Suprabulbar Approach to Jugular Fossa Tumors: 2-Dimensional Operative Video

Owing to their scarcity, location, and intricate neurovascular associations, jugular fossa tumors are among the most challenging pathologies encountered by the neurosurgeon.1 While paragangliomas originate within and often occlude the jugular bulb, schwannomas and meningiomas are extra-bulbar and typically do not impede venous flow.2 Schwannomas typically arise from an extradural origin, expanding the jugular foramen.3-5 Meningiomas are intradural and cause hyperostosis of the jugular tubercle.6 We described and have been exposing and resecting jugular fossa tumors through a presigmoid suprabulbar infralabyrinthine window6 that has been detailed in cadaveric studies.7,8 This approach maintains the patency of the jugular bulb without breaching the labyrinths or manipulating the facial nerve. It is applicable to cases with partially impaired hearing and intact lower cranial nerves. The carotid artery can be identified by neuronavigation and micro-Doppler ultrasonography. This approach provides a direct lateral trajectory with a short distance to the jugular fossa and cerebellopontine angle. Early exposure and central debulking of the tumor minimize manipulation of the exquisitely sensitive lower cranial nerves. The distal aspect of these tumors can be removed with endoscopic assisted techniques.9 The first patient is a 49-yr-old woman with a previously irradiated schwannoma who presented with worsening neurologic deficits—an extradural suprabulbar approach was used to resect this tumor. The second patient is a 27-yr-old woman with an enlarging meningioma and associated neurological dysfunction; this tumor was resected using the suprabulbar approach with opening of the presigmoid dura. Both patients have consented to surgery and publication of images. Image at 2:27 and 6:38 reprinted from Arnautović et al, with permission from JNSPG. Image at 2:50 and 6:45 ©Ossama Al-Mefty 1997, reused with permission.

Bridge technique for hemifacial spasm with vertebral artery involvement

Background To assess efficacy and safety of a newly developed decompression technique in microvascular decompression for hemifacial spasm (HFS) with vertebral artery (VA) involvement. Methods A rigid Teflon (Bard® PTFE Felt Pledget, USA) with the ends placed between the lower pons and the flocculus creates a free space over the root exit zone (REZ) of the facial nerve (bridge technique). The bridge technique and the conventional sling technique for VA-related neurovascular compression were compared retrospectively in 60 patients. Elapsed time for decompression, number of Teflon pieces used during the procedure, and incidences of intraoperative manipulation to the lower cranial nerves were investigated. Postoperative outcomes and complications were retrospectively compared in both techniques. Results The time from recognition of the REZ to completion of the decompression maneuvers was significantly shorter, and fewer Teflon pieces were required in the bridge technique than in the sling technique. Lower cranial nerve manipulations were performed less in the bridge technique. Although statistical analyses revealed no significant differences in surgical outcomes except spasm-free at postoperative 1 month, the bridge technique is confirmed to provide spasm-free outcomes in the long-term without notable complications. Conclusions The bridge technique is a safe and effective decompression method for VA-involved HFS.

Right medium-sized vestibular schwannoma with trigeminal neuralgia post-fractionated radiotherapy

A patient with trigeminal neuralgia secondary to a vestibular schwannoma underwent fractionated radiotherapy without relief of her pain. She was then effectively treated with microsurgical resection of her tumor. Early identification of the lower cranial nerves and the origin of the facial and vestibulocochlear nerves is key to determining the operative corridors for vestibular schwannoma resection. To effectively treat trigeminal neuralgia, the trigeminal nerve root entry zone and motor branch are clearly identified and decompressed. Fractioned radiotherapy does not effectively treat trigeminal neuralgia secondary to vestibular schwannoma compression. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID21112

Foramen Magnum Meningioma—The Attainment of the Intra-Arachnoidal Dissection: 2-Dimensional Operative Video

Ventral foramen magnum meningiomas are a forbidding lesion. The stake is so high with a risk of devastating paralysis and respiratory failure. Careful preoperative clinical and radiological evaluation is necessary to implement the best treatment plan. Successful surgical intervention depends on paying high attention to minute details throughout the case, from intratracheal intubation to extubation. The neural head-on-neck position is critical to avoid further medullary compression at intubation and positioning.1 Extensive neurophysiological monitoring, including somatosensory, motor, brainstem evoked potential, and cranial nerves, during the positioning and throughout the case, is extremely helpful to detect early signs of dysfunction.1 To expose and access ventral tumors, partial condyle resection and vertebral artery transposition are invaluable techniques.2,3 Preservation and minute manipulation of the vital neurovascular structures at this junction that includes the medullar, anterior spinal artery, posterior inferior cerebellar artery, vertebral junction perforators, and lower cranial nerves are essential for good outcomes. This is achieved by microsurgical intra-arachnoidal dissection under high magnification and after debulking the tumor to establish that plane.1,3,4 The demonstration of this technique is the purpose of this article. We demonstrate these surgical tenets applied to the resection of a large ventral foramen magnum meningioma extending from the midclivus to the C3 vertebral body level in a 54-yr-old female presenting with swallowing difficulties. The patient consented to the surgical intervention and the publication of her images. Image at 1:38 reprinted with permission from Al-Mefty O, Operative Atlas of Meningiomas. Vol 1, © LWW, 1998.

