RESUMEN
OBJECTIVES/HYPOTHESIS: The aim of cochlear implantation is to safely insert an electrode array into the scala tympani (ST) while avoiding damage to surrounding structures. There is disagreement on the optimal way of entering the ST-the round window (RW) approach versus cochleostomy. Regardless of the chosen approach, it is vital to understand the regional anatomy, which is complex, difficult to conceptualize, and rarely dissected in temporal bone courses. The goal of this study was to examine the anatomy of the RW to gain more in-depth knowledge on the local relationships of the anatomical structures and propose an approach for entering the ST in cochlear implant surgery tailored to the encountered anatomy. STUDY DESIGN: Cadaveric prevalence study and expert opinion with literature review. METHODS: Cadaveric temporal bone dissection (n = 13) by the first author assessing the RW anatomy. RESULTS: The round window membrane (RWM) and the osseous spiral lamina (OSL) are curved structures, each with a horizontal and a vertical part. The two horizontal portions are very closely apposed. The relationship between the OSL and the RWM determines the best site for a cochleostomy, which if required is best placed anteroinferiorly to the RWM. The distance between the oval window inferior margin and the RW membrane is less than 2 to 3 mm. The ST initially extends inferiorly and medially to the RW. CONCLUSIONS: The findings of our dissection have implications for cochlear implant surgery in aiming to avoid trauma to the OSL and basilar membrane and aid decision making in choosing the safest surgical approach. LEVEL OF EVIDENCE: 5. Laryngoscope, 131:E598-E604, 2021.
Asunto(s)
Ventana Redonda/anatomía & histología , Rampa Timpánica/anatomía & histología , Cóclea/cirugía , Acueducto Coclear/anatomía & histología , Acueducto Coclear/cirugía , Acueducto Coclear/ultraestructura , Implantación Coclear/métodos , Humanos , Ventana Redonda/cirugía , Ventana Redonda/ultraestructura , Rampa Timpánica/cirugía , Rampa Timpánica/ultraestructura , Hueso Temporal/anatomía & histología , Hueso Temporal/cirugía , Hueso Temporal/ultraestructuraRESUMEN
OBJECTIVE: To demonstrate that cartilage interposition between the head of a titanium prosthesis and the tympanic membrane is not necessary to prevent extrusion. STUDY DESIGN: Retrospective review. SETTING: District general hospital. PATIENTS: A retrospective review of 73 ears in patients aged between 5.9 and 64.5 years, which had an ossiculoplasty performed using a titanium prosthesis between the stapes footplate or stapes head and the tympanic membrane. INTERVENTIONS: Use of Spiggle and Theis two part, shortenable titanium PORP and TORP and Grace Alto titanium TORP and PORP. MAIN OUTCOME MEASURES: Number of extruded prostheses. Audiometric results. RESULTS: Five extrusions occurred in 4 patients, follow-up between 6 and 98 months. Extrusions were related to retraction of the tympanic membrane around the prosthesis. Audiometric results compared favorably with other ossiculoplasty techniques. CONCLUSION: The titanium head of the Spiggle and Theis and Grace Alto titanium prostheses interact well with the undersurface of the tympanic membrane in patients with favorable middle ear conditions. In our experience, cartilage interposition is not mandatory.
Asunto(s)
Cartílago/cirugía , Prótesis Osicular , Reemplazo Osicular/métodos , Diseño de Prótesis , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Titanio , Resultado del Tratamiento , Membrana Timpánica/cirugía , Timpanoplastia , Adulto JovenRESUMEN
BACKGROUND: Controversy exists amongst ENT surgeons as to the best way to manage a non-syndromal and otherwise healthy child with suspected OSAS. In 2002, The American Association of Paediatricians stated that the gold standard is a full polysomnography (PSG) for all children with suspected OSA and the revised version in 2012 repeated that requirement but recognized that facilities are not always available. In 2009 a UK Multidisciplinary Consensus Statement disagreed and reserved a full PSG for younger and syndromal or complicated children. We undertook a survey of UK ENT surgeons before and after the UK Consensus Statement to identify common practice with regards to diagnosis and management of suspected paediatric obstructive sleep apnoea syndrome in the UK. METHOD: A questionnaire based on the management of a typical clinical case was sent to 542 ENT consultants in 2005 and repeated in 2011. RESULTS: Less than 2% used PSG in assessing the child presented in our case study in both surveys. About 70% of respondents indicated that they would proceed with management of the child with no form of sleep study at all and this clinical practice has not changed after UK Multidisciplinary Consensus Statement. The majority would treat a child with possible OSAS and no co-morbidities with adenotonsillectomy as an inpatient. DISCUSSION: The availability of paediatric PSG is very limited and because of a lack of normative data, uncertainty about interpretation of abnormal results, the recognition that even moderate snoring without sleep apnoea has detrimental neuro-cognitive effects and the fact that adenotonsillectomy is a very effective treatment for paediatric OSA we felt that a pragmatic and safe approach was to treat selected patients as if they had a positive PSG with appropriate anaesthetic technique and post operative care and monitoring.