Postoperative day 1 access blood flow and resistive index can predict patency in distal forearm arteriovenous fistula.

Abstract

Early access failure is an important complication of autogenous arteriovenous fistulas (AVFs). We prospectively monitored patients who underwent AVF creation using ultrasonography. Color flow imaging was used to assess access blood flow in patients undergoing creation of a new AVF in the distal forearm preoperatively and at 1 day and 1 week postoperatively. We measured the flow volume (FV) and resistive index (RI) of the brachial artery, and the internal diameter of the brachial artery and outflow vein. The primary outcome was the primary patency of the AVF without percutaneous angioplasty (PTA) or surgical revision 40 days after access creation. We recruited 35 patients with newly created AVFs (men, 21; mean age, 73 years). Within one day of operation, the overall FV increased from 62 to 352 mL/min (p<0.0001) while the overall RI decreased from 1.0 to 0.63 (p<0.001). Five patients required PTA or surgical revision (intervention group [IG]), whereas 30 patients did not (non-intervention group [NIG]). The FV increased while the RI decreased from day 1 to week 1 in the NIG, but not in the IG (p<0.0001). The diameter of the brachial artery and outflow vein significantly increased in the NIG at 1 week. The FV of 235 mL/min and RI of 0.63 at 1 day were the thresholds for predicting early fistula failure. Access FV and RI at 1 day after AVF creation can predict primary patency and help plan intervention.