Hearing preservation and cochlear implants according to inner ear approach: multicentric evaluation

IntroductionElectroacoustic stimulation is an excellent option for people with residual hearing in the low frequencies, who obtain insufficient benefit with hearing aids. To be effective, the subject's residual hearing should be preserved during cochlear implant surgery.ObjectivesTo evaluate the hearing preservation in patients that underwent implant placement and to compare the results in accordance with the approach to the inner ear.Methods19 subjects underwent a soft surgical technique, and the electrode MED-EL FLEX™ EAS, designed to be atraumatic, was used. We evaluated pre- and postoperative tonal audiometric tests with an average of 18.4 months after implantation, to measure the rate of hearing preservation.Results17 patients had total or partial preservation of residual hearing; 5 had total hearing preservation and two individuals had no preservation of hearing. The insertion of the electrode occurred through a cochleostomy in 3 patients, and in 2 of these there was no hearing preservation; the other 16 patients experienced electrode insertion through a round window approach. All patients benefited from the cochlear implant, even those who are only using electrical stimulation.ConclusionThe hearing preservation occurred in 89.4% of cases. There was no significant difference between the forms of inner ear approach.     

人工耳蜗植入术中因内耳畸形发生“井喷”的危险因素分析

目的 分析人工耳蜗植入术治疗内耳畸形中发生“井喷”的危险因素。方法 回顾性分析湘南学院附属医院耳鼻咽喉头颈外科及中南大学湘雅二医院耳鼻咽喉科2010年1月～2015年10月收治的25例内耳畸形行人工耳蜗植入术患者的病例资料。结果 8例患者术后出现“井喷”,其中植入右侧6例、左侧2例。畸形类别：双侧耳蜗内听道相通伴Mondini畸形或前庭导水管扩大分别为4例、2例,双侧耳蜗内听道不相通+前庭导水管扩大1例,右侧耳蜗内听道相通+左侧Michel畸形右侧Mondini畸形1例。25例患者术后均获得满意听力。结论 内耳畸形中前庭导水管扩大、Mondini畸形和耳蜗听道相通是人工耳蜗植入术中的常见危险因素,术前需行影像学检查,全面评估“井喷”发生风险,降低其发生率,确保手术效果及人工耳蜗听觉建立。     

Effects of experimental cochlear thrombosis on oxygenation and auditory function of the inner ear

To elucidate the etiology and pathogenesis of sudden hearing loss, the effect of experimental cochlear thrombosis on oxygenation and the auditory function of the inner ear was investigated in anesthetized guinea pigs. Impairment of cochlear blood flow (CBF) was induced by ferromagnetic obstruction of cochlear blood vessels at lowered body temperature. Perilymphatic oxygen partial pressure (PO₂) in the basal scala tympani (about 200 m below the round window membrane) was measured polarographically using micro-coaxial needle electrodes. Auditory function was examined by recording cochlear microphonic (CM) frequency responses, compound action potentials (CAP) and auditory evoked brainstem responses (ABR). Findings demonstrated a considerable decrease in the mean perilymphaticPO₂ of 40%, 2 h after the start of the experiment. Mean CM and N₁ CAP amplitudes were reduced by about 25% each and ABR by 18%. No significant changes were observed in the latencies of either CAP or ABR. Mean basal CBF was found to decrease by 35%, as measured by laser Doppler flowmetry in a parallel study. The present findings demonstrate that vascular impairment in the inner ear results in a considerable drop in intracochlear oxygenation, causing a significant loss in the auditory response.     

Preservation of basal inner ear structures in cochlear implantation

The aim of this report was to examine basal trauma in implanted human temporal bones and discuss modified approaches to the basal cochlear turn to avoid destruction of basal cochlear structures. Thirty-three human temporal bones were implanted with four different cochlear implant electrode arrays manufactured by MED-EL using either a caudal approach cochleostomy or round window membrane insertions. All specimens were processed with a special histological technique that allows sectioning of undecalcified bone with the electrode in situ. All bones were evaluated histologically in terms of basal cochlear trauma. Two pathomechanisms of basal trauma could be distinguished and were evaluated separately, buckling of the basal end of the array and trauma by drilling. Using the caudal approach cochleostomy, the total percentage of destructive basal trauma was 48% compared to less than 15% when performing round window membrane insertions. Although it is still unclear whether basal cochlear trauma influences apical cochlear function or not, adapted surgical procedures and no forceful insertion maneuvers should be used when performing cochlear implantations with hearing preservation.     

