What is a ventral epidural defect?

Break it down: MC Hammer style

Ventral is for humans front part of the body (ie. the chest, knees, face, etc)

Extra is outside

Dural is having to do with the dura mater, one of the layers of the membranes covering the spinal cord.

So a ventral extradural defect would be some sort of defect (probably a weakness) on the outer boundary between the dura mater and the spinal cord at the belly side of the cord. It could represent anything from changes of aging to a herniated disk to a tumor. The rest of the radiology report, as well as the history and physical, will tell you the medical meaning of this description term.