Higher infection risk seen with buttonhole AV fistula access

By Anne Harding

NEW YORK (Reuters Health) - Buttonhole needling does not improve arteriovenous fistula (AVF) survival in patients on dialysis, and may increase the risk of infection, new findings show.

In buttonhole needling, an AVF is cannulated in the exact same spot, by the same person, repeatedly so that a scar tissue tunnel track forms and a blunt needle can be used. In the traditional rope ladder technique, the needling site is changed with each cannulation.

In a randomized controlled trial comparing the two techniques in 140 long-term in-center hemodialysis patients, Dr. Jennifer M. MacRae of the University of Calgary in Canada and her colleagues found that buttonhole needling was associated with a lower risk of hematoma formation.

To investigate whether this would lead to improved AVF survival, Dr. MacRae and her team followed patients in the trial for 17.2 months (standard group) and 19.2 months (buttonhole group). Patients received hemodialysis three times per week for four hours. They report their findings in the American Journal of Kidney Diseases, online November 18.

The study's primary outcome, median access survival, was 16.0 months for the standard group and 18.4 months for the buttonhole group (p=0.2). Rates of thromboses and fistulogram were also similar for both groups.

However, while none of the standard-group patients developed infections, twelve of the buttonhole group patients did. Median time to first infection was 11.1 months.

"These results suggest that the use of buttonhole needling in the conventional HD population should be restricted to patients for whom the AVF would be abandoned without the use of buttonhole needling, specifically AVFs with short lengths or in patients with severe needle phobia," Dr. MacRae and her team write. "Whether these results translate to self-needling is unknown. Future research should include a randomized trial exploring use of the buttonhole technique when done by a consistent cannulator, preferably the patient."

In the current study, neither nurses nor patients wore face masks or full-face visors to prevent possible infection transmission, which should be standard when cannulation is performed, Dr. Leslie Spry, a spokesman for the National Kidney Foundation, told Reuters Health.

"I would caution people who are on dialysis who have multiple people cannulating their buttonhole that infection is the main thing to be concerned about," added Dr. Spry, who is medical director of the Dialysis Center of Lincoln in Lincoln, Nebraska.

Buttonhole needling can be useful for patients who receive home dialysis, according to Dr. Spry, who is also medical director for the Lawrence, Massachusetts-based home dialysis company NxStage.

This is because the same person -- either the patient herself or a family member -- is usually doing the needling, Dr. Spry said. "Having a number of different people trying to use a buttonhole is not a good idea. I think the fewer people that cannulate the same fistula each time, the better."

In his own center, he added, patients with buttonholes are encouraged to cannulate their own fistulas. "It's my impression from doing this personally for 15 years that patients who do this on their own to themselves don't have these kinds of results."

SOURCE: http://bit.ly/IsVG7l

Am J Kidney Dis 2013.

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