Aneurysms Located at the Horizontal Segment of the Anterior Cerebral Artery or the Middle Cerebral Artery

Aneurysms at the horizontal segment of the middle cerebral artery or anterior cerebral artery are relatively rare. The characteristics of 13 cases were analyzed retrospectively. Six of the 13 cases had multiple aneurysms, nine had aneurysmal rupture, and three of these nine were complicated by intracerebral hematoma. Neck clipping of the aneurysm was performed in 11 cases and four developed a new cerebral infarction in the territory of the perforating arteries. Overall mortality and morbidity was 15% and 38%, respectively. The outcome for patients with aneurysms at these sites was evidently poorer than for those with aneurysms at other sites.