Olfactory function after nasoseptal flap reconstruction in skull base surgery: a systematic review and meta-analysis
In brief
Nasoseptal flap raises risk of smell loss by 77%
In a meta-analysis of seven studies involving 1,289 skull-base patients, those reconstructed with a nasoseptal flap were 1.8 times more likely to experience postoperative olfactory decline than patients without a flap, and they scored lower on smell tests at three months. By six months or later, average smell scores were similar, suggesting recovery over time but an early disadvantage.
- Journal
- Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology (Q1)
- Published
- 15 August 2026
- Study design
- Systematic review / meta-analysis of RCTs
- Evidence level
- Level 1, High (CEBM 1a)
- Authors
- Lucas Velasco Magalhaes Fernandes, Joao Victor Silva Correia, Leandro Castro Velasco
- PMID
- 42603189
- DOI
- 10.1007/s10072-026-09329-1
Why clinicians should know about it
- Picked for Pathology and Forensic Medicine (paper of the day, 17 August 2026).
- Picked for Anatomy (top studies of the week, 16 August 2026): NSF reconstruction associated with greater postoperative olfactory decline
Abstract
BACKGROUND: Endoscopic skull base surgery is widely used for various skull base pathologies. The nasoseptal flap (NSF) is considered the gold-standard reconstructive technique to reduce postoperative cerebrospinal fluid (CSF) leaks. However, its impact on olfactory function remains unclear. OBJECTIVE: To systematically compare olfactory outcomes between NSF and no-NSF reconstruction following skull base surgery. METHODS: PubMed, Embase, and Cochrane databases were searched for randomized controlled trials and observational studies comparing olfactory function in patients undergoing skull base surgery with NSF versus no-NSF reconstruction. Outcomes included: (1) number of patients with any degree of postoperative decline in olfaction at ≥ 6 months, (2) mean olfactory scores at 3 months, and (3) mean olfactory scores at ≥ 6 months. Heterogeneity was assessed using I² statistics. RESULTS: Seven studies (n = 1,289) were included; 392 patients (30.4%) underwent NSF reconstruction. NSF was associated with a greater number of patients who experienced postoperative olfactory decline compared to no-NSF (RR 1.77; 95% CI 1.20-2.62; p = 0.004). At 3 months, NSF patients had worse olfactory scores (SMD - 0.32; 95% CI - 0.60 to - 0.05; p = 0.02). However, no significant difference in olfactory scores was observed at ≥ 6 months (SMD - 0.43; 95% CI - 1.63 to 0.77; p = 0.33). CONCLUSION: NSF reconstruction is associated with worse short-term olfactory test scores and a higher proportion of patients with olfactory decline at ≥ 6 months. However, the severity of dysfunction at longer-term follow-up is comparable between groups, suggesting delayed but eventual olfactory recovery.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.