小耳畸形患者的畸形解剖研究及听力重建术中鼓膜材料的有限元分析

发布时间：2018-07-12 21:54

本文选题：小耳畸形 + 畸形解剖　；参考：《中国协和医科大学》2010年博士论文

【摘要】： 目的通过对先天性小耳畸形患者外、中耳的畸形解剖学特征的系统研究,比较其与正常解剖之间的差异,总结重要解剖结构的变异规律及相互关系。完善临床诊断分型,指导手术,为耳廓再造和听力重建的序列治疗提供治疗依据。并通过三维有限元方法分析了听力重建术后小耳畸形伴发CAA患者的声波力学改变,从生物力学的角度重点分析鼓膜材料,得出最佳人工鼓膜材料的选择趋势。材料和方法 1研究对象选取2009年6月～2009年12月期间,中国医学科学院整形外科医院外耳整形中心和中国人民解放军总医院耳鼻咽喉科住院诊断为小耳畸形的患者,采用自身对照研究。研究组50耳,其中单侧畸形22例,22耳(右耳14耳,左耳8耳),双侧畸形14例,28耳,年龄3～28岁,平均年龄12.44岁。对照组为单侧畸形之健耳22例,22耳(右耳8耳,左耳14耳)。所有病例既往无中耳、乳突手术史,排除后天性畸形、伴外中耳畸形的相关综合征。 2研究方法 2.1采用东芝Aquilion16层螺旋CT行颞骨高分辨扫描。扫描参数：层厚0.5mm,135kV,250mA, pitch11.0, speed5.50mm/rot。以听眶上线为基线行常规轴位扫描。重建参数：层厚0.4mm, inernal值2.0mm,窗宽3584HU,窗位600HU。原始影像资料导入Mimics软件,生成冠状位、矢状位图像及三维重建图像。利用软件自带的测量工具,进行距离和角度的测量。 2.2评价指标 2.2.1耳廓分级：根据耳廓畸形情况,采用Max分级。 2.2.2外耳道：根据外耳道畸形情况,分为外耳道骨性闭锁、骨性狭窄及膜性闭锁、膜性狭窄。 2.2.3鼓室：在轴位图像上测量鼓室的前后径、左右径；在冠位图像上测量对照组各个鼓室上下径,测量研究组鼓室的上下径。 2.2.4在冠位图像上测量闭锁／狭窄表面到上、中、下鼓室及听骨表面的距离。在轴位图像上测量闭锁／狭窄表面到鼓窦外侧壁内面、鼓窦外侧壁内面到外半规管隆突的距离。 2.2.5定量测量如下参数：测量颞下颌关节窝后表面到鼓窦入口的距离、颞下颌关节窝后表面到鼓室的距离、咽鼓管鼓口和鼓窦入口的距离、咽鼓管径、前庭导水管远端内径、前庭、乙状窦、鼓室外侧壁与乳突外侧骨皮质之间的距离、蒲氏间隙、内听道长、内耳门长径。 2.2.6定性观察如下结构：颅中窝、鼓室天盖、硬脑膜、颈静脉球、颈动脉、Korner隔、乳突。 2.2.7结合多方向调整MPR技术,并在Mimics软件上重建FN管,参考Takegosh的方法,以直角坐标系描述面神经的走行,并测量相关参数。进一步观察面神经与前庭窗的关系,并测量前庭窗至鼓室段的最短距离、蜗窗至乳突段的距离。 2.2.8听小骨：分别于轴位和冠位耳蜗、前庭窗二个层面上识别听小骨形态,予以分类。 2.3统计学分析采用统计分析软件SPSS17.0 for windows.两组之间的比较采用t检验／秩和检验,多组之间的比较采用方差分析／K-W检验(Kruskal-Wallis Test),两两之间的比较采用SNK；分类变量的描述采用频数和百分比,两组或多组之间的比较采用卡方检验(x2检验)。假设检验结果均以P＜=0.05认为差异有统计学意义。 2.4选取单侧小耳畸形伴发CAA患者一例,对其进行CT扫描获取颞骨数据,进行前处理后导入有限元分析软件Ansya,建立健耳和小耳畸形患者听力重建术后的三维有限元模型,并予以人造鼓膜不同的弹性模量。模拟声波传导,得到鼓膜处的声波力学改变数据。结果 1小耳畸形患者以Max分型,设立研究组,定量参数中的鼓室前后径、鼓室上下径、颞下颌关节窝后表面到鼓窦入口的距离、乙状窦的深、乙状窦的宽、FL(代表颞骨乳突部的发育情况),定性参数中的乳突气化程度、乳突气化类型的分布率,面神经遮盖前庭的发生率、在研究组与对照组间存在统计学差异。 2.通过对小耳畸形患者听力重建术的模拟及有限元分析,可以看到,其最大位移在再造鼓膜与听小骨连接处,最小位移在砧骨体,最大压强在再造外耳道外侧端,最小压强在听小骨内侧端,认为患耳术后的声波力学特性与健耳基本相同。选择人造鼓膜材料时,弹性模量大于100Mpa,小于500Mpa,并尽量使弹性模量较大时,更有助于患耳的听力改进。结论小耳畸形患者的鼓室、颞下颌关节窝、乙状窦、及面神经的部分形态与正常耳存在明显的差异,因畸形程度的不同而有所变化,与Max分型有一定相关性。三维有限元分析结果显示患耳术后的声波力学特性与健耳基本相同。听力重建术时再造鼓膜,材料的弹性模量应在100Mpa到500Mpa之间。
[Abstract]:Purpose

Through a systematic study of the anatomic features of congenital microtia , the differences between normal anatomy and normal anatomy were compared , and the variation law and correlation of important anatomical structures were summarized . The clinical diagnosis typing and guided surgery were used to provide the therapeutic basis for the sequence therapy of auricle reconstruction and hearing reconstruction .

