Early and late fistula failure.

While an arteriovenous fistula is the best available form of hemodialysis access, a significant number of fistulae never mature to support dialysis (early failure) or fail after successful use (late failure). Venous stenosis and the presence of accessory veins are the two main causes of early failure. Recent data have demonstrated that a great majority of such AVFs can be successfully salvaged by percutaneous interventions and become available for dialysis. In addition to early failure, a great majority of thrombosed fistulae can also be successfully declotted using simple endovascular techniques. Fistula thrombosis has clear differences from graft clotting. First of all, cannulation of a clotted fistula is more challenging. Secondly, thrombus volume present in a clotted fistula can be quite variable. A fistula might thrombose with minimal or no thrombus. At other times, there is moderate-to-severe thrombus burden that accompanies fistula clotting. While percutaneous balloon angioplasty to correct the underlying stenosis might be all that is needed to declot a fistula with no thrombus, thromboaspiration is required to successfully declot a fistula with moderate thrombus. Salvage of early and late fistula failure is critical to minimize catheter use and is supported by the National Kidney Foundation Dialysis Outcomes Quality Initiative. Additionally, it is a powerful strategy to maximize AVF use in hemodialysis patients.