Name:
Combined microsurgical-endoscopic paramedian supracerebellar-infratentorial approach for resection of a pineal low-grade glioma
Description:
Combined microsurgical-endoscopic paramedian supracerebellar-infratentorial approach for resection of a pineal low-grade glioma
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Duration:
T00H07M10S
Embed URL:
https://stream.cadmore.media/player/c409b832-fc11-48eb-bea9-3033e1e8a268
Content URL:
https://cadmoreoriginalmedia.blob.core.windows.net/c409b832-fc11-48eb-bea9-3033e1e8a268/21-19.mp4?sv=2019-02-02&sr=c&sig=fR32nkrXdpB7fiIRQmhGctYkwlKidcmq6YFtf5Z5xE4%3D&st=2024-04-28T20%3A08%3A06Z&se=2024-04-28T22%3A13%3A06Z&sp=r
Upload Date:
2021-10-27T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
SPEAKER 1: We present an illustrative case where a combined microsurgical and endoscopic paramedian supracerebellar infratentorial approach was used for resection of a pineal low-grade glioma. The patient is a 20-year-old male with no significant past medical history, who presented with the onset of severe headaches, blurred vision. His MRI with contrast revealed a lesion occupying the entire third ventricle with heterogeneous enhancement as well as obstructive hydrocephalus.
SPEAKER 1: His MR venography showed a dominant right transverse and sigmoid sinus with an absent or hypoplastic left transverse sinus. Due to the acute severity of his hydrocephalus, the patient was admitted for an endoscopic third ventriculostomy as well as endoscopic biopsy of the most anterior aspect of the tumor. The patient tolerated well that procedure, and pathology was consistent with a low-grade neuroepithelial tumor.
SPEAKER 1: An infratentorial supracerebellar paramedian approach was selected, as illustrated above, using a modified Concorde position, with the head tilted toward the right side approximately 30 degrees. That allowed for the operator to stand on the left side of the patient and comfortably reach into microsurgical portion. Somatosensory evoked potentials and motor evoked potentials were monitored throughout the surgery.
SPEAKER 1: Using neuronavigation, the location of the torcula, the transverse sinus, sigmoid sinuses, and superior sagittal sinus were identified. A long midline incision was used to expose superiorly the lower third of the superior sagittal sinus and inferiorly all the way down to the arch of C1. This allowed for a wide craniotomy that allowed us to safely dissect the lower third of superior sagittal sinus as well as the lateral extension of the transverse sinuses bilaterally.
SPEAKER 1: Once the craniotomy was completed, the dura was opened and reflected superiorly. The superior surface of the cerebellum was then carefully separated from the tentorium, and dissection proceeded along the tentorial incisura bilaterally. Next, the thick arachnoid that overlies the quadrigeminal cistern was sharply incised. And using careful dissection, the presenter cerebral vein, the vein of Galen, and the right and left basal veins of Rosenthal were exposed.
SPEAKER 1: Once the venous structures were sufficiently dissected, then the corridor in between the right basal vein of Rosenthal and the vein of Galen was further developed. The endoscope was then introduced into the field, increasing the exposure, and the posteromedial surface of the temporal occipital lobes were carefully elevated, showing the tumor. By alternating between the microscopic and the endoscopic view, additional exposure was reached.
SPEAKER 1: The release of the left superior cerebral artery further expanded that left paramedian corridor, allowing wide and unobstructed access to the posterior aspect of the tumor. Further expansion of the corridor in between the left superior cerebral artery and the vein of Galen provided final release of the left lateral border of the tumor. Attention was then directed to the posterior and inferior border of the tumor.
SPEAKER 1: Extracapsular dissection allowed for some additional increase in exposure. And then the neuronavigation system was used to ascertain that the lateral extent of the tumor on the left side was reached. Next, the tumor was further cauterized, and internal debulking was performed with suction aspiration device. Once the surface of the cerebellar vermis was released from tumor and the endoscope was reintroduced into the field, and the segment of tumor that was extending inferiorly toward the cerebral aqueduct was mobilized superiorly, exposing the posterior aspect of the posterior third ventricle.
SPEAKER 1: The tumor was then subsequently resected in a piecemeal fashion, again using suction, bipolar cautery, and the suction aspiration device. Further elevation of the inferior pole of the tumor finally revealed clear access to the aqueduct. Our attention was then directed to the right lateral margin of the tumor, which was carefully mobilized using microsurgical dissection and further resected also in a piecemeal fashion.
SPEAKER 1: Once the bulk of the majority of the tumor had been resected, the endoscope was reintroduced, and the most anterior aspect of the tumor capsule was identified, cauterized, and resected in the same fashion. At this time, we are working within the remnants of the cavity where the tumor was located. Once the resection was finalized, final hemostasis was achieved with bipolar cautery and Surgicel.
SPEAKER 1: And at this point, the endoscope was retracted, and the dura closure proceeded in a standard fashion. The patient tolerated the procedure without any new neurological deficits and his postoperative MRI revealed a gross-total resection of the tumor. Pathology revealed a pilocytic astrocytoma, and the patient had an uneventful postoperative course and was discharged home in good condition.
SPEAKER 1: He remained neurologically stable during his three-month follow-up, and we will continue with expectant management given the extent of resection and the benign pathological diagnosis.