Outcomes of cochlear implantation in children with inner ear malformations

European Archives of Oto-Rhino-Laryngology - To evaluate the surgical experience and auditory functions and progress of speech development of cochlear implantation in malformed ears. Between...     

先天性内耳畸形患者多通道人工耳蜗植入的效果观察

目的探讨多通道人工耳蜗在先天性内耳畸形患者植入的效果.方法对16例先天性内耳畸形患者(畸形组,Mondini畸形12例,大前庭导水管综合征4例),2例经前庭窗植入电极,3例经鼓岬植入电极,11例经圆窗龛前上缘植入电极.2例术中发生镫井喷.以10例耳蜗发育正常的植入者作为对照组,进行术后效果对比.结果畸形组与对照组术中和术后并发症差异无显著性意义.术后听阈畸形组多数患者达到30～40 dB HL,与正常组相似,仅少数患者听阈稍高.经统计学分析差异无显著性意义(P>0.05).听觉语言康复效果畸形组多数与对照组接近.结论多通道人工耳蜗植入适用于绝大多数先天性内耳畸形的患者,术后听力及语言康复效果满意.     

内耳发育畸形患者人工耳蜗植入术后的疗效分析

目的分析内耳发育畸形患者行人工耳蜗植入术后的疗效。方法回顾性分析2011年1月~2017年7月在西南医科大学附属医院行人工耳蜗植入术的30例内耳发育畸形患者的临床资料,其中大前庭水管综合征(large vestibular aqueduct syndrome,LVAS) 8例,Mondini畸形（不完全分隔Ⅱ型）7例,同时伴有LVAS和Mondini畸形10例,内听道狭窄5例。随机选取同时期临床资料相匹配的30例耳蜗结构正常的人工耳蜗植入患者作为对照组。采用听觉行为分级标准和言语可懂度分级标准进行评估。比较两组患者的术前听力、术中情况以及术后听觉言语康复情况。结果3例LVAS患者在术中耳蜗钻孔后出现外淋巴液不同程度的外涌,1例Mondini畸形患者术中出现脑脊液井喷现象。两组患者术后均获得有意义的听觉反应,术后的听觉言语能力相比较,差异无统计学意义（P>0.05）。同组患者,术后3,6,9,12个月的听觉言语能力均较各自术前均有明显提高（P<0.05）。结论内耳发育畸形患者不是人工耳蜗植入术的绝对禁忌证,其术后言语康复效果与内耳结构正常者无明显差异,但手术难度比内耳结构正常者要大,术前应根据不同的畸形类型制定个性化的手术方案,以减少并发症的发生。     

先天性内耳畸形并中耳畸形患者多通道人工耳蜗植入术3例报告

目的：探讨先天性内耳畸形并中耳畸形患者行多通道人工耳蜗植入术的方法及效果。方法：1995年5月-2002年5月我院为3例罕见的先天性内耳畸形并中耳畸形患者经乳突进路行人工耳蜗植入术,分别植入27、28、32个电极,植入后3个月行声场测听。结果：3例患者均成功地行人工耳蜗植入,术中、术后无严重并发症发生,术后声场测听听阈达35-40dBHL。结论：罕见的先天性内耳畸形并中耳畸形患者也可行人工耳蜗植入术,术后效果满意。     

Middle ear inflammatory mediators and cochlear function

Sensorineural hearing loss (SNHL) has been documented in patients with otitis media. Despite a number of clinical and pathologic works dealing with this common problem, animal studies searching for possible relationships between the middle ear inflammation and cochlear function remain insufficient. Bacterial inoculation and ototoxins and inflammatory products in the middle ear cavity cause SNHL in rodents. Human serum albumin placed in the middle ear cavity in chinchillas also produces SNHL, owing to the effects of nonspecific inflammation in the middle ear cavity. Most of the middle ear inflammatory mediators enter the inner ear through the round window route, and alteration of the permeability of the round window membrane plays an important role in causing cochlear dysfunction. Although an immunologic response in the middle ear plays an important role in otitis media, the immunologic response in the inner ear as it relates to middle ear inflammatory mediators requires further study.     

