There is still considerable uncertainty about the best endovascular treatment strategies for patients with stenosis or occlusion of the superficial femoral artery (SFA) or popliteal artery. Percutaneous transluminal angioplasty (PTA) has been performed for over 30 years now, but there is an evolving body of literature that has documented suboptimal outcomes with PTA for all but only the most focal (<4 cm) femoropopliteal lesions. While there is considerable enthusiasm for atherectomy in some centers, there is a paucity of comparative data demonstrating superiority of any of the atherectomy devices over PTA.
Over the years, there has also been controversy about the role of stents in the SFA. Clinicians currently do not have enough data demonstrating the superiority of stenting over PTA, but more research is accumulating in this field. Two randomized trials comparing stenting with PTA in the SFA and proximal popliteal artery have recently been published. Schillinger et al randomized patients with SFA disease to balloon angioplasty with provisional/bailout stent implantation versus primary nitinol stent implantation. At 12 months, there was a significantly lower rate of restenosis in the primary stent group compared with the angioplasty group (37% vs 63%). Krankenberg et al randomized 244 patients with shorter SFA lesions to balloon angioplasty versus implantation of a single nitinol stent. At 12 months, there was no significant difference in restenosis between the treatment groups (31.7% vs 38.6%). The disparate results from these trials can likely be explained by the significant differences in lesion length as well as differences between the two stent designs.
The RESILIENT Trial
The RESILIENT trial (A Randomized Study Comparing the Edwards Self-Expanding LifeStent vs Angioplasty-Alone In Lesions Involving the SFA and/or Proximal Popliteal Artery) was a multicenter, international, randomized comparison of balloon angioplasty versus stenting with the LifeStent (Bard Peripheral Vascular) that has recently been completed. Patients were included in the trial if they had lifestyle impairing claudication and stenosis or occlusion of up to 15 cm in length in the SFA and proximal popliteal artery. Patients from 24 centers in the United States and Europe were randomized to implantation of the LifeStent or PTA.
Findings from the RESILIENT trial showed that primary implantation of the self-expanding nitinol stent was associated with better acute results and improved patency compared to balloon angioplasty alone. The mean total lesion length was 71 mm for the stent group and 64 mm for the angioplasty group. Acute lesion success—which was defined as less than 30% residual stenosis—was superior for the stent group when compared with the angioplasty group (95.8% vs 83.9%). Twenty-nine patients (40.3%) in the angioplasty group underwent bailout stenting because of a suboptimal angiographic result or flow limiting dissection. Bailout stenting was treated as a target lesion revascularization (TLR) and loss of primary patency in the final analysis. At 12 months, freedom from TLR was 87.3% for the stent group, compared with 45.1% for the angioplasty group. Duplex ultrasound, which derived primary patency at 12 months was also better for the stent group (81.3% vs 36.7%). Through 12 months, fractures occurred in 3.1% of stents implanted, but no stent fractures resulted in loss of patency or TLR.
The hope is that more analyses like the RESILIENT trial will be conducted in the future to further support previous research. Ideally, it would be helpful to provide clinicians with more data regarding the optimal management of lesions in the SFA and proximal popliteal arteries.
Readings & Resources (click to view)
Schillinger M, Sabeti S, Loewe C, et al. Balloon Angioplasty versus implantation of nitinol stents in the superficial femoral artery. N Engl J Med. 2006;354:1879-1888.
Schillinger M, Sabeti S, Dick P, et al. Sustained benefit a 2 years of primary femoropopliteal stenting compared with balloon angioplasty with optional stenting. Circulation. 2007;115:2745-2749.
Krankenberg H, Schluter M, Steinkamp H, et al. Nitinol stent implantation versus percutaneous transluminal angioplasty in superficial femoral artery lesions up to 10 cm in length: the femoral artery stenting trial (FAST). Circulation. 2007;116:285-292.
Laird JR, Katzen BT, Scheinert D, et al. Nitinol stent implantation versus balloon angioplasty for lesions in the superficial femoral artery and proximal popliteal artery: twelve-month results from the RESILIENT randomized trial. Circ Cardiovasc Interven. 2010 (in press).