A persistent stapedial artery is a congenital defect of the inner ear where an artery that in an embryo that passes through the stapes bone in the middle ear remains present well into development of the fetus. In a normal fetus, this artery is eventually destroyed, leaving no arteries that exist within the inner ear behind the eardrum. The condition is difficult to diagnose. The ear will usually appear normal on an external examination. Often, the only clue is that the inner ear has a small, palpable mass.