Retrofacial approach of cochlear implantation in inner ear malformation with aberrant facial nerve: a case report

Cochlear implantation is regarded as a safe surgery for young children with minimal complications. However, inner ear malformations and aberrant course of facial nerves may impede electrode insertion via the round window approach and increase the risk of iatrogenic facial nerve injury. We report a case of cochlear incomplete partition in a patient with anomalous facial nerve anatomy. The anterior and inferior displacement of the facial nerve obscured the round window. A retrofacial approach was used to expose the round window and the electrode was inserted successfully. No surgical complications were found postoperatively, and the child showed significant improvement in speech perception. As the course of the aberrant facial nerve is difficult to track preoperatively, surgeons should proceed with caution to reduce the risk of facial nerve injury during the operation.     

Audiological performance after cochlear implantation in children with inner ear malformations

OBJECTIVES: To prove that cochlear implantation is a beneficial method of rehabilitation in deaf children with malformations of the inner ear. DESIGN: The evaluation of auditory responses to speech (EARS) test battery was performed on the children in this study after an average implant use of 3 years. RESULTS: Individual results of six children with inner ear anomalies receiving cochlear implants are presented in this study. Three of the patients showed an incomplete partition (Mondini dysplasia), one had a cochlear hypoplasia and two suffered from an intraoperative cerebrospinal fluid leak. The majority of the children in this study are successful implant users. Wherever possible, test scores are included and subjective case reports given. CONCLUSIONS: Results are similar to those in children with normal cochleas, therefore inner ear malformations found in as many as 20% of patients with congenital sensorineural hearing loss are no contraindication for cochlear implantation. Nevertheless, factors influencing the success of implantation are multiple, including a thorough preoperative radiological examination, a well-performed surgery and an individually tailored postoperative rehabilitation programme.     

内耳畸形人工耳蜗植入后听力言语康复效果分析

目的探讨内耳畸形患者人工耳蜗植入术,并对术后听力言语康复效果进行评估.方法 1997年至今,北京同仁医院共开展人工耳蜗植入术700余例,其中双侧内耳畸形患者108例,随访并回顾性分析97例,就不同原因内耳畸形的人工耳蜗植入术后开机调试及术后听力言语康复效果进行评估.结果①所有内耳畸形患者人工耳蜗植入术后都有听觉;②术后经正规康复训练,患者听力言语康复效果均有不同程度提高;③目前大部分患者于正常学校就读或已经工作,重返主流社会.结论对内耳畸形患者行人工耳蜗植入术是安全可靠的,人工耳蜗植入术后远期康复效果肯定.     

Congenital malformation of the inner ear and pediatric cochlear implantation.

OBJECTIVES: To study the surgical aspects and performance outcome of cochlear implantation in children with malformed inner ears. STUDY DESIGN: Clinical and audiometric evaluation in 13 patients. METHODS: Patient data concerning surgery, postoperative follow-up, and pre- and postimplantation audiometry were obtained from the cochlear implant center's database and evaluated. A review of the literature has been included. SETTING: Tertiary referral center. PATIENTS: The patients had a variety of inner ear malformations and profound hearing loss. One patient with recurrent meningitis had a severe cochlear malformation (common cavity). RESULTS: Major complications did not occur. In one patient with an abnormal position of the cochlea and concurring middle ear disease, it was difficult to find the scala tympani during surgery. A cerebrospinal fluid gusher was encountered in two patients and an aberrant facial nerve in another, which did not lead to any complications. The patients with mild cochlear malformation such as an incomplete partition demonstrated a good performance in speech perception tests. Even the child with the common cavity deformity had some open-set speech perception 1 year after implantation. CONCLUSIONS: Viewing the patients from this study and patients from a review of the literature concerning cochlear implantation in children with malformed inner ears including severe cochlear malformations, the occurrence of an aberrant facial nerve was 17%, which increases to 27% if one reviews the surgical findings in children with severe malformed cochleae such as a common cavity or a severe cochlear hypoplasia. In the latter patients, results in speech perception vary. Although the result of cochlear implantation may be promising, as in our patient with a common cavity, during preoperative counseling the child's parents must be informed that the result is uncertain.     

