Surgical exposure of the internal auditory canal through the retrosigmoid approach with semicircular canals anatomical preservation

Leal, André Giacomelli; Silva, Erasmo Barros da; Ramina, Ricardo

doi:10.1590/0004-282x20150020

Cited by 10 publications

(7 citation statements)

References 27 publications

(32 reference statements)

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“…36 Symptoms as manifestation of nerves involvement help us also to chose the treatment. Good hearing threshold and vestibular function preservation are findings often present in arachnoid cyst, this suggests that a middle temporal fosse approach 37 or a retrosigmoid one 38 can be the good option to preserve the nerve functions. The endoscopic approach 19,39 would be the best choice but not all surgeons are comfortable with it.…”

Section: Discussionmentioning

confidence: 96%

Arachnoid Cyst of Internal Auditory Canal How the Temporal Bone Findings Explain Ear Symptoms and Suggest the Best Treatment To Do

Stadio¹

2016

Otolaryngol Open J

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PubMed and Google Scholar searches using the following keywords: arachnoid cyst, internal auditory canal, temporal bones study, schwannoma of internal auditory canal, cystic schwannoma, MRI findings, surgery of internal auditory canal. Only the article where three keywords, included always arachnoid cyst, were considered. The study analyzed the etiopathogenesis of arachnoid cyst, hearing and vestibular symptoms and temporal bone findings. Review and conclusion: The author identified and reviewed a total of 46 articles. The results showed high incidence of hearing loss that was the more common symptom than vestibular one. Arachnoid cyst carried out more compression on the vestibular nerves than on the cochlear one. The review allowed us to identify which mechanism of damage arachnoid cyst acting on the nerves. It is necessary to consider the arachnoids cyst in differential diagnosis with tumors and pathologies involving the internal auditory canal.

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Section: Discussionmentioning

confidence: 96%

Arachnoid Cyst of Internal Auditory Canal How the Temporal Bone Findings Explain Ear Symptoms and Suggest the Best Treatment To Do

Stadio¹

2016

Otolaryngol Open J

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“…as previously described. 9 Patients were included in the study if they had diagnosis of VS confirmed by pathological examination and the surgical video was available for analysis. Precise intraoperative facial nerve identification at the brainstem and internal auditory canal by electro-stimulation with 2.0 mA and a minimum of 1-year follow-up were requirements of inclusion in this study.…”

Section: Methods Populationmentioning

confidence: 99%

Facial Nerve Adherence in Vestibular Schwannomas: Classification and Radiological Predictors

Jung

Montibeller

Fraga³

et al. 2020

J Neurol Surg B Skull Base

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Abstract Background Facial nerve palsy is one of the most frequent complications after resection of vestibular schwannomas (VS). Several mechanisms have been implicated in the poor postoperative facial nerve outcome. Adherence between the facial nerve and tumor capsule is one of the most relevant factors. There is no clear preoperative parameter permitting identification of these adhesions. Objective The aim of this study was to identify the correlation between the grade of adherence of the facial nerve to the tumor capsule and its functional outcome after VS resection. Methods A total of 26 patients with sporadic VS (tumor sized T3, T4A, and T4B according to Hannover classification) were evaluated. Grade of adherence of the facial nerve to the tumor capsule was checked during surgery and graduated according to a proposed scale into 1 to 3 different grades. Facial nerve function was assessed postoperatively and after 1-year follow-up. Size of tumor according to Hannover classification, presence of cystic components, “cerebrospinal fluid (CSF) cleft sign,” and the contour of tumor capsule were tested as radiological predictors of grade of adherence to the facial nerve. Results and Conclusion Only Grade 2 (11 cases) and 3 (15 cases) of adherence were seen in large VS. Lower grade of adherence was associated with good facial nerve outcome after 1-year follow-up (p = 0.029). Presence of the “CSF cleft sign” and regular contour of tumor capsule were independent predictors of adherence. When both factors were associated, sensitivity and specificity of this method were 83 and 80%, respectively.

