Endovascular treatment of intracranial aneurysms.

Intracranial aneurysms are abnormal dilations of the intracranial vessels, in which all the layers of the vascular wall are affected by degenerative changes that lead to distension of the vessel. Intracranial aneurysms can be classified based on their anatomic location, size, and morphology. Subarachnoid hemorrhage is the most devastating clinical presentation. The goal of preventing hemorrhage or rehemorrhage can only be achieved by excluding the aneurysm from the cerebral circulation. Endovascular or surgical clipping can achieve this goal. Multiple surgical and endovascular approaches have been described for treatment of intracranial aneurysm. Surgical approaches for anterior-circulation intracranial aneurysms include: pterional, orbitozygomatic, and lateral supraorbital craniotomies. Modern microsurgical techniques involve skull base dissection to achieve adequate exposure with minimal brain retraction. Endovascular techniques can be divided into: parent artery reconstruction with coil deposition (primary coil, balloon-assisted coiling, stent-assisted coiling, and other new techniques such as neck reconstruction devices and intraluminal occlusion devices); reconstruction with flow diversion; and deconstructive techniques with involving parent artery sacrifice with or without bypass.