[Successful Total Resection with Preceding Arterial Coil Embolization of Intradural Extramedullary Tumor at Craniovertebral Junction Encasing Dominant-side Vertebral Artery].

OBJECTIVE The surgical resection of craniovertebral junction(CVJ)meningioma is challenging because of the neighboring brainstem, lower cranial nerves, and vertebral artery(VA). Moreover, encasement of the VA by the tumor can raise the risk of complications and require cautious manipulation during surgery. CASE A 46-year-old woman presented with a one-year history of neck pain. She had temporal hemiplegia and numbness on her left side. Magnetic resonance imaging(MRI)showed a CVJ meningioma pushing the brainstem from the right vertebral side and encasing the right VA. Digital subtraction angiography(DSA)showed two feeding arteries arising from the right VA and a sunburst sign. The right VA was the dominant side but did not have the right posterior inferior cerebellar artery(PICA). The anterior spinal artery(ASA)was dominant in the left VA. We performed a balloon test occlusion(BTO)for 20 min and it did not cause any complications;therefore, we occluded the VA using endovascular coils. After 4 days, we removed the meningioma in the prone position, using a far-lateral approach and C1-laminectomy. The laterally located meningioma pushed the brainstem. After detaching the tumor from the dura, we cut the encased VA and the tumor was resected safely(Simpson grade II). Postoperatively, she developed temporal thermal hypoalgesia on the left side of her body. Magnetic resonance imaging showed a microinfarction in the medulla. CONCLUSION If the VA test occlusion provides a clear result, pre-operative endovascular sacrifice of the VA encased by CVJ meningioma is a feasible treatment strategy.