Vertebral Artery Transposition Via an Extreme-Lateral Approach for Anterior Foramen Magnum Meningioma or Craniocervical Junction Tumors.

OBJECTIVE: Vertebral artery (VA) transposition in the extreme-lateral transcondylar approach can minimize the manipulation of the low cranial nerves and the brain stem. The authors describe the surgical technique of VA transposition. METHODS: From March 2000 to December 2014, 28 of 48 patients underwent VA transposition for anterior foramen magnum meningioma (16 patients) and craniocervical junction (CCJ) tumors (12 patients). Tumor was resected via an extreme-lateral approach with partial condylectomy to expose the anterior portion of the brain stem. For intradural tumors, the VA was mobilized caudomedially after circumferential dural incision around the VA at the level of the foramen magnum. For extradural tumors involving the CCJ, VA was transposed medially from the transverse foramen of C1 without any dural incision. RESULTS: Gross total resection was achieved in 26 of 28 patients (92.9%) with VA transposition. Histologically, meningioma and schwannoma were most common. The origin of the tumors was foramen magnum (57.1%), C1 nerve root (17.9%), clivus (10.7%), jugular foramen (7.1%), posterior skull base (3.6%), and hypoglossal canal (3.6%). VA transposition was performed intradurally in 19 patients (67.9%) and extradurally in 9 patients (32.1%). Surgical morbidity was 17.9% including 4 patients with hypoglossal nerve palsy and 1 patient with quadriparesis. The mean follow-up duration after surgery was 4.2 years (range, 0.1-14.8 years). CONCLUSIONS: VA transposition can provide a wide surgical window for anterior foramen magnum meningioma or tumors involving the CCJ with the least manipulation of the neuraxis.

Extreme lateral transcondylar approach for resection of ventrally based meningioma of the craniovertebral junction and upper cervical spine.

Ventrally based meningiomas at the craniovertebral junction can be challenging tumors to remove because of their deep location anterior to the lower brainstem and upper cervical spinal cord, and close association with complex neurovascular structures. The extreme lateral transcondylar approach provides excellent access and exposure to anterior and anterolateral intradural tumors involving the region of the craniovertebral junction, including the lower third of the clivus, the foramen magnum, and the upper cervical spine. This approach allows safe access for removal of these difficult tumors without any neural retraction. In this operative video manuscript, the author demonstrates an illustrative step-by-step technique for microsurgical resection of a ventrally based meningioma extending from the foramen magnum to C-2 using the extreme lateral transcondylar approach. The operative technique and surgical nuances, including the surgical approach, intradural tumor removal, and cranial base reconstruction, are illustrated in this video atlas. The video can be found here: http://youtu.be/4uvPpEtEShU .

Far Lateral Approaches for Intracranial Aneurysms / 대한뇌혈관학회지

Surgical approaches to the posterior circulation aneurysms are difficult and still remained as a matter of debate. Many skull base approaches has been developed to overcome the inadequate exposure of these aneurysm by conventional surgical approaches. Far lateral approaches are an extension of suboccipital approach to expose neurovascular structures around the lower clivus. Aneurysms locating at the vertebral arteries, vertebrobasilar junction and lower basilar artery could be exposed by these approach. However, it is not still evident which kind of far lateral approach is most appropriate for the aneurysms of various locations at these vascular territory. Among the 3 kinds of far lateral approaches, such as far lateral, far lateral transcondylar and extreme lateral transcondylar approach, far lateral approach is not recently used frequently. Far lateral transcondylar approach is good far the aneurysm at the origin of posterior inferior cerebellar artery and the extreme lateral transcondylar approach is useful to expose aneurysms around vertebrobasilar junction. For an appropriate selection of surgical approaches, useful surgical guidelines are mandatory. The recent use of "intermeatal line" and "K lines" and others are of many help for the lower basilar and vertebral artery aneurysms. Surgical approach itself needs knowledge and experience for an adequate performance. Once exposed appropriately manipulation of aneurysms at these locations are not very complicated. Microsurgical anatomy of each surgical step is essential for the sucessful management of aneurysms locating at the lower clivus.

Intradural Dissecting Aneurysms Treated by Extreme Lateral Transcondylar Approach(2 cases)

We expierenced two cases of intradural verteral artery dissecting aneurysms. The presenting symptom was subarachnoid hemorrhage in one case and ischemic symptom in the other. The preoperative angiographic finding typically showed fusiform dilatation and proximal and/or distal narrowing of the affected artery. In one case, the vertebral artery was clipped distal to the PICA and in the other case trapping was performed through the extreme lateral transcondylar approaches. This approach permits a control of the aneurysm through the direct view of whole length of the vertebral artery, lower cranial nerves and ventral brain stem. In order to obtain ample view and to save the lower cranial nerves and perforating vessels, jugular tubercle should be sufficiently drilled out. Postoperitive neurological outcomes were favorable except mild hoarseness for some period in trapping case.