The Role of Surveillance in Mature Arteriovenous Fistula Management

The role of mineral metabolism and inflammation on dialysis vascular access failure

Thrombosis of arteriovenous fistula (AVF) is the leading cause of vascular access (VA) loss usually due to silent stenosis. Therefore, assessment of relevant risk factors of VA monitoring may provide insight into potential therapeutic targets for stenosis and thrombosis. The aim of this study was to evaluate the influence of cardiovascular risk factors (including inflammation and mineral metabolism dysfunctions) on the failure of internal AVF in HD patients.

128 HD patients with internal AVF were included in the study and followed up for two years. At baseline, VA morphology and function were followed by Doppler ultrasonography and serum albumin, prealbumine, C-reactive protein, orosomucoid, calcium, phosphorus, parathyroid hormone, bone-type alkaline phosphatase, osteoprotegerin and receptor activator of nuclear factor κB ligand were measured.

At baseline, 50 stenoses were detected but none of them required any intervention. Age and biological parameters did not significantly differ between patients with or without VA stenosis. Over the two year- follow up, VA thrombosis occurred in 19 patients. Preexisting stenosis of VA was present in 9/19 patients (47.3% of cases) (chi-square = 3.708, p = 0.0538). Despite the low rate of events, phosphorus [1.75 (0.95–2.77) vs 1.42 (0.47–3.22) mmol/L, p = 0.0416], Calcium x Phosphorus product [4.00 (2.00–5.90) vs 3.40 (1.10–6.80) mmol2/L2, p = 0.0676] and parathyroid hormone [165.00 (1.00–944.00) vs 79.50 (1.00–846.60) ng/L, p = 0.0814) levels were higher in the 19 thrombotic patients whereas all other biological parameters did not significantly differ.

These results, which confirm that VA thrombosis occurs more frequently upon preexisting stenosis, also demonstrate that mineral metabolism disorders, compared to inflammation, may contribute to VA dysfunction leading to thrombosis.

Dialysis access in europe and north america: are we on the same path?

Large differences in dialysis access exist between Europe, Canada, and the United States, even after adjustment for patient characteristics. Vascular access care is characterized by similar issues, but with a different magnitude. Obesity, type 2 diabetes, and peripheral vascular disease, independent predictors of central venous catheter use, are growing problems globally, which could lead to more difficulties in native arteriovenous fistula placement and survival. Creation of dedicated dialysis access teams, including a vascular access coordinator, is a fundamental step in improving vascular access care; however, it might not be sufficient. The possibility that factors other than patient characteristics and surgical skills are important in determining outcomes is likely; it might explain apparent contradictions of end-stage renal disease (ESRD) practices (kidney transplant, peritoneal dialysis, patterns of vascular access use in hemodialysis), where some countries excel in one area and score poorly in another. We are on the same path, but we have a long way to go.

Balancing Fistula First With Catheters Last

The success of Fistula First nationwide has been accompanied by an unplanned increase in hemodialysis catheters. Complications related to prolonged hemodialysis catheter use include increased morbidity, mortality, and cost. We hypothesize that the national focus on increasing fistulas may have inadvertently diverted attention away from initiatives to decrease dependence on hemodialysis catheters. Based on a synthesis of guidelines, reviews, published evidence, and the authors' opinions, we propose that the national vascular access initiative be revised to have a dual goal of Fistula First and "Catheters Last." These goals are not mutually exclusive, but rather complementary. We recommend a systematic refocus on interventions that not only increase fistulas, but help avoid extended catheter use. Clearly, the ideal practice for hemodialysis vascular access remains early placement of fistulas with enough maturation time such that they can be used for initiating long-term hemodialysis therapy when the need arises. To effect this change, a reimbursement policy covering the costs associated with permanent access placement before the need for dialysis is essential. Individualized patient management strategies may consider such innovative approaches as initiating patients on peritoneal dialysis therapy or using nonautogenous grafts as bridge accesses in lieu of catheters. For patients who are dialyzing using catheters, immediate active planning for permanent access placement and removal of the catheter is necessary. In the same vein as Fistula First, the renal community should once again be galvanized in working together toward controlling the catheter epidemic in our dialysis population.