Auditory Brainstem Implant: surgical technique and early audiological results in patients with neurofibromatosis type 2

O implante auditivo de tronco cerebral foi desenvolvido para restaurar alguma audição útil em pacientes que apresentam ausência de nervo coclear bilateralmente. OBJETIVOS: Discutir a indicação, cirurgia e resultados em quatro pacientes submetidos à cirurgia para colocação de implante auditivo de tronco cerebral. CASUÍSTICA E MÉTODOS: Quatro pacientes com diagnóstico de schwannomas vestibulares bilaterais foram submetidos à cirurgia para colocação de Implante Auditivo de Tronco Cerebral durante o mesmo ato cirúrgico utilizado para a exérese de um dos tumores. Aspectos clínicos e técnicos e as referências anatômicas da cirurgia e os resultados auditivos foram analisados. RESULTADOS: Em todos os casos foram identificados as referências anatômicas ao forame de Luschka. As complicações cirúrgicas se resumiram à fístula liquórica em dois pacientes. Os eletrodos foram bem posicionados e a sensação auditiva foi suficiente para reconhecimento de sons e auxílio à leitura labial. CONCLUSÃO: Os resultados auditivos de nossos pacientes abrem uma perspectiva importante aos pacientes com surdez profunda bilateral sem integridade anatômica das vias auditivas centrais.Auditory Brainstem Implants were developed to partially restore the hearing capabilities of patients without cochlear nerves bilaterally. AIM: this paper aims to discuss the clinical and surgical findings of four ABI patients. MATERIALS AND METHOD: four patients diagnosed with bilateral schwannomas received auditory brainstem implants (ABI) and had one of their tumors resected in the same surgical procedure. Clinical aspects, surgical technique, anatomic landmarks, and outcomes were analyzed. RESULTS: the anatomic landmarks were identified in all four patients in relation to the foramina of Luschka. Two patients had CSF leaks. The electrodes were well positioned and hearing sensation was good enough to allow for sound recognition and assist patients perform lip reading. CONCLUSION: the outcomes observed in our patients were quite encouraging and offer great perspectives for those suffering from deep bilateral deafness and impaired central auditory pathways

Cochlear implant: correlation of nerve function recovery, auditory deprivation and etiology

TEMA: a Função de Recuperação do Nervo Auditivo (REC) pode ser extraída do potencial de ação das fibras neurais - ECAP (Eletrically Evoked Compound Action Potential). O ECAP pode ser influenciado pela estimulação recebida pelo nervo e pela etiologia de uma perda auditiva e, consequentemente, afetar a REC. OBJETIVO: verificar se há correlação entre REC e os fatores: etiologia, tempo de surdez e tempo de uso do AASI antes do Implante Coclear (IC). MÉTODO: estudo retrospectivo transversal. Foram coletados dados sobre etiologia, tempo de surdez, tempo de uso do Aparelho de Amplificação Sonora Individual (AASI) e REC de 50 indivíduos, 26 crianças e 24 adultos, submetidos à cirurgia de IC e usuários do dispositivo multicanal Nucleus®24. As medidas da função de recuperação do nervo auditivo foram calculadas e os pacientes foram divididos em grupos (GI: recuperação rápida, GII: recuperação intermediária e GIII: recuperação lenta) para posterior análise de relação com os demais dados coletados. RESULTADOS: a análise dos dados não mostrou correlação estatisticamente significante entre a recuperação e os aspectos pré-cirúrgicos estudados. Entretanto, foi possível observar maior concentração de ambos, crianças e adultos, nas REC intermediárias. GI não agrupou indivíduos com surdez de etiologias infecciosas, tais como a meningite, rubéola e citomegalovírus. A média de REC apresentou-se mais lenta para as etiologias infecciosas, tanto para o grupo de crianças, como para o grupo de adultos. CONCLUSÃO: não houve correlação estatisticamente significante entre função de recuperação do nervo auditivo e os fatores: etiologia, tempo de surdez e tempo de uso do AASI antes do IC.BACKGROUND: the Auditory Nerve Recovery Function (REC) may be extracted from the Electrically Evoked Compound Action Potential (ECAP). ECAP may be influenced by the stimulation received (or the deprivation of stimulation) and by the etiology of the hearing loss, consequently it might affect the REC. AIM: to verify whether there is a correlation between the REC and each of the following factors: etiology, time of auditory deprivation and time of hearing aid use before cochlear implantation (CI). METHOD: retrospective study. Data regarding etiology, time of auditory deprivation, time of hearing aid use before cochlear implantation were collected in children and adults who received a Nucleus®24. All patients who presented neural response at surgery and whose REC was assessed intraoperatively were included in this study. Fifty patients were selected, 26 children and 24 adults. Patients were divided according to the REC classification into three groups (GI: fast recovery; GII: intermediate recovery and GIII: slow recovery) to allow correlation analysis. RESULTS: data analysis did not show any statistically significant correlation between the recovery function and the pre-implant studied characteristics. Nevertheless, it was observed that there was a greater concentration of both, children and adults, in the intermediate recovery function values. GI did not present individuals with infectious etiologies, such as meningitis, rubella and cytomegalovirus. REC average scores were slower in infectious etiologies for both children and adults. CONCLUSION: there was no statistically significant correlation between the recovery function and factors such as etiology, time of auditory deprivation and time of hearing aid use prior to CI

