Results and Problems in the Surgical Treatment of Large/Giant Internal Carotid Artery Aneurysms

Abstract

Direct clipping of large or giant internal carotid artery (ICA) aneurysms is often difficult for various reasons. Flow alteration (FA) using bypass and parent artery occlusion (PAO) could be an alternative treatment for such aneurysms. We retrospectively reviewed 32 patients with large or giant ICA aneurysms who were surgically treated between 2014 and 2018. Aneurysms were divided into three groups, based on location: C3–5 segment (17 cases), C2 segment (including C2–3; 7 cases), and C1 segment (including C1–2; 8 cases). The treatment methods and surgical outcomes were assessed for each group. Postoperative outcomes were evaluated at 6 months using the modified Rankin Scale (mRS). All patients with an aneurysm at the C3–5 segment were treated with FA using PAO with highflow bypass. Treatment-associated mRS score deterioration was observed in one patient (6%) with cerebral infarction. Direct clipping was performed in all patients with C2 segment aneurysms. The mRS score deteriorated in two patients (18%). However, no ischemic complications occurred in the perforator area. Among patients with aneurysms at the C1 segment, six underwent direct clipping, one underwent FA using PAO with bypass, and one underwent trapping with bypass. Deterioration of the mRS score was observed in three patients (38%), including two patients with perforator infarction. Among patients treated with FA, delayed recanalization and aneurysm enlargement occurred. In conclusion, favorable outcomes were achieved following the surgical treatment of large or giant ICA aneurysms located at the C2–5 segment. However, aneurysms located at the C1 segment of the ICA are still associated with complications.