Background: Ruptured blister-like aneurysms arising at non-branching sites of the internal carotid artery (BLICAA's) sometimes cause disaster during aneurysm repair because of their characteristic configurations. Our study was designed to establish the best surgical strategies for such aneurysms.
Method: Eighteen BLICAA's (0.9% of all treated aneurysms) treated at our institute from January 1994 to July 2006 were retrospectively analysed using the database and imaging studies. We assessed the management outcome with the modified Rankin Scale (mRS). The average follow-up period was 17 months.
Findings: Their ages ranged from 30 to 68 years with a mean age of 50. There were 16 females, and two males). The angiographic diameter of the aneurysmal sac sranged from 1.4 to 5 mm with a mean diameter of 2.5 mm. The common origins were dorso-medial (n = 7) or dorsal (n = 6) wall of the ICA. Fifteen patients underwent wrapping with cellulose fabric and clipping. Of the remainder, each underwent direct clipping, suturing, or trapping. The overall outcome was mRS 1 in 11 patients (78.0%), two in three patients, three in one patient, one in one patient, and five in two patients. Intra-operative premature rupture occurred in six patients. There was no rebleeding during the follow-up period. Cerebral infarctions following carotid trapping after premature rupture and stenosis after suturing of perforated carotid wall were causes of mortality. The causes of morbidity included initial brain insult and vasospasm.
Conclusions: The surgeon should be ware of the high risk of premature rupture during dissection of BLICAA's. Wrapping with cellulose fabric (Bemsheet) and holding clipping technique could be chosen as the optimal surgical modality for prevention of rebleeding from these lesions.