Stent Grafts Superior to Balloon Angioplasty in Dialysis Patients

Expanded polytetrafluoroethylene (PTFE) endovascular stent grafts are better than conventional balloon angioplasty in revision of failing arteriovenous (AV) hemodialysis grafts, according to a new study.

Researchers at the University of Maryland Medical Center (UMM, Baltimore, USA) conducted a prospective, random multicenter trial that assigned 190 patients (69 men, 121 women) with failing AV grafts in 13 institutions to undergo either balloon angioplasty alone, or balloon angioplasty plus placement of a PTFE endovascular stent graft. A total of 97 patients received stent grafts, and 93 underwent percutaneous transluminal angioplasty (PTA). Primary end points included patency of the treatment area and patency of the entire vascular access circuit.

The results showed that nearly 51% of dialysis accesses treated with stent grafts remained open (patent) at six months, as compared to just 23% of those treated with balloon angioplasties. The same was true of the incidence of patency of the access circuit (38% compared to 20%), as was the incidence of freedom from subsequent interventions at 6 months (32% in the stent-graft group compared to 16% in the balloon-angioplasty group). The incidences of adverse events at six months were equivalent in the two treatment groups, with the exception of restenosis, which occurred more frequently in the balloon-angioplasty group. Additionally, the treating physicians had a nearly 94% success rate at implanting the stent grafts. The study was published in the February 11, 2010, issue of the New England Journal of Medicine (NEJM).

"Stent grafts overwhelmingly performed better than balloon angioplasty for maintaining access in dialysis patients, providing superior patency and freedom from repeat interventions,” said study coauthor Ziv Haskal, M.D., of UMM. "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.”

When kidneys fail - called chronic kidney or end-stage renal disease - treatment in the form of regular dialysis (or hemodialysis) is needed to take over the failing kidney's function 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, allowing high flow of blood from the artery into the vein. The leading cause of failure of a prosthetic AV hemodialysis-access graft is venous anastomotic stenosis. The failing grafts cause considerable morbidity, discomfort, and inconvenience for dialysis patients, due to the need for invasive procedures to reestablish access flow or graft abandonment and reoperation.

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University of Maryland Medical Center