Kidney Disease Research Updates
Fall 2008

Maintaining Access Sites for Hemodialysis Continues to Pose Challenges

Reducing early blood clots in bloodstream access for kidney failure treatment does not increase the chances of the access site becoming suitable for long-term dialysis.

The Dialysis Access Consortium (DAC), funded since 2000 by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), found that only 12 percent of patients developed blood clots in a fistula when treated with the clot-preventing drug clopidogrel, or Plavix, compared with nearly 20 percent of patients who did not take the drug. Despite this, about 60 percent of new fistulas in each group still could not be used for dialysis treatments. Complications such as bleeding were similar across the study groups.

A fistula—an enlarged vessel where blood is removed and returned to the body during dialysis treatments—is a type of vascular access for hemodialysis. While other types of dialysis vascular access such as synthetic grafts are available, fistulas are preferred because they are less likely than the others to clot and get infected. They also are less costly. However, the failure of fistulas to mature, or enlarge over time, can prevent their effective use. Clotting, infection, and low blood-flow rates in the access site are common reasons for hospitalization of hemodialysis patients, who then must undergo further treatments or surgeries to maintain their fistula.

Lifesaving Treatment

Surgeons create fistulas by joining a section of an artery and a vein to make one large vessel capable of handling high volumes of blood during hemodialysis, a treatment for people with kidney failure. Wastes and extra fluid are filtered from the bloodstream through the vascular access. Most of the 470,000 Americans with kidney failure depend on hemodialysis for survival.

The DAC studied nearly 900 participants at nine U.S. medical centers in academic and community practices in urban and rural settings. Participants received a new fistula and took Plavix or a placebo daily for 6 weeks to determine whether the drug would maintain blood flow in fistulas and increase the number of fistulas suitable for use in regular dialysis treatments.

“Because vascular access is critical for delivering lifesaving care, we are already organizing another multicenter study to better understand why some fistulas fail and how to improve their function once they are placed in dialysis patients,” said study co-author Catherine M. Meyers, M.D., a kidney specialist who oversees the DAC.

The NIDDK has a fact sheet about vascular access for hemodialysis at www.kidney.niddk.nih.gov/kudiseases/pubs/vascularaccess.

NIH Publication No. 09–4531
December 2008

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