Characterization of upper airway obstruction by fiber-optic nasolaryngoscopy and MRI in preoperative OSAHS patients.

OBJECTIVE

To investigate changes in the upper airway and its surrounding soft tissue and to characterize the extent and severity of upper airway obstruction in 136 obstructive sleep apnea/hypopnea syndrome (OSAHS) patients who were awake.

METHODS

OSAHS patients and healthy controls were evaluated by fiber-optic nasolaryngoscopy and MRI. The cross-sectional area and pharyngeal wall thickness of the retropalatal, retroglossal and epiglottic region were determined.

RESULTS

Ninety-five percent of the mild OSAHS subjects had single-plane obstruction (vs. severe OSAHS, p < 0.05), 5.0% of the mild OSAHS subjects had two-plane obstruction (p < 0.05) and none of them had three-plane obstruction (p < 0.05). The cross-sectional area of the retropalatal, retroglossal and epiglottic region progressively declined as the severity of OSAHS increased (severe OSAHS vs. controls, p < 0.05). The lateral pharyngeal wall was significantly thicker in OSAHS subjects than in healthy controls (p < 0.05). The cross-sectional area of the soft palate in moderate and severe OSAHS subjects was markedly larger than that of the healthy controls (p < 0.05) and positively correlated with the apnea/hypopnea index (p < 0.05).

CONCLUSION

Moderate and severe OSAHS patients exhibit multi-plane obstruction of the upper airway, particularly in the retropalatal and retroglossal region. The severity of OSAHS negatively correlates with the thickness, length and cross-sectional area size of the soft palate.