Transcranial translabyrinthine approach to vestibular schwannomas

1993 ◽  
Vol 107 (2) ◽  
pp. 111-114 ◽  
Author(s):  
Joseph G. Feghali ◽  
Allen B. Kantrowitz
Keyword(s):  
Facial Nerve ◽  
Temporal Bone ◽  
Semicircular Canal ◽  
Internal Auditory Canal ◽  
Endolymphatic Sac ◽  
Vestibular Schwannomas ◽  
Translabyrinthine Approach ◽  
Vestibular Aqueduct ◽  
Temporal Bones ◽  
Suboccipital Approach

Surgeons who utilize the suboccipital approach for the removal of large vestibular schwannomas, can perform a planned labyrinthectomy from within the intracranial cavity via the suboccipital exposure. This transcranial translabyrinthine approach provides one of the major advantages of the conventional transmastoid translabyrinthine approach, namely, unambiguous identification of the facial nerve as it exits the internal auditory canal, without the need for complete mastoidectomy and labyrinthectomy. The labyrinthectomy is best performed prior to the complete exposure of the internal auditory canal. The approach requires the surgeon to identify the endolymphatic sac intracranially, then drill the temporal bone and follow the vestibular aqueduct to the utricle. The lateral and superior semicircular canal ampullae, the superior vestibular nerve, Bill's bar, and the facial nerve at the lateral end of the internal auditory canal can then be identified. After testing on multiple cadaver temporal bones, this approach was used in patients with large tumours that extended far laterally in the internal auditory canal. The steps in the technique are described in detail.

Dural Landmark to Locate the Internal Auditory Canal in Large and Giant Vestibular Schwannomas: The Tübingen Line

2011 ◽  
Vol 69 (suppl_1) ◽  
pp. ons99-ons102 ◽  
Author(s):  
Alvaro Campero ◽  
Carolina Martins ◽  
Albert Rhoton ◽  
Marcos Tatagiba
Keyword(s):  
Temporal Bone ◽  
Internal Auditory Canal ◽  
Initial Step ◽  
Senior Author ◽  
Vestibular Schwannomas ◽  
Posterior Surface ◽  
Safe Method ◽  
Vestibular Aqueduct ◽  
Bony Surface ◽  
Temporal Bones

Abstract BACKGROUND: In cases of large and giant vestibular schwannomas (VS), the visualization of the internal auditory canal (IAC) opening is difficult or impossible. OBJECTIVE: To describe the Tübingen line and explore its relationships with the IAC as a landmark to help locate the IAC. METHODS: Ten cadaveric heads were used in this study. Between 2004 and 2009, the senior author (M.T.) used the Tübingen line as a landmark to recognize the IAC in 300 consecutive patients with VS. To locate the Tübingen line, the initial step was to identify several vertical foldings of dura located around the area of the vestibular aqueduct. After this, foldings upward consistently reached a linear level where all of the foldings ended and the dura tightly adhered to the bony surface in a smooth, foldless shape. RESULTS: The Tübingen line was identified in all temporal bones studied and in all 300 patients operated on, with the exception of 2 cases (<1%). Removal of the bone just above the Tübingen line located the IAC in all temporal bone specimens studied. Similarly, the surgical cases showed that the Tübingen line helped locate the IAC in all patients. CONCLUSION: The Tübingen line is an easy, consistent, and safe method to locate the projection of the IAC along the posterior surface of the temporal bone.

scholarly journals Risk of Posterior Semicircular Canal Trauma when using a Retrosigmoid approach for Acoustic Neuroma Surgery and role of Endoscopy: An Imaging Study

2018 ◽  
Vol 97 (1-2) ◽  
pp. 24-30 ◽  
Author(s):  
Ali Kouhi ◽  
Varasteh Vakili Zarch ◽  
Ali Pouyan
Keyword(s):  
Temporal Bone ◽  
Semicircular Canal ◽  
Internal Auditory Canal ◽  
Imaging Study ◽  
Hearing Preservation ◽  
Neoplastic Disease ◽  
Posterior Semicircular Canal ◽  
Temporal Bone Ct ◽  
Temporal Bones

