NI FEATURE: THE EDITORIAL DEBATE II-- PROS AND CONS
Year : 2019  |  Volume : 67  |  Issue : 1  |  Page : 59-60

Far lateral approach to anterior foramen magnum meningiomas – When should condyle be drilled?

Laligam Sekhar, Qazi Zeeshan
Department of Neurosurgery, University of Washington, Seattle, Washington, USA

Correspondence Address:
Dr. Laligam Sekhar
Department of Neurosurgery, University of Washington, Seattle, Washington
USA

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/0028-3886.253594

» Commentary

1. A “complete transcondylar approach” (resection of the occipital condyle and the lateral mass of the  Atlas ^{More Details} [C1]) with full mobilization of the terminal V2 and the V3 segment of the vertebral artery (VA; from the C2 foramen to the dural entrance point of the artery) is only used for chordomas involving the foramen magnum area, which also extend laterally.^[5] In such cases, some type of fusion procedure, including the possible placement of a bone graft between C2-occiput and instrumentation is needed ^[7]
2. In patients with foramen magnum meningiomas, a complete transcondylar approach is never needed. No resection, or a partial resection up to ½ of the bone structures is performed as needed. When a tumor is more anterior and fibrous and the vertebral arteries (one or both) are in close proximity to the tumor, some condylar resection is very helpful.^[5],[8] A fusion procedure is almost never needed in such patients
3. The exposure and mobilization of the ipsilateral VA is very helpful when the tumor is more anteriorly located and the intradural VA (s) are encased. Both proximal control, possibility of repair in the event of injury, and increased exposure due to the posterior mobilization of the artery are the advantages of this approach ^[5],[9]
4. Whenever possible, we try to get a Simpson Grade 1 resection (with the involved dura mater). The only exceptions are when the lower cranial nerves are involved by the tumor (in which case, tumor pieces may be left behind and treated by radiosurgery) or if the tumor is invading the brain stem.^[3],[10] It should be noted that recurrent tumors of this area are very difficult to remove by surgery and are also amenable to undergo radiosurgery.^[11],[12]

» References

1.	Srinivas D SP, Deora H, Beniwal M, Vikas V, Rao KVLN. “Tailored” far lateral approach to anterior foramen magnum meningiomas – The importance of condylar preservation. Neurol India 2019;67:142-8.     [Full text]
2.	Sen CN, Sekhar LN. An extreme lateral approach to intradural lesions of the cervical spine and foramen magnum. Neurosurgery 1990;27:197-204.
3.	Babu RP, Sekhar LN, Wright DC. Extreme lateral transcondylar approach: Technical improvements and lessons learned. J Neurosurg 1994;81:49-59.
4.	Sen CN, Sekhar LN. Surgical management of anteriorly placed lesions at the craniocervical junction--an alternative approach. Acta Neurochir (Wien) 1991;108:70-7.
5.	Sekhar LN, Mantovani A, Brito da Silva H. Extreme lateral approach to intradural lesions. In: Sekhar LN, Fessler R, editors. Atlas of Neurosurgical Techniques. 2nd ed, vol 2. Stuttgart: Thieme; 2016. p. 411-34.
6.	Salas E, Sekhar LN, Ziyal IM, Caputy AJ, Wright DC. Variations of the extreme-lateral craniocervical approach: Anatomical study and clinical analysis of 69 patients. J Neurosurg 1999;90 (2 Suppl):206-19.
7.	Bejjani GK, Sekhar LN, Riedel CJ. Occipitocervical fusion following the extreme lateral transcondylar approach. Surg Neurol 2000;54:109-16.
8.	Liu JK. Extreme lateral transcondylar approach for resection of ventrally based meningioma of the craniovertebral junction and upper cervical spine. Neurosurg Focus 2012;33(Suppl 1):1.
9.	Park HH, Lee KS, Hong CK. Vertebral artery transposition via an extreme-lateral approach for anterior foramen magnum meningioma or craniocervical junction tumors. World Neurosurg 2016;88:154-65.
10.	Kumar CV, Satyanarayana S, Rao BR, Palur RS. Extreme lateral approach to ventral and ventrolaterally situated lesions of the lower brainstem and upper cervical cord. Skull Base 2001;11:265-75.
11.	Komotar RJ, Zacharia BE, McGovern RA, Sisti MB, Bruce JN, D'Ambrosio AL. Approaches to anterior and anterolateral foramen magnum lesions: A critical review. J Craniovertebr Junction Spine 2010;1:86-99.
12.	Mehta GU, Blas K, Kondziolka D, Lee CC, Lunsford LD, Sheehan JP, et al. Outcomes of stereotactic radiosurgery for foramen magnum meningiomas: An international multicenter study. J Neurosurg 2018;129:383-9.