术前颞骨CT扫描影像测量参数预测耳显微外科手术镫骨暴露难易程度的临床价值

Clinical value of preoperative temporal bone CT imaging parameters in predicting the difficulty of stapes exposure in ear microsurgery

目的通过术前颞骨CT测量值径线及角度进行测量和比较,初步预测中耳乳突显微手术中镫骨暴露的难易程度,评价术前影像学评估的准确性与可靠性。方法选取2019年2月-2019年10月行中耳乳突显微外科手术的27例(27耳)慢性中耳炎伴传导性聋或混合性聋住院患者纳入研究,手术均由同一位富有经验的高年资副主任医师主刀。术前利用颞骨薄层CT扫描技术明确患者外耳道、镫骨、砧镫关节、锥隆起、鼓室层面影像,观察和测量外耳道软骨部宽度、峡部宽度、外耳道骨部宽度、镫骨至锥隆起距离、镫骨至鼓室窦距离、与岩锥长轴平行径线和镫骨显影延长线相交之夹角(α),利用软件工作站自带工具对相关监测指标进行数据测量,并与术中探查所见镫骨暴露难易程度为准分为容易暴露组和难暴露组;采用SPSS 17.0软件进行相关数据统计处理。结果镫骨暴露的难易程度与镫骨至锥隆起距离、镫骨至鼓室窦距离、外耳道骨部宽度密切相关,其中与镫骨至锥隆起距离、镫骨至鼓室窦距离具有明显统计学意义(P<0.01),与外耳道骨部宽度具有统计学意义(P<0.05),而与外耳道软骨宽度、峡部宽度、夹角(α)无统计学意义(P>0.05)。结论镫骨至锥隆起距离、镫骨至鼓室窦距离对耳显微外科手术中镫骨暴露的难易程度产生显著的影响,外耳道骨部宽度可能会影响手术的难易程度。术前颞骨高分辨率CT测量值可以预测耳显微镫骨暴露的难易程度,具有一定的临床应用指导价值。

Objective To evaluate the accuracy and reliability of preoperative thin slice computerized tomography(CT)and predict the difficulty of stapes exposure in ear microsurgery by measuring and comparing the preoperative CT imaging parameters.Methods Twenty-seven inpatients(27 ears)undergoing mastoid microsurgery due to chronic otitis media from Feb 2019 to Oct 2019 were enrolled in the study.The operation was performed via retroauricular approach by the same experienced associate senior doctor in all the patients.Preoperative thin slice temporal bone CT was adopted to obtain the images of the external auditory canal,stapes,incudostapedial joint,pyramidal eminence and posterior tympanic cavity.The widths of cartilaginous portion,isthmus and bony portion of the external auditory canal,the distance between stapes and pyramidal eminence and that between stapes and tympanic sinus,as well as the angle between the parallel line of long axis of talus cone and the extension line of stapes were observed and measured by Medical Systems software.The exposure difficulty of stapes was predicted preoperatively and confirmed intraoperatively.All the patients were divided into easily exposed group and difficultly exposed group according to the intraoperative difficulty of exposure.SPSS 17.0 software was used for statistical analysis.Results The difficulty of stapes exposure was closely related to the distance from stapes to pyramidal eminence(P<0.01)and that between stapes and tympanic sinus(P<0.01),as well as the width of bony portion of external auditory canal(P<0.05).Meanwhile,the difficulty of stapes exposure was not related to the widths of cartilaginous portion and isthmus of external auditory canal,and the angle(α)(all P>0.05).Conclusion The distance from stapes to pyramidal eminence and that between stapes and tympanic sinus have dramatic impact on exposure of stapes.The width of bony portion of external auditory canal may affect the difficulty of surgery.Parameters from preoperative high-resolution CT of temporal bone may predict the difficulty of stapes exposure in ear microsurgery,which has certain practical value in clinical application.