Idiopathic Pseudoaneurysm of the Mitral-Aortic Intervalvular Fibrosa.

The mitral-aortic intervalvular fibrosa is an avascular fibrous structure between the anterior mitral leaflet and the aortic annulus. Pseudoaneurysm formation of the mitral-aortic intervalvular fibrosa is a rare but known entity most commonly caused by infective endocarditis or valve surgery. We present a 29-year-old patient with a mitral-aortic intervalvular fibrosa pseudoaneurysm of no evident cause who was successfully managed surgically.