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,  < .001), with no difference from pre-operative (16.40 ± 15.88) to POM6 (16.27 ± 17.92,  = .936) or pre-operative (13.63 ± 13.54) to POM12 (12.60 ± 16.45,  = .651). Average smell-SNOT scores worsened from pre-operative (0.40 ± 1.27) to POM1 (2.09 ± 2.01,  < .001), and pre-operative (0.46 ± 1.29) to POM6 (1.13 ± 2.45,  = .002), with no difference from pre-operative (0.40 ± 1.07) to POM12 (0.71 ± 1.32,  = .100). Female gender had a 0.9-point (95% CI 0.1 to 1.6)  = .021, increase in smell-SNOT at POM1, resolving by POM6 (0.1 [-0.9 to 1.1],  = .800) and POM12 (0.0 [-1.0 to 0.9],  = .942). Septoplasty with tunnel approach had a 1.1 [0.2 to 2.0] out of 5-point ( = .023) increase in smell-SNOT at POM1, resolving by POM6 (0.2 [-1.1 to 1.6],  = .764) and POM12 (0.4 [-0.9 to 1.6],  = .567). Female gender had a 9.5 (4.0 to 15.1)-point ( = .001) increase in SNOT-22 scores at POM1, resolving by POM6 (3.4 [-3.0 to 9.8],  = .292) and POM12 (6.4 [-5.4 to 18.2],  = .276). Intra-operative CSF leak had an 8.6 [2.1 to 15.1]-point ( = .009) increase in SNOT-22 scores at POM1, resolving by POM6 (5.4 [-1.7 to 12.5],  = .135), and POM12 (1.1 [-12.9 to 15.1],  = .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.