Response of renal and femoropopliteal arteries to Palmaz stent implantation assessed with intravascular ultrasound

Purpose: To establish the processes responsible for late lumen loss in rena l and femoropopliteal Palmaz stents using intravascular ultrasound (IVUS). Methods: The first 7 consecutive patients treated with stents for renal (n = 4) and femoropopliteal (n = 3) arterial occlusive disease were studied wi th IVUS immediately after angiographically successful stent placement (< 10 % residual stenosis) and periodically during follow-up. Images of both sten t edges and the most stenotoic site inside the stent at followup were match ed to the same cross sections captured immediately after stent placement fo r quantitative analysis. Results: Late lumen loss in renal artery stents at 5 to 34 months was consi derably less than in femoropopliteal stents (17% versus 62%, respectively). In the renal location, late lumen loss (3.0 +/- 1.3 mm(2)) was due to neoi ntimal hyperplasia, whereas stent area remained unchanged (3% decrease). La te lumen loss (7.4 +/- 8.2 mm(2)) in femoropopliteal stents was due to neoi ntimal hyperplasia and stent area reduction (26%). Overall, in both types o f arteries, neointimal development and stent area reduction were larger at the most stenotic site than at the stent edges. Conclusions: These data suggest that there may be differences between renal and femoropopliteal arteries in the extent of hyperplastic response to ste nts.