Fitting hearing aid in patients candidate for cochlear implants

PURPOSE: to characterize the audiometric and demographic profile of cochlear implant candidates who were referred to hearing aid sector, and if they benefit from the amplification of the hearing aid. METHODS: patients who had been attended from May 2007 to December 2008 were studied. We collected the patients' profile involving: gender, age, education and etiology. The hearing threshold's average for the good and worse ears was calculated and classified according to Frota (2003). The averaged sound field thresholds with hearing aid was calculated for both ears and considered as a benefit when allowed for an access to the speech sounds of Brazilian Portuguese. RESULTS: a hundred and ninety-four medical records were evaluated in this period. Among them, 108 patients had already been wearing hearing aids (55.6%), 100 were male (52%), 94 female (48%), 109 were children (56%) and 85 adults (44%). The average age was 4.8year old for children and 41.9-year old for adults. Among the adults, 24 patients had incomplete high school education (33%). Unknown etiology was the most frequent cause (33%). Nineteen patients have benefited from the use of hearing aids (10%). The averaged sound field thresholds with hearing aid was 47 dBHL and 48 dBHL, in best and worse ears, respectively, for children, and 50 dBHL and 45 dBHL, respectively, for adults. CONCLUSIONS: the profile of the patients was: majority of children, males, unknown etiology, previously hearing aid users, average of age 4.8-year old for children and 41.9 for adults. Pure tone thresholds revealed profound bilateral hearing loss. About 10% of patients were benefited with the use of hearing aids.OBJETIVO: caracterizar o perfil audiométrico e demográfico de pacientes candidatos ao implante coclear encaminhados ao setor de prótese auditiva e entre esses, a frequência de indivíduos que se beneficiaram da amplificação sonora. MÉTODOS: foram estudados os pacientes atendidos no período de maio de 2007 a dezembro 2008. Foi realizado o levantamento do perfil da população segundo sexo, idade, escolaridade e etiologia. Foi calculada a média da melhor e pior orelha e classificada segundo Frota (2003). A média dos limiares auditivos com as próteses auditivas indicadas foi calculada e considerada como benefício quando permitia acesso aos sons da fala do português brasileiro (Russo e Behlau, 1993). RESULTADOS: foram avaliados nesse período 194 prontuários. 108 pacientes já eram usuários de próteses auditivas (55,6%), 100 do sexo masculino (52%), 94 do sexo feminino (48%), 109 eram crianças (56%) e 85 eram adultos (44%). A média de idade foi 4,8 anos (crianças) e 41,9 anos (adultos). Entre os adultos, 24 possuíam ensino fundamental incompleto (33%). A etiologia mais frequente foi a desconhecida (33%). Dezenove pacientes se beneficiaram do uso da prótese auditiva (10%). No grupo de pacientes que se beneficiaram da prótese auditiva, a média dos limiares em campo livre com amplificação foi de 47 dBNA e 48 dBNA, na melhor e na pior orelha, respectivamente, nas crianças e 50 dBNA e 45 dBNA, respectivamente, nos adultos. CONCLUSÃO: o perfil dos pacientes foi: na maioria criança, sexo masculino, etiologia desconhecida, já usuários de próteses auditivas com média de idade 4,8 anos (crianças) e 41,9 anos (adultos), audiometria com perda auditiva neurossensorial profunda bilateral, sendo que a prótese beneficiou 10% dos pacientes.Universidade de São PauloUniversidade Federal de São Paulo (UNIFESP)Universidade de São Paulo Faculdade de Medicina Hospital das ClínicasUNIFESPSciEL

Caloric test and video head impulse test sensitivity as vestibular impairment predictors before cochlear implant surgery

