VII. ARTERIOVENOUS FISTULA (Abnormal communication
between two channels)
Abnormal communications between arteries and veins can arise as developmental
defects, from rupture of an arterial aneurysm into an adjacent vein, or
from traumatic events. A carotid-cavernous fistula, for example, may occur
via trauma-induced rupture of the internal carotid artery into the cavernous
sinus or via rupture of a saccular aneurysm of the carotid artery into the
cavernous sinus. Consequences include effects on vascular dynamics, i.e.,
shunting of blood, leading to cerebral ischemia. Pulsating exophthalmos
is a clinical manifestation.