An aneurysm is a bulge in the wall of an artery, which is like a part of a blown-up balloon with thin walls that can easily rupture. Interventional treatment is also called endovascular treatment. The principle of interventional treatment for aneurysm is to insert some foreign material into the weak aneurysm cavity, which eventually leads to occlusion of the aneurysm cavity, so that blood no longer enters the aneurysm cavity, which also has the effect of stopping bleeding. These commonly used foreign bodies are currently mainly platinum spring coils, which are inserted into the aneurysm lumen through a system of catheters that are temporarily placed in the vessel and then released, leaving it inside, in a process similar to stuffing a shrimp basket with a piece of string and eventually filling it up. If the basket has a large opening and the doctor is concerned that the rope may be flushed out inside, it will need to be blocked with a balloon (temporary) or stent (permanent). You may wonder how a rope can stop the bleeding. Because blood is not water, it has many cellular and fibrin components in it, and when blood flow is blocked by a tight foreign body, it slows down significantly and forms a concrete-like thrombus with these platinum spring coils so that the blood flow in the artery cannot enter the aneurysm lumen, thus acting as a hemostat. These platinum spring coils are so biocompatible that they do not need to be removed later.