OBJECTIVES: Currently, cochlear implant procedures are becoming increasingly broad and have greatly expanded. Bilateral cochlear implants and cochlear implants are more frequently applied in children. Our hypothesis is that the video head impulse test may be more sensitive than the caloric test in detecting abnormal vestibular function before cochlear implant surgery. The objective of this study was to compare the video head impulse test and caloric test results of patients selected for cochlear implant procedures before surgery. METHODS: The patients selected for cochlear implant surgery were submitted to a bithermal caloric test and video head impulse test. RESULTS: By comparing angular slow phase velocity values below 5o in the bithermal caloric test (hypofunction) and video head impulse test with a gain lower than 0.8, we identified 37 (64.9%) patients with vestibular hypofunction or canal paresis and 21 (36.8%) patients with abnormal video head impulse test gain before the cochlear implant procedure. Of the 37 patients with caloric test vestibular hypofunction, 20 (54%) patients exhibited an abnormal gain in the video head impulse test. CONCLUSION: The caloric test is more sensitive than the video head impulse test (Fisher’s exact test, p=0.0002) in detecting the impaired ear before cochlear implant delivery. The proportion of caloric test/video head impulse test positive identification of abnormal vestibular function or caloric test/video head impulse test sensitivity was 1.8:1

Caloric test and video head impulse test sensitivity as vestibular impairment predictors before cochlear implant surgery

OBJECTIVES: Currently, cochlear implant procedures are becoming increasingly broad and have greatly expanded. Bilateral cochlear implants and cochlear implants are more frequently applied in children. Our hypothesis is that the video head impulse test may be more sensitive than the caloric test in detecting abnormal vestibular function before cochlear implant surgery. The objective of this study was to compare the video head impulse test and caloric test results of patients selected for cochlear implant procedures before surgery. METHODS: The patients selected for cochlear implant surgery were submitted to a bithermal caloric test and video head impulse test. RESULTS: By comparing angular slow phase velocity values below 5o in the bithermal caloric test (hypofunction) and video head impulse test with a gain lower than 0.8, we identified 37 (64.9%) patients with vestibular hypofunction or canal paresis and 21 (36.8%) patients with abnormal video head impulse test gain before the cochlear implant procedure. Of the 37 patients with caloric test vestibular hypofunction, 20 (54%) patients exhibited an abnormal gain in the video head impulse test. CONCLUSION: The caloric test is more sensitive than the video head impulse test (Fisher’s exact test, p=0.0002) in detecting the impaired ear before cochlear implant delivery. The proportion of caloric test/video head impulse test positive identification of abnormal vestibular function or caloric test/video head impulse test sensitivity was 1.8:1

Speech perception and audiometry thresholds in Nucleus cochlear 22 and Nucleus 24 implant users

INTRODUÇÃO: Clinicamente observa-se contribuição da tecnologia do implante coclear (IC) Nucleus 24 (N24). A confirmação dessa evidência seria importante pois afeta diretamente os critérios de indicação do implante coclear. OBJETIVO: Verificar a contribuição da atualização da tecnologia do IC sobre limiares audiométricos e desempenho na percepção de sentenças após 12 meses de uso do implante. MÉTODO: Estudo retrospectivo de corte transversal, com coleta em banco de dados. Critérios de seleção: idade igual ou superior a 18 anos, uso do dispositivo de IC N22 ou N24, tempo de privação auditiva até 20 anos, cuja etiologia da surdez não seja meningite. A amostra foi dividida em G22 (usuários do N22), e G24 (usuários do N24). Os grupos foram comparados em relação aos resultados no teste de percepção de sentenças no silêncio e limiares audiométricos após 12 meses de uso. RESULTADOS: Dos 84 pacientes adultos selecionados, 54 preencheram os critérios de seleção, sendo 13 usuários de N22 e 41 usuários de N24. Não houve diferença estatisticamente significante entre resíduo auditivo pré-operatório e tempo de privação auditiva dos usuários do N22 e N24. Os usuários do N24 apresentaram melhores médias nos limiares audiométricos, mas os testes de percepção de sentenças no silêncio não indicaram diferença entre modelos. CONCLUSÃO: A contribuição da tecnologia foi evidenciada apenas nos limiares audiométricos. Novos estudos estão sendo conduzidos para avaliar a contribuição da tecnologia na percepção de fala em situações auditivas mais difíceis.INTRODUCTION: Clinically it was observed the contribution of the Nucleus 24 (N24) cochlear implant (CI) technology. The confirmation of this evidence would be important because it affects directly the indication criteria of the cochlear implant. OBJECTIVE: To verify the contribution of the technologys updating of the CI about the auditory thresholds and the performance in the perception of sentences after 12 mouths of implant use. METHOD: A retrospective, cross-sectional study with database collection. Selection criteria: age equal or higher than 18 years old, CI N22 or N24 device use, auditory privation time until 20 years, which deafness etiology does not be meningitis. The sample was divided into G22 (N22 users), and G24 (N24 users). The groups were compared concerning the result in the sentences perception test in the silence and audiometric thresholds after 12 mouths of use. RESULTS: From 84 adults patients selected, 54 filled the selection criteria, being 13 users of N22 and 41 users of N24. There was no difference statistically significant between preoperative auditory residues and time of auditory privation of the N22 and N24 users. The N24 users presented best averages in the audiometric thresholds, but the sentences perception tests in the silence do not indicated difference between models. CONCLUSION: The contribution of the technology was evidenced only in the auditory thresholds. News studies are being performed in order to evaluate the technology contribution in the speech perception in auditory situations more difficult

