Strategy for the treatment of inaccessible unruptured giant and large aneurysms of the internal carotid artery.

Our goal was to clarify the optimum management of the inaccessible unruptured giant and large aneurysms of the internal carotid artery (ICA). Since 1981, we have treated 18 patients with unclippable unruptured giant or large aneurysms of the ICA. Aneurysms were classified as either intracavernous or intradural. We performed proximal carotid occlusion in 12 patients and conservatively treated six patients. We retrospectively analyzed long-term outcomes in these patients. Four of seven patients with intradural aneurysm underwent proximal carotid occlusion, with good long-term outcomes. The three patients with intradural aneurysm, who were treated conservatively, died of subarachnoid hemorrhage. Eight of 11 patients with intracavernous aneurysm underwent proximal carotid occlusion, one dying of massive nasal bleeding 25 months after the procedure. In this case, the aneurysm was partially thrombosed, and residual lumen growth was revealed 22 months after proximal carotid occlusion. Cranial nerve paresis improved in five of the eight patients (63%), and two patients had a minor ischemic attack. Neurological problems failed to occur in the three patients with intracavernous aneurysm who were treated conservatively. The risk of rupture is relatively high in intradural giant and large aneurysms. Proximal carotid occlusion can effectively prevent bleeding from intradural aneurysms. Aggressive management is justified for intradural aneurysms with poor collateral circulation. Operative procedures in the management of an intracavernous aneurysm require careful consideration.