Transcondylar Approach for Resection of Medullary Cavernous Malformation: 2-Dimensional Operative Video

Cavernous malformations located within the brainstem present with a high rate of neurological symptoms and carry a more aggressive course in both pediatric and adult populations.1,2 Cavernomas within the medulla are the rarest form, representing only 5% of all brainstem lesions.3 Repeated hemorrhage of brainstem cavernomas is associated with significant and cumulative neurological deficits and thus requires treatment.4 Microsurgical resection has become the optimal mode of treatment with the aim of resecting the live malformation and not merely the multiaged, organized hematoma.4 This is best achieved by approaching the cavernoma at the location where it projects to the surface and entering the lesion through a safe brainstem anatomic zone. For ventrally located lesions in the medulla, a transcondylar skull base approach provides a direct trajectory to the entry zone through a short surgical distance without the need to manipulate or retract neurovascular structures.5-8 Neuronavigation and intraoperative neurophysiological monitoring of somatosensory evoked potential, motor, and lower cranial nerves are adjuncts to increase patient safety. Radiosurgery for the treatment of brainstem cavernous malformations has been proposed; however, it demonstrates high risk and variable and often poor response rates.9 We present a surgical video demonstrating the transcondylar approach and resection of a medullary cavernoma in a 54-yr-old woman who has had multiple known prior hemorrhages and presented with a new onset of facial numbness and weakness, ataxia, and left body sensory loss. The patient consented to surgery and to photograph publication. Images at 1:28, 1:43 (left), 2:02 from Al-Mefty O, Operative Atlas of Meningiomas, © LWW, 1997,5 with permission. Images at 1:43 (right) from Arnautovic et al,8 with permission from JNSPG.

RARE-09. POORLY DIFFERENTIATED CLIVAL CHORDOMA IN EXTREME YOUNG AGE; CASE ILLUSTRATION AND REVIEW OF LITERATURE

Chordomas are rare tumors believed to be originated from notochordal remnants. Of all intracranial neoplasms, the incidence of cranial chordomas is less than 1%1. The youngest patient with an intracranial chordoma reported in the literature was a newborn in the first few days after birth9. Intracranial chondroma are more predominant in males compared to females1. The clinical features of intracranial chondroma in the pediatric age group commonly include increased Intracranial pressure, lower cranial nerves palsy, and torticollis2. There is no optimum treatment, however, surgical resection of the tumor followed by radiation therapy reported successful outcome3. This is a case of a poorly differentiated clival chordoma of a 23-month old boy. The clinical features, pathological, radiological findings, and surgical technique are discussed with an elaboration of the current review of the literature of clival chordoma in the extreme young age group. To the best of our knowledge, this is the youngest age of clivus chordoma reported in Saudi Arabia.

Selective Dysarthria due to Clival Chordoma

Chordoma is a rare, slow-growing malignant bone tumor originating from the remains of the notochord and predominantly affecting the axial skeleton (especially the sacrum and occipital region). Clival chordomas represent 1-4% of intracranial neoplasms and only 0.2% of central nervous system tumors, so their prevalence is very low (1 case per 2 million inhabitants). The mean age of onset is in the 4th decade of life and its usual symptoms are diplopia due to involvement of the ocular pairs, dysphagia and headache (1,2). More rarely, it affects phonetics in isolation due to the involvement of the lower cranial nerves (hypoglossal or glossopharyngeal) (3-5).

Endoscopic-Assisted Resection of Anterior Foramen Magnum Meningiomas through a Midline Suboccipital Subtonsillar Approach

Objective This study was aimed to demonstrate the resection of anterior foramen magnum meningiomas through an endoscopic-assisted posterior midline suboccipital subtonsillar approach. Design This study was designed with illustration of the surgical steps and safety of this approach. Setting Evidence of cerebrospinal fluid (CSF) cleft between the tumor and brainstem on MRI was studied (Fig. 1A and B). Preoperative tracheotomy was considered in cases of preoperative dysphagia to prevent any further neurological deterioration due to the bilateral access through the lower cranial nerves corridors. Semisitting position with extensive electrophysiological neuromonitoring and transesophageal echocardiogram was adopted. A standard midline incision with bilateral suboccipital craniotomy and C1-laminotomy was performed (Fig. 2A). After partial resection and elevation of the tonsils, tumor was debulked unilaterally around the lower cranial nerves and the vertebral artery, devascularized from the clival dura and then dissected from the brainstem (Fig. 2B, C). Endoscopic-assisted removal of its anterior portion followed. The same procedure was repeated from the opposite site for the contralateral portion, before approaching the purely anterior part with endoscope assistance (Fig. 2D). Participants Four consecutive patients were included in the study. Main Outcome Measures Grade of tumor resection and outcome (mRS) were primary measurement of this study. Results Clinical outcome and grade of resection are comparable to other series of patient treated with other foramen magnum approaches (Fig. 1C and D). Conclusion Anterior foramen magnum meningiomas can be safely removed through this relatively faster midline suboccipital approach with bilateral exposure of lower cranial nerves (CNs) and vertebral arteries and lower approach-related morbidity (no condyle drilling). The surgical corridor is created by the tumor during debulking reducing need for brain retraction and the removal of the anterior dural attachment coagulated under the microscope is verified and completed endoscopically with pituitary curettes (Simpson's grade II) (Fig. 1C and D).The link to the video can be found at: https://youtu.be/9eACAJVwQBs.