Alpha-tricalcium phosphate bone cement in the surgical treatment of mastoid cavity. Experimental study

Introdução: A mastoidectomia cavidade aberta é considerada por muitos autores o procedimento cirúrgico de escolha para o tratamento da otite média colesteatomatosa, devido à alta incidência de recidiva da doença. Porém, a formação desta cavidade única pode gerar algumas complicações e a obliteração da cavidade mastóidea é uma técnica descrita e estudada para a eliminação desta cavidade. Materiais aloplásticos têm sido estudados em cirurgias de obliteração da cavidade mastóidea, porém estes materiais podem apresentar problemas de biocompatibilidade e de rejeição O cimento de osso alfa -tricálcio-fosfato é um material composto por cálcio e fosfato e apresenta composição bioquímica semelhante à fase mineral do osso. Embora já utilizado em cirurgias há mais de 10 anos, não existem estudos sobre a sua aplicação nas cirurgias de obliteração de cavidade mastóidea na literatura. Objetivo: Estudar a biocompatibilidade do cimento de osso alfatricálcio- fosfato na obliteração da cavidade mastóidea em guinea pigs. Casuística e Métodos: Vinte Cavia porcellus (guinea pig) fêmeas foram submetidos a procedimento cirúrgico na bula timpânica esquerda. Em 10 cobaias (grupo cimento) a bula timpânica foi obliterada com o cimento de osso alfa-tricálcio-fosfato e em 10 cobaias (grupo controle) a cavidade foi deixada sem preenchimento. 60 dias após o procedimento os animais foram sacrificados e avaliados quanto à presença de sinais clínicos de rejeição ao material e outras complicações. Os ossos temporais foram removidos e submetidos à análise histopatológica. Foram avaliados o tipo e o grau de resposta inflamatória e o grau de ossificação. Resultados: A taxa de mortalidade foi igual em ambos os grupos. As mortes foram atribuídas a complicações anestésicas. Entre as cobaias que completaram o estudo não foram observados sinais de complicações em nenhum caso. Oito animais (100%) do grupo cimento em e cinco animais (62,5%) apresentaram resposta inflamatório graus I e II que correspondem histopatologicamente a alterações cicatriciais normais ao procedimento cirúrgico. Não foi observado presença de reação inflamatória crônica tipo corpo estranho em nenhuma amostra de ambos os grupos. Quanto ao grau de ossificação, a média dos escores de ossificação no grupo controle (3,5) foi maior que o observado no grupo cimento (1,0). O grupo controle (3,5 ± 5) apresentou grau de ossificação estatisticamente maior quando comparado com o grupo cimento (1,0 ± 0,0) (p < 0,01). Conclusões: 1) O cimento de osso alfa-tricálciofosfato é biocompatível em osso temporal de cobaia. 2) O cimento de osso alfa-tricálcio-fosfato sofre remodelação óssea, porém não apresenta propriedade de osteoconduçãoIntroduction: Many authors consider open cavity mastoidectomy the surgical procedure of choice for the treatment of otitis media with cholesteatoma, due to the high incidence of recurrence of the disease. However, the formation of this open cavity can generate some complications and mastoid cavity obliteration is one type of technique for the elimination of this cavity. Alloplastic materials have been testes in mastoid cavity obliteration, however such materials can present problems of biocompatibility and rejection. Alphatricalcium phosphate bone cement is a material compose of calcium and phosphate and presents physicochemical characteristics similar to the bone mineral fase. Although it has been used for more than 10 years, there are no studies in the literature on its application in mastoid cavity obliteration. Objective: This study aimed to evaluate the biocompatibility of alphatricalcium phosphate bone cement in the obliteration of the mastoid cavity in guinea pigs. Methods: We studied 20 Cavia porcellus (guinea pig) submitted to surgical manipulation of the left dorsal tympanic bulla. In the study group animals (n = 10), mastoid cavity obliteration was conducted with alphatricalcium phosphate bone cement. In the control group animals (n = 10), the cavity was left unfilled. On postoperative day 60, the animals were sacrificed and studied for signs of rejection of the material and other complications. Temporal bones were removed for histopathological study, in which the type and degree of inflammatory response, as well as the degree of ossification, were analyzed. Results: The mortality rate was the same in both groups. Deaths were attributed to anesthetic complications in the initial postoperative period. In the animals that survived, there were no complications. The histological analysis of the degree and type of inflammatory response shown no signs of foreign body in both groups, 8 (100%) of the samples in cement group and 5 (62,5%) of the samples in control group presenting category I or II inflammatory responses that corresponds histopathologically to an inflammatory response that normally occurs in tissues submitted to surgical trauma. There were no histopathological signs of foreign body reaction in none samples of both groups. As for the study of the degree of ossification, the mean ossification in the control group (3.5) was greater than that shown by the cement group (1.0). The control group showed statistically significant (p < 0.01) higher degrees of ossification (mean 3.5 ± 0.5) when compared to the cement group (1.0 ± 0.0). Conclusion: 1) Alpha-tricalcium phosphate bone cement is biocompatible in the mastoid cavity of guinea pigs 2) Alphatricalcium fosfato bone cement undergoes bone remodeling but it doesn´t present osteoconductive propertie

