Reconstruction for Skull Base Tumors

BACKGROUND: Endoscopic skull base surgery is now the preferred treatment option to remove skull base tumors. OBJECTIVE: To evaluate the patient's sense of smell and mucociliary clearance time (MCT) after skull base surgery. METHODS: Patients with pituitary adenoma underwent a transnasal transsphenoidal endoscopic approach (TTEA group, n = 36), whereas patients with other benign parasellar tumors underwent an expanded endonasal approach (EEA group, n = 14) with a vascularized septal flap. Assessment of symptoms (Visual Analogue Scale), olfactometry (Barcelona Smell Test, BAST-24), and MCT (saccharin test) were performed before and 3 months after surgery. RESULTS: Before surgery, patients reported poorer BAST-24 scores on detection, identification, and forced choice than the healthy population, but both study groups had similar sinonasal symptoms, BAST-24, and MCT scores. After surgery, no changes in symptom scores (Visual Analogue Scale) were observed except for the loss of smell (26.7 ± 30.5 mm, P < .05) and posterior nasal discharge (29.7 ± 30.3 mm, P < .05) compared with baseline (5.2 ± 11.3, 19.1 ± 25.3, respectively). EEA patients reported higher loss of smell and posterior nasal discharge compared with TTEA. TTEA and EEA groups had similar scores on postoperative BAST-24. After surgery, however, patients showed prolonged saccharin test (15.6 ± 10.8 min, P < .05) compared with baseline (8.4 ± 4.4 min). In addition, EEA patients reported longer MCT than TTEA patients. CONCLUSION: EEA but not TTEA has a short-term (3 months) negative impact on patient's olfaction and mucociliary clearance. Patients should be informed about smell loss as a consequence of skull base surgery to prevent legal claims. Likewise, further research and some modifications on reconstruction flaps are encouraged to avoid damaging the olfactory neuroepithelium.