CT angiography of lower extremity vascular bypass grafts

Over the past several years computed tomography (CT) technology has advanced to such a degree that CT angiography (CTA) has become the study of choice at our institution for imaging lower extremity vascular bypass grafts. CTA quickly provides anatomic information about the state of the graft and identifies virtually all forms of bypass graft failure and related complications. Furthermore, detailed vascular anatomy is seen beyond the graft and affords sufficient anatomic detail for surgical revision without the need for other angiographic studies. Although catheter angiography, duplex-ultrasound, magnetic resonance angiography, and nuclear medicine studies all continue to play some role in the evaluation of vascular grafts, they are more often used as problem solving modalities when CTA findings are equivocal. Whereas it was once essential to catheterize directly through a failing bypass graft or pass catheters into the graft from a distant arterial puncture to obtain an angiogram of a failing bypass graft, CTA produces arteriograms with only intravenous contrast administration, a brief visit to the CT scanner, and return to daily activities without catheterization, discomfort, or risk to the bypass conduit.