Olfactory Sequelae of Nasal Surgeries: A Systematic Review with Meta-Analysis

Importance Septoplasty, turbinoplasty, and septorhinoplasty are common and generally-safe procedures. However, their effects on the olfactory system, despite its anatomical proximity, are not well documented. Given the importance of olfaction for quality of life, evaluating the olfactory impact of these surgeries is warranted. Objective This study aimed to assess the olfactory sequelae of nasal surgeries. Design Systematic review with meta-analysis Setting and Participants A search equation used in PubMed/Medline, Cochrane Library, Web of Science, and Embase identified 7780 articles published since 1990, evaluating the adverse events of nasal surgeries. Exposure The studies included evaluated adult patients exposed to one of the following nasal surgeries: septoplasty, septorhinoplasty, and/or inferior turbinoplasty. Main outcome measures Olfactory assessment results and number of patients presenting with preoperative or postoperative hyposmia were extracted, as well as the number of patients presenting with surgery-induced hyposmia. A meta-analysis was conducted to compare different surgical subgroups. Results One hundred and two studies were ultimately included in the analysis, centralizing data from 16,072 patients. Surgery-induced hyposmia was identified in 2.7% of cases, regardless of the surgical intervention performed. Overall, nasal surgeries led to a postoperative improvement in hyposmia scores 3.73 (±1.58) vs 2.39 (±1.45), P < .001 and a reduction in the number of patients with hyposmia 22.2% (945/4254) vs 14.5% (380/2620), P < .001. The meta-analysis revealed no significant difference between the surgical subgroups. Conclusion and Relevance The present systematic review and meta-analysis suggest that nasal surgery may impair olfaction in a non-negligible number of cases and highlight the need for objective and systematic olfactory assessment in nasal surgery studies.