Far-lateral Transcondylar Approach to Anterior Foramen Magnum Lesions - Our Experience

Approaching Intradural Lesions of the Anterior Foramen Magnum and Craniocervical Junction: Anatomical Comparison of the Open Posterolateral and Anterior Extended Endonasal Endoscopic Approaches

BACKGROUND

Lesions of the foramen magnum (FM) and craniocervical junction area are traditionally managed surgically through anterior, anterolateral, and posterolateral skull-base approaches. This anatomical study aimed to compare the usefulness of a modified extended endoscopic approach, the so-called far-medial endonasal approach (FMEA), versus the traditional posterolateral far-lateral approach (FLA).

METHODS

Ten fixed silicon-injected heads specimens were used in the Skull Base ENT-Neurosurgery Laboratory of the University Hospital of Strasbourg, France. A total of 20 FLAs and 10 FMEAs were realized. A high-resolution computed tomography scan was performed for quantitative analysis of the different approaches. The analysis aimed to estimate the extent of surgical exposure and freedom of movement (maneuverability) through the operating channel using a polygonal surface model to obtain a morphometric estimation of the area of interest (surface and volume) on postdissection computed tomography scans using Slicer 3D software.

RESULTS

FMEA allows for a more direct route to the anterior FM, with wider brainstem exposure compared with the FLA and an excellent visualization of all anterior midline structures. The limitations of the FMEA include the deep and narrow surgical corridor and difficulty in reaching lesions located laterally over the jugular foramen and hypoglossal canal.

CONCLUSIONS

The FMEA and FLA are both effective surgical routes to reach FM and craniocervical junction lesions. Modern skull base surgeons should have a good command of both because they appear complementary. This anatomical study provides the tools for comprehensive preoperative evaluations and selection of the most appropriate surgical approach.

Craniocervical junction intradural extramedullary meningioma with cord compression

Craniocervical spine meningiomas are rare. They often present with non-specific motor or sensory symptoms. Presenting symptoms can include gait ataxia, radiculopathy, myelopathy, back pain and sensory deficits. Spinal meningiomas are slow-growing tumours, with an insidious onset. Due to the critical location of craniocervical meningiomas, severe symptoms such as respiratory distress and quadriparesis are possible. We describe the clinical presentation of a craniocervical junction meningioma, its relevant neuroimaging findings, diagnostic challenges and management. A woman in her 30s presented with a subacute onset of neck pain, headaches, paresthesia and a Hoffman's sign of the left upper extremity. A cervical spine MRI revealed an intradural extramedullary craniocervical junction meningioma involving the C1 segment with cord compression. The tumour measured 1.4×2×2.2 cm. A mid-line suboccipital craniectomy, tumour resection (Simpson grade II) with cervical laminectomy, and dural grafting were completed for definitive management. A brief literature review was conducted yielding a total of 24 cases.

Modified retrosigmoid extended approach to jugular tubercle meningioma: A video abstract

Background:

Primary jugular fossa meningiomas are one of the rarest subgroups of meningioma, with an estimated incidence of 0.7–4.3% of all skull base meningiomas. Indeed, only 145 cases of jugular foramen meningiomas have been reported in the literature to date. While meningiomas of this region are typically referred to as “jugular foramen meningiomas,” we make a distinction between meningiomas arising directly from the foramen itself, and those arising from the jugular tubercle. Jugular tubercle meningiomas, therefore, represent an even smaller subset of an already uncommon location for meningiomas. The jugular tubercle is the upper surface of the lateral parts of occipital bone presents an oval eminence, which overlies the hypoglossal canal and is sometimes crossed by an oblique groove for the glossopharyngeal, vagus, and accessory nerves. Only eight cases in the anterior foramen magnum lesions excised by a far lateral retrosigmoid approach have been described. The aim of this video article is to describe the surgical approach the senior author used to access lesion involving the jugular tubercle.

Case Description:

In this surgical video, we present a case of a 56-year-old female presented to our hospital with dizziness, headache, lower cranial nerves deficits, and lower limbs weakness. On exam, she was noted to have a left paraparesis, 9th, 10th, and 11th nerves palsies. An MRI scan demonstrated a mass in the region of the left jugular tubercle. Frozen section was suggestive of meningioma and our patient underwent a successful near total resection with no permanent neurologic sequelae.

Conclusion:

Jugular tubercle meningiomas are one of the rarest subgroups of meningioma. The described modified retrosigmoid approach provides outstanding access to the entire ventrolateral brainstem and cerebellopontine angle, with reduced approach related morbidity.

An investigation of craniocervical stability post-condylectomy

Background:

Occipital condylectomy is often necessary to gain surgical access to various neurological pathologies. As the lateral limit of the craniovertebral junction (CVJ), partial condylectomy can lead to iatrogenic craniocervical instability. What was once considered an inoperable location is now the target of various complex neurosurgical procedures such as tumor resection and aneurysm clipping.

