Ultrasonographic assessment of the airway to evaluate for obstructive sleep apnea - a systematic review and meta-analysis.

BACKGROUND

Ultrasound (US) has gained attention as a bedside screening tool for obstructive sleep apnea (OSA), with studies evaluating various parameters for its assessment. We conducted this systematic review and meta-analysis to determine whether US assessment of the airway can differentiate between OSA and Non-OSA individuals.

METHODS

PubMed, Scopus, clinicaltrials.gov, GoogleScholar and Embase databases were searched from inception through July 01, 2024 for studies reporting neck ultrasonography in OSA, diagnosed using polysomnography. 1703 studies were identified, and after removing duplicate studies, 798 studies were screened. 23 prospective, cross sectional and case control studies evaluating US parameters for OSA screening were evaluated in the systematic review and 12 studies were included in the quantitative analysis. Weighted mean differences were calculated for various US parameters between OSA and non-OSA groups.

RESULTS

Of the 1703 references reviewed, 23 articles were included in the systematic review and 12 underwent quantitative analysis. 11 of the 12 studies were found to be of high quality using Newcastle-Ottawa scale. Significant heterogeneity was observed across studies, with multiple US parameters assessed for OSA screening. We included three static and two dynamic parameters in the meta-analysis; and calculated mean weighted difference (WMD) in dimensions between OSA and non-OSA individuals. The static parameters that significantly differentiated OSA and non-OSA individuals were distance between lingual arteries (WMD 4.43 ± 3.05 mm), mean base of tongue thickness (WMD 6.34 ± 4.86 mm), and lateral pharyngeal wall thickness (WMD 3.59 ± 1.99 mm); while the dynamic parameters included retropalatal diameter during inspiration (WMD -9.41 ± 6.16 mm), expiration (WMD -6.10 ± 2.61 mm) and muller's maneuver (WMD -10.49 ± 7.31 mm); and retroglossal diameter during inspiration (WMD -3.84 ± 1.46 mm) and expiration (WMD -2.27 ± 1.39 mm).

CONCLUSIONS

Increased distance between the lingual arteries, greater mean tongue base thickness, and thicker lateral pharyngeal walls; or reduced retropalatal diameter during inspiration, expiration, or Muller's maneuver; or reduced retroglossal diameter during inspiration or expiration were consistently able to differentiate individuals with OSA from non-OSA individuals. However, standardized cutoff values are not yet available, underscoring the need for larger, methodologically uniform studies before routine clinical application can be recommended.