Intracavernous (saccular, fusiform) aneurysms of the internal carotid artery

Abstract

Intracavernous saccular and fusiform aneurysms of the ICA can be located anywhere from the lateral to the distal dural rings of the ICA. Most of them are located on the concave aspect of the anterior loop of the intracavernous ICA. The intracavernous aneurysms vary not only in location but also in size. Symptoms and signs of local compression of the surrounding structures only occur when the aneurysm is large or giant. However, small intracavernous aneurysms may be responsible for TIA due to aneurysm to artery embolism. This is much more true for large and giant intracavernous aneurysms which are partially thrombosed or filled with blood clot. Small intracavernous aneurysms may rupture and cause CCFs. Large and giant aneurysms of the ICA in the CS are the origin of emboli to the peripheral cerebral vascular tree in a much higher proportion than small intracavernous ICA aneurysms. At the same time, large and giant ICA intracavernous aneurysms cause local symptoms, due to compression of the surrounding structures thus causing paresis of nerves III through VI. Headache caused by large and/or giant intracavernous aneurysms is usually more disturbing than headache caused by tumorous lesions of the CS. While rupture of a small intracavernous aneurysm usually leads to a CCF and only occasionally to a large or giant false aneurysm, rupture of a large or giant aneurysm is much more dangerous and may, along with the local symptoms and signs, also cause intradural catastrophic hemorrhage [14]. Small intracavernous aneurysms in most cases are discovered incidentally during carotid angiography in patients with SAH, due to the rupture of an aneurysm intradurally.