Restenosis In Superficial Femoral Artery Research Articles

Prognostic Factors for Restenosis of Superficial Femoral Artery after Endovascular Treatment.

High incidence of superficial femoral artery (SFA) restenosis after percutaneous transluminal angioplasty (PTA) poses a persistent challenge in peripheral arterial disease (PAD) treatment. We studied how the patients' and lesions' characteristics, thrombin generation, overall haemostatic potential (OHP), and single nucleotide polymorphisms (SNPs) of the NR4A2 and PECAM1 genes affected the likelihood of restenosis. In total, 206 consecutive PAD patients with limiting intermittent claudication due to SFA stenosis who were treated with balloon angioplasty with bailout stenting when necessary were included. Patients' clinical status and patency of the treated arterial segment on ultrasound examination were assessed 1, 6, and 12 months after the procedure. Restenosis occurred in 45% of patients, with less than 20% of all patients experiencing symptoms. In the multivariate analysis, predictors of restenosis proved to be poor infrapopliteal runoff, higher lesion complexity, absence of treated arterial hypertension, delayed lag phase in thrombin generation, and higher contribution of plasma extracellular vesicles to thrombin concentration. Poor infrapopliteal runoff increased the risk of restenosis in the first 6 months, but not later. The negative effect of poor infrapopliteal runoff on SFA patency opens questions about the potential benefits of simultaneous revascularisation of below-knee arteries along with SFA revascularisation.

A Novel Marker Indicating Restenosis in Superficial Femoral Artery: C Reactive Protein to Albumin Ratio

In this study, we aimed to investigate the prognostic value of C-reactive protein (CRP) to albumin ratio (CAR) for predicting restenosis in superficial femoral artery (SFA) lesions and its association with subsequent clinical outcomes in patients undergoing endovascular intervention. The records of 685 consecutive patients who underwent endovascular intervention due to symptomatic peripheral artery disease were analyzed. Patients were divided into 2 groups, based on the CAR values. For each group, technical aspects of procedures and subsequent clinical outcomes were analyzed. According to our study, patients with high CAR values had higher rates of restenosis (30.2% vs. 10.3%, P<0.05) and mortality (31.3% vs. 12.9%, P<0.05). The rate of lower extremity amputations was also significantly higher in patients with high CAR values compared to those with low CAR values (9.1% vs. 3%, P<0.05). With respect to Receiver operating characteristic ROC curves of inflammatory markers, the area under the curve (AUC) value of CAR was statistically significant (AUC: 0.659; 95% confidence interval CI:0.611-0.706; P<0.01). Our data showed that CAR is an independent predictor of restenosis and poor clinical outcomes in patients undergoing endovascular intervention.

Effect of Target Lesion Revascularization on Restenosis Lesions of the Superficial Femoral Artery without Recurred Symptoms after Endovascular Therapy.

Aim: This study aims to elucidate the effects of early application of target lesion revascularization (TLR) to restenosis lesions of the superficial femoral artery (SFA) without recurrence of symptoms. Despite recent improvements in endovascular therapy (EVT) for the SFA, restenosis remains to be a problem. However, restenosis is not always associated with the recurrence of limb symptoms. Although early application of TLR is not generally approved for restenosis lesions of the SFA without recurred symptoms, it is expected to contribute to long-term patency and other favorable outcomes. Nonetheless, its effectiveness remains to be determined. Methods: We retrospectively analyzed 616 patients who developed restenosis after undergoing femoro-popliteal EVT for claudication (Rutherford category 1 to 3) due to de novo femoro-popliteal lesions between January 2010 and December 2016 at 11 centers in Japan. Recurred symptoms were defined as symptoms of the same or higher Rutherford categories than those immediately before the initial EVT. Results: Of the patients, 291 (47 %) lacked recurred symptoms; 69 (24 %) underwent TLR for restenosis. After propensity matching, the risk of occlusion was determined to be not significantly different between the TLR and observation groups; the 3-year occlusion-free rate was 68 % and 62 %, respectively (P=0.84). The risk of recurring symptoms, critical limb ischemia, and all-cause death was also found to be comparable between groups. The incidence of target vessel revascularization was significantly higher in the TLR than in the observation group (1.55 [95 % confidence interval: 1.25–1.93] vs. 0.59 [0.41–0.85] per 3 person-years). Conclusions: In patients with SFA restenosis without recurred symptoms, early application of TLR showed no advantages.

The relationship between neutrophil-lymphocyte ratio and in-stent restenosis in superficial femoral artery.

The present study aimed to investigate the relationship between an increase in the pre- and post-operative neutrophil–lymphocyte ratio (NLR) and superficial femoral artery in-stent restenosis (ISR) rate. We recruited 199 patients that underwent superficial femoral artery stenting for lower extremity arteriosclerosis obliterans at our hospital from March 2015 to July 2018. Patients were divided into two groups according to the occurrence of ISR within 1 year (group 1, ISR and group 2, Non-ISR). The after NLR (NLRafter) and NLR change ratio (NLRratio) (P<0.001) were significantly higher in group 1. A NLRafter > 4.3 was associated with an odds ratio of 1.946 (95% CI [1.51–2.50]; P<0.001) for the presence of ISR. A NLRratio > 37.5% was associated with an odds ratio of 3.6 (95% CI [2.03–6.36]; P<0.001) for occurrence of ISR. A NLRafter level > 4.3 had 75% sensitivity and 76% specificity for the prediction of ISR, as identified by the ROC curve. A NLRratio level > 37.5% predicted ISR with 77% sensitivity and 60% specificity. Multivariate logistic regression analysis demonstrated that NLRratio was the strongest independent predictor of ISR (P<0.001). In conclusions, NLRratio could be used as a prognostic marker in superficial femoral artery stents.

