Study of Upper Airway Obstruction Sites in Patients with ObstructiveSleep Apnea Syndrome

Objective To evaluate the upper airway of patients with obstructive sleep apnea syndrome (OSAS) while they were awake, asleep and apneic by means of multislice CT scan and analyse its value in pre - operative topodiagnosis. Methods Twenty patients with OSAS underwent multislice CT scan while awake and during sleep apnea episodes under monitoring of capnography, 18 age - matched normal subjects were selected as the control group. Results The pharyngeal cross - sectional area of OSAS patients was smaller than that of normal subjects, mainly at the velopharynx and tongue - pharynx. This difference became greater when patients were asleep and apneic, particularly at the tongue - pharynx. All patients had obstructive changes at the velopharynx and 65% of them had both velopharynx and tongue -pharynx airway abnormalities. Conclusion This method may show the obstructive lesions in the anatomic and physiologic state and provide more accurate information of localizing the upper airway obstruction sites in patients with OSAS. The results can be used for selection of appropriate therapy and prediction of surgical outcome.