The rate of hearing preservation after vestibular schwannoma surgery is variable and is not as high as expected, possibly due to injuries to the posterior semicircular canal while exposing the tumor. The aim of this study was to estimate the risk of posterior semicircular canal injuries using temporal bone computed tomography (CT) scan findings. Temporal bone CT scans of 30 patients selected between 2013 and 2015 were studied. The median age of the patients was 40 years. Two planes were studied: (1) the axial plane that shows the common crus of the posterior semicircular canal and (2) the coronal plane that shows the two crura of the posterior semicircular canal. Five lines were drawn and four angles and three distances were measured. In this study, we divided the patients into three groups consisting of 10 patients each: (1) patients with no evidence of inflammatory or neoplastic disease, (2) those with chronic ear disease, and (3) those with vestibular schwannomas. The portion of the internal auditory canal that was exposed by drilling while preserving the posterior semicircular canal was 53 to 64% and 61 ± 9% in whole temporal bones in the three groups. The mean angle of vision with an endoscope was less than 105° in 56% of cases, which means even with a 30° endoscope, the fundus could not be visualized. Therefore, according to our data, it seemed impossible to expose the whole length of the internal auditory canal from the porus to the fundus without causing injury to the posterior semicircular canal. However, the use of endoscopes may help to prevent injury.

Relative Preservation of Superior Semicircular Canal Architecture in CHARGE Syndrome

2019 ◽  
Vol 160 (6) ◽  
pp. 1095-1100 ◽  
Author(s):  
Kareem O. Tawfik ◽  
Brittany A. Leader ◽  
Zoe A. Walters ◽  
Daniel I. Choo
Keyword(s):  
Temporal Bone ◽  
Semicircular Canal ◽  
High Frequency ◽  
Care Center ◽  
Internal Auditory Canal ◽  
Charge Syndrome ◽  
Venous Anatomy ◽  
Temporal Bone Imaging ◽  
Temporal Bones ◽  
Clinical Diagnostic Criteria

Objectives (1) Describe common patterns of semicircular canal (SCC) anomalies in CHARGE syndrome (CS) and (2) recognize that in CS, the architecture of the superior SCC may be relatively preserved. Study Design This is a retrospective review of temporal bone imaging studies. Setting Quaternary care center. Subjects and Methods A sample of 37 patients with CS. All subjects met clinical diagnostic criteria for CS. The presence/absence of anomalies of the middle ear, mastoid, temporal bone venous anatomy, inner ear, and internal auditory canal was recorded. Anomalies of each SCC were considered separately and by severity (normal, dysplasia, aplasia). Results Thirty-seven subjects (74 temporal bones) were reviewed. Thirty-four (92.0%) patients demonstrated bilateral SCC anomalies. Three (8.0%) had normal SCCs. In patients with SCC anomalies, all canals demonstrated bilateral abnormalities. Thirty-two (86.5%) patients had bilateral horizontal SCC aplasia. These 32 patients also demonstrated posterior SCC aplasia in at least 1 ear. Of 74 temporal bones, 37 (50.0%) had superior SCC dysplasia. All dysplastic superior SCCs showed preservation of the anterior limb. Complete superior SCC aplasia was found in 28 (37.8%) temporal bones. Conclusion SCC anomalies occur with high frequency in CS. Complete absence of the horizontal and posterior canals is typical and usually bilateral. By contrast, the superior SCC often demonstrates relative preservation of the anterior limb.

scholarly journals Risk of Posterior Semicircular Canal Trauma When Using a Retrosigmoid Approach for Acoustic Neuroma Surgery and Role of Endoscopy: An Imaging Study

2018 ◽  
Vol 97 (1-2) ◽  
pp. 24-30
Author(s):  
Ali Kouhi ◽  
Varasteh Vakili Zarch ◽  
Ali Pouyan
Keyword(s):  
Temporal Bone ◽  
Semicircular Canal ◽  
Internal Auditory Canal ◽  
Imaging Study ◽  
Hearing Preservation ◽  
Neoplastic Disease ◽  
Posterior Semicircular Canal ◽  
Temporal Bone Ct ◽  
Temporal Bones

The rate of hearing preservation after vestibular schwannoma surgery is variable and is not as high as expected, possibly due to injuries to the posterior semicircular canal while exposing the tumor. The aim of this study was to estimate the risk of posterior semicircular canal injuries using temporal bone computed tomography (CT) scan findings. Temporal bone CT scans of 30 patients selected between 2013 and 2015 were studied. The median age of the patients was 40 years. Two planes were studied: (1) the axial plane that shows the common crus of the posterior semicircular canal and (2) the coronal plane that shows the two crura of the posterior semicircular canal. Five lines were drawn and four angles and three distances were measured. In this study, we divided the patients into three groups consisting of 10 patients each: (1) patients with no evidence of inflammatory or neoplastic disease, (2) those with chronic ear disease, and (3) those with vestibular schwannomas. The portion of the internal auditory canal that was exposed by drilling while preserving the posterior semicircular canal was 53 to 64% and 61 ± 9% in whole temporal bones in the three groups. The mean angle of vision with an endoscope was less than 105° in 56% of cases, which means even with a 30° endoscope, the fundus could not be visualized. Therefore, according to our data, it seemed impossible to expose the whole length of the internal auditory canal from the porus to the fundus without causing injury to the posterior semicircular canal. However, the use of endoscopes may help to prevent injury.

