Pre-Operative Vessel Mapping and Early Post-Operative Surveillance Duplex Scanning of Arteriovenous Fistulae

Abstract

This study shows that preoperative vessel mapping provides useful information regarding the choice of AVF. Access surveillance duplex scanning at 6-8 weeks post-operatively is viable and has a high sensitivity and specificity for final outcome of fistula. Identifying AVF with potential problems early means that further intervention or surgery can be planned earlier, which will have a positive impact on patients.

The Significance of Inflow Artery and Tourniquet Derived Cephalic Vein Diameters on Predicting Successful Use and Patency of Arteriovenous Fistulas for Haemodialysis

“…There is conflicting evidence in the literature, with some studies showing that pre-operative radial artery diameters <1.5e1.6 mm predict early failure, 8,10,11 while other studies similar to this one, using a 2 mm minimum diameter failed to demonstrate an association. 7,16 Similarly, no association was found between cephalic vein diameter and primary radiocephalic AVF failure, probably the result of including patients with a minimum cephalic vein diameter of 3 mm, unlike others who used a minimum diameter of 1.8 mm. 10,11 The present study confirmed the results of two studies showing that in upper arm fistulas that failed to become functional, pre-operative brachial artery diameters were significantly smaller compared with those that became functional 5,14 ; these studies did not provide minimum diameters useful in clinical practice.…”

“…16 Regarding optimum minimum venous diameter, patients with a larger vein have a higher probability of functionality, 6 particularly in the presence of a vein >4 mm in diameter, 4,5 although another study failed to demonstrate such an association. 16 The present study also failed to confirm these associations, and this is considered to be the result of appropriate use of preoperative vessel mapping to exclude small and diseased cephalic veins, unlikely to be successfully used for dialysis. Of note, one study on a mixed population showed that AVFs made with small arteries and veins had a higher rate of early thrombosis than those with more advantageous anatomy; however, no minimum diameters were provided.…”

“…4,5,7e16 As a result, generally accepted minimum arterial diameters useful in clinical practice have not been provided and a possible effect of brachial artery diameters on long-term patency has not been investigated. For radiocephalic AVFs, several studies have demonstrated poor functionality rates with a radial artery smaller than 1.5e2.3 mm, 8,10,11,13 and a cephalic vein smaller than 1.6e2.7 mm, 7,10,11,13,16 but others have failed to confirm the above associations for arterial 7,9,16 and venous diameters. 7,9 One study showed an association between radial artery diameter and primary patency.…”

“…7 For brachiocephalic AVFs, two studies have demonstrated that pre-operative brachial artery diameters were significantly smaller for upper arm fistulas that failed to become functional, compared with those that became functional 5,14 ; however, a third study failed to confirm these findings. 16 Additionally, a minimum suggested diameter useful in clinical practice was not provided and a possible effect of brachial artery diameter on long-term patency was not investigated. Vein diameter has been shown to be a predictor of success, with a cephalic vein diameter exceeding 4 mm being a predictor of functionality.…”

We Refuse to Give up on Nonmaturing Fistulas

“…These studies have shown that at 6-8 weeks postcreation, a Qa of 400-500 ml/minutes had a sensitivity of 67-89%, a specificity of 65-87%, and an accuracy of 75-87% for radio-cephalic AVF success. A blood flow value of 600 ml/minutes for a brachial-cephalic access had a sensitivity and specificity of 89% and 87%, respectively at this same time period (6). These same studies have shown that an AVD at 4-6 weeks in the range of 0.4-0.5 cm correlated with a successful AVF with a sensitivity in the range of 75% and a specificity in the range of 68-75% (5).…”