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James K. Liu

The angle of the straight sinus and tentorium cerebelli can often influence the choice of surgical approach to the pineal region. The supracerebellar infratentorial approach can be technically challenging and a relative contraindication in cases where the angle of the straight sinus and tentorium is very steep. Similarly, an occipital transtentorial approach, which uses a low occipital craniotomy at the junction of the superior sagittal sinus and transverse sinus, may not provide the best trajectory to the pineal region in patients with a steep tentorium. In addition, this approach often necessitates retraction on the occipital lobe to access the tentorial incisura and pineal region, which can increase the risk of visual compromise. In this operative video, the author demonstrates an alternative route using an endoscopic-assisted interhemispheric parieto-occipital transtentorial approach to a pineal region tumor in a patient with a steep straight sinus and tentorium. The approach provided a shorter route and more direct trajectory to the tumor at the tentorial incisura, and avoided direct fixed retraction on the occipital lobe when performed using the lateral position, thereby minimizing visual complications. This video atlas demonstrates the operative technique and surgical nuances, including the application of endoscopic-assisted microsurgical resection and operative pearls for preservation of the deep cerebral veins. In summary, the parieto-occipital transtentorial approach with endoscopic assistance is an important approach in the armamentarium for surgical management of pineal region tumors.

The video can be found here: https://youtu.be/Ph4veG14aTk.

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James K. Liu

Large deep-seated meningiomas of the falcotentorial region present a formidable surgical challenge. In this operative video, the author demonstrates the combined bi-occipital suboccipital transsinus transtentorial approach for microsurgical resection of a large falcotentorial meningioma. This approach involves division of the less dominant transverse sinus after assessment of the venous pressure before and after clipping of the sinus with continuous neurophysiologic monitoring. Mild retraction of the occipital lobe and cerebellum results in a wide supra- and infratentorial exposure of extensive pineal region tumors. This video atlas demonstrates the operative technique and surgical nuances, including patient positioning, supra- and infratentorial craniotomy, transsinus transtentorial incision, and tumor removal with preservation of the vein of Galen complex. In summary, the combined bi-occipital suboccipital transsinus transtentorial approach provides a wide supra- and infratentorial surgical corridor for removal of select falcotentorial meningiomas.

The video can be found here: https://youtu.be/3aD8h2uwBAo.

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James K. Liu

The surgical management of petroclival meningiomas remains a formidable challenge. These tumors are deep in the base of the skull and arise medial to the fifth cranial nerve. In this operative video, the author demonstrates the extended middle fossa approach with anterior petrosectomy to resect an upper petroclival meningioma extending into Meckel’s cave with brainstem compression. This approach is very useful for accessing deep tumors located above and below the tentorium, and between the fifth and seventh cranial nerves. Access to Meckel’s cave is readily achieved by opening the fibrous ring of the porous trigeminus. This video demonstrates the operative technique and surgical nuances of the skull base approach, useful anatomic landmarks of the middle fossa rhomboid for safe petrosectomy drilling, pearls for cranial nerve and neuro-otologic preservation, and exposure of Meckel’s cave. A gross-total resection was achieved, and the patient was neurologically intact. In summary, the extended middle fossa approach with anterior petrosectomy is an important strategy in the armamentarium for surgical management of petroclival meningiomas.

The video can be found here: https://youtu.be/jttwJIYPHC8.

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James K. Liu

The interhemispheric transcallosal approach is a versatile approach to access intraventricular tumors of the lateral and third ventricles. The advantages of using a transcallosal approach over a classical transcortical approach include a direct midline orientation with symmetrical access to both lateral ventricles and both walls of the third ventricle. In addition, violation of the cerebral cortex and the risk of postoperative seizures can be avoided. Central neurocytomas are rare benign tumors that represent approximately 0.1 to 0.5% of all primary brain tumors. They are typically located in the lateral ventricles and tend to present clinically with hydrocephalus. Currently, surgical removal with a gross-total resection is the treatment of choice. In this operative video manuscript, the author demonstrates an illustrative step-by-step technique for microsurgical resection of a large central neurocytoma involving both lateral ventricles in a patient with hydrocephalus using the interhemispheric transcallosal approach. A complete removal was performed without the need for permanent shunting. The operative technique and surgical nuances, including the surgical approach, intraventricular tumor removal, and closure are illustrated in this video atlas.

The video can be found here: http://youtu.be/KzC8QYsTKeg.

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James K. Liu

Retrochiasmatic third ventricular craniopharyngiomas are formidable tumors to remove surgically. Access to the third ventricle can be achieved through the lamina terminalis corridor. A skull base approach to the lamina terminalis can be performed using either an anterolateral approach (orbitozygomatic, pterional, supraorbital) or a midline approach (extended transbasal, subfrontal). The major disadvantage of an anterolateral approach is the lack of visualization of the ipsilateral wall of the third ventricle and hypothalamus. However, a midline transbasal approach eliminates this blind spot thereby providing direct visualization of both ependymal walls for safe dissection of the tumor. In this operative video manuscript, the author demonstrates an illustrative step-by-step technique for translamina terminalis resection of a retrochiasmatic retroinfundibular craniopharyngioma within the third ventricle via a modified one-piece extended transbasal approach. This approach uses the standard bifrontal craniotomy and incorporates the anterior wall of the frontal sinus as a one-piece flap. The inferior limit of the osteotomy is based along the coronal contour of the anterior skull base which eliminates any bony overhang that can obstruct the line of sight to the lamina terminalis. Additional removal of the supraorbital bar is not necessary. The operative technique for this skull base approach and surgical nuances for craniopharyngioma resection are illustrated in this video atlas.

