Name:
Endoscopic-assisted resection of vestibular schwannomas in high-riding jugular bulb
Description:
Endoscopic-assisted resection of vestibular schwannomas in high-riding jugular bulb
Thumbnail URL:
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Duration:
T00H07M42S
Embed URL:
https://stream.cadmore.media/player/e732f92a-a22f-4bfe-a6de-e2f23343c9df
Content URL:
https://cadmoreoriginalmedia.blob.core.windows.net/e732f92a-a22f-4bfe-a6de-e2f23343c9df/21-98.mp4?sv=2019-02-02&sr=c&sig=G0We%2FicGRiwBpaAHCm0V2gL%2Fk5prbytLMleC5ewZ9KQ%3D&st=2024-04-29T06%3A11%3A41Z&se=2024-04-29T08%3A16%3A41Z&sp=r
Upload Date:
2021-10-27T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
[MUSIC PLAYING]
SPEAKER: This video demonstrates the endoscopic-assisted resection of vestibular schwannoma in high-riding jugular bulb. The MRI demonstrates a T2 size vestibular schwannoma, with a dumbbell-shaped configuration of the internal auditory canal. And growing of the tumor in the CP angle. The CT scan confirms the remodeling of the bone, as well as the high-riding jugular bulb in relationship to the internal auditory canal, the semicircular ducts in the cochlea.
SPEAKER: The high-riding jugular bulb is in the trajectory from the retrosigmoid approach, if the internal auditory canal is drilled open. The patient experienced mild tumor growth on MRI imaging, as well as progressive hearing loss over the years. He opted for microsurgical resection after discussing alternatives, such as radiosurgery, translabyrinthine approach or the extended middle fossa approach in the supine position.
SPEAKER: However, due to the dumbbell shape of the tumor, the inferior part would be difficult to reach. The retrosigmoid approach in the supine position would be more difficult due to the expected venous bleeding during the drilling and opening of the IAC. We also discussed radiosurgical options. The key steps for a semisitting position includes pre- and intraoperative transesophageal echo. All patients receive a central line and continuous intraoperative neuromonitoring, including SSEPs and MEPs for positioning, followed by acoustic evoked potentials, as well as facial EMG and MEP recordings.
SPEAKER: For the drilling of the internal auditory canal, we use only diamond burrs if we attempt hearing preservation. Otherwise, it can be started with a cutting burr. The drilling in high jugular bulb is more limited and more superior rather than wide opening and posterior. The suction irrigation device is demonstrated and tested.
SPEAKER: After retrosigmoid skin incision, dissection of the muscles and waxing of mastoid veins to avoid air entry in the sitting position. Preservation of some muscles for sealing of the internal auditory canal later on, osteoplastic craniotomy after dissection of the dura at the sinus angle. Care should be taken at the sigmoid sinus as the dura frequently is very thin in that area.
SPEAKER: After dural incision, under the microscope, release of CSF. After cerebellar retraction against gravity, the CP angle comes into view. Here, the anticipated location of the internal auditory canal is outlined, as well as the high jugular bulb, which can be seen as a discoloration of the bone just posterior of the IAC. The typical line marks the inferior border of the opening of the internal auditory canal to avoid drilling of the endolymphatic sac.
SPEAKER: After removal of the dura over the temporal bone, the discoloration and the location of the high jugular bulb is much more visible, due to a very thin line of bone just overlying the sinus.
SPEAKER: The drilling of the internal auditory canal is performed with diamond burrs of decreasing sizes under controlled and continuous bilateral jugular compression by the anesthesiologists to avoid air entry in case of drilling and injury of the jugular bulb. The direction of drilling is superior anterior towards inferior posterior to open the anterior part of the internal auditory canal first, and then later on, around the high jugular bulb, the posterior edge.
SPEAKER: After sufficient opening of the internal auditory canal, the vestibular schwannoma is partially resected with microsurgical and bimanual techniques until the remaining intracanalicular parts in this dumbbell-shaped widened internal auditory canal are approached by a 30- degree endoscope, which is introduced into the CP angle.
SPEAKER: Here, we'll see the anatomic location of the facial nerve, separated through the transverse crest from the superior vestibular nerve and the high-riding jugular bulb at the inferior posterior area of the temporal bone. With microsurgical instruments, the remaining tumor parts are mobilized first from the nerve and then later on in the remaining enlarged cavity to achieve complete resection.
SPEAKER: This is performed under continuous electrophysiological monitoring with brainstem auditory evoked potentials and facial nerve EMG, as well as MEPs. In this safe zone away from the nerves, the remaining tumor part in this excavated IAC can be mobilized and subsequently removed.
SPEAKER: Following tumor resection, the internal auditory canal is sealed with a muscle plug and fibrin glue. The postop CT scan shows opening of the internal auditory canal with preserved semicircular ducts. The postop audiogram shows preserved hearing with a mild deterioration in higher frequencies. Patient was discharged with full facial nerve integrity on day 5.
SPEAKER: Thank you very much.