Native arteriovenous fistulas: correlation of intra-access blood flow with characteristics of stenoses found during diagnostic angiography.

Surveillance of the intra-access blood flow (Qa) has improved identification of thrombosis risk (Qa < or = 500 ml/minute), and these patients are referred for angiogram and angioplasty. The purpose of this study was to correlate the Qa with patient and stenotic lesion characteristics both before and after angioplasty in a retrospective cohort of 210 patients who were preselected on the basis of reduced Qa (369 +/- 121 ml/minute). Angiograms revealed a total of 643 stenoses, and all patients had at least one significant stenosis (>50% luminal narrowing). There was no significant association between the preangioplasty Qa and the number, location, or length of stenoses, but there was a significant negative correlation between the degree of stenosis and the preangioplasty Qa. Five hundred eighty stenoses in 190 patients were treated with angioplasty; the postangioplasty Qa was 633 +/- 208 ml/minute. Of the residual stenoses, all had less than 50% narrowing. There was no correlation between the postangioplasty Qa and the length or degree of stenoses, but there was a significant negative correlation between the postangioplasty Qa and the number of stenoses. We conclude that the primary determinant of reduced preangioplasty Qa is the degree of stenosis, when stenoses are over 50%, whereas the primary determinant of reduced postangioplasty Qa is the number of stenosis. For patients with two or more residual stenoses and failure to achieve Qa > 500 p;ml/minute postangioplasty, the alternative procedure is a prompt surgical revision in order to maintain the goal of access patency.