Prospective study of riskfactors of difficult laryngeal exposure in suspension laryngoscopy

: Objective:The aim of this study was to demonstrate the risk factors which affect the exposure of glottis in suspension laryngoscopy.Method: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. Result:Univariate analysis showed that parameters like age(P=0.038), Cormack-Lehane score(P=0.007),maximuminterincisors gap(P=0.007),hyoid-mental distance(HMD) in full extension(P=0.033), thyroid-mental distance(TMD) in full extension(P=0.014), vertical thyroid-mental distance(VTMD) in full extension(P=0.042), sternum-mental distance(SMD) in full extension(P=0.01) and degree of neck flexion-extension(P=0.003) were related to intraoperative difficult exposure of the glottic area.In logistic regression analysis, Cormack-Lehane score(P=0.003), maximuminterincisors gap(P=0.001) and degree of neck flexion-extension(P=0.002) were significantly risk factors of difficult laryngealexposure. Conclusion: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.