Side asymmetry in nasal resistance correlate with nasal obstruction severity in patients with septal deformities: Computational fluid dynamics study

Abstract

Objectives The objective of this study was to investigate the relationship between side asymmetry in nasal resistance (NR) and severity of the nasal airway obstruction (NAO) in patients with different types of nasal septal deformity (NSD). Design Computational fluid dynamics (CFD) study. Setting The study was conducted in a tertiary medical centre. Participants The study included 232 patients, who were referred to the CT examination of the paranasal sinuses. Exclusion criteria were sinonasal and respiratory diseases that may interfere with the nasal obstruction. The presence and the type of NSD were recorded according to the Mladina's classification. Main outcome measures The presence and severity of NAO in each patient were assessed by NOSE questionnaire. Eight computational models of the nasal cavity were created from CT scans. Models represented seven Mladina's NSD types and a straight septum of a symptomless patient. CFD calculated airflow partitioning and NR for each nasal passage. Side differences in NR were calculated by the equation increment NR = NRleft - NRright. The relationship between NOSE scores, airflow partitioning and side differences in NR was explored using Spearman's correlation analysis. Results Mladina's types of NSD showed differences in airflow partitioning and the degree of side asymmetry in NR. A significant positive correlation was detected between side differences in NR and NOSE scores (R = .762, P = .028). A significant negative correlation was found between the per cent of unilateral airflow and NR (R = -.524, P = .037). Conclusions Our results demonstrated that side asymmetry in NR could explain differences in NAO severity related to the NSD type.