Occipital Artery-Posterior Inferior Cerebellar Artery Bypass for the Treatment of Aneurysms Arising from the Vertebral Artery and Its Branches

OBJECTIVE: To report experience with 7 cases of intracranial aneurysms of the vertebral artery (VA) and its branches that were treated with occipital artery (OA)posterior inferior cerebellar artery (PICA) bypass. METHODS: Over 4 years, 7 cases of intracranial aneurysms arising from the VA and its branches were treated with OA-PICA bypass. The clinical data, characteristics of aneurysms, and results of treatment were analyzed. RESULTS: There were 4 aneurysms that arose from the VA-PICA junction, 2 aneurysms that occurred at the distal PICA, and 1 aneurysm that occurred at the collateral artery from the distal end of the occluded VA to the ipsilateral PICA. OA-PICA bypass was performed before obliteration of the aneurysms in all patients. Of the 7 aneurysms, 4 were totally obliterated with surgery, 2 were treated with additional endovascular coiling or trapping, and 1 was partially obliterated by surgery and gradually disappeared during the follow-up period. Postoperative angiography revealed that the patency of the grafts was good in 6 patients. In 1 patient with an occluded bypass graft, multiple infarctions developed in the left cerebellum, but the patient had almost fully recovered after rehabilitation. CONCLUSIONS: OA-PICA bypass with obliteration of the aneurysm is one of the optimal treatments for intracranial aneurysms that occur at the VA and its branches because it can preserve the perforators and distal blood flow from the PICA.