蜗轴缺失内耳形态学表现与人工耳蜗植入入路的选择

Morphologic feature and cochlear implant surgical approach for cochlear modiolus deficiency

目的:总结人工耳蜗植入手术患者耳蜗蜗轴缺失的类型和人工耳蜗植入手术入路的选择,为掌握人工耳蜗植入手术的适应证提供参考。方法:人工耳蜗植入患者按术前颞骨高分辨CT检查,将存在的耳蜗蜗轴发育缺失分为3种类型:1耳蜗发育不良形成的蜗轴缺失(Mondini畸形);2耳蜗前庭半规管发育不良(Common cavity畸形);3内耳道与耳蜗共腔(IP-Ⅲ)畸形。将蜗轴缺失的内耳畸形人工耳蜗植入手术入路分成3种类型:Ⅰ型,常规面神经隐窝入路将圆窗扩大开放入耳蜗内;Ⅱ型,常规面隐窝入路后鼓岬表面开放入畸形的耳蜗腔内,电极沿侧壁摆放;Ⅲ型,乳突侧开放外半规管突入共腔将电极摆放于耳蜗侧的腔内骨壁。结果:1246例内耳畸形中耳蜗蜗轴发育缺失共166例,其中Mondini畸形的215例患者中存在蜗轴缺失135例;Conmon cavity畸形18例,全部存在耳蜗蜗轴缺失;内耳道与耳蜗共腔(IP-Ⅲ)畸形13例,全部存在耳蜗蜗轴缺失。2内耳畸形存在耳蜗蜗轴缺失的人工耳蜗植入手术入路的选择:Ⅰ型136例,其中Mondini畸形123例,内耳道与耳蜗共腔(IP-Ⅲ)畸形13例;Ⅱ型12例,全部为Mondini畸形存在蜗轴缺失患者;Ⅲ型18例,全部为Conmon cavity畸形。33种内耳畸形人工耳蜗植入术后效果:Mondini畸形声场测试平均为65dB,单韵母言语识别为95%,单声母言语识别为25%;Conmon cavity畸形声场测试平均为80dB,单韵母言语识别为60%,单声母言语识别为0;内耳道与耳蜗共腔(IP-Ⅲ)畸形声场测试平均为55dB,单韵母言语识别为100%,单声母言语识别为45%。结论:耳蜗蜗轴缺失的内耳畸形人工耳蜗植入术后患者听觉言语识别效果很差,Conmon cavity畸形最差,Mondini畸形次之,内耳道与耳蜗共腔(IP-Ⅲ)畸形较前两者好。

Objective：To review the classification of cochlear modiolus deficiency and decision on surgical ap- proach for above case,in order to provide mastery for cochlear implant （CI） indication. Method：Basing on temporal bone H RCT pre-operation, CI subjects with modiolus deficiency were defined as following groups： （1） deficiency caused by cochlear dysplasia （Mondini malformation）; （2）deficiency caused by dysplasia of cochlear and vestibule （Common cavity malformation） ; （3）deficiency caused by absence of internal acoustic meatus fundus （IP-III malfor- mation）. Three types of surgicai approach were utilized： type I , electrode array was introduced through facial recess, enlarged the round window, type II ,opened the surface of chchlea, electrode array was introduced through facial recess, fenestration on posterior promontory and then inserted around lateral wall of inner-cochlear cavity. type III , electrode array was introduce through fenestration of lateral semicircular canal and then placed close to the bony wall of common cavity. Result： One hundred and sixty-six cochlear modiolus deficiency cases were identi- fied into 3 groups as following： 135 Mondini malformation cases into group a, 18 common cavity malformation ca- ses into group b, and 13 IP-1]I malformation cases into group c. Surgical approach： type I were used in 136 cases （123 Mondini cases and 13 IP-III cases）, while approach type II in 12 cases （12 Mondini cases）, and approach type HI in 18 cases （18 common cavity cases）. Income post-operation of CI： For group a （Mondini malformation）, post-activation mean hearing threshold in sound field was 65 dB, speech recognition score is 95% （single finals test） and 25% （signal initials test）, while it was 80 dB, 60% and 0 for group b （Conmon cavity malformation）,