To the Editor: In their randomized trial, Dr Dember and colleagues1 studied the effect of clopidogrel on early failure of arteriovenous fistulas. They concluded that clopidogrel was able to prevent thrombosis but did not lead to a higher incidence of functional fistulas. The authors made the valuable distinction between preventing thrombosis and providing patients with a functional fistula for dialysis. Functional vascular access is a major concern to dialysis patients and their clinicians, especially against the background of low primary patency rate of arteriovenous fistulas.
However, we are concerned about the use of antiplatelet and anticoagulation therapies as a means to prevent primary access failure. Access thrombosis has been cited as the most common reason for primary arteriovenous fistula failure.2 Despite this, observational trials have failed to demonstrate a difference in the primary failure rates of arteriovenous fistulas in patients receiving antiplatelet and anticoagulation medications.2 - 3 A possible explanation for this discrepancy may be related to the definition of fistula thrombosis. As described by Beathard et al,4 fistula thrombosis is frequently clinically diagnosed, but angiographic evidence of actual thrombus in the fistula is minimal to absent in most cases. Stenotic lesions restricting flow either at the inflow or outflow of the access are the cause of this low flow state that prevents maturation of the fistula. Early intervention either percutaneously or surgically is able to salvage a majority of these fistulas.
Vascular access creation remains a major problem for the dialysis community. Preoperative vascular mapping may not adequately improve the primary patency rates of arteriovenous fistulas, leaving few diagnostic or therapeutic measures to ensure functional access placement in patients.5 However, it seems unlikely that pharmacologic therapy will prevent fistula failure from thrombosis until the role (if any) that thrombus formation actually plays in this disorder is understood.
Financial Disclosures: None reported.
Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature
Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal
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