New England Journal of Medicine publishes first study to show minimally invasive interventional radiology approach for end-stage kidney disease patients is “superior” in treating blocked access
A randomised multicentre study of 190 patients at 13 medical centres shows—for the first time—the “superior” benefit of stent grafts over balloon angioplasty for maintaining the function of dialysis access grafts in kidney failure patients who undergo dialysis. Until now, no other therapy has proven more effective than angioplasty. At six months, the stent grafts allowed dialysis patients to continue life-saving treatment with significantly fewer interruptions and invasive procedures, according to a study published in the New England Journal of Medicine (N Engl J Med 2010;362:494-503.). Haemodialysis is the leading treatment for more than 340,000 patients in the United States with end-stage renal disease (ESRD), or kidney failure.
Trial investigators wrote in the NEJM that the leading cause of failure of a prosthetic arteriovenous haemodialysis-access graft is venous anastomotic stenosis. Balloon angioplasty, the first-line therapy, has a tendency to lead to subsequent recoil and restenosis, but, no other therapies have yet proved to be more effective. This study was designed to compare conventional balloon angioplasty with an expanded polytetrafluoroethylene endovascular
stent graft for revision of venous anastomotic stenosis in failing haemodialysis grafts.
“Stent grafts are a game changer for dialysis patients, especially for those who suffer due to the repeated need for invasive procedures to maintain their ability to get dialysis,” said Ziv J Haskal, vice chair of Strategic Development, and chief of Vascular and Interventional Radiology at the University of Maryland Medical Center in Maryland, USA.
“This study—the first large prospective controlled study of its kind—shows that this novel therapy, stent grafts, provide clear improvement over balloon angioplasty by prolonging the function of a patient’s bypass without surgery—helping individuals avoid additional invasive procedures and time in the hospital,” noted Haskal, who is also professor of Radiology and Surgery at the University of Maryland School of Medicine. “Stent grafts overwhelmingly performed better than balloon angioplasty for maintaining access in dialysis patients, providing “superior” patency and “freedom from repeat interventions,” added the lead investigator and author of Stent Graft Versus Balloon Angioplasty for Dialysis Access Graft Failure. “What we have done, is arguably supersede the results of surgery by improving the flow dynamics beyond those achievable with an operation.”
Thirteen participating sites—including academic, community-based, inpatient and freestanding outpatient dialysis centres—enrolled 190 patients (69 men, 121 women) with failing arteriovenous (AV) grafts in this study, said Haskal. Ninety-seven patients received stent grafts, with 93 undergoing balloon angioplasty (percutaneous transluminal angioplasty or PTA). There were no significant differences between graft and PTA groups with respect to demographics or relevant medical history. Nearly 51% of dialysis accesses treated with stent grafts remained open at six months, as compared to just 23% of those treated with balloon angioplasties. Treating physicians had a nearly 94% success rate at implanting the stent grafts. There were no differences in adverse events between the two approaches.
Results from the study led investigators to conclude that “percutaneous revision of venous anastomotic stenosis in patients with a prosthetic haemodialysis graft was improved with the use of a stent graft, which appears to provide longer-term and superior patency and freedom from repeat interventions than standard balloon angioplasty.”
Since then, the NEJM has commissioned an editorial commentary on the paper by Drs Kerlan and Laberge, from University of California, San Francisco, USA.
“Interventional radiologists work to keep access to the circulatory system open to ensure that patients with end-stage renal disease can continue to receive regular life-saving dialysis,” noted Society of Interventional Radiology President Brian F Stainken, who represents a national organisation of nearly 4,500 doctors, scientists and allied health professionals dedicated to improving health care through minimally invasive treatments. “This study is another example of the way in which interventional radiologists pioneer advances to improve health care for patients—in this case, specifically for kidney failure patients,” added Stainken, an interventional radiologist who is also president of the Imaging Network of Rhode Island and chair of the diagnostic imaging department at Roger Williams Medical Center in Rhode Island, USA.
In chronic kidney or end-stage renal disease treatment, haemodialysis is needed to maintain fluid, electrolyte and acid–base balance. Before dialysis can begin, patients often have a vascular access graft surgically placed in the arm to provide a high-flow site. This prosthetic fistula works by connecting a patient’s vein with an artery in their forearm, allowing high flow of blood from the artery into the vein.
Over time, the accesses occlude due to buildup of 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 re-establish 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.