Materials and Methods

1 Study Object

During the period from June 2009 to December 2009 , the external ear shape center of the General Hospital of Chinese Academy of Medical Sciences and the General Hospital of the People ' s Liberation Army ( PLA General Hospital ) were diagnosed as small - ear deformity patients . The study group was 50 ears , including 22 cases of unilateral deformity , 22 ears ( 14 ears in the right ear , 8 ears in left ear ) , 14 cases of bilateral deformity , 28 ears , 3 - 28 years of age and 12 . 44 years of mean age . All cases had no previous middle ear , history of mastoid surgery , elimination of acquired deformity , and associated syndrome with external middle ear deformity .

2 Study Methods

2.1 The scanning parameters were 0.5 mm , 135 kV , 250 mA , 11 . 0 , speed5 . 50 mm / rot . The parameters were as follows : layer thickness 0.4 mm , inernal value 2.0 mm , window width 3584HU , and window position 600HU .

Raw image data is imported into Mimics software to generate coronal , sagittal and three - dimensional reconstruction images . Distance and angle measurements are performed using the software ' s own measuring tool .

2.2 Evaluation Indicators

2.2 . 1 Auricular classification : According to the deformity of auricle , Max classification is adopted .

2.2 . 2 External ear canal : According to the condition of external auditory canal deformity , it is divided into external auditory canal bone atresia , ostenosis and membranous atresia , and membranous stenosis .

2.2 . 3 tympanometry : Measure the front and rear diameter and left and right diameter of the drum on the axial image ;
Measure the upper and lower diameter of each drum in the control group on the coronal image , and measure the upper and lower diameters of the tympanum of the study group .

2.2 . 4 Measure the distance between the locking / narrow surface on the coronal image to the upper , middle , lower and auditory surfaces . Measure the distance between the locking / narrow surface to the inner surface of the lateral wall of the outer wall of the drum sinus and the inner surface of the outer wall of the drum sinus to the external semicircular canal on the axial image .

2.2 . 5 The following parameters were quantitatively measured : the distance from the posterior surface of the joint fossa to the entrance of the drum sinus , the distance between the posterior surface of the tympanic tube and the entrance of the drum sinus , the diameter of the pharyngeal tube , the inner diameter of the distal end of the vestibular aqueduct , the anterior chamber , the sigmoid sinus , the distance between the lateral wall of the tympanic cavity and the outer cortical cortex of the mastoid process , the Pu ' s gap , the length of the inner ear canal and the length of the inner ear .

2.2 . 6 The following structures were qualitatively observed : cranial fossa , tympanoplasty , dura , jugular bulb , carotid artery , Korner septum , mastoid process .

2.2 . 7 In combination with multi - direction adjustment of MPR technique , and reconstruct FN tube on Mimics software , refer to the method of Takeoff . The relationship between facial nerve and vestibular window was further observed and the shortest distance between vestibular window and vestibular section was measured . The distance between vestibular window and mastoid segment was measured .

2.2 . 8 To listen to the bone : identify the morphology of the auditory cortex at the two levels of the axial and coronal cochlea , vestibular window , and classify them .

2.3 Statistical Analysis

Statistical analysis software SPSS 17.0 for windows was used . The comparisons between the two groups were t - test / rank and test , and the comparisons between the two groups were analyzed by means of variance analysis / K - W test ( Kruskal - test ) , and SNK was used between the two groups .
The frequency and percentage of the classification variables were used , and the Chi - square test ( x2 test ) was adopted for the comparison between the two groups or groups .

2.4 One case of unilateral small - ear malformation with CAA was selected , the temporal bone data were acquired by CT scanning , and the three - dimensional finite element model was introduced into the finite element analysis software Ansya after the pre - treatment , and the elastic modulus of the artificial tympanic membrane was established . The acoustic wave conduction was simulated to obtain the acoustic wave mechanics change data at the tympanic membrane .

Results

There was statistical difference between the study group and the control group .

2 . Through the simulation and finite element analysis of the hearing reconstruction of patients with small ear deformity , it can be seen that the maximum displacement is at the juncture of the reconstructed tympanic membrane and the icular bone , the minimum displacement is at the outer end of the reconstructed external auditory canal , the minimum pressure is the same as that of the ear . When the artificial tympanic membrane is selected , the elastic modulus is greater than 100Mpa , less than 500Mpa , and the hearing improvement of the ear is more helpful when the elastic modulus is larger .

Conclusion

There was a significant difference between the partial morphology and the normal ear of the tympanic membrane , the temporo - mandibular joint fossa , the sigmoid sinus and the facial nerve in the patients with small ear deformity .

The results of three - dimensional finite element analysis showed that the mechanical properties of the acoustic wave were almost the same as that of the healthy ear , and the elastic modulus of the reconstructed tympanic membrane and the material should be between 100Mpa and 500Mpa .
【学位授予单位】：中国协和医科大学
【学位级别】：博士
【学位授予年份】：2010
【分类号】：R764

【参考文献】