Advanced endovascular procedures for treating intracranial aneurysms

Abstract

The basic technique for endovascular treatment of intracranial aneurysms is putting as many detachable coils as possible through a single microcatheter. However, if the aneurysm has characteristics that are unsuitable for the basic technique, such as an irregular shape or wide neck then treatment requires an advanced technique. With the development of the hyper-compliant balloon, a balloon assisted method has been introduced. In this procedure, a single lumen non-detachable balloon is inflated in front of the aneurysm neck during coil embolization to avoid coil protrusion to the parent artery. Additionally, this procedure also affords management of intra-procedural rupture. Now, this balloon assisted technique can be widely used for both ruptured and unruptured aneurysms. However, even when the current balloon system can navigate to intracranial arteries safely, sometimes a double catheter method is safer and more useful for irregularly shaped aneurysms. This method creates a stable frame within the aneurysm by using multiple microcatheters, packed tightly together with the framing coil. Another recently developed and rapidly growing technique is the stent-assisted method. The development of self-expanding stents dedicated to intracranial use has significantly widened the applicability of endovascular therapy to many intracranial aneurysms that would otherwise have been untreatable by endovascular techniques alone. Stents provide structural support for coil embolization by preventing coil herniation in wide-necked aneurysms, allowing increased packing density, causing flow diversion, and potentially providing a scaffold for orifice endothelialization. Compared with the balloon-assisted method and multiple catheter method, stent-assisted embolization may have a much higher rate of ischemic complications due to its thrombogenicity and a need for prolonged antiplatelet therapy. Advanced techniques have greatly increased the indications for endovascular treatment of intracranial aneurysms. One of the limitations of these techniques is that they require using multiple devices in the same parent artery. however, these advanced techniques are valuable in the treatment of irregularly shaped and wide-neck aneurysms.