Endovascular Treatment of Basilar Trunk Saccular Aneurysms

Basilar artery (BA) trunk aneurysms are rare and still remain a formidable surgical challenge. The purpose of this retrospective study was to report the clinical entities and results of endovascular surgery of BA trunk saccular aneurysms. Between 1995 and 2009, 14 patients with 14 BA trunk saccular aneurysms underwent endovascular surgery. Six patients presented subarachnoid hemorrhage (SAH), three patients had another associated aneurysm which developed SAH, one patient presented with mass effect to the brain stem, and four patients were incidentally discovered. Five ruptured and seven unruptured aneurysms were successfully treated by endovascular surgery. Another one incompletely embolized aneurysm had grown to huge size five years later and the patient underwent a Hunterian ligation with a radial artery graft between the extracranial vertebral artery and the posterior cerebral artery. In one ruptured case, we attempted neck clipping, but this was abandoned because of concern for neck tearing by clipping. The aneurysm was embolized using detachable coils later. BA trunk aneurysms showed characteristic features such as so-called lateral aneurysm (43%), multiple aneurysms (43%) and four BA fenestrations (36%). The unusual high incidence of associated various vascular anomalies suggests that focal wall weakness must be based on the mechanism of aneurysm initiation on the BA trunk. Most patients presented with SAH. Pre-treatment neurological state was predictive for clinical outcome. Endovascular surgery is an effective therapeutic alternative that is associated with low morbidity and mortality rates, and should be considered the first choice treatment.