Technique Nuances for Functional Preservation of Lower Cranial Nerves during Surgical Management of Ventral Foramen Magnum Meningiomas Via a Dorsal Lateral Approach

Object Aneurysms of the vertebral artery (VA) and proximal posterior inferior cerebellar artery (PICA) are rare and challenging lesions, as they are located in front of the brainstem and surrounded by the lower cranial nerves. Many different approaches have been described for their treatment, and have yielded different results. With the use of different examples of lesions, the authors describe their surgical strategy in the management of VA and PICA aneurysms. Methods The far-lateral approach was used, and the potential of its different extensions according to the specific anatomical location and configuration of different types of aneurysms is emphasized. Conclusions With the present knowledge of the microsurgical anatomy in the region of the foramen magnum, the far-lateral approach can be tailored to the specific anatomical and morphological configuration of an aneurysm in this region with good surgical results.

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Far Lateral Craniotomy for Resection of Foramen Magnum Meningioma

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0039-1698828 ◽

2019 ◽

Vol 80 (S 04) ◽

pp. S355-S357

Author(s):

Robert T. Wicks ◽

Xiaochun Zhao ◽

Celene B. Mulholland ◽

Peter Nakaji

Keyword(s):

Cranial Nerves ◽

Craniocervical Junction ◽

Foramen Magnum ◽

Occipital Condyle ◽

Formidable Challenge ◽

Close Proximity ◽

Vertebrobasilar Circulation ◽

Far Lateral ◽

Lower Cranial Nerves ◽

Gain Access

Abstract Objective Foramen magnum meningiomas present a formidable challenge to resection due to frequent involvement of the lower cranial nerves and vertebrobasilar circulation. The video shows the use of a far lateral craniotomy to resect a foramen magnum meningioma. Design, Setting, and Participant A 49-year-old woman presented with neck pain and was found to have a large foramen magnum meningioma (Fig. 1A, B). Drilling of the posterior occipital condyle was required to gain access to the lateral aspect of the brain stem. The amount of occipital condyle resection varies by patient and pathology. Outcome/Result Maximal total resection of the tumor was achieved (Fig. 1B, C), and the patient was discharged on postoperative day 4 with no neurologic deficits. The technique for tumor microdissection (Fig. 2) is shown in the video. Conclusion Given the close proximity of foramen magnum meningiomas to vital structures at the craniocervical junction, surgical resection with careful microdissection and preservation of the overlying dura to prevent postoperative pseudomeningocele is necessary to successfully manage this pathology in those patients who are surgical candidates.The link to the video can be found at: https://youtu.be/Mds9N1x2zE0.

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Surgical approaches to posterior fossa tumours

Oxford Textbook of Neurological Surgery ◽

10.1093/med/9780198746706.003.0031 ◽

2019 ◽

pp. 375-382

Author(s):

Jacques J. Morcos ◽

Osaama Khan ◽

Ashish H. Shah

Keyword(s):

Posterior Fossa ◽

Fourth Ventricle ◽

Cranial Nerves ◽

Surgical Techniques ◽

Foramen Magnum ◽

Surgical Approaches ◽

Tumour Resection ◽

Surgical Morbidity ◽

Preoperative Workup ◽

Lower Cranial Nerves

Lesions of the fourth ventricle and foramen magnum can be difficult to manage surgically due to their proximity to critical brainstem structures. Understanding the anatomy of the fourth ventricle, lower cranial nerves, and basilar cisterns remains paramount for deciding surgical approaches to this location. Detailed preoperative workup and planning are necessary to minimize surgical morbidity and maximize tumour resection. This chapter provides an overview of the relevant anatomy and surgical techniques for lesions in the posterior fossa, specifically the fourth ventricle the foramen magnum. We will split this chapter into two main sections: microsurgical approaches to the fourth ventricle and skull base approaches to the foramen magnum.

