Risk factors associated with arteriovenous fistula failure after first radiologic intervention

Improving arteriovenous fistula (AVF) patency is an integral part of the care of hemodialysis patients, often requiring procedures such as percutaneous transluminal angioplasty (PTA). However, these interventions may fail to reduce AVF dysfunction and failure. The purpose of this study was to determine predictive factors for subsequent AVF failure post-PTA.

Data from 155 consecutive AVFs in 155 patients at a single institution who had undergone a first PTA and had at least 1 year of follow-up data were analyzed. Using survival analysis, we assessed primary and secondary patency, and identified predictive factors taking into account competing risks.

Of the 155 patients, 52% required multiple subsequent PTAs; 32% of the AVFs were not in use prior to the first PTA. At first PTA, 83% had outflow vein stenosis (OVS), 26% had multiple stenoses and 43% of stenoses were longer than 2 cm. During follow-up, 1-, 2-, 3-year postintervention primary patency was 41%, 32%, 32% and secondary patency was 80%, 71% and 68%. AVFs with stenoses greater than 2 cm or OVS were at higher risk of requiring multiple PTAs (p = 0.04, 0.006). Factors associated with requiring a second PTA included stenosis greater than 2 cm (hazard ratio (HR) = 1.8, 95% confidence interval (CI) = 1.2-2.9), OVS (HR = 2.5, 95% CI = 1.1-5.4) and primary renal diagnosis of diabetes or renal vascular diseases (HR = 1.8, 95% CI = 1.1-2.9); after adjustments for competing risks, OVS and stenosis length remained associated with requiring subsequent PTAs.

The location and size of the AVF stenosis at first PTA appear to be consistent factors associated with worse postintervention primary patency.