Endovascular treatment of intracranial aneurysms began in the early 1970s – Serbinnenko pioneered the detachable balloon technique of embolization of intracranial aneurysms. Shortcomings of the balloon technique: (1) balloon leakage; (2) incomplete matching with the aneurysm, leaving the neck of the aneurysm; (3) water hammer effect; (4) rebleeding during the acute phase of hemorrhage. In 1991, Guglielmi developed the use of electrolytic platinum micro-spring coils (GDC), which has become an important treatment for intracranial aneurysms.On October 26, 2002, Lancent published the results of the 8-year International Multi-Center Prospective Randomized Trial of the International Arachnoid Hemorrhagic Aneurysm Trial Writing Group (ISAT) on the treatment of ruptured saccular aneurysms by neurosurgical clipping and embolization with an endovascular spring coil. The ISAT trial data suggest that spring coil embolization should be considered first for small, clinically graded, anterior circulation ruptured saccular aneurysms when the morphology is amenable to both surgical and endovascular treatment. In contrast, the superiority of posterior circulation aneurysm intervention over clamping has long been recognized. After the publication of the ISAT paper, it had a great impact on the global neurosurgical field, and even directly changed the ratio of clamping to embolization. The latest statistics show that the proportion of aneurysms treated with interventional therapy has reached 90% in European medical centers, and in the United States the proportion has exceeded 50%. Interventional therapy has become the treatment of choice for aneurysms. I. New Products: TRUFILL® DCS — Water-detachable Spring Coil System DCS (Detachable Coil System) consists of high-pressure syringe, spring coil delivery tubing and platinum spring coils, and its detachment is water-detachable, which is different from the electro-detachable of GDC, and the main features are: The main features are: the coil is always coiled along the aneurysm wall from the outside to the inside when it is released from the aneurysm, and when the filling is incomplete, the gap is located in the center of the aneurysm cavity, which facilitates the entry of the next coil; the coils are soft, and the Complex model releases them randomly in three dimensions, which is a better conformity to the aneurysm morphology; and the coils are released by hydraulic pressure generated by the high-pressure syringe. Coils from MicroVention (USA) General Coils MicroPlex® Coil System; MicroPlex XT Coil System Biological Coils HydroCoil ® Embolic System The coils are coated with hydrogel, a water-expandable propylene glycol coating. –Hydrogel is a water-swelling acrylic copolymer that provides a denser filling of the aneurysm cavity than other non-biologic spring coils, reducing the rate of aneurysm recanalization; incompletely embolized aneurysms have shown progressive occlusion on follow-up; and, in selected cases, the amount of spring coils used can be reduced, resulting in lower complications and lower surgical costs. Release Methods HydroLink® Release Technology Matrix – The new generation GDC Matrix is a copolymer-coated platinum spring coil with a polyglycolic-polylactic acid (PGLA) copolymer. Acid (PGLA), which makes up 70% of the total volume of the spring coil and is fully absorbed in the body within 90 days. Compared with the old generation of GDC, it has strong thrombogenic ability and can promote the proliferation of connective tissue in the aneurysm, so it is expected to reduce the long-term recanalization rate of the aneurysm, and at the same time, with the absorption of copolymers, the volume of the aneurysm can be gradually reduced after embolization. Onyx–non-adhesive liquid embolic material Ingredients: ethylene vinyl alcohol heteropolymer (EVOH), dimethyl sulfoxide solvent (DMSO), micronized tantalum powder (developer) Principle of action EVOH is a non-adhesive embolic material that is insoluble in water and soluble in DMSO, which rapidly disperses when it meets blood or any water solvent. When DMSO meets blood or any aqueous solvent, it rapidly disperses, while EVOH precipitates and precipitates as a spongy mass that becomes a permanent embolus at the target site. Spherical Coil–Spherical Spring Coil Spherical Spring Coil is a new type of three-dimensional spring coil that is suitable for both narrow carotid aneurysms and wide carotid aneurysms. It has been shown that there is no significant difference in real-time and long-term follow-up results between embolization of narrow carotid aneurysms and wide carotid aneurysms. 32P-Coil–Radioactive Spring Coil Ion implantation of 32P on the surface of the spring coil forms a radioactive spring coil; the local radiation effect of 32P prevents distant recanalization after embolization of the aneurysm; the β-particles released by 32P are extremely weak in penetration, so that the tissues around the spring coil are protected from the radiation effect Fibered Coil –Indications: occlusion of aneurysm-carrying arteries; giant aneurysms; wide carotid aneurysms; subcapsules of ruptured aneurysms (rupture sites) Neuroform – a new type of intracranial vascular scaffolding The Neuroform scaffold is specifically designed for the reconstruction of intracranial blood vessels in combination with spring coil embolization. reconstruction and combined with spring coil embolization for the treatment of wide neck aneurysms. It is characterized by: (1) microcatheter delivery; (2) self-expanding release; (3) open