Parent Artery Reconstruction for Small Unruptured Cerebral Aneurusms Using Flow DiverTers: a Multicenter Randomized Trial(PARAT-MT)

Inclusion Criteria: 1. Age 18-75 years. 2. Previously unruptured saccular cerebral aneurysm arising from intradural segments of the internal carotid artery and intracranial segments of the vertebral artery. 3. Measuring ≤10mm in maximum diameter 4. Subjects capable of understanding the study's purpose, willing to participate, and have signed an informed consent form. Exclusion Criteria: 1. Subjects with two or more multiple aneurysms requiring treatment within one year. 2. Subjects with arteriovenous malformations or moyamoya disease. 3. Subjects with ruptured, recurrent, or dissecting aneurysms. 4. Subjects with symptomatic cerebral stenosis \>70%; 5. Subjects who have experienced a stroke (cerebral hemorrhage, cerebral infarction) within the past month. 6. Clinical condition is extremely poor with a modified Rankin score of ≥3. 7. Subjects planned for surgical/interventional procedures within three months. 8. Subjects deemed inappropriate for interventional treatment by the investigator (e.g., no suitable vascular access, excessively tortuous vessels, difficult stent delivery, etc.). 9. Subjects with severe comorbidities, unsuitable for anesthesia or endovascular surgery (e.g., major cardiac, pulmonary, hepatic, splenic, renal diseases, atrial fibrillation ,brain tumors, severe active infections, disseminated intravascular coagulation, history of severe mental illness). 10. Subjects unable to tolerate antiplatelet or anticoagulant therapy. 11. Subjects who has had or are likely to have a severe reaction to contrast media. 12. Subjects with a history of allergy to nickel-titanium, cobalt-chromium, or platinum-tungsten alloys. 13. Subjects who have participated in other drug or medical device clinical trials and have not reached the primary endpoint time limit. 14. Pregnant or breastfeeding women. 15. Subjects with an expected lifespan of less than 12 months. 16. Subjects deemed by the investigator to have poor compliance, unable to complete the study as required.