Inside-Out Transcanal Endoscopic Mastoidectomy: Literature Revision

Introduction Recently, there have been significant advancements in transcanal endoscopic ear surgery (TEES). The combination of rigid and thin otoendoscopes with high-definition cameras enabled a less invasive transcanal access to the middle ear and a clearer view of the surgical field. Several surgeons have recently published studies about cholesteatoma resection via transcanal endoscopic surgery, even in cases where the disease has extended to the mastoid, requiring transcanal endoscopic mastoidectomy. Objectives To analyze the currently available literature on transcanal endoscopic inside-out mastoidectomy, and to determine its efficacy as a surgical technique by evaluating the disease's relapse/recurrence rate. Data Synthesis Initially, the titles and abstracts of articles identified were analyzed. At this stage, 117 articles were analyzed, 97 of which were excluded for not meeting the inclusion criteria. The 20 remaining articles were further evaluated. The articles were classified on the basis of five levels of scientific evidence. Final Comments The analysis of the studies showed that the transcanal endoscopic approach is effective in providing access to the attic or antrum, especially in cases of sclerotic mastoids. There was only one study with grade A recommendation, which showed the efficacy of endoscopic ear surgery in the treatment of cholesteatoma. Furthermore, there were three studies with grade B recommendation, showing less relapse/recurrence after TEES. More studies with grade A and B recommendations are needed to better evaluate the effectiveness of TEES, especially compared with that of traditional microscopic surgery

Use of alpha-tricalcium phosphate bone cement in the surgical treatment of mastoid cavity

Introduction: Open cavity mastoidectomy can generate some complications and mastoid cavity obliteration is a technique described and studied for the elimination of this cavity. Alloplastic materials have been studied in mastoid cavity obliteration surgery. Alpha-tricalcium phosphate bone cement is a material composed by calcium and phosphate and presents biochemical characteristics similar to the bone mineral phase. Objective: This study is aimed at evaluating the biocompatibility of alpha-tricalcium phosphate bone cement in the obliteration of the mastoid cavity in guinea pigs. Methods: 20 guinea pigs were submitted to surgical procedure. In 10 cement study group animals, the tympanic bulla was obliterated with alpha-tricalcium phosphate bone cement and in 10 guinea pigs (control group), the cavity was left unfilled. The animals were evaluated for clinical signs of material rejection and other complications. The temporal bones were removed and analyzed as for the type and degree of inflammatory response, as well as the degree of ossification. Results: In the animals that completed the study, there were no complications. There were not either the presence of foreign body inflammatory reaction in none of the samples of both groups. As for the ossification degree, the average ossification scores in the control group (3.5) was greater than that shown by the cement group (1.0). Conclusions: 1) The alpha-tricalcium phosphate bone cement is biocompatible in guinea pig's temporal bone 2) The alphatricalcium phosphate bone cement undergoes bone remodeling, but it doesn´t present osteoconductive properties