The purpose of this study is to assess the efficacy and safety of the Flow Diverter (Tonbridge) for endovascular treatment of intracranial aneurysms.

This is a prospective, multi-center, randomized, open, positive-controlled, non-inferiority trial. This clinical trial is conducted at more than 5 centers in China. Eligible patients are randomized into experimental group using Flow Diverter (Tonbridge) or control group using Tubridge (MicroPort) in a 1:1 ratio. The primary objective of this study is to verify the complete occlusion rate of aneurysms at 12 months of Flow Diverter (Tonbridge) is non-inferior to Tubridge, for treatment of intracranial aneurysms, and evaluate the effectiveness and safety of the Flow Diverter (Tonbridge).

Inclusion Criteria:

• Age 18 to 80 years, any gender;
• Unruptured intracranial aneurysms locate in the internal carotid artery (ICA) or vertebral artery (VA) with a neck ≥ 4 mm and a maximal diameter ≥ 10 mm, which diagnosed by DSA;
• The target aneurysm with a parent vessel diameter of 2.0-6.5 mm;
• Subject or guardian is able to understand the purpose of study, shows sufficient compliance with the study protocol and provides a signed informed consent form.

Exclusion Criteria:

• Diagnosed as multiple aneurysms which cannot be covered by a single stent or with cerebrovascular malformations;
• Subarachnoid hemorrhage of the target aneurysm within 30 days pre-procedure;
• Modified Rankin Scale (mRS) score > 2 in pre-procedure;
• Platelet (PLT) < 60×10^9/L or known platelet dysfunction or International Normalized Ratio (INR) > 1.5;
• Heart, lung, liver and renal failure or other severe diseases (such as brain tumor, systemic infection, disseminated intravascular coagulation, myocardial infarction within 12 months before enrollment, history of severe psychosis);
• The lesion which is not appropriate for flow diverter delivery and deployment judged by investigators (severe stenosis of parent artery, severe tortuosity of parent artery, stent failing to reach the lesion, etc.);
• Major surgery within 30 days before enrollment, or intending to receive surgery within 180 days after enrollment;
• Allergic history of anesthetics and contrast agents, or contraindication for dual antiplatelet or/and anticoagulant therapy;
• Allergic History of metals such as nickel-titanium alloy;
• Life expectancy < 12 months;
• Pregnant or breastfeeding women;
• Subject has participated in other drug or medical device clinical trials within 1 month before signing informed consent;
• Other conditions judged by the investigators as unsuitable for enrollment.