Abstract Dural arteriovenous fistulas (DAVFs) are rare and complex intracranial vascular disorders whose etiology and pathogenesis are unknown. However, because DAVFs are usually multiple fistulas with complex blood supply arteries, they are difficult to be cured by simple arterial embolization, and complete resection of the lesion is risky, so some authors focus on the treatment of venous circuits, such as occlusion or severance of the diseased sinus and drainage veins to achieve a cure. In recent years, the transvenous end has been treated with good results. Dural arteriovenous fistula (DAVF) is a common intracranial vascular disease, accounting for 10%-15% of all intracranial arteriovenous malformations in foreign countries, most commonly in perimenopausal women and rarely in men. The disease is more common in adults, especially in the 40-60 age group, and most dural arteriovenous fistulas are acquired lesions. (1) Inflammation or thrombosis of the dural sinuses It is generally believed that dural arteriovenous fistulas often coexist with thrombosis of the cerebral venous sinuses and are associated with surgery, trauma, infection, inflammation and other factors. Chronic stimuli such as thrombophlebitis, trauma, intracranial surgery, or dural vein thrombosis can cause an inflammatory response in the dural venous sinuses, and various cytokines/ mitogenic factors (TGFβ, IL21, HBGF22) secreted by inflammatory cells are strong stimulators of angiogenesis. (2) Venous sinus stenosis and venous hypertension The stimulation of large amounts of arterialized blood flow in the dural venous sinuses can cause intimal damage or vascular stenosis or even occlusion, resulting in obstruction and increased resistance of the draining veins. Common triggers include head trauma, cranial surgery and clinical conditions that can cause hypercoagulable states such as pregnancy and infection. Venous sinus thrombosis and concomitant venous hypertension are closely related to the development of DAVF. Under normal conditions, there are small arteriovenous traffic branches in the dura mater adjacent to the venous sinuses, which are normally closed. When the pressure in the venous sinus is increased by the above mentioned factors, these embryonic arteriovenous traffic open and short circuit between arterioles is formed. (3) Hormonal effects The effect of estrogen on DAVF is based on clinical observations, and the disease is most common in perimenopausal women and less common in men, suggesting a possible hormonal effect. 21 of the 24 cases of DAVF reported by Roy et al were women. The incidence of DAVF in postmenopausal and pregnant women was found to be higher than that of the general population, so it is believed that estrogen plays an important role in the development of DAVF. 2. Classification of DAVF Currently, most of them are classified by fistula site and drainage vein, especially the latter is more helpful for understanding its clinical manifestations, risk determination, and treatment selection. Among the various classification systems of DAVF, the classification proposed by Cognard et al. is widely accepted. It states that the risk of intracranial hemorrhage is related to the pattern of venous return. DAVFs are classified into five types according to the drainage pattern: type I: venous drainage into the venous sinus with blood flowing in a centripetal direction. type II: venous drainage into the venous sinus with blood flowing backwards (IIa) and blood flowing backwards into the cortical veins (IIb), both of which are present (IIa+IIb). Type III: direct inflow into cortical veins without venous dilatation. Type IV: direct inflow into cortical veins with venous dilatation. Type V: a perimedullary vein with intracranial DAVFs flowing into the spinal cord. As the pathophysiology evolves, the low-risk fistula becomes a high-risk fistula when there is narrowing of the draining veins and occlusion of the venous sinuses. Any change in the patient’s symptoms, such as an increased headache or a change in the nature of pulsatile tinnitus, suggests a change in the drainage pattern and an increased risk of bleeding. both CT and MRI are helpful diagnostically, but catheter arteriography is useful in clarifying the diagnosis, risk.