Methods:

In this study, we will review the anatomical structure of the CVJ and provide the first comprehensive assessment of studies investigating craniovertebral stability following condylectomy with the transcondylar surgical approaches. Furthermore, we discuss future considerations that must be evaluated to optimize the chances of preserving craniocervical stability postcondylectomy.

Results:

The current findings postulate upward of 75% of the occipital condyle can be resected without significantly affecting mobility of the CVJ. The current findings have only examined overall dimensions and have not established a significant correlation into how the shape of the occipital condyles can affect mobility. Occipitocervical fusion should only be considered after 50% condyle resection. In terms of indicators of anatomical stability, components of range of motion (ROM) such as the neutral zone (NZ) and the elastic zone (EZ) have been discussed as potential measures of craniocervical mobility. These components differ by the sense that the NZ has little ligament tension, whereas the EZ does represent ROM where ligaments experience tension. NZ is a more sensitive indicator of instability when measuring for instability postcondylectomy.

Conclusion:

Various transcondylar approaches have been developed to access this region including extreme-lateral and far-lateral condylectomy, with hopes of preserving as much of the condyle as possible and maintaining postoperative craniocervical stability.

Complete resection of pure anterior foramen magnum meningioma without neurovascular injuries poses a big challenge: Case report

Introduction and importance

Meningiomas are common neoplasms representing 14.3–19% of all intracranial tumors. Among all the meningiomas, only 1.8–3.2% arises at the foramen magnum (FM) level.

Most of the lesions (68%–98%) arising anterolaterally, followed by postolateral, purely posterior and, more rarely, purely anterior.

Case presentation

We report a case of A 42-year-old female presented with a history of neck pain with progressive spastic hemiparesis.

Clinical Discussion

MRI revealed well-defied pure anterior and on both sides of vertebral artery, foramen magnum lesion. Through conservative transcondylar approach, Lesion was removed totally in a piecemeal fashion. Histopathology revealed meningothelial meningioma. The patient had a dramatic recovery.

Conclusion

The exposure allowed by the far-lateral retrocondylar or partial transcondylar approach is adequate for resecting even anterior intradural FMMs.

Reports about Foramen magnum meningioma aren't common, but reports on pure anterior foramen magnum meningioma are very rare. The prerequisite for treating FM meningiomas (FMMs) is the perfect knowledge of the surgical anatomy. The opportunity to give the patient a symptom-free and normal life should not be missed in such cases.

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Only 1.8–3.2% of all meningiomas are located at foramen magnum (FM).

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Foramen magnum meningiomas (FMMs) represent a common histological tumor in a rare and eloquent location.

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FMMs are one of the most surgically complex conditions in neuro-oncologic surgery.

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The transcondylar approach is a more advanced technique and the total removal of ventral lesion could be achieved.

Far-Lateral Approach for Ventral and Ventrolateral Upper Cervical Meningiomas: A Case Series and Literature Review

STUDY DESIGN

Retrospective cohort study.

PURPOSE

To evaluate the safety and efficacy of the far-lateral approach in the resection of ventral and ventrolateral upper cervical meningiomas.

OVERVIEW OF LITERATURE

Upper cervical meningiomas are a common disease entity. These lesions can be surgically treated via many accesses. The far-lateral approach is a very appealing technique for these lesions.

METHODS

We assessed 23 patients with a mean age of 57.3±15 years. According to the Japanese Orthopedic Association (JOA) scale; eight patients had grade 0, nine had grade I, and six had grade II. All patients underwent plain radiography and magnetic resonance imaging of the cervical spine. The foramen magnum was involved in 10 patients, C1-2 in seven, C2-3 in four, and C3-4 in two. All patients were operated via the far-lateral approach.

RESULTS

Gross total resection was achieved in 21 patients. Sixteen lesions were psammomatous, five were fibroblastic, and two were meningothelial meningiomas. The mean operative duration was 135±40 minutes, while the mean operative blood loss was 450±210 mL, and the mean hospital stay was 4.3±2.2 days. At the final follow-up that was conducted at 27.6±21 months and as per the JOA score; 16 patients were classified into grade 0 and 7 into grade II. The condition of none of our patients deteriorated postoperatively. There was no significant correlation of the clinical outcome with tumor level, pathological subtype of the tumor, symptom duration, age, and sex. There was no significant correlation of tumor resection completeness with tumor level, tumor pathological subtype, or tumor topography (ventral or ventrolateral).

CONCLUSIONS

The far-lateral approach is a safe and effective access for ventral and ventrolateral cervical meningiomas. It allows direct access to tumor with no spinal cord or nerve roots traction, and thus may yield a fairly better outcome than the standard posterior approach.

Contralateral Transcondylar Fossa Approach with Bilateral V3 Segment Exposure for Clipping of Vertebral Artery Aneurysm Which Deviates Across Midline: A Case Report and Review Article

This article reports a patient with unruptured right vertebral artery aneurysm which deviates across the midline to the left side. The contralateral (left) transcondylar fossa approach with bilateral V3 exposure is used for aneurysm clipping. The literature related to this technique is also reviewed.