I. Overview Pseudoaneurysm is a disease in which the whole arterial wall ruptures and bleeds due to trauma and other factors, and is wrapped by the surrounding tissues to form a hematoma, which is clinically manifested by local pain, fluctuating mass and local compression symptoms. With the development of intra-arterial therapy in recent years, the incidence of pseudoaneurysm at arterial puncture has also increased. Most of the pseudoaneurysms are secondary to vascular injuries such as trauma, stab wounds, surgical trauma, post-pancreatitis complications, atherosclerosis, etc. Due to the thick soft tissue around the vessel, a hematoma is formed around the vessel rupture, and due to the continuous impact of arterial pulsation, the vessel rupture is connected to the hematoma to form a pulsatile hematoma, and the hematoma is mechanized to form an outer wall, and the inner surface of the hematoma cavity is the extension of arterial endothelial cells to form an endothelium, which is called pseudo Aneurysm. The difference between a true aneurysm and a pseudoaneurysm is that the true aneurysm has the middle and outer layers of the arterial wall. Pseudoaneurysms are characterized by localized masses, superficial pulsations that can be felt at the same frequency as the heart rate, localized pain and localized occupational effects. Depending on the location, the symptoms may vary. Intracranial pseudoaneurysms can cause headache, nausea, vomiting, and hemiplegia; in the internal carotid artery, they can cause protruding eyes and nasal bleeding; in the thoracic aorta, they can compress the mediastinum and the recurrent laryngeal nerve; in the abdominal cavity, they can cause compression of local organs and blood vessels and multiple organ ischemia; in the extremities, local masses and pain are the main causes; ultrasound, CT, MR, etc. have good auxiliary diagnostic effects on pseudoaneurysms, and angiography is a good diagnostic tool for pseudoaneurysms. Angiography is an important indicator to diagnose pseudoaneurysm, but it is an invasive test. Treatment Pseudoaneurysm treatment can be divided into conservative treatment, surgical treatment and interventional treatment. Conservative treatment: The main method is compression, which means that the proximal artery of the pseudoaneurysm is compressed by manipulation to slow down the blood flow, coagulate the blood and finally close the fistula. This method is suitable for superficial, smaller and shorter pseudoaneurysms. Surgical treatment: Mainly arterial repair, arterial replacement, arterial ligation, etc., are highly traumatic, complicated and have more complications, and can be used as a bailout treatment after conservative treatment fails. Interventional treatment: Interventional treatment is currently the preferred method for the treatment of pseudoaneurysm, and is divided into extravascular and endovascular treatments. Extracorporeal treatment: Under the positioning of X-ray or B-ultrasound, the aneurysm is punctured percutaneously and blood flow in and out of the aneurysm cavity is confirmed by X-ray imaging or B-ultrasound, then thrombin is injected to make the blood coagulate and close the rupture so as to cure the pseudoaneurysm. This method is simple, less invasive, more effective, less costly and has a shorter treatment period. Endovascular treatment: Under the angiography machine, a catheter is inserted into the fistula to image the fistula and select the appropriate treatment material and method to treat the pseudoaneurysm. A microcatheter can be inserted into the fistula to inject thrombin, NBCA gel, etc. to close the lumen and disable the spring ring. This method is suitable for pseudoaneurysms with deeper locations and smaller fistula openings, such as lesions at the thoracic abdomen and internal carotid artery. For larger fistulae, we can use overlapping stent placement and aneurysm isolation to close the fistula and isolate the aneurysm lumen, such as aortic pseudoaneurysm and intracranial pseudoaneurysm. For pseudoaneurysms with compensating branches of the aneurysm-carrying artery, the aneurysm-carrying artery can be directly closed with spring-ring embolization at the proximal artery of the lesion. The above methods can be used in 1-3 types depending on the condition. Interventional treatment of pseudoaneurysm is one of the first methods for pseudoaneurysm because of the small trauma, only one needle eye in the wound, complete closure of the aneurysm cavity, few complications and good efficacy.