The effect of angioplasty of single arteriovenous fistula-associated stenosis on arteriovenous fistula blood flow rate

INTRODUCTION: Percutaneous balloon angioplasty of arteriovenous fistula-associated stenosis is performed for a variety of indications. Successful percutaneous transluminal angioplasty (PTA) is expected to increase in arteriovenous fistula blood flow rate (Qa). A validated approach to predicting changes in Qa based upon stenosis characteristics is not available.

METHODS: Three baseline parameters were determined in a group of patients with a single arteriovenous fistula-associated stenosis undergoing PTA. These were percent estimated stenosis, stenosis minimum luminal diameter, and baseline Qa. The relationship between these parameters and changes in Qa following PTA was analyzed using Spearman's rank correlation and linear regression.

RESULTS: 113 patients (total group) were studied. Of these,106 had peripheral stenosis (total peripheral subgroup) and 7 had central stenosis. For the total group and total peripheral subgroup, a highly significant inverse correlation was seen between changes in Qa and baseline Qa. A weaker correlation was seen between changes in Qa and minimum luminal diameter, but no correlation was seen with percent estimated stenosis. A minimum luminal diameter ⩽2.0 mm was predictive of ⩾300-mL/min increases in Qa, whereas a minimum luminal diameter >4.5 mm was associated with <300-mL/min increases in Qa. PTA of Central vein stenosis was not associated with significant changes in Qa.

CONCLUSION: Baseline Qa is the best predictor for change in Qa following PTA. Stenosis minimum luminal diameter cutoffs of ⩽2.0 and >4.5 mm are useful in predicting the magnitude of changes in Qa. Percent estimated stenosis is not predictive of change in Qa. PTA of central veins does not seem to change Qa.