To the Editor.—We wish to comment on the article, "The Importance of Abdominal Wall Collateral Blood Vessels: Planning Incisions and Obtaining Arteriography." A1980 article by Vine and Sacks2 that outlined various angiographic approaches to opacifying vessels distal to aortic occlusions was cited. Their observations remain valid but the development of digital subtraction arteriography (DSA) provides an important advance in the arteriography of such problems.
Satisfactory opacification of vessels distal to high-grade obstructions such as infra-aortic occlusion has been a major problem. The injection site is usually remote and satisfactory opacification of distal vessels may be difficult. Injection at any one site will not opacify all of the collateral systems so that ingress of unopacified blood will dilute the contrast in the vessels being studied.
The major advantage of the recently developed technique of DSA is increased contrast detection.3 Opacification insufficient for diagnosis with standard films will result