内耳结构异常患者人工耳蜗植入术的疗效观察

目的分析研究内耳结构异常患者人工耳蜗植入术的安全性及手术后的疗效情况。方法选取2011.07-2015.06在我院住院接受人工耳蜗植入的17例内耳结构异常患者的临床资料,其中语前聋14例,语后聋3例,针对内耳结构异常情况采用不同术式。用听觉分级行为标准(Categorise of Auditory Performance,CAP)、言语可懂度分级标准(Speech Intelligibility Rating,SIR)进行术后效果评估。选取24例同期接受人工耳蜗植入的内耳正常的语前聋患者作为对照组,分析并比较两组患者手术并发症及术后疗效。结果:17例患者手术顺利,术后出现1例眩晕,所有患者术后均无脑脊液耳漏、面瘫等并发症。内耳结构异常语前聋患者术后CAP和SIR值分别为5.8±1.4、3.5±1.1;对照组CAP和SIR值分别为6.9±1.3、3.8±0.9,两者差异无统计学意义(P>0.05)。结论内耳结构异常非人工耳蜗植入术的绝对禁忌证,根据异常程度制定个性化的手术方案,可以减少并发症的发生。内耳结构异常语前聋患者术后言语康复情况、对声音的自发性觉察能力与耳蜗形态正常患者术后无明显差异。     

The effect of hydrogen peroxide applied to the middle ear on inner ear function

OBJECTIVES/HYPOTHESIS: The objective was to assess the effect of hydrogen peroxide applied to the middle ear on cochlear and vestibular function. STUDY DESIGN: Prospective animal study. METHODS: Sand rats underwent a right-side total labyrinthectomy, and a polyethylene tube was inserted into the left-side middle ear. Following baseline recordings of vestibular evoked potentials in response to linear acceleration stimuli and auditory brainstem response, each experimental animal received five daily applications of hydrogen peroxide into the left-side middle ear. Two control groups received saline and gentamicin, respectively. Subsequently, recordings were repeated and compared with baseline measurements. RESULTS: Saline administration affected neither vestibular evoked potentials nor auditory brainstem response. In contrast, both responses could not be recorded following gentamicin application. After hydrogen peroxide administration, auditory brainstem response could not be recorded in 25% (3 of 12) of the animals, whereas in the remaining nine animals the average auditory brainstem response threshold was significantly elevated by 55 dB (P =.000002). Linear vestibular evoked potentials could not be recorded in 42% (5 of 12) of the animals. CONCLUSION: It appears that topical hydrogen peroxide adversely affects both cochlear and vestibular function of the sand rat. The study demonstrated the effect of a reactive oxygen species on inner ear function and may be useful in the study of mechanisms responsible for this damage and its protection. Clinically, although an animal model was used in the present study, caution should be exercised when large amounts of hydrogen peroxide are applied to a dry, perforated ear.     

Radiologic anatomy of the round window relevant to cochlear implantation and inner ear drug delivery

ObjectiveTo determine anatomic relationships and variation of the round window membrane to bony surgical landmarks on computed tomography.Study designRetrospective imaging review.Methods100 temporal bone images were evaluated. Direct measurements were obtained for membrane position. Vector distances and angulation from umbo and bony annulus were calculated from image viewer software coordinates.ResultsThe angle of round window membrane at junction with cochlear basal turn was (42.1 ± 8.6)°. The membrane''s position relative to plane of the facial nerve through facial recess was (14.7 ± 5.2)° posterior from a reference line drawn through facial recess to carotid canal. Regarding transtympanic drug delivery, the round window membrane was directed 4.1 mm superiorly from the inferior annulus and 5.4 mm anteriorly from the posterior annulus. The round window membrane on average was angled superiorly from the inferior annulus (77.1 ± 27.9)° and slightly anteriorly from the posterior annulus (19.1 ± 11.1°). The mean distance of round window membrane from umbo was 4 mm and posteriorly rotated 30° clockwise from a perpendicular drawn from umbo to inferior annulus towards posterior annulus. Together, these measurements approximate the round window membrane in the tympanic membrane''s posteroinferior quadrant.ConclusionsThese radiologic measurements demonstrate normal variations seen in round window anatomy relative to facial recess approach and bony tympanic annulus, providing a baseline to assess round window insertion for cochlear implantation and outlines anatomic factors affecting transtympanic drug delivery.