Endovascular treatment of basilar artery aneurysms

Abstract

International experience regarding the treatment of basilar artery aneurysms using the Guglielmi Detachable Coil (GDC) system was reviewed. The four patient series included in this critique were composed of similar numbers of patients who had aneurysms that predominantly involved the basilar artery bifurcation and who presented clinically after a subarachnoid hemorrhage. Consistent results observed between the individual outcome experiences were as follows: (1) complication rates associated with the endovascular treatment of basilar artery aneurysms compared favorably with the historical rates associated with direct surgical clipping; (2) smaller aneurysms in this location could be more safely and completely occluded than their larger counterparts; (3) the endosaccular thrombus produced after GDC placement is a dynamic, rather than permanent, entity; (4) progressive thrombosis, thrombolysis, or compaction of the coil mass — singly or in combination — can account for changes in the extent of aneurysm occlusion observed over time; (5) even if an aneurysm could not be obliterated completely, treatment with GDC coils immediately after subarachnoid hemorrhage appeared to confer a protective effect upon patients compared to the natural history of untreated, ruptured intracranial aneurysms. In summary, these studies support the following conclusions regarding GDC-mediated electrothrombosis for the treatment of aneurysms: (1) aneurysm morphologies that are the most troublesome to treat by a conventional open surgical approach are also the most difficult to treat endovascularly; (2) although a useful therapeutic option for high-risk surgical candidates after aneurysmal hemorrhages, the endovascular treatment of intracranial aneurysms (basilar or otherwise) as more than a temporizing (i.e., not curative) intervention is not yet supported by data; (3) when comparing the complications and expenses associated with open surgical and endovascular therapy for aneurysms, long-term morbidity and cost analyses must incorporate the respective requirements for subsequent angiographic evaluation and repeat treatment sessions to address aneurysm residuals; (4) limited clinical and angiographic follow-up data preclude conclusions regarding the value of endovascular treatment for the management of asymptomatic aneurysms; (5) direct clip ligation of intracranial aneurysms remains the definitive treatment strategy until appropriate prospective, controlled, randomized studies prove otherwise.