[Prospective study of riskfactors of difficult laryngeal exposure in suspension laryngoscopy].

The aim of this study was to demonstrate the risk factors which affect the exposure of glottis in suspension laryngoscopy.We performed a prospective study about 90 cases of vocal cord lesions underwent microlaryngosurgery(including polyps,vocal nodules,cyst and papilloma).Then we recorded the clinical data related to glottic exposure, both preoperatively and intraoperatively. Univariate analysis showed that parameters like age(=0.038), Cormack-Lehane score(=0.007),maximuminterincisors gap(=0.007),hyoid-mental distance(HMD) in full extension(=0.033), thyroid-mental distance(TMD) in full extension(=0.014), vertical thyroid-mental distance(VTMD) in full extension(=0.042), sternum-mental distance(SMD) in full extension(=0.01) and degree of neck flexion-extension(=0.003) were related to intraoperative difficult exposure of the glottic area.In logistic regression analysis, Cormack-Lehane score(=0.003), maximuminterincisors gap(=0.001) and degree of neck flexion-extension(=0.002) were significantly risk factors of difficult laryngealexposure. Combination of Cormack-Lehane score, maximuminterincisors gap and degree of neck flexion-extensionmay help to predict the difficult laryngealexposure, so we should evaluate patients before operations of suspension laryngoscopy to decrease the surgical complication.