RESUMEN
UNLABELLED: Utriculostomy is a new surgical alternative for Ménière's disease. The basis of this procedure is that the outcome of an electrocautery-induced utricular trauma does not affect cochlear function. However, a demonstration of the hypothesis that this approach to the utricle would preserve hearing is still pending. OBJECTIVE: To determine whether any changes would occur in the electrical potentials evoked in the cochlea and auditory nerve before, during, and 1 month after a surgical procedure in the utricule in an animal model. MATERIALS AND METHODS: An experimental study. Eight sheep underwent electrocautery-induced utricular trauma, and their cochlear function was assessed by electrocochleography--recording of electrical evoked potentials, in the preoperative, immediate postoperative and medium-term postoperative periods. The results were analyzed statistically. RESULTS: There were no statistically significant variations in amplitude (p = 0.099) and latency (p = 0.591) before and 1 month after the surgical procedure. There was a statistically significant change in the summation of the potential/action potential area ratio (p = 0.0122), a calculated loss of 11.8 dB. CONCLUSION: The intervention performed in this study enabled us to conclude that, taking into account the impaired electrophysiological responses observed during and 1 month after the surgical procedure, hearing was preserved in the operated sheep.
Asunto(s)
Potenciales Evocados Auditivos , Pérdida Auditiva Sensorineural/etiología , Enfermedad de Meniere/cirugía , Sáculo y Utrículo/cirugía , Animales , Modelos Animales de Enfermedad , Electrocoagulación/efectos adversos , Femenino , Sáculo y Utrículo/fisiología , OvinosRESUMEN
A utriculostomia é uma nova alternativa cirúrgica para a doença de Ménière. A hipótese cirúrgica desse procedimento é a de que o desfecho de uma lesão do utrículo por eletrocauterização não interfere na função coclear. Contudo, a hipótese de que essa abordagem do utrículo preserva a audição ainda não foi comprovada. OBJETIVO: Determinar se ocorrem mudanças nos potenciais elétricos evocados na cóclea e no nervo auditivo antes, durante e 1 mês após o procedimento cirúrgico no utrículo em modelo animal. MATERIAIS E MÉTODOS: Estudo experimental: Oito ovelhas foram submetidas à lesão do utrículo por eletrocauterização e sua função coclear foi avaliada por meio de eletrococleografia, registrando-se os potenciais elétricos evocados nos períodos pré-operatório, pós-operatório imediato e pós-operatório de médio prazo. Os resultados foram analisados estatisticamente. RESULTADOS: Não houve variação estatisticamente significativa na amplitude (p = 0,099) e na latência (p = 0,591) antes e 1 mês após o procedimento cirúrgico. Houve alteração estatisticamente significativa na razão entre potencial de somação/potencial de ação (p = 0,0122), representando uma perda calculada de 11,8 dB. CONCLUSÃO: A intervenção realizada no utrículo neste estudo permite concluir que, tendo em conta respostas eletrofisiológicas deficientes observadas durante e 1 mês após o procedimento cirúrgico, houve preservação da audição nas ovelhas operadas.
Utriculostomy is a new surgical alternative for Ménière's disease. The basis of this procedure is that the outcome of an electrocautery-induced utricular trauma does not affect cochlear function. However, a demonstration of the hypothesis that this approach to the utricle would preserve hearing is still pending. OBJECTIVE: To determine whether any changes would occur in the electrical potentials evoked in the cochlea and auditory nerve before, during, and 1 month after a surgical procedure in the utricule in an animal model. MATERIALS AND METHODS: An experimental study. Eight sheep underwent electrocautery-induced utricular trauma, and their cochlear function was assessed by electrocochleography - recording of electrical evoked potentials, in the preoperative, immediate postoperative and medium-term postoperative periods. The results were analyzed statistically. RESULTS: There were no statistically significant variations in amplitude (p = 0.099) and latency (p = 0.591) before and 1 month after the surgical procedure. There was a statistically significant change in the summation of the potential/action potential area ratio (p = 0.0122), a calculated loss of 11.8 dB. CONCLUSION: The intervention performed in this study enabled us to conclude that, taking into account the impaired electrophysiological responses observed during and 1 month after the surgical procedure, hearing was preserved in the operated sheep.
Asunto(s)
Animales , Femenino , Potenciales Evocados Auditivos , Pérdida Auditiva Sensorineural/etiología , Enfermedad de Meniere/cirugía , Sáculo y Utrículo/cirugía , Modelos Animales de Enfermedad , Electrocoagulación/efectos adversos , Ovinos , Sáculo y Utrículo/fisiologíaRESUMEN
The objective of this study was to develop and test an endolabyrinthic microsurgical procedure for treatment of vertigo, the utriculostomy. This involves the application of local heat for obtaining a fistula in the membranous labyrinth, so as to establish communication between the endolymphatic and perilymphatic spaces at the utricle level. Before the procedure, an experimental model using quail eggs was built for pre-evaluation, and macroscopic and histological studies were performed in the temporal bones of three healthy sheep. Following this, the utriculostomy was performed through the oval window in 12 sheep. A microthermocautery was conceived by the first author and developed at Hospital de Clinicas de Porto Alegre. This equipment allows for control of temperature and duration of exposure to heat. Three months after the surgery, the animals were killed. A histological study of the temporal bones was performed to assess whether communication had been created between the endolymphatic and perilymphatic spaces, or whether a neomembrane had developed in the cauterized region. Histological sections of the vestibule of eight animals (three normal, five surgical) were analysed. All non-surgical cases presented a normal utricle wall. Three surgical cases (60%) presented a neomembrane. The absence of identifiable perforations in the utricle wall and the presence of neomembrane areas in 60% of the operated bones suggest that utriculostomy is a promising procedure for the treatment of Meniere's disease.
Asunto(s)
Sáculo y Utrículo/cirugía , Vértigo/cirugía , Animales , Modelos Animales de Enfermedad , Electrocoagulación/instrumentación , Electrocoagulación/métodos , Endolinfa , Anastomosis Endolinfática , Calor , Masculino , Enfermedad de Meniere/cirugía , Microcirugia/instrumentación , Microcirugia/métodos , Ventana Oval/cirugía , Perilinfa , Codorniz , Sáculo y Utrículo/patología , Ovinos , Hueso Temporal/patología , Hueso Temporal/cirugía , Factores de Tiempo , Vestíbulo del Laberinto/patología , Cicatrización de HeridasRESUMEN
Objetivo: apresentar uma nova técnica alternativa para o tratamento cirúrgico de vertigem causada pela Doença de Menière, a utriculostomia, desenvolvida no HCPA...
Asunto(s)
Animales , Vértigo/etiología , Vértigo/cirugía , Enfermedad de Meniere/complicaciones , Sáculo y Utrículo/cirugía , OvinosRESUMEN
Cochleosacculotomy has been described as a simple, efficacious treatment for relief of vertigo in patients with Meniere's disease in whom medical therapy has failed. We reviewed records of 11 elderly patients with good vestibular function who were thought to be ideal candidates for this procedure. Average follow-up was 17 months. Contrary to previous reports, long-term control of vertigo was poor, and more than 80% of the patients suffered a significant hearing loss from this procedure. Four of 11 patients required a second surgical procedure to control their vertigo. Audiometric measures revealed statistically significant postoperative increases in puretone thresholds at all frequencies and speech reception threshold, and a decrease in discrimination scores. Based on the results of this study, we no longer plan to use cochleosacculotomy for the treatment of elderly patients with Meniere's disease.