Pertaining to the convergence at both ends of something: An amphicentric plexus of blood vessels have one afferent and one efferent trunk.

This refers to the joining or meeting at both ends, said of a "rete mirabile" (vascular network interrupting the continuity of an artery or vein) that starts when a blood vessel breaks up into a number of branches and ends by the branches joining again to form the same vessel.