Predictors of Subjective Olfactory Dysfunction and Sinonasal Quality-of-Life After Endoscopic Transsphenoidal Pituitary Surgery

Background This is the largest study in North America investigating olfactory outcomes after pituitary surgery to date. Objective Characterize factors associated with subjective olfactory dysfunction (OD) and worsened sinonasal quality-of-life (QOL) after endoscopic TSA. Methods Patients undergoing primary TSA for secreting and non-secreting pituitary adenomas between 2017 and 2021 with pre- and post-operative SNOT-22 scores were included. Subjective OD was determined by the smell/taste dysfunction question on the SNOT-22 (smell-SNOT). Results 159 patients with pre- and post-operative SNOT-22 scores were included. Average total SNOT-22 scores worsened from pre-operative (16.91 +/- 16.91) to POM1 (25.15 +/- 20.83, P < .001), with no difference from pre-operative (16.40 +/- 15.88) to POM6 (16.27 +/- 17.92, P = .936) or pre-operative (13.63 +/- 13.54) to POM12 (12.60 +/- 16.45, P = .651). Average smell-SNOT scores worsened from pre-operative (0.40 +/- 1.27) to POM1 (2.09 +/- 2.01, P < .001), and pre-operative (0.46 +/- 1.29) to POM6 (1.13 +/- 2.45, P = .002), with no difference from pre-operative (0.40 +/- 1.07) to POM12 (0.71 +/- 1.32, P = .100). Female gender had a 0.9-point (95% CI 0.1 to 1.6) P = .021, increase in smell-SNOT at POM1, resolving by POM6 (0.1 [-0.9 to 1.1], P = .800) and POM12 (0.0 [-1.0 to 0.9], P = .942). Septoplasty with tunnel approach had a 1.1 [0.2 to 2.0] out of 5-point (P = .023) increase in smell-SNOT at POM1, resolving by POM6 (0.2 [-1.1 to 1.6], P = .764) and POM12 (0.4 [-0.9 to 1.6], P = .567). Female gender had a 9.5 (4.0 to 15.1)-point (P = .001) increase in SNOT-22 scores at POM1, resolving by POM6 (3.4 [-3.0 to 9.8], P = .292) and POM12 (6.4 [-5.4 to 18.2], P = .276). Intra-operative CSF leak had an 8.6 [2.1 to 15.1]-point (P = .009) increase in SNOT-22 scores at POM1, resolving by POM6 (5.4 [-1.7 to 12.5], P = .135), and POM12 (1.1 [-12.9 to 15.1], P = .873). Conclusion Changes in subjective olfaction and sinonasal QOL after TSA may be associated with gender, operative approach, and intra-operative CSF leak, resolving 6-12 months post-operatively.