The Application Value Of Soft Tissue CT Measurement In The Upper Airway Evaluation Of Patients With Severe OSAHS

ObjectiveTo investigate the application value of soft tissue CT measurement in the upper airway evaluation of patients with severe OSAHS during they awake. Combined with related indicators of the PSG to find out the meaningful datas of the measurement of upper airway in patients with severe OSAHS and the flats where are narrow.So it can make surgical treatment success.Method70patients with severe OSAHS were observed from December2010to October2013in Tianjin the first central hospital, who are contained68male cases and2female cases. They had no disease of rhinology or pharyngology. All the70patients are in line of "obstructive sleep apnea syndrome diagnosis and surgical treatment guidelines" which is made of the Chinese Medical Association of Otolaryngology Head and Neck Surgery Branch throat study group in February2009. All the70patients were excluded from these causes of OSAHS:nasal stenosis, hypothyroidism, obviously a narrow jaw and other special causes:history of severe respiratory, circulatory, neurological diseases. All the70patients were non-related surgery.SIEMENS Emotion16multi-slice CT scanner was used to check all the patients, who should be supine, and the head is he mostest near the marchine. During the text, the patients should try to ensure symmetrical on both sides of the head, not swallowing and chewing, and the upper and lower teeth hold on together naturally. The text begins at the end of quiet breathing with continuous scan. Scan range from the orbital margin to the level of the cricoid cartilage. The scan parameters:110kV,80mA, speed:1.0s/circle, screw pitch:1.35, detector:1.2mm×16, reconstruction thickness1.2mm, reconstruction interval:0.6mm. After the text, the images were transmitted to the SIEMENS Leonardo workstation for multiplanar reformation, and measure the reference plane in the direction of multi-diameter of each line, area by the software. The following datas were measured.①palate area (edge to the area between the lower tip of the uvula palate) at the narrowest anteroposterior diameter, transverse diameter, cross-sectional area; between the tongue area②(uvula tip to the free edge of the tip of the epiglottis③soft palate length,④whole tongue length,⑤pharynx length; area) at the narrowest anteroposterior diameter, transverse diameter, cross-sectional area.PSG was used to record the OSAHS patients. Based sleep apnea hypopnea index (AHI), the patients are divided into group Al (48cases,30times/h≤AHI<70times/h), group A2(22cases,AHI≥70times/h);based sleep apnea per hour hypopnea time(AHIT),the patients are divided into group B1(35cases,AHIT<30min/h), group B2(35cases,AHIT≥30min/h); based oxygen desaturation index (ODI), the patients are divided into group C1(34cases,30times/h<ODI≤60times/h), group C2(36cases,ODI>60times/h), according to the oxygen saturation<90%of the time as a percentage of total time monitoring (TS90),the patients are divided into group D1(35cases,TS90≤25%), D2group (35cases,TS90>25%). Based on the lowest oxygen saturation (LSO2), the patients are divided into group El (38cases,85%>LSO2≥65%), group E2(32cases,LSO2<65%).Statistical analysis by SPSS17.0, and the independent samples t test were used.Result1. According to AHI, all the patients were divided into two groups:①A1group (severe OSAHS):30times/h≤AHI<70times/h (48cases),②A2group (very severe OSAHS patients):AHI≥70times/h(22cases). Compared with group A2, group A1is larger in retropalatal (P<0.05, a statistically significant difference).2. According to AHIT, all the patients were divided into two groups:①B1group: AHIT<30minutes/hour (35cases),②B2group:AHIT≥30minutes/hour (35cases). Compared with group B2, group B1is larger in retropalatal (P<0.05, a statistically significant difference).3. According to ODI, all the patients were divided into two groups:①C1Group:30times/hour<ODI≤60times/h (34cases),②C2group:ODI>60times/hour (36cases). Compared with group C2, group C1is larger in retropalatal and lingual region, with shorter soft palate (P<0.05, a statistically significant difference). 4. According to TS90, all the patients were divided into two groups:①D1group: TS90≤25%(35cases),②D2group:TS90>25%(35cases). Compared with D1and D2group, P>0.05, the difference was not statistically significant.5. According to LSO2, all the patients were divided into two groups:①E1group:85%> LSO2≥65%(38cases),②E2group:LSO2<65%(32cases). Compared with El and E2group, P>0.05, the difference was not statistically significant.Conclusion1. The soft tissue CT measurements can more accurately measure the nasopharynx to the hypopharynx about any area of the left-right diameter, anteroposterior diameter and cross-sectional area to provide accurate anatomical informations for the clinical surgery. And it can be more visually observe the most narrow area of the upper airways with the OSAHS patient awake.2.16multi-slice CT scanning was used to each plane airway soft tissue anteroposterior diameter, transverse diameter line, these measurements are simple, easy, which can alternative the cross-sectional area measurement.3. All of the severe OSAHS patients are narrow in the retropalatal, and the left-right diameter is more meaningful than the anteroposterior diameter.4. With the increase of the length of the soft palate, and the decreases of length of the lingual, cross-sectional area, further exacerbating the narrow of the retropalatal and also the lingual. It lead to further aggravate the disease of the OSAHS patients.5. where all aspects of the area around trail, and pharynx pharynx posterior wall of the left and right sidewall thickness coronal, and so are the smallest diameter of about OSAHS important indicator of the upper airway CT evaluation.