On posttraumatic intracavernous false aneurysms and arteriovenous fistulas.

Posttraumatic high-flow communications between the intracavernous internal carotid artery (ICA) and the cavernous sinus may give rise to two different pathological entities. A connection between the ICA and one of the adjacent intracavernous veins will result in a carotico-cavernous fistula (CCF). A false aneurysm will develop if the arterialized rent from the injured ICA flows directly into the bare perivenous spaces within the cavernous sinus, without a shunt with one of the veins. A CCF and a false aneurysm can be present in the same patient. Angiographically these two entities may be demonstrated, and clinically have a somewhat different behaviour. Life-threatening massive epistaxis is the most serious complication, particularly in false intracavernous aneurysms. Most high-flow CCFs are the result of a small side-wall laceration of the ICA, while large ICA injuries or even complete transection of the artery are responsible for the origin or false aneurysms.