Predictors of restenosis in the use of helical interwoven nitinol stents to treat femoropopliteal occlusive disease

Abstract

Background: The femoropopliteal arteries are subjected to considerable axial and bending deformity due to flexion at the hip and knee joints. The Supera helical interwoven nitinol stent system (IDEV Technologies, Inc/Abbott Laboratories, Inc, Webster, Tex) has good conformability and flexibility, with a very low incidence of mechanical fatigue. This study reviewed our experience with the use of Supera stents for femoropopliteal atherosclerotic lesions and identified risk factors for restenosis or occlusion.

Methods: Patients with symptomatic femoropopliteal atherosclerotic diseases who underwent lower limb angioplasty and Supera stent insertion were studied. All patients had regular clinical follow-up and underwent a Doppler ultrasound examination at 3 months and then every 6 months, and radiography of the stents at 6, 12, 18, 24, 30, and 36 months. Patency rates were analyzed using Kaplan-Meier curves. We also evaluated the prospectively maintained cohort to identify predictors of restenosis.

Results: From October 2011 to December 2014, 164 legs in 153 symptomatic patients (96 male, 57 female) with femoropopliteal occlusive disease, with mean age of 76.7 years (range, 46-100 years), were included. Ninety-five patients (58%) had claudication, nine (5%) had rest pain, and 60 (37%) had tissue loss. Disease distribution was 64 proximal superficial femoral arteries (SFAs; 39%), 107 middle SFAs (65%), 127 distal SFAs (77%), 78 above-knee popliteal arteries (48%), and 19 below-knee popliteal arteries (12%). Lesion classification by TransAtlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II) A, B, C, and D was 49 (30%), 79 (48%), 31 (19%), 3 (1%), respectively. The mean lesion length was 105.6 mm (range, 3-400 mm), and more than one Supera stent was inserted in 26 patients. Procedure success (residual stenosis <30%) was achieved in 100% of procedures. The primary patency rates (>50% patency) at 6, 12, 24, and 30 months were (±standard error) 86.7% ± 3.1%, 81.4% ± 3.7%, 79.9% ± 4.0%, and 77 ± 3.0%, respectively. The ankle-brachial pressure index increased from 0.57 ± 0.15 preoperatively to 0.87 ± 0.14 postoperatively. No stent fractures occurred. There were three 30-day deaths not related to the procedure or device, one major amputation 3 months after revascularization, and 29 late deaths (>30 days) of unrelated medical causes in follow-up. In-stent restenosis was associated with younger patient age and with dyslipidemia, long lesion, and stent length.

Conclusions: Our midterm experience showed that the implantation of the helical interwoven nitinol stents in patients with femoropopliteal occlusive disease is safe and effective, with encouraging patency rates and clinical results.