Intimal Hyperplasia, Stenosis, and Arteriovenous Fistula Maturation Failure in the Hemodialysis Fistula Maturation Study

Abstract

Intimal hyperplasia and stenosis are often cited as causes of arteriovenous fistula maturation failure, but definitive evidence is lacking. We examined the associations among preexisting venous intimal hyperplasia, fistula venous stenosis after creation, and clinical maturation failure. The Hemodialysis Fistula Maturation Study prospectively observed 602 men and women through arteriovenous fistula creation surgery and their postoperative course. A segment of the vein used to create the fistula was collected intraoperatively for histomorphometric examination. On ultrasounds performed 1 day and 2 and 6 weeks after fistula creation, we assessed fistula venous stenosis using pre-specified criteria on the basis of ratios of luminal diameters and peak blood flow velocities at certain locations along the vessel. We determined fistula clinical maturation using criteria for usability during dialysis. Preexisting venous intimal hyperplasia, expressed per 10% increase in a hyperplasia index (range of 0%-100%), modestly associated with lower fistula blood flow rate (relative change, -2.5%; 95% confidence interval [95% CI], -4.6% to -0.4%; =0.02) at 6 weeks but did not significantly associate with stenosis (odds ratio [OR], 1.07; 95% CI, 1.00 to 1.16;=0.07) at 6 weeks or failure to mature clinically without procedural assistance (OR, 1.07; 95% CI, 0.99 to 1.15; =0.07). Fistula venous stenosis at 6 weeks associated with maturation failure (OR, 1.98; 95% CI, 1.25 to 3.12;=0.004) after controlling for case mix factors, dialysis status, and fistula location. These findings suggest that postoperative fistula venous stenosis associates with fistula maturation failure. Preoperative venous hyperplasia may associate with maturation failure but if so, only modestly.

Prediction of Arteriovenous Fistula Clinical Maturation from Postoperative Ultrasound Measurements: Findings from the Hemodialysis Fistula Maturation Study

“…The presence of AVF stenosis exhibited a somewhat weaker, but statistically significant, inverse association with unassisted clinical maturation for each of the three ultrasound visit assessments, consistent with a prior HFM study report. 31 Unassisted clinical maturation was not associated with either arterial diameter or the presence of accessory veins at any of the three ultrasound assessments. Arterial diameter was also associated with overall maturation at 2 and 6 weeks, but, otherwise qualitatively similar results were observed for the association of the ultrasound parameters with overall AVF clinical maturation (Table 3).…”

AIUM Practice Parameter for the Performance of Vascular Ultrasound Examinations for Postoperative Assessment of Hemodialysis Access

“…However, any anastomotic stenosis should be confirmed with grayscale imaging because there is often sharp angulation of the venous origin at the anastomosis, which may elevate the PSV, simulating a stenosis . It is important to note that although a stenosis is present, AVF vein blood flow may be adequate and the AVF useable for hemodialysis …”

Oral Charcoal Adsorbents Attenuate Neointima Formation of Arteriovenous Fistulas

“…Native AV fistulas are the best vascular access of choice owing to the low incidence of stenosis, thrombosis, or infection as compared to prosthetic grafts or central vein catheters. However, failure rate of AV fistula within two years of creation is as high as 50% [1]. In the United States, the average cost of maintaining functional vascular accesses is over 1 billion US dollars per year, and this number is on a continuous rise [2].…”