Figure 8: A selected cineangiographic frame from a postero-anterior view of an aortogram prior to balloon angioplasty, showing aortic coarctation (arrow) and a large number of collateral vessels (a). Immediately following balloon angioplasty (b), the aortogram shows marked decreased in collateral vessels. In b, the site of dilated coarctation segment (arrows) is wide open. Also, note a greater opacification of the descending aorta (DAo) in b than in a. Ao, aorta.