The endoscopic transcanal approach to the internal auditory canal: an anatomic study.

PURPOSE: The internal auditory canal (IAC) plays a key role in lateral skull base surgery. Although several approaches to the IAC have been proposed, endoscope-assisted transcanal corridors to the IAC have rarely been studied. We sought to provide a step-by-step description of the transcanal transpromontorial approach to the IAC and analyze anatomic relationships that might enhance predictability and safety of this approach. METHODS: Ten cadaveric specimens were dissected and the extended transcanal transpromontorial approach to the IAC was established. Various morphometric measurements and anatomic landmarks were reviewed and analyzed. RESULTS: The proposed technique proved feasible and safe in all specimens. There was no inadvertent injury to the jugular bulb or internal carotid artery. The chorda tympani, a key landmark for the mastoid segment of the facial nerve, was identified in all dissections. The spherical recess of the vestibule and middle turn of cochlea are important landmarks for identification of the labyrinthine segment of the facial nerve. Identification of all boundaries of the working area is also essential for safe access. Among various morphometric measurements, the modiolus-IAC angle (≈ 150°) proved particularly consistent; given its ease of use and low variability, we believe it could serve as a landmark for identification and subsequent dissection of the IAC. CONCLUSIONS: The extended transcanal transpromontorial approach to the IAC is feasible and safe. Relying on anatomic landmarks to ensure preservation of the involved neurovascular structures is essential for a successful approach. The modiolus-IAC angle is a consistent, reproducible landmark for IAC identification and dissection.

Comparação da abordagem endoscópica transcanal e microscópica na timpanoplastia tipo 1

Resumo Introdução: A timpanoplastia endoscópica é uma cirurgia minimamente invasiva que pode ser feita através de uma abordagem exclusivamente transcanal. O uso de endoscópios em procedimentos otológicos tem aumentado no mundo todo. A abordagem endoscópica facilita a timpanoplastia transcanal mesmo em pacientes com canal auditivo externo estreito e com uma protrusão da parede anterior. Objetivos: O presente estudo teve como objetivo comparar os resultados cirúrgicos e audiológicos das abordagens endoscópica transcanal e microscópica convencional na timpanoplastia tipo 1. Método: As taxas de sucesso do enxerto, os resultados auditivos, as complicações e a duração da cirurgia em pacientes submetidos a timpanoplastia endoscópica e microscópica entre outubro de 2015 e abril de 2018 foram analisados retrospectivamente. Resultados: As taxas de sucesso do enxerto foram de 94,8% e 92,9% para o grupo endoscópico e microscópico, respectivamente (p > 0,05). Os valores de gap aéreo-ósseo no pós-operatório melhoraram significantemente em ambos os grupos (p < 0,001). A duração média da cirurgia foi significantemente menor no grupo endoscópico (média de 34,9 minutos) em relação ao grupo microscópico (média de 52,7 minutos) (p < 0,05). O tempo médio de internação foi de 5,2 horas (variação de 3-6 horas) no grupo operado por endoscopia e de 26,1 horas (variação de 18-36 horas) no operado por microscopia (p < 0,05). Conclusão: A timpanoplastia transcanal via endoscópica é uma opção razoável à timpanoplastia microscópica convencional no tratamento da otite média crônica, com taxas de sucesso de enxertos e resultados auditivos comparáveis à microscópica.

Comparison of endoscopic transcanal and microscopic approach in Type 1 tympanoplasty.

INTRODUCTION: Endoscopic tympanoplasty is a minimally invasive surgery that may be performed via a solely transcanal approach. The use of endoscopes in otologic procedures has been increasing worldwide. The endoscopic approach facilitates the transcanal tympanoplasty, even in patients having the narrow external ear canal with an anterior wall protrusion. OBJECTIVES: The present study aimed to compare the surgical and audiological outcomes of endoscopic transcanal and conventional microscopic approach in Type 1 tympanoplasty. METHODS: The graft success rates, hearing outcomes, complications, and duration of surgery in patients who underwent endoscopic and microscopic tympanoplasty between October 2015 and April 2018 were retrospectively analysed. RESULTS: Graft success rates were 94.8 per cent and 92.9 per cent for the endoscopic and microscopic group, respectively (p >  0.05). Postoperative air-bone gap values were improved significantly in both groups (p <  0.001). The average duration of surgery was significantly shorter in the endoscopic group (mean 34.9 min) relative to the microscopic group (mean 52.7 min) (p <  0.05). The average hospitalization period was 5.2 h (range 3-6 h) in Group I whereas it was 26.1 h (range 18-36 h) in Group II (p <  0.05). CONCLUSION: The endoscopic transcanal tympanoplasty approach is a reasonable alternative to conventional microscopic tympanoplasty in the treatment of chronic otitis media, with comparable graft success rates and hearing outcomes.

