Relationship between the morphological characteristics and the transmucosal gas exchange function in human middle ear cavity

关于中耳腔功能与形态特征之间关系的研究报道较少。本研究探讨了经黏膜气体交换功能与中耳腔表面积和容积的关系。正常中耳腔表面积与体积关系的研究材料为无中耳炎病史的听力学肿瘤患者23例颞骨CT。CT扫描图像数据以DICOM格式数据传输到个人计算机上，通过图像分析软件进行分析。测量每个空气细胞的周长和面积，然后计算乳突空气细胞系统的表面积和体积。证实了面积和体积之间的强烈线性关联。研究中耳腔形态学特征与经黏膜气体交换功能的关系。材料为10例中耳腔干性鼓膜穿孔行鼓膜成形术，无活动性炎症的患者。全麻下手术时吸入氧化亚氮，测量氧化亚氮扩散引起的中耳压升高，定量评价气体交换功能。CT扫描测定中耳腔表面积和体积。气体交换能力与比表面积、比表面积与体积之间存在较强的相关性。人体中耳腔由于具有空气细胞系统，其体积大，表面积大，通过中耳粘膜的气体交换功能依赖于该表面积。中耳腔的形态特征有利于通过粘膜气体交换功能调节中压。

There are few reports to evaluate the relationship between the function and morphological characteristic of middle ear cavity. In this research, the relationship between the transmucosal gas exchange function and the surface area and volume of middle ear cavity was investigated.1.Study to evaluate the relationship between surface area and volume in normal middle ear cavityMaterials were temporal bone CT scans of 23 patients with acoustic tumor without a past history of otitis media. The image data of CT scans were transported to a personal computer as DICOM formatted data, and analyzed by image analysis software. The perimeter and area of each air cell were measured, and then the surface area and volume of mastoid air cell system were calculated. The strong linear con-elation between the area and volume was confirmed.2.Study to evaluate the relationship between the morphological characteristics and the transmucosal gas exchange function in human middle ear cavityMaterials were 10 patients who undergo myringoplasty with dry tympanic membrane perforations without active inflammation in the middle ear cavity. At the time of operation under general anesthesia with the inhalation of nitrous oxide, increasing middle ear pressure caused by the diffusion of nitrous oxide was measured, and the gas exchange function was quantitatively evaluated. Surface area and volume of middle ear cavity were measured by CT scans. The strong correlations between the gas exchange ability and surface area, and the surface area and volume were confirmed.Human middle ear cavity had a large surface area corresponding to its large volume by having air cell systems, and the gas exchange function through the middle ear mucosa depended on the surface area. The morphological characteristic of middle ear cavity is of great advantage to regulating middle pressure by transmucosal gas exchange function.