The primary goal of the trial is to investigate whether the experimental arms (receiving the P2Y12 inhibitor Ticagrelor) compared with the control arm (taking dual antiplatelet therapy) could reduce bleeding complications in patients with intracranial aneurysms undergoing Stent-Assisted Coiling.

Bleeding complications associated with the use of DAPT have been of great concern, with up to one-third of PCI patients treated with DAPT previously reported to suffer from nuisance bleeding. Once any of these bleeding complications occur, adherence to the DAPT regimen may become difficult. Antiplatelet agents are necessary for patients undergoing stent-assisted spring coil embolisation of intracranial aneurysms and are key to reducing thrombosis leading to ischaemic stroke events in post-procedural patients.

Currently neither long-term DAPT nor short-duration DAPT followed by aspirin monotherapy is fully satisfactory. Patients with aneurysms without underlying intracranial atherosclerotic disease have relatively lower ischaemic risk factors, and antiplatelet medication after stenting remains to be improved. Ticagrelor monotherapy was associated with a lower risk of major bleeding and no measurable increase in ischaemic events after a short course of 1- or 3-month DAPT. The study indicated no difference in stroke or death between mono- and dual-antiplatelet therapy after carotid artery placement, and P2Y12 inhibitor monotherapy may be an effective strategy to reduce severe bleeding complications while preserving ischemic benefits for patients. This study investigates the comparative efficacy and safety of stent-assisted coiling therapy for intracranial aneurysms after ticagrelor monotherapy as an alternative to dual antiplatelet therapy, to reduce the incidence of bleeding complications in patients, and thus to improve the antiplatelet strategy after stent-assisted coiling therapy for intracranial aneurysms.

Inclusion Criteria:

1. Patients with a definitive diagnosis of an unruptured intracranial aneurysm with imaging suggestive of an aneurysm <10 mm
2. Patients who successfully underwent stent-assisted spring coil treatment for intracranial aneurysms without acute ischaemic or bleeding stroke events in the perioperative period
3. Age 18-60 years old
4. Patients with no previous history of chronic diseases such as hypertension, diabetes mellitus, coronary heart disease, hyperlipidaemia and so on
5. Agreed to participate in this study and gave informed consent for the collection and preservation of case data and the follow-up process.

Exclusion Criteria:

1. Planned surgery or intervention during the experiment requiring study drug discontinuation; (2) Contraindications requiring oral anticoagulation or aspirin or clopidogrel; (3) History of severe central nervous system damage (e.g., as a result of tumour, aneurysm, intracranial or spinal cord surgery); (4) Severe liver disease, including hepatic failure, cirrhosis, portal hypertension (oesophageal varices), active hepatitis; (5 ) severe renal dysfunction (creatinine more than 1.5 times the upper limit of the normal range); (6) severe heart failure (NYHA class:III ~ IV); high risk for chronic arrhythmias (1st or 2nd degree atrioventricular block due to sinus node disease, bradycardic syncope without pacemaker); diagnosis or suspected diagnosis of acute coronary syndrome; bacterial endocarditis, pericarditis; (7) severe comorbidities or patients with active cancer with a life expectancy of less than 2 years; (8) participation in another clinical study using an experimental product within the past 30 days; currently receiving an experimental drug or device; and (9) pregnant, currently pregnant, or of childbearing potential without birth control or breastfeeding.

Individual participant data (IPD) will be available to other researchers under the approval of the ethical committee.

the data will be available when summary data are published.