Disección cadavérica endoscópica de oído medio / Endoscopic cadaver dissection of middle ear / Dissecção endoscópica de orelha média em cadáveres

El avance tecnológico en los últimos tiempos ha permitido la creación de nuevos abordajes quirúrgicos. En este sentido surge el endoscopio como elemento capaz de ofrecer una gran visualización de los diferentes accidentes anatómicos de la cavidad timpánica sin necesidad de resecar tejido óseo circundante, ofreciendo de alguna manera la posibilidad de resolver patologías otológicas mediante un abordaje mínimamente invasivo. En este trabajo se demuestran los diferentes pasos de la disección cadavérica endoscópica de oído con el fin de facilitar al cirujano en formación el inicio en la materia.

Technological advances during the last time have enabled the creation of new surgical approaches. Endoscopic surgery comes out in this sense as an element capable of offering great visualisation of the different anatomical structures within the tympanic cavity without the need of removing surrounding bone structure bringing the possibility of treating otological pathology with a minimum invasive approach. In this paper the different steps to cadaveric disection are shown in order to initiate the novel surgeon in the subject.

O avanço tecnológico nos últimos tempos tem permitido a criação de novas abordagens cirúrgicas. Neste sentido surge o endoscópio como elemento capaz de oferecer uma visualização de diferentes acidentes anatômicos da cavidade timpânica sem necessidade de ressecar tecido ósseo circundante, oferecendo de alguma maneira a possibilidade de resolver patologias otológicas usando uma abordagem minimamente invasiva. Neste trabalho se mostra as diferentes etapas da dissecção endoscópica de ouvido com o fim de facilitar o cirurgião em formação o início na matéria.

Experiencia en miringoplastía transcanal con pericondrio tragai inlay / Experience in transcanal myringoplasty with inlay tragal perichondrium

Introducción: La timpanoplastía está orientada a la reconstrucción anatomofuncional del oído medio que realizada en la membrana timpánica se denomina miringoplastía. Objetivo: Evaluar los resultados anatomofuncionales de la miringoplastía transcanal con pericondrio tragal inlay en pacientes intervenidos en el Servicio de Otorrinolaringología del Hospital San Camilo entre 2004 y 2009. Material y método: Estudio retrospectivo descriptivo de fichas de 56 pacientes entre 7 y 77 años. Universo: 60 oídos, muestra: 48 oídos con edad promedio de 34 años. Se evaluaron resultados anatómicos según sexo, edad, ubicación, causa de perforación y mejoría funcional objetivada por audiometría. Resultados: La integridad anatómica posquirúrgica es de 81,3% sin diferencias según género. Según edad existe diferencia significativa de 93,3% para el tramo 7-19 años respecto del total. Las perforaciones centrales tuvieron un éxito de 100%. La causa más frecuente de perforación fue por otitis media crónica simple (75%) con una integridad posquirúrgica del 80,5%. El 97,6% logró mejorar o mantener el nivel de audición, estableciéndose diferencialmente mejoría funcional en 52,4%, y una mantención en 45,2%. Conclusión: Los mejores resultados para esta técnica se obtienen en menores de 20 años con perforaciones centrales, siendo una técnica ideal que conserva la estructura de la membrana timpánica para futuras intervenciones.

Introduction: Tympanoplasty is orientated to the anatomofunctional reconstruction of the middle ear, which is named myringoplasty, when performed in the tympanic membrane. Aim: To evaluate the anatomofunctional results of transcanal myringoplasty with inlay tragal perichondrium in patients controlled in the Otorhinolaryngology Unit of San Camilo Hospital, between 2004 and 2009. Material and method: Retrospective descriptive study on files of 56 patients between 7 and 77 years of age. Universe: 60 ears, sample: 48 ears with average age 34 years. Anatomical results were evaluated according to sex, age, location, cause of perforation and functional improvement measured by audiometry. Results: The overall anatomical postsurgical integrity is 81,3 % without differences between sexes. According to age there is a significant difference for the section between 7-19 years of age respect of the total (93,3 %). Central perforations had a 100% success rate. The most frequent reason of perforation was simple chronic otitis media (75%) with a postsurgical integrity of 80,5 %. 97,6 % managed to improve or maintain hearing level, (52,4 % gained functional improvement, and 45,2 % maintained hearing level). Conclusion: Using this technique, best results are obtained in patients younger than 20 years of age, with central perforations. It is an ideal method that preserves the structure of the tympanic membrane for future interventions.