Arteriovenous grafts in hemodialysis patients


Have a short life span and are prone to recurrent stenosis and thrombosis, requiring multiple procedures to maintain their patency.

Hypoalbuminemia a strong predictor of early graft intervention.

Typically made by using a synthetic tube connecting the artery and vein.

More easily cannulated than fistulas and can be use for hemodialysis sooner after surgery than fistulas.

Most patients prefer arteriovenous fistulas or grafts  given the risk of infection associated with these treatments is lower than that associated with the central venous hemodialysis catheter.

In a study of 649 randomized patients to receive this agent plus aspirin or placebo in patients undergoing hemodialysis the incidence of patency at 1 year was 23% in the placebo group and 28% in a Dipyridamole-aspirin group, and the treated group had a prolonged duration of primary unassisted patency: the incidence of graft failure, death and serious events did not differ in the two groups (Dixon B.S.).

In the above study over three fourths of patients required intervention to maintain patency or to treat another access complication within the first year after graft placement (Dixon B.S.)

The percentage of patient to undergo repeat intervention within six months is estimated to be approximately 50%.

Arteriovenous dialysis grafts have a thrombosis in more than 50% of cases within one year after placement, necessitating a salvage procedure in more than 75%of cases.

Arteriovenous graft thrombosis usually occurs at the venous anastomosis in

proximity to a stenotic lesion that has resulted from aggressive neo-intimal hyperplasia.

The Dept. of Veterans Affairs Cooperative trial of aspirin plus clopidogrel in patients undergoing hemodialysis, who had established grafts was terminated early because of increased risk of bleeding, and the study failed to show a benefit of the drug compared to placebo for the prevention of thrombosis (Kaufman JS).

In a study of low dose warfarin in patients with an arteriovenous graft there was no reduction in the risk of thrombosis, but there was an increase risk of bleeding (Crowther MA).

Currently, treatment to maintain patency of such graft is the use of angioplasty to treat stenosis and thrombosis after it occurs.

Long-term outcomes of percutaneous transluminal angioplasty remains poor.
Drug-coated balloon angioplasty is superior to standard angioplasty for the treatment of stenotic lesions in dysfunctional hemodialysis arteriovenous fistulas. (Lookstein RA).

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