Successful endovascular treatment of a growing megadolichoectasic vertebrobasilar artery aneurysm by flow diversion using the "diverter-in-stent" technique.

Giant dolichoectatic and fusiform aneurysms of the vertebrobasilar artery are among the most difficult and dangerous aneurysms to treat. Conservative management may be reasonable in asymptomatic elderly patients. Nevertheless, due to the frequent presence of mass effect on the brainstem and the risks of thromboembolic events and rupture, these aneurysms often demand treatment rather than observation. With the advancement of endovascular techniques some of these lesions have become treatable without the high morbidity and mortality rates associated with open surgical treatment. When dealing with giant, progressively enlarging symptomatic aneurysms, more limited therapeutic alternatives are available. The authors present a case of a growing megadolichoectatic vertebrobasilar artery aneurysm causing major disability due to increasing mass effect in a 51-year-old man. The aneurysm was treated with flow diversion by placing multiple telescoped stents and diverters ("diverter-in-stent" technique), achieving thrombosis of the aneurysm and reduction of the mass effect on the brainstem, with neurological improvement. The successful clinical and angiographic results observed in our case of giant dolichoectasic vertebrobasilar aneurysm contribute to the literature on giant aneurysms treated by means of flow diversion.