Effect of CT localization of upper airway obstruction site after inducing sleep on the value of obstructive sleep apnea hypopnea syndrome and the effect of surgery

Objective:To explore the value of CT location of the upper airway obstruction site after inducing sleep on the condition of obstructive sleep apnea（OSA） and its surgical efficacy. Methods:Forty patients with moderate-to-severe OSA diagnosed by polysomnography, first performed awake CT scan, then, the patient was slowly injected intravenously with dexmedetomidine to induce sleep, when the patient was apnea during sleep, CT scan of the corresponding part of the upper airway was performed. Compare and measure the cross-sectional area of the upper airway stenosis level in the two states, and evaluate the correlation between the cross-sectional area of the stenosis level after induction of sleep and the patient's AHI, blood oxygen saturation<90% of the time（CT90）. According to the change value of the cross-sectional area of each plane, it was divided into 2 groups, 22 cases in first group underwent hypothermia plasma uvulapalatopharyngoplasty, and 18 cases in second group underwent multi-plane combined surgery. After 12 months of follow-up, compare the post-long-term efficacy, changes in cross-sectional area values of various narrow planes before and after surgery, and changes in indicators related to sleep quality between the two groups. Results:Compared with the cross-sectional area of the nasopharyngeal area, posterior soft palate area, the posterior tongue area, and the epiglottis area measured by upper airway CT under awake breathing state, the cross-sectional area of each obstruction plane during sleep state decreased（P<0.01）. The minimum cross-sectional area of the upper airway plane sleep phase was negatively correlated with AHI and CT90, and the posterior soft palate and the posterior lingual base were highly correlated with AHI and CT90.12 months after treatment, the minimum cross-sectional area of each phase of the sleep phase in the experimental group 1 was significantly improved（P<0.01） compared with that before treatment, followed by the posterior tongue area（P<0.05）. There was no statistical difference between the nasopharyngeal area and the epiglottis area. The differences in nasopharyngeal area, posterior soft palate area, posterior tongue area, and epiglottis area in experimental group 2 after treatment were statistically significant（P<0.01 or P<0.05）, compared with that before treatment. The sleep-related indexes ESS, CT90, AHI, and LSaO₂ of the two groups were better than those before treatment after 12 months of treatment（P<0.01）. Comparison of experiment group 1 and 2, the effective rates were 72.72% and 95.23%（χ²=10.62, P<0.01）, the significant efficiency was 58.33% and 80.45%（χ²=8.62, P<0.01）, and the cure rates were 12.37% and 17.48%（x²=7.62, P<0.01）. Conclusion:CT examination of OSA patients after drug-induced sleep is safe and feasible, and it has important value for the accurate location of the upper airway obstruction site. 64-slice spiral CT upper airway scanning under induced sleep has guiding significance for the evaluation of OSA patients' condition and long-term surgical efficacy.