Internal Auditory Canal Variability: Anatomic Variation Affects Cisternal Facial Nerve Visualization

2020 ◽  
Vol 19 (3) ◽  
pp. E251-E258 ◽  
Author(s):  
Michael A Cohen ◽  
Hussam Abou-Al-Shaar ◽  
Yair M Gozal ◽  
Michael Karsy ◽  
Gmaan Alzhrani ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Temporal Bone ◽  
Anatomic Variation ◽  
Internal Auditory Canal ◽  
Substantial Effect ◽  
Translabyrinthine Approach ◽  
Surgical Exposure ◽  
Petrous Temporal Bone ◽  
Position And Orientation ◽  
The Individual

Abstract BACKGROUND The internal auditory canal (IAC) is an important landmark during surgery for lesions of the cerebellopontine angle. There is significant variability in the position and orientation of the IAC radiographically, and the authors have noted differences in surgical exposure depending on the individual anatomy of the IAC. OBJECTIVE To test the hypothesis that IAC position and orientation affects the surgical exposure of the IAC and facial nerve, especially when performing the translabyrinthine approach. METHODS The authors retrospectively reviewed magnetic resonance imaging studies of 50 randomly selected patients with pathologically confirmed vestibular schwannomas. Measurements, including the anterior (APD) and posterior (PPD) petrous distances, the anterior (APA) and posterior (PPA) petro-auditory angles, and the internal auditory angle (IAA), were obtained to quantify the position and orientation of the IAC within the petrous temporal bone. RESULTS The results quantitatively demonstrate tremendous variability of the position and orientation of the IAC in the petrous temporal bone. The measurement ranges were APD 10.2 to 26.1 mm, PPD 15.1 to 37.2 mm, APA 104 to 157°, PPA 30 to 96°, and IAA –5 to 40°. CONCLUSION IAC variability can have a substantial effect on the surgical exposure of the IAC and facial and vestibulocochlear nerves. Specifically, a horizontally oriented IAC with a small IAA may have significant impact on visualization of the facial nerve within its cisternal segment with the translabyrinthine approach. The retrosigmoid approach is less affected with IAC variability in position and angle.

Otopathologic Abnormalities in CHARGE Syndrome

2021 ◽  
pp. 019459982110089
Author(s):  
Rafael da Costa Monsanto ◽  
Renata Malimpensa Knoll ◽  
Norma de Oliveira Penido ◽  
Grace Song ◽  
Felipe Santos ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Middle Ear ◽  
Spiral Ganglion ◽  
Internal Auditory Canal ◽  
Semicircular Canals ◽  
Charge Syndrome ◽  
University Of Minnesota ◽  
Bony Canal ◽  
Ganglion Neurons ◽  
Temporal Bones

Objective To perform an otopathologic analysis of temporal bones (TBs) with CHARGE syndrome. Study Design Otopathologic study of human TB specimens. Setting Otopathology laboratories. Methods From the otopathology laboratories at the University of Minnesota and Massachusetts Eye and Ear Infirmary, we selected TBs from donors with CHARGE syndrome. These TBs were serially sectioned at a thickness of 20 µm, and every 10th section was stained with hematoxylin and eosin. We performed otopathologic analyses of the external ear, middle ear (middle ear cleft, mucosal lining, ossicles, mastoid, and facial nerve), and inner ear (cochlea, vestibule, internal auditory canal, and cochlear and vestibular nerves). The gathered data were statistically analyzed. Results Our study included 12 TBs from 6 donors. We found a high prevalence of abnormalities affecting the ears. The most frequent findings were stapes malformation (100%), aberrant course of the facial nerve (100%) with narrow facial recess (50%), sclerotic and hypodeveloped mastoids (50%), cochlear (100%) and vestibular (83.3%) hypoplasia with aplasia of the semicircular canals, hypoplasia and aplasia of the cochlear (66.6%) and vestibular (91.6%) nerves, and narrowing of the bony canal of the cochlear nerve (66.6%). The number of spiral ganglion and Scarpa’s ganglion neurons were decreased in all specimens (versus normative data). Conclusions In our study, CHARGE syndrome was associated with multiple TB abnormalities that may severely affect audiovestibular function and rehabilitation.

