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

Abstract

Endoscopic skull base surgery is now the preferred treatment option to remove skull base tumors. To evaluate the patient's sense of smell and mucociliary clearance time (MCT) after skull base surgery. 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. 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. 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.