Upper Airway Obstruction In Male Adult Patients With OSAHS:Dynamic CT And 3-Dimensional Imaging Study

Part One Evaluation of Airway Obstruction at Soft Palate Level in Male OSAHS Patients:Dynamic CT and 3-Dimensional Imaging Study of Upper AirwayOBJECTIVE:To observe dynamic characters of upper airway collapse at soft palate level, and to explore the method in evaluating upper airway obstruction at soft palate level in patients with obstructive sleep apnea/hypopnea syndrome(OSAHS).METHODS:41 male patients with at least 2 of 3 major symptoms of daytime sleepiness and fatigue, frequent snoring, and apnea with witness were included in this prospective study. After a whole night polysomnography, all the subjects underwent upper airway CT during quiet breathing and Muller's maneuver. Between these two breathing states the soft palate length(SPL), the minimal cross-sectional area of retropalatal region (mXSA-RP), and the vertical distance from the hard palate to the upper posterior part of the hyoid (hhL) were compared. Following parameters were compared between mild/moderate and severe OSAHS groups:SPL, mXSA-RP, hhL, hard palate length(HPL), and these parameters were correlated with the severity of OSAHS (apnea/hypopnea index, AHI and lowest saturation of blood oxygen, LSaO2).RESULTS:31 patients had severe OSAHS, and 10 patients had mild/moderate OSAHS. All the patients had airway obstruction at soft palate level. Compared to the quiet breathing state, the minimal cross-sectional area of RP(mXSA-RP) was significantly decreased while the soft palate length(SPL) significantly was increased in Muller's maneuver state. Between severe and mild/moderate OSAHS groups, there were no significant differences in those airway changes except the position of hyoid bone. And there were no significant correlation between these airway parameters and severity of OSAHS except the position of hyoid bone. Compared to the patients in BMI<26 group, the patients in BMI≥26 group had bigger collapse ratio of mXSA-RP, bigger neck circumference and smaller mXSA-RP in Muller's maneuver, with the significant differences.CONCLUSION:By using dynamic 3D-CT imagine technique we have showed significant dynamic upper airway changes at soft palate level in patients with OSAHS. All the subjects had airway obstructions at soft palate level in different degrees. But there was no correlation between the degree of the airway changes at soft palate level and severity of OSAHS. The position of hyoid was lower in severe OSAHS group than that in mild/moderate OSAHS group. The patients in BMI>26 group seemed to have airway obstructions at soft palate level more easily than that in BMI<26 group did; but to the serious obesity OSAHS patients with BMI≥30, the collapse degree did not increased or even decreased. Part Two Evaluation of Improvement in Retroglossal Upper Airway Obstruction in Male Adult OSAHS Patients:Dynamic CT and 3-Dimensional Imaging StudyOBJECTIVE:To observe the dynamic variation of retroglossal airway collapse in male patients with obstructive sleep apnea-hypopnea syndrome, then to explore the characteristic of glossa-caused upper airway obstruction and to explore the feasible strategy of surgical treatment for the obstruction.METHODS:From May 2010 to March 2011, male adult patients in our sleeping center of ENT department were included in the study, with symptoms of daytime sleepiness and fatigue, frequent snoring, and apnea with witness. After a whole night polysomnography, all the subjects underwent upper airway CT during quiet breathing, Muller maneuver and cross bite maneuver. The minimal cross-sectional area of retroglossal region (mXSA-RG), the horizontal range from mental spine to posterior wall of pharynx, the horizontal range from hyoid bone center to posterior wall of pharynx, the vertical dimension from hyoid bone center to horizontal line through mental spine, the distance from hyoid bone center to mental spine, and the farthest distance from mental spine to the margin of corpus linguae were measured respectively in the three different states. Above parameters and their variations were compared between mild/moderate and severe OSAHS groups, and were correlated with the severity of OSAHS (apnea/hypopnea index, AHI and lowest saturation of blood oxygen, LSaO2).RESULTS:36 patients had severe OSAHS, and 11 patients had mild/moderate OSAHS. Compared to the quiet breathing state, the minimal cross-sectional area of retroglossal region(mXSA-RG) was decreased with statistical significance, while the variation of corpus linguae length and hyoid bone position had no statistical significance in Muller maneuver. In cross bite maneuver,,the mXSA-RG, the horizontal range from mental spine to posterior wall of pharynx, the horizontal range from hyoid bone center to posterior wall of pharynx, the distance from hyoid bone center to mental spine were significantly increased while the vertical dimension from hyoid bone center to horizontal line through mental spine was increased in cross bite maneuver. The increase value of mXSA-RG was correlated with the increase value of the horizontal range from mental spine to posterior wall of pharynx. Compared with mild/moderate OSAHS groups, the vertical dimensions from hyoid bone center to horizontal line through mental spine were larger while the variations and variation rates of the distance from hyoid bone center to mental spine were smaller. The difference of corpus linguae length and hyoid bone position between the two OSAHS subgroups had no statistical significance.And the vertical dimension from hyoid bone center to horizontal line through mental spine was correlated with AHI. Through the observation of glossa-caused airway obstruction, four types of upper airway obstruction were classified:obstruction with corpus linguae agent at soft palate level, obstruction caused by lingual root, obstruction caused by corpus linguae and lingual root and obstruction with neither corpus linguae nor lingual root agent.CONCLUSION:By using dynamic 3D-CT imagine technique we have simulateed dynamic variation of retroglossal airway obstruction in male patients with OSAHS. The minimal cross-sectional area of retroglossal region(mXSA-RG) was decreased in Muller maneuver. The mXSA-RG was significantly increased in cross bite maneuver. The more antelocation of mandible, the larger improvement in retroglossal airway obstruction was occurred in the cross bite maneuver. The lower lacation of hyoid bone was correlated with AHI, but there was no correlation between the upward movement of hyoid bone and the improvement in retroglossal airway obstruction. We could calculate the AHI caused by retroglossal upper airway (RG-AHI), and correlate RG-AHI with the parameter of retroglossal upper airway. As a whole the hyoid bone moved forward and upward following the antelocation of mandible. The variation of relative position between hyoid bone and mandible was smaller in patient with more serious OSAHS. According to the different types of glossa-caused airway obstruction, we could perform individual surgical treatments for patients with OSAHS. It would provid a new method to make the feasible strategy of surgical treatment for the obstruction.