Anatomical Characteristics of Facial Nerve and Cochlea Interaction

2017 ◽  
Vol 22 (1) ◽  
pp. 41-49 ◽  
Author(s):  
Nadine Schart-Morén ◽  
Sune Larsson ◽  
Helge Rask-Andersen ◽  
Hao Li
Keyword(s):  
Facial Nerve ◽  
Semicircular Canal ◽  
Otic Capsule ◽  
Micro Ct ◽  
Superior Semicircular Canal Dehiscence ◽  
Topographic Anatomy ◽  
3D Rendering ◽  
Superior Semicircular Canal ◽  
Archival Collection ◽  
Temporal Bones

Objective: The aim was to study the relationship between the labyrinthine portion (LP) of the facial canal and the cochlea in human inner ear molds and temporal bones using micro-CT and 3D rendering. A reduced cochlea-facial distance may spread electric currents from the cochlear implant to the LP and cause facial nerve stimulation. Influencing factors may be the topographic anatomy and otic capsule properties. Methods: An archival collection of human temporal bones underwent micro-CT and 3D reconstruction. In addition, cochlea-facial distance was assessed in silicone and polyester resin molds, and the association between the LP and upper basal turn of the cochlea was analyzed. Results: Local thinning of the otic capsule and local anatomy may explain the development of cochlea-facial dehiscence, which was found in 1.4%. A reduced cochlea-facial distance was noted in 1 bone with a superior semicircular canal dehiscence but not in bones with superior semicircular canal “blue line.” The otic capsule often impinged upon the LP and caused narrowing. Conclusion: Micro-CT with 3D rendering offers new possibilities to study the topographic anatomy of the human temporal bone. The varied shape of the cross-section of the LP could often be explained by an “intruding” cochlea.

scholarly journals Bilateral temporal bone fractures: a case report

2017 ◽  
Vol 4 (1) ◽  
pp. 271
Author(s):  
Kiran Natarajan ◽  
Koka Madhav ◽  
A. V. Saraswathi ◽  
Mohan Kameswaran
Keyword(s):  
Hearing Loss ◽  
Case Report ◽  
Facial Nerve ◽  
Temporal Bone ◽  
Facial Paralysis ◽  
Bone Fractures ◽  
Clinical Manifestations ◽  
Csf Leak ◽  
The Right ◽  
Temporal Bones

<p>Bilateral temporal bone fractures are rare; accounting for 9% to 20% of cases of temporal bone fractures. Clinical manifestations include hearing loss, facial paralysis, CSF otorhinorrhea and dizziness. This is a case report of a patient who presented with bilateral temporal bone fractures. This is a report of a 23-yr-old male who sustained bilateral temporal bone fractures and presented 18 days later with complaints of watery discharge from left ear and nose, bilateral profound hearing loss and facial weakness on the right side. Pure tone audiometry revealed bilateral profound sensori-neural hearing loss. CT temporal bones &amp; MRI scans of brain were done to assess the extent of injuries. The patient underwent left CSF otorrhea repair, as the CSF leak was active and not responding to conservative management. One week later, the patient underwent right facial nerve decompression. The patient could not afford a cochlear implant (CI) in the right ear at the same sitting, however, implantation was advised as soon as possible because of the risk of cochlear ossification. The transcochlear approach was used to seal the CSF leak from the oval and round windows on the left side. The facial nerve was decompressed on the right side. The House-Brackmann grade improved from Grade V to grade III at last follow-up. Patients with bilateral temporal bone fractures require prompt assessment and management to decrease the risk of complications such as meningitis, permanent facial paralysis or hearing loss. </p>

scholarly journals The depth of the facial nerve in the mastoid bone

2018 ◽  
Vol 4 (3) ◽  
pp. 666
Author(s):  
B. Y. Praveen Kumar ◽  
K. T. Chandrashekhar ◽  
M. K. Veena Pani ◽  
Sunil K. C. ◽  
Anand Kumar S. ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Temporal Bone ◽  
Significant Variation ◽  
Canal Wall ◽  
Stylomastoid Foramen ◽  
Cortical Mastoidectomy ◽  
Canal Wall Down ◽  
Canal Wall Down Mastoidectomy ◽  
The Mean ◽  
Temporal Bones

<p class="abstract"><strong>Background:</strong> The hallmark of the temporal bone is variation. Various important structures like the facial nerve run in the temporal bone at various depths which can be injured during mastoidectomy.</p><p class="abstract"><strong>Methods:</strong> Twenty wet cadaveric temporal bones were dissected. A cortical mastoidectomy was performed followed by a canal wall down mastoidectomy and the depth of the vertical segment of the facial nerve in the mastoid was determined.  </p><p class="abstract"><strong>Results:</strong> The mean depth of the second genu was 13.82 mm. The mean depth of the stylomastoid foramen was 12.75 mm and the mean distance from the annulus at 6’0 clock to the stylomastoid foramen was 10.22 mm.</p><p><strong>Conclusions:</strong> There is significant variation in the average depth of the facial nerve in the mastoid. </p>

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