Endovascular brachytherapy for renal artery in-stent restenosis

Renal artery in-stent restenosis (RAISR) is not an infrequent occurrence and may be in part responsible for the failure of renal stents to improve clinical outcome. A variety of treatments have been used to restore patency, with mixed results. These include repeated percutaneous transluminal renal angioplasty (PTRA), repeated PTRA with bare-metal stents, and repeated PTRA with drug-eluting stents or covered stents. Endovascular brachytherapy (EVBT) has been proven effective in preventing recurrent neointimal hyperplasia in coronary bare-metal stents. This prompted our group to study the effect of EVBT on RAISR.

From 2004 to 2012, 21 patients (23 renal arteries) developed RAISR ≤ 30 months after the initial procedure and were subsequently treated with EVBT. Five patients had at least one prior PTRA for recurrent restenosis. Renal artery duplex scanning was performed as a baseline study within a few days of the EVBT and then every 6 months. All patients who had EVBT were concurrently treated by PTRA and EVBT on the basis of existing protocols. Patency of the treated stents was evaluated by Kaplan-Meier survival curves.

The average onset of the original RAISR was 11 ± 9 months (range, 2-30 months; median, 8 months). The initial technical success of combined PTRA and EVBT was 100%. Mean follow-up was 44 ± 18 months (range, 14-84 months). Of five patients who had PTRA before EVBT, four were available for long-term follow-up. These four patients had a combined total number of five PTRAs before EVBT, with recurrent stenosis developing on average by 12 months. After EVBT, three stents were patent at 39, 48, and 65 months, and one stent restenosed at 42 months. This was the only patient in the entire series to develop restenosis after EVBT.

This retrospective experience with a relatively small number of patients undergoing concurrent EVBT/PTRA for recurrent stenosis in stents placed to treat atherosclerotic renal artery stenosis suggests that EVBT is safe and provides long-term freedom from recurrent stenosis.