Endoscopic Endonasal Approach to Foramen Magnum Meningioma­Technical Note and Case Example

Foramen 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 posteriormidline approach including far lateral, and extremelateral 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.

Foramen magnum meningiomas: surgical treatment in a single public institution in a developing country / Meningiomas do forame magno: tratamento cirúrgico em uma instituição pública em um país em desenvolvimento

Objective: To analyze the clinical outcome of patients with foramen magnum (FM) meningiomas. Method: Thirteen patients (11 Feminine / 2 Masculine with FM meningiomas operated on through lateral suboccipital approach were studied. Clinical outcome were analyzed using survival (SC) and recurrence-free survival curves (RFSC). Results: All tumors were World Health Organization grade I. Total, subtotal and partial resections were acchieved in 69.2%, 23.1% and 7.7%, respectively, and SC was better for males and RFSC for females. Tumor location, extent of resection and involvement of vertebral artery/lower cranial nerves did not influence SC and RFSC. Recurrence rate was 7.7%. Operative mortality was 0. Main complications were transient (38.5%) and permanent (7.7%) lower cranial nerve deficits, cerebrospinal fluid fistula (30.8%), and transient and permanent respiratory difficulties in 7.7% each. Conclusions: FM meningiomas can be adequately treated in public hospitals in developing countries if a multidisciplinary team is available for managing postoperative lower cranial nerve deficits. .

Objetivo: Analisar as evoluções clínicas de 13 pacientes com meningiomas do forame magno (FM). Método: Foram estudados 13 pacientes com meningiomas do FM (11 Feminino / 2 Masculino) operados por abordagem suboccipital lateral. As evoluções clínicas foram analisadas usando curvas de sobrevida (SC) e de sobrevida livre de doença (RFSC). Resultados: Os 13 tumores eram Grau I da Organização Mundial de Saúde. Ressecções total, subtotal and parcial foram obtidas em 69,2%, 23,1 e 7,7%, respectivamente. A SC foi melhor para homens e a RFSC foi melhor para mulheres. Localização/ extensão da ressecção/envolvimento da artéria vertebral/nervos cranianos baixos não influenciaram a SC/RFSC. A taxa de recorrência foi 7,7%. A mortalidade operatória foi zero. As principais complicações foram déficits de nervos cranianos baixos transitórios (38,5%) e permanentes (7,7%); fístula de líquido cefalorraquidiano (30,8%) e dificuldades respiratórias transitórias e permanentes em 7,7% cada. Conclusões: Meningiomas do FM podem ser adequadamente tratados em hospitais públicos em países em desenvolvimento se houver uma equipe multidisciplinar para cuidar de déficits de nervos cranianos baixos pós-operatórios. .

achondroplasic case with foramen magnum stenosis, hydrocephaly, cortical atrophy, respiratory failure and sympathetic dysfunction

Achondroplasia is a relatively frequent genetic disorder that may lead to limb weakness, motor-mental retardation, hydrocephaly, and respiratory disorders. In this pathology, foramen magnum stenosis and accompanying disorders like respiratory depression is well documented. A 2.5 year-old child with the diagnosis of achondroplasia admitted to our clinic with severe respiratory depression, limb weakness, and motor mental retardation as well as sympathetic dysfunction. In radiologic evaluations, severe foramen magnum stenosis was detected. The patient was operated and posterior fossa decompression was accomplished to prevent compression of respiratory centers and neurons. This case is unique with the narrowest foramen magnum reported up to date and the sympathetic dysfunction which is not reported as a complication in achondroplasic patients. The authors review the relevant literature, focusing on the indications for cervicomedullary decompression in infants with achondroplasia

Microsurgical excision of anterior and anterolateral intradural lesions of the foramen magnum

The most important factors that influence the surgical outcome in foramen magnum lesions are comprehensive and three-dimensional understanding of the specific anatomy of the region, tailoring the exposure of the underlying lesion, maintaining a nearly bloodless surgical field intradurally, and applying an adequate microsurgical technique. This study describes in detail the far lateral approach for intradural tumours in the craniocervical region, with special emphasis placed on the management of the vertebral artery and on the anatomic variations encountered in the region. The study included 31 patients with different pathologies at the lateral foramen magnum. All were operated using the far lateral approach to access the lateral angle of the foramen magnum after mobilizing the vertebral artery. Total resection was achieved in 17 cases whereas subtotal resection with superadded foramen magnum decompression was done for 14 cases. In the study there have been no mortalities, yet 3 cases of CSF leakage were encountered, and another patient suffered from intradural vertebral artery injury. Far lateral approach can provide a good working angle to the anterior of the brainstem without extra drilling of the occipital condyle. The aim of surgery at the foramen magnum should be directed at brainstem decompression rather than unsafe total excision of the tumour. The more the vertebral artery is well prepared and mobilized extradurally the less the incidence of its intradural injury

The outcome of surgical treatment for tumors of the craniocervical junction.

