Congenital arteriovenous fistula
Arteriovenous fistula refers to an abnormal channel between arteries and veins. This abnormal channel is called an arteriovenous fistula. Congenital arteriovenous fistula is caused by the abnormal channel left over from the arteries and veins during the development and evolution of the embryonic mesoderm. The lesion can occur in any part of the human body, usually in the limbs, often involving many small arteriovenous branches, with multiple fistulas and diffuse lesions. When the fistula is small, there is generally no vascular pulsation or murmur, and it is often difficult to observe the location of the fistula through arterial angiography, so there are certain difficulties in diagnosis and treatment.