Name:
10.3171/2022.1.FOCVID21227
Description:
10.3171/2022.1.FOCVID21227
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Duration:
T00H10M25S
Embed URL:
https://stream.cadmore.media/player/9a1d37a7-a766-4af8-83ce-4c99edd66ce7
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https://cadmoreoriginalmedia.blob.core.windows.net/9a1d37a7-a766-4af8-83ce-4c99edd66ce7/21-227.mp4?sv=2019-02-02&sr=c&sig=JAFFLkUcsdEMM1FkKyfelEvZquSMcasxqKptVSGXXes%3D&st=2024-05-06T05%3A38%3A12Z&se=2024-05-06T07%3A43%3A12Z&sp=r
Upload Date:
2022-02-16T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
SPEAKER: Here we presenting a case of a right posterior petrosectomy for a resection of a petroclival meningioma. The vision is a 40-year-old female who began noticing tingling and numbness in her right cheek and jaw shortly after delivery of her second child. She had been tolerating this well for 2 months prior to presentation until she developed throbbing headaches. On exam, the patient had reduced pinprick sensation in V3 by 5% on a formal pinprick testing an otherwise normal function.
SPEAKER: Her audiogram was normal with 100% word recognition. Axial T1 contrasted imaging demonstrated a 3-cm mass that was congest enhancing along the petroclival junction eccentric to the right. T1 sagittal and coronal imaging also demonstrates the tumor extending with its superior portion all the way up to the peduncle. Here we have axial FIESTA imaging.
SPEAKER: The image on the left demonstrates a blue arrow that highlights the internal auditory canal, and the image on the right demonstrates a green arrow demonstrating exactly where the vertebral artery on the right is and where the visceral artery is in relation to the tumor. Surgical intervention was chosen because of the patient's young age and progression of symptoms. Although the symptoms may have been exacerbated by hormonal fluctuations, patients who have progressive symptomatology and growth in tumors typically progress.
SPEAKER: Serial imaging and radiosurgery were options, but given the sensitivity of neural structures in the area, radiosurgery in an isolated fashion was not thought to be the best option. This image shows a blue triangle that demonstrates an isolated middle fossa approach, an orange triangle that demonstrates an isolated retrosigmoid approach, and a green triangle that represents a combined posterior petrosectomy approach.
SPEAKER: We do our approach in one sitting for a combined posterior petrosectomy. Patient was positioned in a lateral decubitus position with the head in the Mayfield head holder. An operative microscope and neuromonitoring specifically for cranial nerves V, VI, VII, VIII, X, and XI were used. The scalp and muscle were mobilized as separate flaps prior to the craniotomy to allow for better cosmesis upon closure.
SPEAKER: The craniotomy consists of a temporo-occipital craniotomy over the distal transverse sinus with large troughed burr holes over the sinus to allow for adequate dural separation. A transmastoid approach to the presigmoid dura, which is retrolabyrinthine opens the surgical corridor to access the higher portion of the tumor as well as to allow for easier and safer division of the tentorium. And the insertion of the vein of Labbe into the dural venous sinus should be continuously searched for to avoid inadvertent injury to critical venous structures.
SPEAKER: Finally, in addition, some surgeons use a lumbar drain for brain relaxation, and we believe in opening cisternal fluid to allow for sufficient brain relaxation for this procedure. After the craniotomy, a retrolabyrinthine mastoidectomy is performed. Here we're using a cutting board to go through the mastoid air cells and mastoid antrum. This is done to skeletonize the sigmoid sinus.
SPEAKER: The sigmoid sinuses decompress all the way down to the jugular bulb. We drilled Trautmann's triangle using a diamond burr in this situation. We drill the remainder of the mastoid down until we see a normal dural surface. CSF can be released from the cochlear aqueduct to help with cerebellar relaxation.
SPEAKER: We complete drilling Trautmann's triangle and exposing posterior fossa dura. The sigmoid sinus is protected with Surgicel. The posterior fossa dura is open in a curvilinear fashion. This dura is tacked up anteriorly and the cisterns are opened to allow for sufficient cerebellar relaxation.
SPEAKER: Similarly, we then open the middle fossa dura. The middle fossa dura is dissected medially until the edge is identified. We then clip the superior petrosal sinus. This is then sharply divided, and the tentorium is divided all the way to the medial edge.
