Background: Access flow dysfunction, often associated with stenosis, is a common problem in hemodialysis access and may result in progression to thrombosis. Timely identification of accesses in need of evaluation is critical to preserving a functioning access. We hypothesized that a risk score using measurements obtained from the Vasc-Alert surveillance device could be used to predict subsequent interventions.
Methods: Measurement of five factors over the preceding 28 days from 1.46 million hemodialysis treatments (6163 patients) were used to develop a score associated with interventions over the subsequent 60 days. The score was validated in a separate dataset of 298,620 treatments (2641 patients). Results: Interventions in arteriovenous fistulae (AVF; n = 4125) were much more common in those with the highest score (36.2%) than in those with the lowest score (11.0). The score also was strongly associated with interventions in patients with an arteriovenous graft (AVG; n = 2,038; 43.2% vs. 21.1%). There was excellent agreement in the Validation datasets for AVF (OR = 2.67 comparing the highest to lowest score) and good agreement for AVG (OR = 1.92).Conclusions: This simple risk score based on surveillance data may be useful for prioritizing patients for physical examination and potentially early referral for intervention.
| INTRODUCTIONMaintaining a functioning arteriovenous (AV) access is critical to providing adequate dialysis clearance, reducing catheter exposure, and lowering the costs of care in patients on chronic hemodialysis. Indeed, vascular accesses (VAs) are considered to be the "Achilles' heel" of hemodialysis. 1 Vascular access-related expenses and complications account for approximately 20% of hospitalizations, $2.8 billion in healthcare costs in the US, and substantial morbidity and mortality. 2 As surgical procedures and hospitalizations associated with attempts to maintain a functioning AV access are major contributors to these costs, 3 methods to avoid these adverse outcomes are needed.Inadequate access blood flow is a common problem in mature AV fistulas (AVF) and grafts (AVG), resulting in inefficient dialysis and an inability to attain prescribed Kt/V as an indicator of adequate dialysis. 4 Hemodynamically significant stenoses may occur in the inflow, main body, or outflow of the vascular access, reducing blood flow in the access. Stenosis can occur at a single site or develop at multiple sites; these may develop concurrently or more commonly sequentially.Stenosis invariably leads to access dysfunction. Inadequate access flow most often is associated with one or more underlying stenoses, 5