Name:
Hydroxyapatite cement cranioplasty in the setting of simultaneous translabyrinthine resection of cerebellopontine angle tumors and cochlear implantation
Description:
Hydroxyapatite cement cranioplasty in the setting of simultaneous translabyrinthine resection of cerebellopontine angle tumors and cochlear implantation
Thumbnail URL:
https://cadmoremediastorage.blob.core.windows.net/ecebe2c2-1477-4012-bb8b-590fbefa7c37/videoscrubberimages/Scrubber_428.jpg
Duration:
T00H09M27S
Embed URL:
https://stream.cadmore.media/player/ecebe2c2-1477-4012-bb8b-590fbefa7c37
Content URL:
https://cadmoreoriginalmedia.blob.core.windows.net/ecebe2c2-1477-4012-bb8b-590fbefa7c37/21-1.mp4?sv=2019-02-02&sr=c&sig=53I1tBIos1vD%2Bsu2RDoefxSw2NPssjJyH8M9zDPE39c%3D&st=2024-05-05T11%3A05%3A16Z&se=2024-05-05T13%3A10%3A16Z&sp=r
Upload Date:
2021-10-27T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
[MUSIC PLAYING]
SPEAKER: The purpose of this video is to demonstrate the surgical technique regarding translabyrinthine resection of vestibular schwannoma with simultaneous cochlear implantation, utilizing a hydroxyapatite cement cranioplasty for closure. Cochlear Corporation supplied a minor number of cochlear implants for the research study that the patient was a part of. There are no direct conflicts of interest with the presented case.
SPEAKER: Cochlear implantation is a viable option for hearing rehabilitation when the cochlear nerve is preserved during translabyrinthine resection of the tumor. Cochlear implantation after vestibular schwannoma removal has been performed previously, both as a two-stage and a single-stage procedure. However, there is limited audiologic data on simultaneous implantation.
SPEAKER: The typical closure after translabyrinthine resection of cochlear implantation at our institution varies, with both abdominal fat grafting and hydroxyapatite cement having been utilized. HA cement has the benefit of decreased donor site morbidity, as well as improved surgical times. However, given the significant cost, for their cost-effectiveness, evaluation is still needed. In our institution, hydroxyapatite cement is not utilized in cochlear implantation without translabyrinthine resection.
SPEAKER: The surgery presented here is of a 67-year-old male, undergoing right-sided translabyrinthine excision of a 1.3- by 1.4-cm vestibular schwannoma. Gross-total resection was performed, and the cochlear nerve was kept intact throughout the surgery. This patient initially presented to the clinic with sudden hearing loss and tinnitus on the right side. The audiogram of the patient is shown below, with a significant right-sided hearing loss and a word recognition score of 40%.
SPEAKER: Preoperative imaging can be seen here, depicted as a T1 postcontrast axial and coronal MRI, depicting the right side of the vestibular schwannoma. Seen here is the typical surgical positioning, with the patient in the supine position and the head turned toward the contralateral side. The postauricular incision can be seen here, approximately two centimeters from the postauricular crease.
SPEAKER: After the postauricular incision is completed, a typical canal wall-up mastoidectomy is started. Seen here, the tegmen and sigmoid sinus are decompressed, and the dura has begun to be exposed. The labyrinthectomy is then started. In this case, the posterior semicircular canals taken down initially.
SPEAKER: Further drilling of the labyrinth is completed. Seen here is exposure of the superior semicircular canal. The ampullated ends of the semicircular canals can be seen here, along with the common crus and bleeding from the subarcuate artery. The completed labyrinthectomy can be seen here, with bone overlying the IAC.
SPEAKER: Posterior fossa dura is seen exposed. Once the majority of the bony labyrinthectomy work is completed, a facial recess approach is utilized to expose the round window. Attention is then returned to the remaining bony coverage of the internal auditory canal. A superior and inferior trough is drilled, in order to isolate and expose the internal auditory canal.
