Stents May Shorten Dialysis Duration
In a small study, 50% of hemodialysis patients with renal artery stenosis were able to stop dialyzing
Renal artery stent placement in hemodialysis (HD) patients who have renal artery stenosis (RAS) can restore sufficient kidney function to allow discontinuation of HD, a study suggests.
Investigators at the Mayo Clinic in Rochester, Minn., reviewed data on 16 HD patients with RAS (average age 74.6 years). All underwent renal artery angioplasty with stent placement. Five patients had bilateral RAS. The researchers, led by Sanjay Misra, MD, defined RAS as a greater than 50% reduction in renal artery diameter by visual estimate using renal duplex ultrasonography.
The researchers defined technical success as the presence of less than 30% residual stenosis. Patients who could and could not discontinue HD following stent placement were considered responders and nonresponders, respectively. Average follow-up was 448 days.
The technical success rate was 100%, researchers reported in the Journal of Vascular and Interventional Radiology (2008;19:1563-1568). Following stent placement, eight patients were responders and remained free of HD over a mean period of 564 days. After adjustments for age, gender, and other cardiovascular risk factors, the potential for HD discontinuation was predicted by 24-hour proteinuria, estimated glomerular filtration rate (eGFR) at baseline, and mean treated kidney size.
The mean predicted 24-hour proteinuria for responders and nonresponders differed significantly, however (0.4 g/24 hr vs. 4.8 g/24 hr). The mean baseline eGFR was 10.13 and 12.35 mL/min/1.73 m2 for responders and nonresponders, respectively. The mean size of the treated kidneys was 11.22 cm in responders compared with 9.88 in nonresponders.
“In the present study, we have shown that renal artery revascularization with stents is a viable option in RAS patients undergoing hemodialysis and can provide a benefit in 50% of patients such that hemodialysis can be discontinued after the procedure,” the authors wrote.
Regarding study limitations, the investigators noted that the power of their conclusions is limited by the small sample size. In addition, the study was not population-based, with subjects making up a select group of patients referred to their tertiary-care center. Thus, their results are associated with selection bias and cannot be generalized, the authors observed.
“Despite these limitations, the study highlights the potential role of percutaneous renovascular revascularization in improving dialysis-free survival of patients with dialysis-dependent ischemic nephropathy.”
The authors pointed out, however, that their study did not demonstrate a survival benefit with revascularization, “potentially because of the short follow-up and small group of patients,” they noted.