Brain Aneurysm Coil and Flow Diversion Embolization
Some brain aneurysms can be closely observed with periodic surveillance imaging. For aneurysms that require treatment, endovascular therapy can be performed from inside the blood vessel. Access to the inside of the aneurysm is achieved with the same techniques used in diagnostic catheter cerebral angiography, by advancing a catheter (a hollow plastic tube) through an artery in the leg and navigating it to the blood vessels in the brain. After the catheter is positioned at the site of the brain aneurysm, several techniques are used to close the aneurysm and prevent any further blood flow entry. Coil embolization, or “coiling,” is the most commonly practiced endovascular treatment for brain aneurysms. In this procedure, a very small catheter is advanced into the aneurysm and platinum coils are sequentially introduced to create a tightly packed coil mass within the aneurysm, thereby promoting clot formation within the aneurysm, and preventing entry of blood flow. In some cases, a stent or balloon is required to remodel the neck of the aneurysm for safe coil placement and to promote healing. A balloon is temporarily inflated at the aneurysm neck, while a stent is permanently implanted to provide continuous support at the opening of the aneurysm. Newer technology and techniques now include flow diversion devices for endovascular aneurysm treatment. In this method, a mesh stent-like device is placed within the vessel and across the neck of the aneurysm to divert blood flow away from the aneurysm and down the normal course of the blood vessel. This promotes aneurysm closure and scaffolding for healing of the blood vessel wall. The rapid pace of technology development and evolution of techniques for endovascular repair of brain aneurysms will likely continue to advance safety and efficacy of minimally invasive therapies.