[Congenital middle ear malformation: clinical analysis and discussion of classification].

Objective: To analyze the clinical characteristics and appropriate surgical procedures, and discuss the classification of congenital middle ear malformation. Methods: All cases were from the Center of Otorhinolaryngology, the Sixth Medical Center of Department of PLA General Hospital. All of these cases, including 26 male patients (ears) , 10 female patients (11 ears) , aged from 7 to 57 years old, had normal external auditory canal, tympanic membrane, conductive hearing loss, type A tympanogram and negative Gelle's test. Tympanoplasty was performed in all cases. The deformity was classified to three types,i.e., Type I (stapes foot plate mobility): Ⅰa, ossicular chain deformity with normal stapes suprastructure; Ⅰb, ossicular chain deformity with abnormal stapes suprastructure; Type Ⅱ (stapes foot plate fixation): Ⅱ a,normal ossicular chain, Ⅱ b, ossicular chain malformation; and Type Ⅲ: vestibular window osseous atresia or undeveloped, or with round window atresia. The malformation of type Ⅱ and Ⅲ may be accompanied with abnormal facial nerve. In addition, the papers on middle ear malformation published from 1982 to 2017 were analyzed retrospectively. The clinical data of 451 ears malformation were summarized. Results: According to the revisional classification criteria in 37 ear samples from our hospital, 20 ears were type I. 6 type Ⅰa cases were used PORP (partial ossicular replacement prosthesis) to reconstruct the ossicular chain; 14 type Ⅰb cases were used TORP (total ossicular replacement prosthesis) to reconstruct the ossicular chain. For the 5 ears of type Ⅱ, 2 of which were type Ⅱ a and 3 were type Ⅱ b. 4 ear samples of type Ⅱ were implanted with Piston ossicular prosthesis, 1 was implanted with TORP in which the ossificated foot plate was removed with periosteum preserved. 12 ear samples were type Ⅲ, with vestibular window osseous atresia, facial nerve malformation, and stapes suprastructure malformation. The pistons ossicular prosthesis were implanted in vestibular window in 3 ears with facial nerve covering vestibular window partially. The surgery had to be given up in 5 ears, and TORP was implanted in 4 ears at the opening with preserved periosteum at the beginning of the tympanic scala because of facial nerve covering vestibular window totally. 30 ears with complete follow-up data had no sensorineural hearing loss and the average air-bone conduction decreased 23.3±10.7 dB (P<0.05).There were 234 ears of type Ⅰ in 451 ears of congenital middle ear malformation reported in the literature. 113 of which were type Ⅰa, the basic surgery was ossicular chain shaking and artificial or autogenous PORP implantation. Type Ⅰb was 121 ears, with autogenous or artificial TORP and PORP. Type Ⅱ was125 ears, including type Ⅱa 22 ears, Ⅱb 60 ears, and no subclassification for 43 ears. The surgery of type Ⅱ was the same as otosclerosis. The vestibular window atresia of type Ⅲ was 92 ears, the surgery of 17 ears had to be abandoned, the other ears underwent vestibular window, promontory or semicircular canal opening to reconstruct hearing with Piston, autogenous or artificial TORP. Conclusion: Referring to the classification of congenital middle ear malformation combining with appropriate surgical materials and methods, otologists can better understand and choose appropriate surgical method to the middle ear malformation.目的： 分析先天性中耳畸形患者的畸形特点及手术术式的选择，探讨更适合临床应用的先天性中耳畸形分类方法，便于耳科医师理解掌握。 方法： 回顾性分析2010年9月至2018年1月在解放军总医院第六医学中心（原海军总医院）耳鼻咽喉头颈外科手术治疗的36例37耳（1例为双侧）先天性中耳畸形患者，其中男26例（耳），女10例（11耳），年龄7~57岁。所有病例鼓膜、外耳道均正常，纯音测听为传导性听力损失，声导抗鼓室图为A型曲线。全部病例均行鼓室成形术，根据手术所见对畸形进行分类统计，将其修正为三种类型。Ⅰ型（镫骨足板活动）：Ⅰa，镫骨上结构正常的听骨链畸形；Ⅰb：镫骨上结构不正常的听骨链畸形。Ⅱ型（镫骨足板固定）：Ⅱa，听骨链正常；Ⅱb，听骨链畸形。Ⅲ型：前庭窗骨性闭锁或未发育，或伴蜗窗闭锁。其中Ⅱ、Ⅲ型可伴有面神经畸形。同时回顾分析1982—2017年在国内期刊公开发表的有关中耳畸形论文中的451耳中耳畸形的临床资料，总结其分类特点。 结果： 按照修正的分类标准，本院37耳先天性中耳畸形中Ⅰ型20耳，其中Ⅰa型6耳，以部分听骨赝复物(partial ossicular replacement prosthesis, PORP)重建听骨链；Ⅰb型14耳，以全听骨赝复物(total ossicular replacement prosthesis, TORP)重建听骨链。Ⅱ型5耳，其中Ⅱa型2耳，Ⅱb型3耳,4耳植入Piston听骨重建听力，1耳磨薄骨化足板后保留前庭窗骨内膜，表面覆盖筋膜后以TORP建立听骨链连接。Ⅲ型12耳，前庭窗骨性闭锁、面神经畸形、镫骨上结构及砧骨畸形同时存在；3耳面神经部分覆盖前庭窗，在前庭窗处植入Piston听骨重建听力；9耳面神经全部覆盖前庭窗，其中5耳放弃手术，4耳在鼓岬处鼓阶起始段开窗后保留骨内膜，覆盖筋膜后，以TORP连接鼓膜重建听骨链。术后随访资料完整者30耳，均无感音神经性听力下降，平均气骨导差缩小（23.3±10.7）dB。文献报道的451耳先天性中耳畸形中Ⅰ型共234耳，其中Ⅰa型113耳，基本术式为听骨链撼动及人工或自体PORP植入；Ⅰb型121耳，以自体或人工TORP、PORP重建听力。Ⅱ型125耳,其中Ⅱa型22耳，Ⅱb型60耳，未分亚型43耳；手术与耳硬化症手术方式相同。Ⅲ型前庭窗闭锁共92耳，17耳因面神经异常放弃手术，其余病例在前庭窗或鼓岬、半规管开窗后以Piston、钢丝、自体或人工TORP重建听力。 结论： 以镫骨为中心，结合现代外科假体材料及重建方法对先天性中耳畸形进行分类，便于耳科医师理解，同时有助于听力重建手术方式的选择。.