One hundred consecutive patients with upper extremity prosthetic grafts referred for either an angioplasty or treatment of a thrombosed graft were included in the study. After the patient's treatment was concluded, the angiographic images that had been created during the case were evaluated to determine if an upper arm vein was evident that would be suitable for the construction of an arteriovenous fistula (AVF). Criteria used to determine suitability included vein size measured at the level of the elbow, feeding artery size at the level of the elbow, absence of stenosis within the vein, and continuity with downstream unobstructed veins. Thirty-eight percent of patients had an upper arm graft and 62% had a lower arm graft. Since it was not possible to adequately evaluate patients with an upper arm graft, these patients were not included in any further evaluations. A total of 46 patients (74%) with a forearm loop graft had one or both of the upper arm veins that appeared to be optimum for the creation of an AVF. If the percentage of graft patients with venous anatomy conducive to the creation of a fistula revealed in this study is representative, then the percentage of fistulas in use could be very quickly increased to more than 50% by simply seizing the opportunity. This effort directed toward prevalent patients could yield results much more rapidly than limiting one's focus to incident patients.