The craniocervical junction area arteriovenous fistula belongs to the category of crestal crestal vascular malformation, and crestal crestal vascular malformation is a kind of difficult disease, the cure improvement rate reported in the world is less than 50%. We have combined skillful interventional techniques and micro-neurosurgery techniques to maximize the elimination of vascular malformation clusters, with an overall recovery rate of 82.8%, breaking through a forbidden area of clinical medicine, and establishing a platform for academic research and long-term follow-up system, making China a world leader in this field, and winning the second prize of the National Science and Technology Progress Award. Since 1986, we have treated a total of more than 1700 patients with crestal vascular malformations, making us the largest clinical center in China and even in the world for this type of disease. At the same time, we are working with the rehabilitation department and the Hyperbaric Oxygen Therapy Center of Haidian Hospital to develop a systematic post-operative hyperbaric oxygen rehabilitation program to save the maximum amount of neurological deficits. 1.Where is the craniocervical junction area located in the body? Generally speaking, the craniocervical junction area refers to the area where the skull meets the neck and mainly includes the occipital bone, atlanto-occipital joint and atlanto-axial spine as well as the nerve tissues of the corresponding segments, such as the cerebral bridge, medulla oblongata, high cervical medulla, and the first two pairs of cervical nerve roots. 2.What is arteriovenous fistula? The normal tissue supply of the body comes from arterial blood delivered by the arteries, which is then supplied to the cells by the network of blood vessels at all levels, and then collected by capillaries back to the veins. An arteriovenous fistula is a short circuit between the arteries and veins when blood flows directly from the arteries to the veins without passing through the network of vessels mentioned above. 3.What is arteriovenous fistula in the craniocervical junction? What is its incidence? As the name suggests, arteriovenous fistulas occur in the craniocervical junction area and are a special category of cremasteric arteriovenous fistulas, for which no clear incidence statistics have been reported, but their incidence is extremely low, about one tenth of the incidence of cerebral arteriovenous fistulas. 4. What is the clinical presentation of craniocervical junction arteriovenous fistula? The clinical manifestations are summarized as follows: 1) subarachnoid hemorrhage: sudden headache with nausea and vomiting, no obvious limb movement disorder and sensory abnormalities; 2) medulla oblongata or cremaster medullary edema: cervico-occipital pain, dizziness, limb weakness, sensory abnormalities, urinary and fecal difficulties; 3) asymptomatic or mild symptoms: intermittent dizziness or incidental found. 5.How to detect arteriovenous fistula in the craniocervical junction? Because of its extremely low incidence, craniocervical junctional arteriovenous fistula should be considered when trauma or other cerebrovascular diseases causing subarachnoid hemorrhage or signal changes of medulla oblongata or high cervical medulla intraparenchymal edema can be seen in MRI, and whole brain angiography is needed to make a clear diagnosis, which is the gold standard for the diagnosis of this disease. 6.How to treat craniocervical junction arteriovenous fistula? Once the diagnosis of craniocervical junction arteriovenous fistula is made, the best treatment plan is chosen based on the characteristics of the blood supplying arteries and draining veins and the location of the fistula. Currently, the disease is treated with open surgery to sever the communication between the abnormal arteries and veins, and good results have been obtained. 7.What is the prognosis of arteriovenous fistula in the craniocervical junction? The prognosis of nearly 100 patients with craniocervical junction arteriovenous fistula is as follows: the prognosis of patients with craniocervical junction arteriovenous fistula with hemorrhage is relatively good, basically they can return to the state before the onset of the disease and can live and work normally. The prognosis of patients with crestal or medullary edema is closely related to the preoperative functional deficit, but the surgery avoids further deterioration of symptoms, and the postoperative treatment with regular hyperbaric oxygen and rehabilitation can achieve a more satisfactory functional recovery.