What is CCF and what are its risks? CCF is the acronym for Carotid Cavernous Fistula. Under normal circumstances, arteries and veins do not communicate directly with each other, they are like two railroads that go in different directions, accompanying each other but not merging. The relationship between the carotid artery and the cavernous sinus is very peculiar, as the carotid artery enters the skull and is wrapped in the cavernous sinus, then branches out to supply the brain after the carotid artery has exited the cavernous sinus. When head trauma or intracranial infection and other causes cause rupture or dissection of the arterial wall of the cavernous sinus segment of the carotid artery, an abnormal arterial and venous communication is formed, called carotid cavernous fistula (CCF). Patients develop protruding eyes and beat with the pulse, diplopia, redness of the eyeballs, eyelid ectropion, loss of vision or even blindness; intracranial murmurs synchronized with the pulse can be heard, and even violent nosebleeds, which can be life-threatening in severe cases. How to diagnose CCF? The diagnosis can be clearly made based on whole brain angiography. How is CCF treated? The treatment of this disease is to block the fistula in order to eliminate the intracranial murmur, improve the blood supply to the brain and preserve vision. The treatment of this disease has been a very difficult problem for neurosurgeons in the past, and many methods were considered, but they were gradually eliminated because of the large cranial trauma and inaccurate treatment results. With the rapid development of endovascular interventional technology in neurosurgery in China, detachable balloon endovascular embolization was carried out, which can not only occlude the fistula of CCF, but also preserve the patency of internal carotid artery and restore the normal pressure and drainage direction of cavernous sinus, so that this disease can be fundamentally cured. This method does not require craniotomy, is less invasive, and has a high cure rate, making it the preferred method for the treatment of CCF.