In cerebral AVMs the feeding arteries are easily identifiable. The draining veins are usually termed "abnormal veins". The author describes how these veins are identifiable with reference to their origins in the embryo. These are veins that have failed to undergo the normal process of atresia and persisted in the adult due to the abnormal flow.
The book also deals with the complex flow patterns of the fistula based on experimental and CFD studies.