Endovascular Therapy of Intracranial Aneurysms - Methods, Indications, Complications

Endovascular therapy of intracranial aneurysms has become the first-line treatment option whenever this option is available; it appears to be straightforward and with promising long-term effect. A neurointerventionalist performing the procedure should have appropriate radiographic equipment, training and appropriate number of patients. This can be appropriately accomplished within a specialized neurovascular center in which appropriate neurosurgical care can be instituted promptly. There are two endovascular strategies to treat cerebral aneurysms. The first involves an occlusion of the aneurysmal sac with metallic coils and preserving the parent artery. The second involves occlusion of the parent artery in order to exclude otherwise untreatable aneurysms from blood circulation. Implantation of intracranial stents stabilizes implanted coils in the aneurysmal sac of wide neck aneurysms and expands indication spectrum of endovascular therapy with long-term effect. High density mesh cylinder stents modify the blood flow by disrupting aneurysm inflow, leading to remodeling of the entire diseased arterial segment. Standard imaging protocol of acute SAH includes non-enhanced CT and CT angiography. Catheterization angiography is the imaging modality used for patients with non-conclusive or negative findings. Detection and detailed imaging of small (less then 3 mm in size) aneurysms is more reliable using catheterization angiography with 3D volume rendering technique. MR angiography is a reliable, non-invasive and cost-effective method that is gradually replacing catheterization angiography in a long-term follow-up of patients with coiled aneurysms. In comparison to neurosurgical therapy, endovascular therapy of acutely ruptured aneurysms was proved, in a one-year follow up, to significantly reduce mortality and postsurgical disability. Unruptured aneurysms form a heterogeneous entity with extreme variation in reported risk of rupture. Their prevalence is estimated at 1-2% of the adult population. However, with an increasing availability of non-invasive brain imaging methods, they are now diagnosed more frequently.