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Unilateral extended suboccipital approach for a C1 dumbbell schwanoma

Romanian Neurosurgery ◽

10.1515/romneu-2015-0004 ◽

2015 ◽

Vol 22 (1) ◽

pp. 38-42

Author(s):

R.M. Gorgan ◽

Angela Neacşu ◽

A. Giovani

Keyword(s):

Vertebral Artery ◽

Fibrous Tissue ◽

Cranial Nerves ◽

Gain Control ◽

Complete Removal ◽

Craniovertebral Junction ◽

Lateral Approach ◽

Far Lateral Approach ◽

Far Lateral ◽

Lower Cranial Nerves

Abstract Craniovertebral junction tumors represent a complex pathology carrying a high risk of injuring the vertebral artery and the lower cranial nerves. Dumbbell C1- C2 schannomas are very rare tumors in this location. We present a case of a 66 years old male accepted for left laterocervical localized pain, headache and vertigo, with a large C1 dumbbell schwannoma extending in lateral over the C1 arch and displacing the C3 segment of the vertebral artery superiorly and anteriorly. Complete removal of the tumor was achieved using a far lateral approach. The approach is discussed with focus on the vertebral artery anatomy as the approach should give enough space to gain control of the artery without creating instability. Safe removal of C1 nerve root schwanomas can be achieved even if they compress and displace the vertebral artery by entering a fibrous tissue plane between the tumor and the vertebral artery.

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Endoscopic Endonasal Approach to Foramen Magnum Meningioma—Technical Note and Case Example

Arquivos Brasileiros de Neurocirurgia Brazilian Neurosurgery ◽

10.1055/s-0038-1673428 ◽

2018 ◽

Vol 37 (04) ◽

pp. 362-366

Author(s):

Flavio Romero ◽

Rodolfo Vieira ◽

Bruno Ancheschi

Keyword(s):

Cranial Nerves ◽

Craniocervical Junction ◽

Foramen Magnum ◽

Technical Note ◽

Open Approach ◽

Endoscopic Endonasal Approach ◽

Endonasal Approach ◽

Endoscopic Endonasal ◽

Midline Approach ◽

Lower Cranial Nerves

AbstractForamen magnum (FM) tumors represent one of the most complex cases for the neurosurgeon, due to their location in a very anatomically complex region surrounded by the brainstem and the lower cranial nerves, by bony elements of the craniocervical junction, and by the vertebrobasilar vessels. Currently, the open approach of choice is a lateral extension of the posterior midline approach including far lateral, and extreme lateral routes. However, the transoraltranspharyngeal approach remains the treatment of choice in cases of diseases affecting the craniocervical junction. For very selective cases, the endoscopic endonasal route to this region is another option. We present a case of a ventral FM meningioma treated exclusively with the endoscopic endonasal approach.

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

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0041-1727126 ◽

2021 ◽

Author(s):

Florian Roser ◽

Luigi Rigante

Keyword(s):

Anterior Part ◽

Tumor Resection ◽

Cranial Nerves ◽

Foramen Magnum ◽

Anterior Portion ◽

Suboccipital Craniotomy ◽

Dural Attachment ◽

Surgical Corridor ◽

Lower Cranial Nerves ◽

Brain Retraction

Abstract 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.

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Endoscope-Assisted Resection of Extra-Axial Premedullary Neurenteric Cyst via Far Lateral-Supracondylar Approach: 2-Dimensional Operative Video

Operative Neurosurgery ◽

10.1093/ons/opab300 ◽

2021 ◽

Author(s):

Kunal V Vakharia ◽

Ryan M Naylor ◽

Jamie J Van Gompel

Keyword(s):

