Extended approach or usage of nasoseptal flap is a risk factor for olfactory dysfunction after endoscopic anterior skullbase surgery: results from 928 patients in a single tertiary center

Abstract

Background:The aim of this study was to compare olfactory function change in patients who underwent endoscopic skull-base surgery.Methodology: A total of 928 patients were included in this retrospective study. Olfactory function was measured using the nonvalidated Likert scale (0-100), the Cross-Cultural Smell Identification Test (CC-SIT) and the butanol threshold test (BTT). Patients were divided into two groups: an endoscopic trans-sellar approach group (ETA, n = 768) and an extended endoscopic endonasal approach group (EEEA, n = 160). The ETA group was sub-divided into Nasoseptal flap (NSF) and no NSF groups.Results: Non-validated olfactory function significantly worsened in the EEEA and ETA-NSF groups compared with that in the ETAno NSF group for at least 6 months post-operatively. Validated olfactory impairment (BTT and CC-SIT) was also significantly worse in the EEEA and NSF groups compared with that in the ETA-no NSF group 3 months post-operatively. Additionally, the degrees of non-validated and validated olfactory deterioration were not significantly different between the EEEA and ETA-NSF groups. We also found that CC-SIT score changes were significantly impaired in tuberculum sellae meningioma patients than in craniopharyngioma patients. Conclusions:We conclude that NSF was the key factor that led to olfactory impairment after endoscopic skull-base surgery.

Olfaction after endoscopic surgery for sellar and parasellar disease: an updated systematic review and meta-analysis

“…If lacking, the median, range, and sample size were used to estimate the mean and variance (20) . We assumed that the median was equal to the mean Finally, 26 studies (3,(5)(6)(7)(11)(12)(13)(14)(15)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42) (6 retrospective, 18 prospective, and 2 RCTs) met the eligibility criteria and were included in this review. The characteristics of the studies are summarized in Table 1.…”

“…A total of 1858 patients were enrolled (mean age, 37.5-65.8 years; % male, 16-76.5%. The olfactory function reported using standardized olfactory testing methods included UPSIT outcomes (8 studies (6,11,12,15,(25)(26)(27)32) ), CCSIT outcomes (8 studies (28)(29)(30)(36)(37)(38)(39)42) ), Sniffin's Sticks outcomes (5 studies (3,34,35,40,41) ), CCCRC outcomes (2 studies (5,13) ), SDOT outcomes (2 studies (7,33) ) and the BAST-24 identification test (1 study (31) ).…”

“…No significant difference between pre-and postoperative olfaction outcome measured by standardized olfactory testing methods among patients with NSF elevation (7 studies (5,13,15,25,32,39,42) ; 224 patients; pooled SMD, −0.15; 95% CI, −0.61 to 0.31) was observed. The analysis also reveals no significant difference in olfaction before and after surgery in patients without NSF elevation (8 studies (7,15,26,28,30,33,36,41) ; 508 patients; pooled SMD, −0.06; 95% CI, −0.26 to 0.13) (Table 3).…”

“…Sixteen of the 26 studies (3,5,6,11,13,(25)(26)(27)(28)(29)(30)(34)(35)(36)41,42) , including 880 patients, provided quantitative data for olfactory function evaluated prior to surgery and 1-3 months after surgery (Table 2, A). Evidence indicated heterogeneity across the 16 studies (Q statistic = 49.39; I 2 = 69.63; P < 0.001).…”

“…Only 5 studies (28)(29)(30)36,42) , including 413 patients, reported subjective olfaction preoperatively and 3 months postoperatively (Table 2, C). Moderate heterogeneity was observed (Q statistic = 6.85; I 2 = 41.56; P = 0.144).…”