SPEAKER: During this process, we make sure to visualize the trochlear nerve for the entirety of the dissection. Arachnoid dissection and tumor biopsy are performed early in the procedure. We start by wide arachnoid dissection within the posterior fossa to allow for sufficient access to all borders of the tumor. This is then followed by an early biopsy of the tumor.
SPEAKER: So we can get frozen pathology intraoperatively. Here you can see us taking a biopsy just above cranial nerve number V. The arachnoid is dissected all the way back to the origin of the trigeminal nerve given the patient's symptoms. And the surgical corridor between cranial nerve V and VII is then opened up. And tumor is dissected off of the edge of the cerebellum.
SPEAKER: Early cautery of the tumor capsule allows for early internal debulking of the tumor, which allows for manipulation of the tumor capsule. This allows for safer dissection around cranial nerves. An ultrasonic aspirator is used to internally debulk the tumor for easier manipulation of the tumor capsule.
SPEAKER: Here you can see us working along the tumor capsule and bipolaring it, and then this is also resected using an ultrasonic aspirator. We then work toward mobilizing and debulking the superior edge of the tumor. Internal debulking of all compartments of the tumor particularly the superior end allows for easier manipulation of the tumor and tumor capsule away from surrounding cranial nerves.
SPEAKER: Here we dissect the tumor capsule off the adjacent brainstem and cerebellum. We stimulate the facial nerve and then debulk the tumor between the trigeminal nerve and vestibulocochlear complex. Here we inspect the trigeminal nerve and ensure adequate decompression, and here we can see the motor root of the trigeminal nerve.
SPEAKER: The tumor is then debulked from underneath the trochlear nerve working within the trochlear and trigeminal corridor. The infratrochlear portion of the tumor is then coagulated and sharply divided, and this portion of the tumor is then dissected and taken out. We then focus our attention to debulking the tumor above the trochlear nerve, initially by dissecting the arachnoid off of the tumor and then coagulating the tumor capsule to allow us to create a corridor for internal debulking.
SPEAKER: We incise the tumor in a linear fashion and internally debulk the tumor for better manipulation of the tumor and tumor capsule. Using microdissectors, we're able to pull the tumor inferiorly and then coagulate the tumor capsule to allow us to be able to resect it safely from within our surgical corridor.
SPEAKER: This portion of the tumor that is supratrochlear is then debulked, and the capsule is sharply dissected from the posterior margin and resected. The oculomotor nerve and cerebral peduncle are visualized at the top end of the tumor. Here we retract along the tumor capsule at the superior margin. As we're pulling down, you can clearly visualize the cerebral peduncle.
SPEAKER: This portion of the tumor is debulked using an ultrasonic aspirator as well. And then our attention focuses on the fourth cranial nerve and dissecting it off of the tumor capsule. A papaverine-soaked Gelfoam is placed along the trochlear nerve, and the tumor along the trochlear nerve corridor is then debulked using the ultrasonic aspirator. After tumor resection, the facial nerve is reinspected to confirm that no inadvertent injury occurred.
SPEAKER: Dural sealant was used to protect the surgical site. A small piece of temporal fascia was used to cover the antrum of the middle ear. The remaining mastoid air cells were covered with bone wax and the middle fossa dura was reapproximated with 4-0 Nurolon sutures. The remainder of the defect including the mastoidectomy defect was filled with autologous fat graft from the abdomen.
SPEAKER: Six months postop, the patient was doing well with a resolution of all her trigeminal pain. She had no cranial neuropathies and her audiogram, demonstrated good hearing with 100% word recognition. T1 axial contrast imaging demonstrates a small residual tumor along the petroclival junction with adequate decompression of the cerebral peduncle and brainstem. In addition, sagittal and coronal imaging demonstrates that there's a small round of tumor, which is a much smaller radiosurgical target.
SPEAKER: Learning points for this case include preservation of cranial nerve function being paramount when resecting petroclival meningiomas. Adjunct radiosurgery can be a good option to manage these tumors long-term and preserve patient quality of life. A posterior petrosal approach allows for sufficient visualization from the jugular foramen up to the premedullary cistern.
SPEAKER: And the additional exposure of the presigmoid retrolabyrinthine dura allows for maneuverability to access higher portions of the tumor.