Posterior Inferior Cerebellar Artery ◽

Cranial Nerves ◽

Craniocervical Junction ◽

Foramen Magnum ◽

Lateral Approach ◽

Neurenteric Cyst ◽

En Bloc ◽

Icg Angiography ◽

Far Lateral Approach ◽

Far Lateral

Abstract Neurenteric cysts are rare congenital lesions that may compress the ventral brainstem.1-9 In this operative video, we illustrate the surgical treatment of an intradural extra-axial neurenteric cyst extending from the lower pons to the craniocervical junction. The patient, an asymptomatic 52-yr-old female, underwent surveillance imaging of the premedullary lesion for 14 yr without progression. However, after developing progressive strain-induced headaches, imaging revealed a significant enlargement of the lesion with brainstem compression and partial obstruction of the foramen magnum. Therefore, surgical resection was pursued. The patient consented to the procedure. The patient underwent a lateral suboccipital craniotomy and C1 laminectomy through a far lateral approach. The lesion was immediately visualized upon opening the dura. After identifying the cranial nerves, we resected the tumor while taking care to preserve the neurovascular elements of the cerebellopontine angle and foramen magnum. During the resection, we unexpectedly encountered a firm nodule that was adherent to the right posterior inferior cerebellar artery. This was meticulously dissected and removed en bloc using intraoperative indocyanine green (ICG) angiography. The cavity was inspected with 0-degree and 30-degree endoscopes to ensure complete resection of the lesion. Gross total resection was confirmed on postoperative magnetic resonance imaging. The patient was neurologically intact with no cranial nerve abnormalities and discharged home on postoperative day 3. This case demonstrates that the far lateral-supracondylar approach affords safe access to the ventral pontomedullary and craniocervical junctions and that intraoperative adjuncts, including ICG angiography and endoscopic visualization, can facilitate complete lesion resection with excellent clinical outcomes.

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Intraoperative Mapping and Monitoring for Rootlets of the Lower Cranial Nerves Related to Vocal Cord Movement

Neurosurgery ◽

10.1227/neu.0000000000001109 ◽

2015 ◽

Vol 78 (6) ◽

pp. 829-834 ◽

Cited By ~ 3

Author(s):

Masahiko Wanibuchi ◽

Yukinori Akiyama ◽

Takeshi Mikami ◽

Katsuya Komatsu ◽

Toshiya Sugino ◽

...

Keyword(s):

Endotracheal Tube ◽

Vocal Cord ◽

Cranial Nerves ◽

Jugular Foramen ◽

Visual Signals ◽

Electromyographic Activity ◽

Intraoperative Mapping ◽

Lower Cranial Nerves ◽

Risk Of Aspiration ◽

Functional Preservation

Abstract BACKGROUND: Damage to the motor division of the lower cranial nerves that run into the jugular foramen leads to hoarseness, dysphagia, and the risk of aspiration pneumonia; therefore, its functional preservation during surgical procedures is important. Intraoperative mapping and monitoring of the motor rootlets at the cerebellomedullary cistern using endotracheal tube electrodes is a safe and effective procedure to prevent its injury. OBJECTIVE: To study the location of the somatic and autonomic motor fibers of the lower cranial nerves related to vocal cord movement. METHODS: Twenty-four patients with pathologies at the cerebellopontine lesion were studied. General anesthesia was maintained with fentanyl and propofol. A monopolar stimulator was used at amplitudes of 0.05 to 0.1 mA. Both acoustic and visual signals were displayed as vocalis muscle electromyographic activity using endotracheal tube surface electrodes. RESULTS: The average number of rootlets was 7.4 (range, 5-10); 75% of patients had 7 or 8 rootlets. As many as 6 rootlets (2-4 in most cases) were responsive in each patient. In 23 of the 24 patients, the responding rootlets congregated on the caudal side. The maximum electromyographic response was predominantly in the most caudal or second most caudal rootlet in 79%. CONCLUSION: The majority of motor fibers of the lower cranial nerves run through the caudal part of the rootlets at the cerebellomedullary cistern, and the maximal electromyographic response was elicited at the most caudal or second most caudal rootlet.

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“Far-Medial” Expanded Endonasal Approach to the Inferior Third of the Clivus

Operative Neurosurgery ◽

10.1227/01.neu.0000369926.01891.5d ◽

2010 ◽

Vol 66 (suppl_2) ◽

pp. ons211-ons220 ◽

Cited By ~ 15

Author(s):

Victor A. Morera ◽

Juan C. Fernandez-Miranda ◽

Daniel M. Prevedello ◽

Ricky Madhok ◽

Juan Barges-Coll ◽

...

