A Contralateral Transcondylar Fossa Approach with Bilateral V3 Segment Exposure for Repairing Complex Vertebral Artery Aneurysms.

BACKGROUND AND IMPORTANCE: Microsurgical treatment for vertebral artery aneurysms can be approached through the lateral aspect of the brainstem and cerebellum. A contralateral approach may be selected in complex aneurysms with tortuous running and the intracranial vertebral artery distal to the aneurysm located in the contralateral cerebellopontine angle. When repairing the aneurysm, exposing the V3 segment before craniotomy is advantageous. We describe the detailed surgical procedures of the contralateral transcondylar fossa approach with bilateral V3 segment exposure for the repair of a complex vertebral artery aneurysm.

CLINICAL PRESENTATION: A 48-year-old woman presented with a 23-mm unruptured thrombosed fusiform aneurysm in the right vertebral artery. The aneurysm and the V4 segment distal to it deviated to the left, and the aneurysm was compressing the left anterior aspect of the medulla oblongata. We treated the patient with trapping and thrombectomy, using a contralateral transcondylar fossa approach with bilateral V3 exposure. During the procedure, proximal vascular control was achieved by occluding the contralateral V3 segment and distal control was achieved by occluding the V4 segment. The aneurysm was successfully trapped and decompressed. The patient's postoperative course was good and she was discharged with a modified Rankin Scale score of 0.

CONCLUSIONS: The contralateral transcondylar fossa approach with bilateral V3 exposure is feasible for the repair of complex vertebral artery aneurysms showing a deviated and difficult to access V4 segment proximal to the aneurysm. Bilateral V3 exposure may also facilitate aneurysm bypass procedures such as those using a V3-V4 anastomosis.