Vascular mapping techniques: advantages and disadvantages.

At present, an arteriovenous fistula is the best available access when compared with an arteriovenous graft or a tunneled hemodialysis catheter. Preoperative vascular mapping has been shown to result in an increased placement of arteriovenous fistulae. In general, 3 modalities (physical examination, ultrasound examination and angiographic evaluation) are available for vascular evaluation. Both arterial as well as venous examination can be conducted using physical examination. However, this technique is known to miss veins, especially in the obese, and result in exclusion of patients who do not show adequate veins on clinical inspection, but who have suitable veins (proven by the other modalities) for AVF construction. Ultrasound examination of the vessels is an objective assessment. It provides an excellent evaluation of both arteries and veins for creation of an arteriovenous fistula. The technique is limited by its inability to directly visualize the central veins. Although imaging of the veins by the administration of radiocontrast dye optimally visualizes peripheral as well as central veins, it exposes the patient to the risk of radiocontrast-induced nephropathy. This article presents advantages and disadvantages of the 3 mapping techniques and proposes a strategy to conduct vascular mapping in patients with chronic kidney disease.