Localized open-window malformation of the anterior cerebral artery, segment A2, is a vascular malformation that occurs when the blood vessel of the anterior cerebral artery splits from one to two in this portion of segment A2, and then re-fuses back into one when it reaches the distal end. Open window malformation of the cerebral arteries is a developmental abnormality of the cerebral blood vessels. An open window malformation occurs when a cerebral blood vessel suddenly splits into two, shares a common ependymal membrane, and then re-fuses into one at the distal end. If this occurs locally in the A2 segment of the anterior cerebral artery, it is called an open window malformation of the anterior cerebral artery. Open window malformations of the basilar and vertebral arteries are also common. Open-window malformations of the anterior cerebral artery are often detected during cerebrovascular-related tests, and patients may have no obvious symptoms. When the malformed blood vessel presses on the surrounding brain tissue and nerves, it can cause some symptoms. This open-window malformation can make arterial intervention more difficult. When a localized open-window malformation of the A2 segment of the anterior cerebral artery is detected, it is recommended to consult a physician to further improve the examination and evaluate the condition.