[Clinical correlations between lumbar superficial veins and Batson's epidural plexus congestion in chronic low back pain: analysis of two case reports].

Batson's epidural venous plexus plays a crucial role for the generation of vascular back pain, in particular in those conditions characterized by venous congestion, such as heart failure or pregnancy. Except some rudimentary cuspids, the vertebral venous system is considered to be a valveless anastomotic system; as a result the blood is supposed to flow in either direction depending on changes of cardiovascular conditions during the day. Within the narrow boundaries of the neural canal, the epidural veins can therefore get congested, inducing low back pain.