SPEAKER: After complete bony removal over the IAC, the dura is incised. Further dissection of the dura was completed, exposing the cerebellopontine angle. After exposure of the internal auditory canal and cerebellopontine angle, the nerve-stimulating spatula instrument is used to ensure that the facial nerve is not on the posterior aspect of the tumor.
SPEAKER: Once confirmed, tumor debulking is then begun with the intention of finding the facial nerve. Debulking is then continued using an ultrasonic aspirator. After tumor debulking is completed, the eighth cranial nerve is identified approximately in the cerebellopontine angle.
SPEAKER: Tumor dissection is continued from proximal to distal along the nerve, being careful to preserve the overlying blood supply. Further dissection is completed in the distal aspect of the cerebellopontine angle. Dissection is performed using a stimulating dissector, in order to prevent injury to the facial nerve in this location.
SPEAKER: As can be seen here, the last segment of tumor is removed, and gross-total resection is achieved. The eighth cranial nerve can be seen here, still intact, along with the labyrinthine segment of the facial nerve, which is obscured with blood. After complete resection of the tumor, the orientation is shifted to be the brainstem route entry zone of the facial nerve for final stimulation.
SPEAKER: At this point in the surgery, a dural repair substitute was placed in the defect to assist with dural closure, and a well and trough was then drilled for the cochlear implant to be placed. A cochleostomy was then performed using a one diamond burr.
SPEAKER: In this case, a Cochlear Nucleus Profile Plus with Contour Advance was placed into the cochleostomy site, and the electrode was inserted. The stylet is seen being removed here. Fascia was then used to pack the eustachian tube in and around the cochlear implant site. This prevents fistula formation, as well as prevents the hydroxyapatite cement from leaking into the cochleostomy site.
SPEAKER: After the cochlear implant is confirmed to be activated with neural response telemetry, closure is begun. Cranioplasty is then performed using hydroxyapatite cement. In our experience, it is important to hold and maintain pressure immediately after applying the HA cement, as this prevents CSF from creating a pathway through the cement prior to cement hardening.
SPEAKER: Of the patients at our institution undergoing concurrent translabyrinthine tumor resection with cochlear implantation, seven have had closure with abdominal fat graft, and five have had closure with HA cement. One patient had a CSF leak in the HA cement group. However, this was able to be managed conservatively. A separate patient had delayed incomplete facial nerve weakness in the HA cement group that is currently being observed.
SPEAKER: A postoperative T1 postcontrast axial MRI as shown here, with gross- total resection being achieved. Postoperatively, the patient's CNC testing in the infected ear went from 52% to 34%, demonstrating some viable hearing even after translabyrinthine resection. His AzBIO testing in both +10 and +5 signal-to-noise ratio improved from his preoperative state, demonstrating an improved ability to hear in background noise after surgery.
SPEAKER: To our knowledge, this is the first report of simultaneous translabyrinthine vestibular schwannoma resection and cochlear implantation with hydroxyapatite cement cranioplasty closure. Hydroxyapatite is a calcium phosphate-based biomaterial, with similar properties to bone and teeth, that has a isothermic reaction when hardening. It has been shown that HA cement is a viable alternative to fat grafting, with no donor site morbidity and a similar complication profile.
SPEAKER: It has been shown to have both long-term efficacy and safety with use in translabyrinthine repairs. A concern with HA cement includes that free exploration of the wound is required, most commonly for CSF leak. In the experience of the senior author, HA cement has been easily removed and reapplied for revision cases without cochlear implantation. However, this has not been needed for a case with cochlear implantation to this point.
SPEAKER: Simultaneous cochlear implantation with translabyrinthine resection of vestibular schwannoma provides hearing rehabilitation to the patients that would otherwise have profound deafness on the affected side. The demonstrated technique is the authors' preferred method of surgical steps, and it has been shown that cranioplasty with HA cement is a viable closure option even with cochlear implantation.
SPEAKER: