Long-term outcomes of trapping vertebral artery-posterior inferior cerebellar artery dissecting aneurysms after revascularization

Objective: This study is designed to evaluate the long-term outcome of trapping vertebral artery-posterior inferior cerebellar artery (VA-PICA) dissecting aneurysms after revascularization. Materials and Methods: Five patients with VA-PICA dissecting aneurysms were treated surgically between 2007 and 2010. All the aneurysms were trapped through a far-lateral approach after revascularization of the PICAs by occipital artery-posterior inferior cerebellar artery (OA-PICA) bypass. All patients were scheduled for clinical follow-up in the out-patient department at 3 months, 6 months, then annually. Computed tomography (CT) scan and CT angiography, or magnetic resonance (MR) imaging and MR angiography were performed to assess the anastomosis and cerebral blood supply. Results: Among the five patients, two of them did not have any neurological deficit after surgery, the other three had post-operative lower cranial nerve palsy but recovered completely within 6 months. Post-operative cerebral angiography (received by two patients) and CT angiography (received by the other three patients) showed patent bypasses in all patients and there was no reappearance of the aneurysms. After following-up from 47 to 74 months (61 month is the median follow-up period), all patients showed excellent outcomes. Conclusion: Trapping the aneurysms after revascularization of PICAs by OA-PICA bypass is a safe method to treat the VA-PICA dissecting aneurysms.