[Angiographic analysis of the internal carotid-vertebrobasilar system with cerebral aneurysms--with special interest in the morphological aspect including so-called vascular anomalies].

In a series of 704 aneurysm patients who were admitted to the Research Institute for Brain and Blood Vessels-AKITA during the last 9.5 years (from October, 1974 to March, 1983), angiographic features of the internal carotid-vertebrobasilar system and related vascular anomalies were analyzed with reference to the site of aneurysms. The age distribution was from 20 to 78 years (mean age 53 years) and the men to women ratio was 1:1.1. The total number of the aneurysms was 866. The site distribution of aneurysms consisted of 230 (27%) anterior communicating, 269 (31%) middle cerebral, 282 (38%) internal carotid, 54 (6%) anterior cerebral, 45 (5%) vertebrobasilar and 6 other arteries. More than one aneurysm were found out in 137 cases. The total number of performed cerebral angiograms was 1840, in which right carotid arterial angiograms were 652, left carotid 644 and vertebral 544. Angiographic features of the posterior communicating arteries (Pcom) with or without internal carotid-Pcom aneurysm were compared one side with the other, statistically revealing that the morphological factor of the Pcom did not play an important role in the development of the cerebral aneurysm at this portion. Anomalies of the posterior cerebral artery directly originated from the internal carotid artery were found in 9 cases, and three of them had the aneurysm at their origin. Anomalous carotid-basilar anastomoses were seen in 7 cases, namely 6 persistent primitive trigeminal arteries (2 of them were PTA variants) and one persistent primitive hypoglossal artery.(ABSTRACT TRUNCATED AT 250 WORDS)