Flow Diverter Versus Conventional Endovascular Treatment for Unruptured Wide-Neck Bifurcation Aneurysms (FD-BWA Trial)

Brief Summary： The goal of this clinical trial is to compare whether the traditional approach (stent-assisted coiling) is associated with a lower complication rate than flow diverter (Pipeline™) treatment for unruptured intracranial wide-neck bifurcation aneurysms. It will also evaluate the long-term imaging outcomes and safety of both treatments. The main questions it aims to answer are: * Does the traditional approach result in a lower rate of any stroke or all-cause death within one year after treatment compared to the flow diverter? * What medical problems do participants experience during and after each treatment? * What are the imaging cure and stability rates at 1, 2, and 5 years after treatment? Researchers will compare the traditional approach (stent-assisted coiling) with the flow diverter (Pipeline™) to determine which treatment has better safety and efficacy outcomes. Participants will: * Be randomly assigned to receive either the flow diverter or traditional stent-assisted coiling * Undergo the assigned endovascular procedure * Return for follow-up visits at 30 days, 6 months, 1 year, 2 years, and 5 years after surgery for clinical assessments and imaging examinations (DSA, MRA, or CTA)