Paradigm Shift of Endovascular Therapy after Clinical Introduction of a Flow Diverter for Large Intracranial Aneurysms

Abstract

  Intracranial aneurysms are a result of pathological damage to the normal arterial wall, which mainly consist of breakdown of the muscular middle layer and the internal elastic lamina. Therefore, the repair or reinforcement of the damaged arterial wall is necessary to achieve the improvement of the durability and curability in the intracranial aneurysm treatments. Because the endosaccular coil embolization simply occludes a part of the saccular dilation, the recurrence risk is very high in large or giant intracranial aneurysms with a large area of damaged arterial wall. Furthermore, the aneurysm induced mass effect may deteriorate due to the coil mass. Because flow diverter embolization has benefits, such as the repair of damaged arterial walls, preservation of the surrounding small, perforator vessels, and resolution of aneurysm-induced mass effect, it could be the first-line therapy of large intracranial aneurysms, with the exception of those acutely ruptured. However, the risks of procedure-related complications are relatively not low, and the long-term efficacy in the prevention of aneurysm rupture or recurrence has not yet been elucidated. Therefore, the decision of interventional strategies for large intracranial aneurysms requires an accurate assessment of the risks of existing treatment modalities compared with those of flow diverter embolization.