Investigating the value of a surveillance scan of the superficial femoral artery at one year post-bare metal stent insertion

Abstract

Introduction Placing a bare metal stent within the superficial femoral artery (SFA) can prolong vessel patency when compared with balloon angioplasty alone. Subsequent in-stent re-stenosis does occur in some individuals. In our institution, a surveillance programme to identify and treat ‘clinically silent’ stenoses has been running for two years and the purpose of this study was to evaluate this programme. Methods Retrospective review of cases was performed making note of indication for stenting, initial clinical outcome and the results of follow-up diagnostic and interventional radiological procedures. Results In total, 41 patients were included in the study. The majority (76%) had a good clinical outcome maintained during the first year at which stage a surveillance ultrasound was performed. Sixteen of these showed no evidence of significant in-stent stenosis or occlusion. Eleven of the remainder had ‘clinically silent’ in-stent stenosis. Nine of these had successful in-stent angioplasty. Ten (24%) patients became symptomatic within the first year. Ultrasound in seven of these patients revealed two in-stent occlusions, one in-stent re-stenosis and four with no significant findings. One patient went straight to have angiography, revealing in-stent re-stenosis. Conclusion Our surveillance programme has successfully identified and treated clinically silent in-stent stenoses in 22% of patients with an SFA stent who may have progressed to symptomatic stenosis or occlusion. Our results highlight the importance of ultrasound surveillance following stent placement. Based on only one asymptomatic patient experiencing stent occlusion at one year, and symptomatic stent problems occurring anywhere from six to 193 days, we consider that one year surveillance is acceptable.