mesh design with high compliance to minimize branch vessel blockage, can be used in curved vessels, and automatically adapts to the diameter of the near and far vessels after release while allowing spring coil embolization of the aneurysm to be delivered through the mesh holes of the stent; (4) four dotted platinum markers on each of the proximal and distal ends of the stent, which are clearly visible under fluoroscopic vision; and (5) stent The shortening rate after release is low, 1.8%-5.4%. Stent Graft – Coated Stent The stent is coated with a copolymer film, i.e., coated stent, also known as artificial blood vessel. The film can be composed of degradable copolymers (e.g. polyglycolic acid, polylactic acid, etc.) or non-degradable copolymers (e.g. polyurethane, silicone, polyester, etc.). The indications for laminated stents in cerebrovascular disease are narrow, and they should only be used in arterial segments without side branches or perforating branches emanating from them, such as wide-necked or giant aneurysms of the internal carotid arteries below the level of the posterior communicating arteries; wide-necked or pike aneurysms of the vertebral arteries; and carotid cavernous sinus fistulas. Required Microcatheter Characteristics Superior travel properties; head end moldable and morphologically intact; stability of the catheter head within the aneurysm Required Characteristics of the Guidewire Adequate support for catheter advancement; strong resistance to torsion for precise vessel selection; soft and pliable head end of the guidewire. Second, new technology of endovascular treatment of intracranial aneurysm Microcatheter head end shaping Microcatheter head end shaping is important for aneurysm super-selective micro-spring coil tamponade, 45 °, 90 ° single-bend shaping is more common, but also should be different from person to person. Double-bend shaping is conducive to microcatheter stabilization and is more suitable for small aneurysms and micro aneurysms with small necks. Microcatheter super-selective in place method to avoid causing aneurysm rupture bleeding. 1, microcatheter downstream or retrograde introduction method; 2, microcatheter wire-assisted method (rotary/direct introduction); 3, micro-spring coil introduction method (micro-AN). Successful techniques for aneurysm embolization Basket technique The basket technique is a technique in which a three-dimensional spring coil is used as the “coil of choice” for embolization of wide neck aneurysms. It has the property of automatically forming a three-dimensional basket after release, providing a stable framework for continued filling of the conventional spring coil, thus reducing the risk of the coil protruding into the lumen of the aneurysm-carrying artery; Dual Microcatheter Technique Two microcatheters are placed inside the aneurysm, alternately delivering the spring coils, and then releasing them after observing that they have stabilized. The interwoven spring coils are more stable in the aneurysm lumen and less likely to protrude into the aneurysm-carrying artery. This technique is suitable for embolization of wide carotid aneurysms. Balloon reshaping technique A non-detachable balloon is first placed at the opening of the aneurysm. The microcatheter is then inserted into the aneurysm cavity. The balloon is filled to close the aneurysm opening, a spring coil is fed through the microcatheter to fill the aneurysm cavity, the balloon is emptied, and the spring coil is released if it is stable. The process is repeated until the aneurysm is satisfactorily filled. The balloon reshaping technique is indicated for embolization of wide carotid aneurysms. Stenting technique The stent alone technique is used to close a laminated aneurysm by placing a stent across the aneurysm opening and using the support of the stent to close the laminated layer. The stent combined with a spring coil technique is used to occlude a wide-necked aneurysm or a syrinx aneurysm by placing a stent across the aneurysm opening, inserting a microcatheter into the aneurysm lumen through the stent mesh and placing a spring coil to close the aneurysm. The pre-positioning of the stent helps to tightly fill the aneurysm and prevent the spring coil from protruding into the aneurysm-carrying artery. How to develop an embolization treatment plan? 1, narrow neck aneurysm Simple application of spring coil embolization, recommended the first application of 3-D spring coil; 2, wide neck aneurysm Wide neck aneurysm concept 1, “relative” wide neck aneurysm Sacculus-neck ratio (the shortest diameter of the aneurysm body / the width of the neck of the aneurysm) ≤ 2 or no neck; 2, “absolute” wide neck aneurysm The aneurysm is the result of a wide neck aneurysm, which is the result of a wide neck. “Wide carotid aneurysm: neck width ≥4 mm; Wide carotid aneurysm application techniques (1) double catheter technique; (2) balloon reshaping technique combined with spring coil technique; (3) stenting technique combined with spring coil technique. Treatment principle: effective and simple (from simple to complex, simplify to simplify). In conclusion, the future of endovascular therapy ranges from the continued improvement of delivery systems, the combination of endovascular endoscopy with microcatheters and microguidewires, to endovascular navigation, toward the trend of artificial intelligence in delivery systems. With advances in material science and methodology, endovascular intervention is expected to become the treatment of choice for intracranial aneurysms.