OBJECTIVETo evaluate the safety and efficacy of stent placement for the treatment of complex intracranial aneurysms.

DATA SOURCESWe searched six databases, including Pubmed, Embase, SCI-expanded, the Cochrane Library, ISI Proceedings and ProQuest Dissertations & Theses for the relevant studies using multiple key words from December, 1997 to February, 2009.

STUDY SELECTIONThirty-three studies about stent placement for intracranial aneurysms were identified, which reported data from a total of 1069 patients with 1121 intracranial aneurysms.

DATA EXTRACTIONWe prepared a standardized data extraction form (DEF), which was used by two independent researchers to extract data from the included 33 studies.

RESULTSThe overall initial complete occlusion rate was 52.5% (456/869, 95%CI: 49.2% - 55.8%). The overall complication rate was 14.3% (162/1130, 95%CI: 12.3% - 16.4%), of which 3.6% (38/1044, 95%CI: 2.5% - 4.8%) were permanent. Clinical follow-up showed a dependence rate of 8.4% (39/465, 95%CI: 5.9% - 10.9%). Angiographic follow-up showed an improvement rate of 24.3% (117/481, 95%CI: 20.5% - 28.2%) and a recurrence rate of 12.9% (62/481, 95%CI: 9.9% - 15.9%). Chi-squared tests were performed to compare the following subgroups: self-expandable vs. balloon-expandable stents, unruptured vs. acutely ruptured aneurysms, and with vs. without pre-medication. Statistical significance was reached in eight tests.

CONCLUSIONSIntracranial stent is a safe and effective tool for embolizing complex intracranial aneurysms. Self-expandable stents are significantly easier and safer than balloon-expandable stents with respect to navigation and deployment through the tortuous cerebral vasculature. Patients with acutely ruptured aneurysms are more likely to be dependent, but not more likely to suffer more procedure-related complications.