Clinical and radiological findings and surgical management of ruptured aneurysms at the non-branching sites of the internal carotid artery.

Ruptured aneurysms located at the non-branching sites of the internal carotid artery, including blister-like aneurysms, possess unique clinical and technical features. This report presents nine consecutively managed patients with these types of aneurysm, detailing the clinical and radiological characteristics and surgical outcomes. The initial angiography identified aneurysmal lesions in six of the nine patients with two of these patients requiring additional three-dimensional (3D) angiography. In three patients the aneurysm was only diagnosed on second or third angiograms. Six patients had blister-like aneurysms, and two had saccular-shaped aneurysms diagnosed on the basis of intraoperative findings. One patient with a saccular aneurysm died without surgery. Eight patients underwent a microsurgical procedure: clipping in five, clipping on wrapping with suturing in two and trapping in one. Three of these eight patients had an intraoperative rupture. A favorable outcome was obtained in seven patients. Advances in microsurgical techniques to prevent premature rupture and 3D radiological diagnosis with careful pre-operative consideration of the surgical strategies will be required for a further improvement of the clinical outcome.