OBJECTIVE: The authors report the clinical, radiological, and surgicalfindings ofpatients with craniocervical junction tumors surgically treated in the institution over the last 8 years. MATERIAL AND METHOD: A retrospective study was performed. Clinical, radiological, and operative data were evaluated, and follow-up information was obtained from outpatient examinations, and telephone interviews. RESULTS: There were 25 patients consisting of nine chordomas, eight meningiomas, three cysts, two schwannomas, one each of aneurysmal bone cyst, plasmacytoma, and metastasis. Twenty-nine operative procedures were performed, classified as 12 anterior nine posterior-lateral, and eight posterior approaches. Gross total removal was achieved in 17 cases, subtotal removal in six cases, and partial removal in two cases. Re-operation was performed in six cases. Median follow-up time was 31 months. The authors found significant improvement in Karnofsky Performance Scale scores. CONCLUSION: Appropriate surgical approaches provide successful tumor removal with less surgical morbidities, nevertheless recurrent tumors occasionally occur and so, long-term follow-up is mandatory.

Giant dumbbell foramen magnum neurinomas presenting as posterior neck masses: single-stage removal by posterior midline approach.

Two patients with giant dumbbell foramen magnum neurinomas are reported. The intradural component was located anterior to the cervicomedullary junction while the extradural and extraspinal portion of the tumor had grown large enough to present as a neck swelling. In both patients total surgical removal was achieved by a single-stage posterior midline approach. Both patients had complete neurological recovery.

Abordaje extremo lateral transcondilar para resecar un meningioma anterior del foramen magno / Extreme lateral transcondylar approach to resect an anterior foramen magnum meningioma

Objetivo. Describir el abordaje extremo lateral transcondilar realizado para resecar un meningioma del sector aterior del foramen magno. Descripción. Mujer de 24 años con una tetraparesia a prediminio derecho y déficit de los nervios craneanos IX, X y XI del lado derecho, de 9 meses de evolución. La resonancia magnética mostró un proceso expansivo a nivel del sector anterior del foramen magno (isointenso en T1 y T2, captando en forma homogénea y bien marcada luego de la administración del gadolinio). Intervención. En diciembre de 2005 se realizó la cirugía (abordaje extremolateral transcondilar), con resección completa de la lesión. Anatomía patológica: meningioma cordoide. La paciente evolucionó mejorando completamente de su clínica neurológica, encontrándose actualente sin ninguna secuela. Conclusión. En este caso el abordaje extremo lateral transcondilar fue la vía de elección para resecar completamente el meningioma del sector anterior del foramen magno. Palabras clave: abordaje extremolateral, cóndilo occipital, foramen magno, meningioma

Objective: To describe the far-lateral transcondylar approach performed toremove a meningioma of the anterior portion of the foramen magnum. Description: A woman, 24-years old, with tetraparesis, greater in the right side, and paresis of the IX, X and XI right cranial nerves, with a 9 months history. The MRI showed a tumor in the anterior aspect of the foramen magnum (isointense in T1 and T2, with homogeneous enhace after galolinium administration). Intervention. In December 2005 the surgery was performed (far-lateral transcondylar approach), with complete removal of the lesion. Histology: cordoid meningioma. The patient had a good outcome, with complete recovery of her neurological deficits. In the last control, she was asymptomatic. Conclusion. In this case, the far-lateral transcondylar was the most appropiate approach to completely resect a meningioma of the anterior portion of the foramen magnum. Key words: condyle, far-lateral approach, foramen magnum, meningioma.

Foramen magnum metastatic malignant melanoma.

The foramen magnum as a site for brain metastasis is extremely rare. We report the case of a 24-year-old male who presented with features of increased intracranial pressure and lower cranial nerve palsies. Imaging revealed a foramen magnum tumor with extension up to the cerebellar vermis superiorly and into the spinal canal inferiorly (craniospinal mass) with mild obstructive hydrocephalus. A malignant melanoma was completely excised. The patient continued to be tumor-free 24 months later.