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“…However, various studies reported potential usefulness and thereby corroborate an unmet clinical need for accurate and precise instrument localization in neurotologic surgery (5). Based on intraoperative judgement by the operating surgeon potential usefulness during surgical access creation to the petrous apex (7,11,13,27,52) and to the internal auditory canal (16,27,43,52), resection of (pseudo)neoplasms (27,52,53), congenital bony aural atresia surgery (12), cochlear implantation (6, 9, 10) and revision surgery (27) was reported. In the presented study, during the removal of the facial nerve schwannoma, the imageguidance system was subjectively judged useful by the operating surgeon, mostly to delineate the facial nerve and determine the instrument's proximity to the dura.…”

Section: Usefulness Assessmentmentioning

confidence: 93%

“…The technology was reported as useful for identifying anatomy and pathology in (pseudo)neoplasm resection (7,8,13), cochlear implantation (9,10), congenital aural atresia (12), and auricular implant (14) surgery but no significant effects on safety or efficacy were demonstrated. Other attempts have suggested potential usefulness in otologic, petrous apex, and internal auditory canal surgery (6,11,15,16). The persistent lack of proven effects and absence in routine use, however, indicate that the clinically available freehand image-guidance systems still do not meet the needs of neurotologic surgery, most importantly the need for sub-half-millimeter localization accuracy and precision.…”

Section: Introductionmentioning

confidence: 99%

Freehand Stereotactic Image-Guidance Tailored to Neurotologic Surgery

et al. 2021

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Hypothesis: The use of freehand stereotactic image-guidance with a target registration error (TRE) of μTRE + 3σTRE < 0.5 mm for navigating surgical instruments during neurotologic surgery is safe and useful.Background: Neurotologic microsurgery requires work at the limits of human visual and tactile capabilities. Anatomy localization comes at the expense of invasiveness caused by exposing structures and using them as orientation landmarks. In the absence of more-precise and less-invasive anatomy localization alternatives, surgery poses considerable risks of iatrogenic injury and sub-optimal treatment. There exists an unmet clinical need for an accurate, precise, and minimally-invasive means for anatomy localization and instrument navigation during neurotologic surgery. Freehand stereotactic image-guidance constitutes a solution to this. While the technology is routinely used in medical fields such as neurosurgery and rhinology, to date, it is not used for neurotologic surgery due to insufficient accuracy of clinically available systems.Materials and Methods: A freehand stereotactic image-guidance system tailored to the needs of neurotologic surgery–most importantly sub-half-millimeter accuracy–was developed. Its TRE was assessed preclinically using a task-specific phantom. A pilot clinical trial targeting N = 20 study participants was conducted (ClinicalTrials.gov ID: NCT03852329) to validate the accuracy and usefulness of the developed system. Clinically, objective assessment of the TRE is impossible because establishing a sufficiently accurate ground-truth is impossible. A method was used to validate accuracy and usefulness based on intersubjectivity assessment of surgeon ratings of corresponding image-pairs from the microscope/endoscope and the image-guidance system.Results: During the preclinical accuracy assessment the TRE was measured as 0.120 ± 0.05 mm (max: 0.27 mm, μTRE + 3σTRE = 0.27 mm, N = 310). Due to the COVID-19 pandemic, the study was terminated early after N = 3 participants. During an endoscopic cholesteatoma removal, a microscopic facial nerve schwannoma removal, and a microscopic revision cochlear implantation, N = 75 accuracy and usefulness ratings were collected from five surgeons each grading 15 image-pairs. On a scale from 1 (worst rating) to 5 (best rating), the median (interquartile range) accuracy and usefulness ratings were assessed as 5 (4–5) and 4 (4–5) respectively.Conclusion: Navigating surgery in the tympanomastoid compartment and potentially in the lateral skull base with sufficiently accurate freehand stereotactic image-guidance (μTRE + 3σTRE < 0.5 mm) is feasible, safe, and useful.Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT03852329.

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Surgical exposure of the internal auditory canal through the retrosigmoid approach with semicircular canals anatomical preservation

Cited by 10 publications

References 27 publications

Arachnoid Cyst of Internal Auditory Canal How the Temporal Bone Findings Explain Ear Symptoms and Suggest the Best Treatment To Do

Arachnoid Cyst of Internal Auditory Canal How the Temporal Bone Findings Explain Ear Symptoms and Suggest the Best Treatment To Do

Facial Nerve Adherence in Vestibular Schwannomas: Classification and Radiological Predictors

Freehand Stereotactic Image-Guidance Tailored to Neurotologic Surgery

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