Normal anatomical variation and asymmetry of the Galenic venous system.

Abstract

Abstract A retrospective study of 200 bilateral normal carotid angiograms was made. Variation in the appearances of the deep veins between different individuals and their asymmetry in one person was analysed. There are two main conclusions. Firstly, the deep veins are symmetrical in 65 per cent of cases. In these there are various differences between one individual and the other in the configuration of the internal cerebral vein and/or its tributaries. Secondly, in 35 per cent, the deep veins are asymmetrical. This asymmetry may result from difference in the position of the venous angle, the length of the internal cerebral vein, the number of the septal or striate veins, the junction of the septal vein with the internal cerebral vein, or from minor variation in the shape of the arc formed by the internal cerebral vein.