Stent Grafts For Dialysis Patients Keep Access Sites Open Significantly Longer Than Angioplasty Alone

[Pendragon]

Stent Grafts For Dialysis Patients Keep Access Sites Open
Significantly Longer Than Angioplasty Alone
17 Apr 2013

Kidney failure patients on dialysis derive long-term benefit from the
minimally invasive placement of a stent that improves the function of
dialysis access grafts, according to 12-month trial results presented
at the Society of Interventional Radiology's 38th Annual Scientific
Meeting in New Orleans.

"Results of the study exceeded our expectations, and that is a boon
for dialysis patients," said Ziv J Haskal, M.D., FSIR, lead author and
professor of vascular and interventional radiology at the University
of Maryland School of Medicine in Baltimore.

"Dialysis is very demanding, and anything that prevents access sites
from failing and reduces the need for invasive treatments of surgery
will dramatically improve patients' quality of life - while reducing
health care costs," he added.

Every year nearly 400,000 people undergo dialysis, said Haskal.
Doctors access and filter the blood through delicate grafts or veins
that often collapse because they can't handle the high-pressure
circuit of purified blood being fed back into the body, forcing
doctors to continually reopen them or create new treatment access
sites. Twelve-month results of RENOVA, a prospective, multicenter,
randomized trial , show these dialysis sites can be successfully kept
open using tiny scaffolds called stent grafts for far longer than
previously reported. In the study - named SIR's Abstract of the Year -
270 dialysis patients treated for collapsed access sites at 28 U.S.
centers were randomized and 138 subjects underwent stent grafts while
the remaining 132 had balloon angioplasty. After 12-month follow-up,
researchers found that two and half times more patients in the stent
graft group were able to continue to use their dialysis access grafts,
than those who were being treated by balloon angioplasty alone
(without invasive interim procedures). Until this data, grafts have
been considered short-term solutions, with 75 percent requiring
invasive interventions in under a year, said Haskal.

An estimated 1 in 10 Americans has some form of chronic kidney
disease, according to the National Institutes of Health. End-stage
renal disease means the kidneys have failed and can no longer filter
waste products from the blood. This condition is fatal without a
kidney transplant or dialysis to prevent blood poisoning. An
arteriovenous fistula is the gold standard for dialysis access and
involves creating a natural blood vessel bypass, but many patients,
especially those who are too ill to undergo the invasive surgery, have
an arteriovenous graft - a plastic tube sewn into the vein, which
easily clogs, explained Haskal.

"This area where the graft is sewn in, that allows blood to flow back
up the arm toward the heart, has particular turbulence," said Haskal.
"That turbulence, like a river bend, tends to incite tissue growth at
the sides. Just like a river depositing sediment along a bend, these
veins thicken and narrow. More than 100,000 angioplasties are
performed a year due to this narrowing. What this stent method does is
not only reopen the vein, but turn the graft into an inline flow, so
that the blood enters the vein at a more natural angle," he added.

The stents, made of a medical-grade plastic, are implanted at the time
of balloon angioplasty, a minimally invasive technique interventional
radiologists perform using just a small incision and medical imaging
to guide it to the narrowed vein. A small balloon is inflated
expanding the vein and setting the stent in place. The resulting
reduction of wear and tear due to these stent grafts helps dialysis
access sites stay healthy and open months and even years longer than
researchers had hoped.

"It was a wholly foreign concept when we started," said Haskal.
"People told me it was crazy. Anecdotally we now have patients who
have these stent grafts that are still open after three years. That is
practically unheard of," said Haskal, who is also editor of the
Journal of Vascular and Interventional Radiology. "This controlled
study proves that we can achieve durable long-term solutions for these
patients, reducing their invasive procedures and thus improving their
quality of life," he added.
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References:
Abstract 237: "Twelve-month Results of the RENOVA Trial: A Prospective
Multicenter Randomized, Concurrently Controlled Comparison of the
Flair� Endovascular Stent Graft vs. Balloon Angioplasty in Dialysis
Access Grafts," Z. J Haskal, interventional radiology, University of
Maryland, Baltimore, SIR 38th Annual Scientific Meeting, April 13-18,
2013. Society of Interventional Radiology
This abstract can be found at http://www.SIRmeeting.org.
Society of Interventional Radiology


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MLA
Society of Interventional Radiology. "Stent Grafts For Dialysis
Patients Keep Access Sites Open Significantly Longer Than Angioplasty
Alone." Medical News Today. MediLexicon, Intl., 17 Apr. 2013. Web.
24 Apr. 2013. <http://www.medicalnewstoday.com/releases/259127.php>
APA
Society of Interventional Radiology. (2013, April 17). "Stent Grafts
For Dialysis Patients Keep Access Sites Open Significantly Longer Than
Angioplasty Alone." Medical News Today. Retrieved from
http://www.medicalnewstoday.com/releases/259127.php.
Please note: If no author information is provided, the source is cited
instead.