A case of endovascular treatment for followed by side to side bypass for vertebral artery dissecting aneurysms involved posterior inferior cerebellar artery.

Treatment of complex aneurysms usually entails not only direct clipping but also alternative treatment modality. We recently experienced a case of vertebral artery dissecting aneurysm and obtained good treatment outcomes. Our case suggests that the endovascular segmental occlusion with posterior inferior cerebellar artery (PICA) to PICA side anastomosis might be a good treatment option in patients with complex vertebral artery dissecting aneurysms. A 45-year-old woman has a left vertebral dissecting aneurysm with dizziness. Based on the aneurysmal morphology and the involvement of PICA, the patient underwent side to side anastomosis of the PICA. This was followed by the endovascular segmental coil occlusion. The aneurysmal sac was completely obliterated. At a 2-year follow-up, the patient achieved a good patency of both PICA. In conclusion our case suggests that the endovascular segmental occlusion of the parent artery followed by PICA to PICA bypass surgery through a midline suboccipital approach is a reasonable multimodal treatment option in patients with complex vertebral artery dissecting aneurysms.