Stent graft outperforms balloon angioplasty

A large, multi-center trial of 190 patients shows a new nonsurgical interventional radiology technique can benefit the more than 287,000 kidney failure patients undergoing dialysis in the United States each year.

Research presented today at the Society of Interventional Radiology's 30th Annual Scientific Meeting shows that a stent graft keeps dialysis access open for at least six months longer than balloon angioplasty, allowing dialysis patients to continue life-preserving treatment without undergoing more invasive procedures.

"Interventional radiologists are constantly working to keep access to the circulatory system open to ensure patients with end stage renal disease can receive regular life-saving dialysis," says lead investigator and interventional radiologist Ziv Haskal, M.D. "This study, the first large study of its kind, shows this new stent graft technique provides improvement over the current treatment by prolonging the function of a patient's bypass nonsurgically -- helping them avoid additional invasive procedures and time in the hospital."

Patients with chronic renal failure need regular hemodialysis because their kidneys are no longer functioning properly. Dialysis clears toxic waste out of the patient's body and helps maintain the body's fluid, electrolyte, and acid-base balance. These patients often have a vascular access graft surgically placed in the arm to provide a high flow site for dialysis. These prosthetic fistulas work by connecting a patient's vein with an artery in their forearm, allowing high flow of blood from the artery to flow into the vein.

Over time, the accesses narrow and block off (occlude) due to buildup of intimal hyperplasia (scar tissue). Failing or occluded dialysis access grafts causes considerable morbidity, discomfort, and inconvenience for dialysis patients due to the need for invasive procedures to reestablish access flow, or to graft abandonment and reoperation. When failure occurs, per National Kidney Foundation Guidelines, an interventional radiologist normally performs a balloon angioplasty to reopen the fistula and regain access for dialysis.

"Stent grafts overwhelmingly perform better than balloon angioplasty for maintaining access in dialysis patients, according to this large scale prospective randomized study," says Dr. Haskal. "In the study, 53 percent of the stent grafts remained open at six months, as compared to just 29 percent of balloon angioplasties. By clinical patency measures, at six months 81 percent of stent graft patients had functioning accesses -- a highly statistically better percent than the gold standard balloon angioplasty group. This is potentially a great boon to a very large number of United States patients who suffer due to the repeated need for invasive procedures to maintain their ability to get dialysis." Interventional radiologists conducting the procedure also had a 99 percent success rate at performing the stent graft. There was no difference in adverse events between the two techniques.