Keyword(s):

Cranial Nerves ◽

Foramen Magnum ◽

Direct Access ◽

Occipital Condyle ◽

Endonasal Approach ◽

Endoscopic Endonasal ◽

Hypoglossal Canal ◽

Expanded Endonasal Approach ◽

Surgical Corridor ◽

Lower Cranial Nerves

Abstract OBJECTIVE The endoscopic endonasal transclival approach is a valid alternative for treatment of lesions in the clivus. The major limitation of this approach is a significant lateral extension of the tumor. We aim to identify a safe corridor through the occipital condyle to provide more lateral exposure of the foramen magnum. METHODS Sixteen parameters were measured in 25 adult skulls to analyze the exact extension of a safe corridor through the condyle. Endonasal endoscopic anatomic dissections were carried out in nine colored latex–injected heads. RESULTS Drilling at the lateral inferior clival area exposed two compartments divided by the hypoglossal canal: the jugular tubercle (superior) and the condylar (inferior). Completion of a unilateral ventromedial condyle resection opens a 3.5 mm (transverse length) * 10 mm (vertical length) lateral surgical corridor, facilitating direct access to the vertebral artery at its dural entry point into the posterior fossa. The supracondylar groove is a reliable landmark for locating the hypoglossal canal in relation to the condyle. The hypoglossal canal is used as the posterior limit of the condyle removal to preserve more than half of the condylar mass. The transjugular tubercle approach is accomplished by drilling above the hypoglossal canal, and increases the vertical length of the lateral surgical corridor by 8 mm, allowing for visualization of the distal cisternal segment of the lower cranial nerves. CONCLUSION The transcondylar and transjugular tubercle “far medial” expansions of the endoscopic endonasal approach to the inferior third of the clivus provide a unique surgical corridor to the ventrolateral surface of the ponto- and cervicomedullary junctions.

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Suboccipital Lateral Approach for Resection of Cerebellopontine Angle Meningioma: Operative Video and Technical Nuances

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0038-1669982 ◽

2018 ◽

Vol 79 (S 05) ◽

pp. S397-S398

Author(s):

Mateus Reghin Neto ◽

Heros Melo Almeida ◽

João Almeida ◽

Ygor Alexim ◽

Matheus de Almeida ◽

...

Keyword(s):

Treatment Options ◽

Cranial Nerves ◽

Lateral Approach ◽

Magnetic Resonance Imaging Scan ◽

Extensive Resection ◽

Tumor Margins ◽

Postoperative Mri ◽

History Of ◽

The Right ◽

Lower Cranial Nerves

We present the case of a 34-year-old woman, who presented to our department with a 4 months history of dizziness, hearing loss, and tinnitus on the right side. MRI (magnetic resonance imaging) scan demonstrated a large extra-axial lesion, suggestive of a meningioma, with dural attachments to the petrosal bone surface and tentorium, closely related with the trigeminal, abducens, facial, vestibulocochlear, and lower cranial nerves in the right side. Treatment options were discussed with the patient, and surgical resection was selected to remove the lesion, and decompress the cranial nerves and brainstem. The surgery was performed with a patient in a semi-seated position with head placed in a flexed, nonrotated position. A right lateral suboccipital approach was performed, exposing the right transverse and sigmoid sinuses. After dura opening, microsurgical dissection was used to open the cisterna magna, and obtain cerebellum relaxation. That was followed by identification of cranial nerves VII–XII and then identification of the tumor itself. Tumor debulking was then performed with use of suction and ultrasonic aspirator. After extensive resection, the tumor margins were dissected away from brainstem, cerebellum, and cranial nerves. Finally, the tumor attachment to the tentorium was coagulated and cut and the tumor was completely removed. Postoperative MRI confirmed complete resection of the tumor. The patient was discharged on the 1st week after surgery, with no additional postoperative deficits or complications.The link to the video can be found at: https://youtu.be/aZ3jhZTAeAA.

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