[Endovascular treatment for vertebral artery dissecting aneurysm: effectiveness of internal trapping with proximal flow arrest].

Ruptured vertebral artery (VA) dissecting aneurysms are associated with a higher incidence of rebleeding than saccular aneurysms, so, it is encouraged that diagnosis be followed by early treatment. The standard treatment for VA dissecting aneurysms is internal trapping using an endovascular technique. In this procedure, a proximal flow arrest is sometimes used to ensure safety. In this report, we demonstrated the usefulness of proximal flow arrest. The subjects consisted of seven patients treated with endovascular treatment for ruptured VA dissecting aneurysms from 1997 to 2005. Two of the seven patients were treated without proximal flow arrest and one of the two encountered rerupture of the aneurysm at coil embolization. Five patients were treated with proximal flow arrest. Internal trapping was safely completed in these patients. Overall outcomes measurment by Glasgow Outcome Scale were good recovery in three, moderate disability in one, vegetative state in one and dead in two. Proximal flow arrest is considered to be useful for the following four reasons: 1) for the prevention of distal embolism; 2) for the prevention of distal coil migration; and 3) to block blood flow upon rerupture; 4) for the balloon occlusion test, but the necessity of this technique is now controversial. However it is difficult to prove the necessity, we believe it is an effective optional technique for safety embolization.