The video can be found here: http://youtu.be/E3Bsp6dUdAE.

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James K. Liu

The surgical management of intramedullary spinal cord ependymomas remains a formidable challenge amongst neurosurgeons because of the potential risk of surgical morbidity. From on an oncological perspective, complete resection—if technically feasible—should be the goal of surgery, since this can result in excellent local control and progression-free survival. Advances in microsurgical techniques, intraoperative neurophysiological monitoring, and the use of lasers have contributed to our ability to achieve gross-total resection. This is also largely dependent on the presence of an identifiable surgical plane of dissection between the tumor and spinal cord, which appears to have a positive prognosis with overall neurological improvement. In this operative video manuscript, the author demonstrates an illustrative step-by-step technique for microsurgical resection of a thoracic intramedullary spinal cord ependymoma (T-3 to T-5) associated with an extensive cervicothoracic syrinx. The application of a handheld non-contact CO2 laser for performing the midline myelotomy is also highlighted. The operative technique and surgical nuances, including the surgical approach, intradural tumor removal, and closure, are illustrated in this video atlas.

The video can be found here: http://youtu.be/itE2tuBFmgw.

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James K. Liu

Intramedullary spinal cord cavernous malformations account for approximately 5% of all intraspinal lesions. These lesions can present with either acute neurological compromise secondary to hemorrhage inside the spinal cord, or with chronic progressive myelopathy due to repeated microhemorrhages. Surgical resection of spinal cord cavernous malformations remains the definitive treatment strategy for symptomatic lesions. Because of the intimate relationship with surrounding eloquent neural tissue, these lesions can be technically challenging to remove with a significant risk for morbidity. In this operative video, the author demonstrates an illustrative step-by-step technique for microsurgical resection of a large intramedullary spinal cord cavernous malformation at C4–5 causing progressive myelopathy. Complete resection was achieved without neurologic compromise. The operative technique and surgical nuances, including the surgical approach, intradural cavernoma removal, and spinal stabilization are illustrated.

The video can be found here: http://youtu.be/3FUjGSyrKO0.

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James K. Liu

Intraventricular meningiomas are rare tumors, accounting for approximately 0.5 to 3% of all intracranial meningiomas. The majority arise in the atrium of the lateral ventricle. The surgical management of these tumors remains a considerable challenge because of their deep location and proximity to critical structures. Complete resection, if safely possible, should be the goal of surgery since this results in the best rates of local control. Although various approaches exist to access the lateral ventricular system, selection of the optimal approach should be individualized to the patient based upon the location of the tumor within the ventricle, the tumor size, the origin of the vascular supply to the tumor, and the relationship to neighboring neurovascular structures at risk. In this operative video manuscript, the author demonstrates an illustrative step-by-step technique for microsurgical resection of a giant intraventricular meningioma of the left atrium via a transcortical parieto-occipital approach. The patient illustrated in this video presented with a large recurrent meningioma (> 5 cm) approximately 10 years after the initial resection. The tumor had grown around a pre-existing shunt catheter and resulted in loculated hydrocephalus. A complete resection and shunt revision were both performed at the same sitting. The operative technique and surgical nuances, including the surgical approach, intradural tumor removal, closure, and management of hydrocephalus are illustrated in this video atlas.

The video can be found here: http://youtu.be/vpdmZ1ccWSM.

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James K. Liu

Ventrally based meningiomas at the craniovertebral junction can be challenging tumors to remove because of their deep location anterior to the lower brainstem and upper cervical spinal cord, and close association with complex neurovascular structures. The extreme lateral transcondylar approach provides excellent access and exposure to anterior and anterolateral intradural tumors involving the region of the craniovertebral junction, including the lower third of the clivus, the foramen magnum, and the upper cervical spine. This approach allows safe access for removal of these difficult tumors without any neural retraction. In this operative video manuscript, the author demonstrates an illustrative step-by-step technique for microsurgical resection of a ventrally based meningioma extending from the foramen magnum to C-2 using the extreme lateral transcondylar approach. The operative technique and surgical nuances, including the surgical approach, intradural tumor removal, and cranial base reconstruction, are illustrated in this video atlas.

The video can be found here: http://youtu.be/4uvPpEtEShU.

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James K. Liu

Direct microsurgical clipping of complex paraclinoid carotid artery aneuryms remains a formidable technical challenge due to the auneurysm's deep location at the skull base, with adjacent bony anatomy, large size, wide neck, and complex neuroanatomical relationships. In this operative video atlas manuscript, the author demonstrates a step-by-step technique for microsurgical clip reconstruction of a large complex ventral paraclinoid carotid artery aneurysm, using a trapping and direct suction decompression strategy followed by multiple fenestrated clip reconstruction of the internal carotid artery (ICA) via a modified orbitozygomatic approach. The nuances of skull base techniques are illustrated including extradural optic nerve decompression, extradural anterior clinoidectomy, incision of the falciform ligament to untether the optic nerve, and release of the distal durai ring to obtain proximal control. Reconstruction of the ICA and preservation of the anterior choroidal artery were achieved with multiple fenestrated clips. Aneurysm obliteration and patency of flow through the ICA was confirmed on video indocyanine green and catheter angiography. Although novel endovascular strategies continue to evolve, these microsurgical skull base techniques should remain in the surgical armamentarium for treating these complex cranial base vascular lesions.

The video can be found here: http://youtu.be/IPS6lslk1ds.