Name:
Occipital posterior interhemispheric supratentorial approach for resection of midbrain cavernous malformation
Description:
Occipital posterior interhemispheric supratentorial approach for resection of midbrain cavernous malformation
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Duration:
T00H08M49S
Embed URL:
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Content URL:
https://cadmoreoriginalmedia.blob.core.windows.net/6ce7b13e-36c6-4674-8042-7cb50eb55d2c/21-33.mp4?sv=2019-02-02&sr=c&sig=BWUaYig7ieTmSMAR73CPP9I%2BApEQL1q9oLrRnJX0uRU%3D&st=2025-05-09T09%3A42%3A58Z&se=2025-05-09T11%3A47%3A58Z&sp=r
Upload Date:
2021-10-27T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
[MUSIC PLAYING]
SPEAKER: We present the case of an occipital, posterior, interhemispheric, supratentorial approach for resection of a midbrain cavernous malformation. This is a 50-year-old female diagnosed with a midbrain cavernous malformation who underwent radiosurgery at an outside institution. Her symptoms progressed into near-complete vertical gaze palsy, right hemiparesis, and dysarthria. She was referred to our institution for further management.
SPEAKER: Her neurological examination included a complete vertical gaze palsy, 4/5 power in her right upper and right lower extremity, as well as hyperreflexia on the right. This T2 sequence MRI shows a classic appearance of a cavernous malformation with a hemosiderin ring visualized.
SPEAKER: There is a T1 coronal and sagittal image showing the cavernous malformation. The rationale for the procedure were the patient's progressive neurological deficits and prevention of mass effect and hemorrhage. The risks of the procedure are listed below. The benefits were the prevention of a rehemorrhage and to remove the mass effect.
SPEAKER: There were no good alternatives for treatment. The setup included a Mayfield head holder in a supine position with the head rotated toward the right with a posterior midline incision. The microscope as well as intraoperative, neuronavigation and neuromonitoring were used. The key surgical steps are listed below.
SPEAKER: The approach of choice was an occipital, posterior, interhemispheric supratentorial approach. This cartoon shows the planned craniotomy site, which extends across the sagittal sinus. This is a Rhoton image illustrating the regional anatomy including the relationship of the pineal gland and the third ventricle, the tectal plate, fourth nerve, and the tentorium.
SPEAKER: Here we are with the craniotomy performed. The right side is down with gravity retraction. This is the beginning phase of the interhemispheric dissection. Neuronavigation is used to identify the location of the straight sinus.
SPEAKER: This Rhoton image shows the relationship of the straight sinus, the third ventricle, the cavernous malformation, and the pineal gland. We now prepare to divide the tentorium. One can appreciate the retractor-less surgical corridor provided by the right side of the head being down with gravity-assisted retraction.
SPEAKER: Microsurgical techniques are used to visualize both sides of tentorium to prevent neurovascular injury. The tentorium is now divided to widen the surgical corridor. The surgical corridor is now widened. We can visualize the deep venous system, which includes the vein of Galen, Rosenthal, the internal cerebral vein, and the pineal gland.
SPEAKER: This view is more posterior. Our approach came from a slightly more posterolateral trajectory. The arachnoid over the vein of Galen is visualized then divided. The pineal gland now comes into view.
SPEAKER: One can appreciate the splenium of the corpus callosum. The pineal gland is now transgressed. The pineal gland has now been removed, and the cavernous malformation is well visualized.
SPEAKER: Throughout this process, neuronavigation was used in order to confirm our trajectory was appropriate. The resection of the cavernous malformation now begins using standard microsurgical techniques.
SPEAKER: SSEP and MEP as well as cranial nerve monitoring was utilized throughout this resection. One can appreciate the direct access to this lesion provided by the occipital interhemispheric approach.
SPEAKER: Cavernous malformation is now removed. The surgical cavity is inspected to ensure no residual remains. Cavernous malformations are low-flow lesions. Brainstem cavernous malformations comprise 9% to 30% of cavernous malformations with the rehemorrhage rates listed below. We chose the occipital, posterior, interhemispheric, supratentorial approach because it offered a direct access to the lesion, given the fact that a steep tentorium was present.
SPEAKER: These supracerebellar infratentorial approach, even with a paramedian extension, was not the approach of choice due to the steepness of the tentorium and the superior extension of the cavernous malformation into the third ventricle. The indications, advantages, and disadvantages are listed here. Other approaches have been described, but were not the approach of choice in this situation. The anterior interhemispheric transcallosal approach could access the third ventricle.
SPEAKER: However, the working corridor would have been much longer and less direct to the lesion. The anterolateral transsylvian approach or endoscopic supracerebellar infratentorial approach have also been described, but were not considered appropriate for this lesion. Their indications, advantages, and disadvantages are listed here.
SPEAKER: The patient remained at her neurological baseline in the immediate postoperative period and showed significant improvement in her right upper and right lower extremity and vertical gaze palsy in long-term follow-up. The postoperative MRI shows gross total resection of the cavernous malformation.
SPEAKER: Our references are listed here.
