Incidence and Predictors of In-stent Re-Stenosis in the Superficial Femoral Artery: Evaluation of Long-Term Outcomes by Color Duplex Ultrasound

This study aimed to investigate the incidence and predictors of in-stent re-stenosis (ISR) for nitinol stents in the superficial femoral artery (SFA) by color duplex ultrasound (CDU). In total, 235 patients undergoing SFA stenting were included in the present study. The cumulative ISR rates at 3, 6, 12, 24 and 36 mo post-procedure were 5.4%, 24.0%, 49.0%, 61.5% and 71.5%, respectively. The markedly low peak systolic velocity of the popliteal artery (PSV2) post-operation was inversely correlated with the ISR. The threshold for ≥50% re-stenosis was PSV2 ≤ 63 cm/s with 86.6% sensitivity and 90.5% specificity. With regard to re-occlusion, the PSV2 was ≤40 cm/s with 98.1% sensitivity and 93.4% specificity. Cox regression analysis indicated that the cumulative stent length, diabetes, and pre-stent stenosis level were independent risk factors of ISR. In conclusion, the ISR incidence after SFA stenting is relatively high and CDU follow-up is a feasible method for evaluating ISR.