Effects of carotid ligation on the size of internal carotid aneurysms.

Aneurysms of the intrathecal portion of the internal carotid artery are commonly treated by ligation of one of the carotid arteries in the neck. After ligation of the internal carotid artery, subsequent angiographic demonstration of the site ofsuch an aneurysm may prove difficult or impossible; but if ligation has been confined to the common carotid the internal carotid artery usually remains patent, and its injection either by percutaneous puncture or after its exposure then gives good filling of the aneurysm site. This study has been undertaken to examine 25 such cases in detail, to discover what happens to these aneurysms following carotid ligation. With the exception of cases 6, 21, and 24 they were extracted from a consecutive series of carotid aneurysms reported elsewhere (Gibbs, 1962). In the illustrations, traced in the first instance on polythene film, the posterior communicating and ophthalmic arteries have been reproduced whenever filled on angiography. In each case the anterior cerebral artery is identified by dots: two dots if it is continued on to fill the pericallosal artery and one if it fades away at that level. Clinical features have been summarized in the table. T1th