Flow Diverter (FD) devices are developed based on reconstructing the parent artery's lumen. FDs are designed with a denser mesh compared to conventional intracranial stents. By covering the aneurysm neck, these stents redirect blood flow away from the aneurysm, promoting intra-aneurysmal flow stagnation and subsequent thrombosis formation. Currently, FDs are primarily used for the treatment of wide-neck aneurysms.

Based on the evaluation of imaging results, the treatment of aneurysms was classified according to the following criteria. Digital Subtraction Angiography (DSA), Magnetic Resonance Angiography (MRA), or Computed Tomography Angiography (CTA) are acceptable, and it is recommended base CTA. The purpose of imaging follow-up information collection is to observe the effect of on the long-term closure of the aneurysm after treatment. Complete closure of the aneurysm would be associated with increased safety.

Adequate Occlusion is defined as Raymond-Roy Grade I or Grade II on imaging evaluation of the target aneurysm.

The technical success rate refers to the proportion of technically successful patients in the total number of patients. Technical success is defined as successful stent placement and meet following criteria: Stent fully cover the aneurysm neck; Good wall apposition; Perfusion of the parent artery; Retention of contrast agent within the aneurysm;

During procedure, the observational device can be retrieved / re-sheathed into the microcatheter and re-deployed at the desired target location or removed completely from the patient. But it must not be re-deployed more than three times. Re-sheath performance refers to the retrieving and re-deploying of observational device recorded during the procedure. Information such as the number of recoveries and the number of re-sheathings, the success rate of re-opening and other information are recorded to evaluate the re-sheath performance of the observational device.