P3567Long term usefulness of target lesion revascularization for asymptomatic restenosis of superficial femoral artery after endovascular therapy

P3567Long term usefulness of target lesion revascularization for asymptomatic restenosis of superficial femoral artery after endovascular therapy

TCT-560 Paclitaxel-Eluting Balloon versus conventional Balloon Angioplasty for In-Stent Restenosis of Superficial Femoral Artery. The ISAR-PEBIS randomized trial

TCT-560 Paclitaxel-Eluting Balloon versus conventional Balloon Angioplasty for In-Stent Restenosis of Superficial Femoral Artery. The ISAR-PEBIS randomized trial

Treatment of Superficial Femoral Artery Restenosis

PurposeTo determine the predictors of restenosis, major adverse limb events (MALEs), postoperative death (POD), and all-cause mortality after repeat endovascular treatment of superficial femoral artery (SFA) restenosis. Materials and MethodsThis was a retrospective review of 440 patients with 518 SFA lesions who were treated between January 2002 and October 2011. Ninety-six limbs were treated for restenosis with bare metal stents (BMSs) or percutaneous transluminal angioplasty (PTA), of which 28 limbs developed another restenosis requiring a third procedure. The interaction measured in this study was between the second and third intervention. Predictors of SFA patency, MALEs, POD, and all-cause mortality after SFA restenosis treatment were identified. ResultsPatients who were treated with BMSs (n = 51) had similar rates of restenosis compared with patients who were treated with PTA (n = 45) (hazard ratio [HR] 1.40; 95% confidence interval [CI] 0.68–2.90; P = .37). Patients in the BMS group who took statins had a significantly lower risk of restenosis than patients who did not take statins (HR 0.13; 95% CI 0.04–0.41; P < .001). Stage 4–5 chronic kidney disease (CKD) (n = 12) was associated with a significantly higher risk of MALE + POD (HR 6.17; 95% CI 1.45–26.18; P = .014) and all-cause mortality (HR 2.83; 95% CI 1.27–6.33; P = .01). Clopidogrel was protective against all-cause mortality (HR 0.41; 95% CI 0.20–0.80; P = .01). ConclusionsPatients in the BMS group who took statins at the time of intervention had a significantly lower risk of developing restenosis. Stage 4–5 CKD was a risk factor for MALE + POD and all-cause mortality, while clopidogrel decreased all-cause mortality risk.

P21-Activated Kinase 4 Promotes Intimal Hyperplasia and Vascular Smooth Muscle Cells Proliferation during Superficial Femoral Artery Restenosis after Angioplasty.

The aim of this study is to explore the function of p21-activated kinase 4 (PAK4) in intimal hyperplasia (IH) and vascular smooth muscle cells (VSMCs) proliferation. We choose vascular samples from patients undergoing angioplasty in superficial femoral artery (SFA) as the experimental group and vascular samples from donors without clinical SFA restenosis as the control group, respectively. We draw from the results that both levels of mRNA and protein of PAK4 in the experimental group increased dramatically compared with the control group. IH arose from angioplasty of SFA. Moreover, overexpression of PAK4 dramatically contributed to cell proliferation of VSMCs and promoted cell cycle progression from G0/G1 phase (71.12 ± 0.69% versus 58.77 ± 0.77%, P < 0.001) into S phase (23.99 ± 0.21% versus 31.35 ± 0.33%, P < 0.001). Besides, PAK4 downregulated the level of p21 and enhanced the activity of Akt as well. And we conclude that PAK4 acts as a regulator of cell cycle progression of VSMC by mediating Akt signaling and controlling p21 levels, which further modulate IH and VSMCs' proliferation.

TCT-838 Effects of Oversizing on Neointimal Formation after Self-Expanding Bare Metal Stents in Porcine Femoral Arteries

Stent oversizing has been suggested as a cause of restenosis in superficial femoral artery (SFA) in previous animal studies with stents lacking reported clinical performance. In this study, we investigated whether oversizing of a clinically available stent also promotes restenosis in a porcine model

Ability of Fractional Flow Reserve to Predict Restenosis After Superficial Femoral Artery Stenting

Purpose: To evaluate the clinical efficacy of poststenting fractional flow reserve (FFR) in terms of predicting restenosis in superficial femoral artery (SFA) disease. Methods: This prospective, single-center, nonrandomized study enrolled 48 patients (mean age 76±9 years; 38 men) with 51 SFA lesions from July 2013 to June 2014. Mean FFR (distal mean pressure/proximal mean pressure) and systolic FFR (distal systolic pressure/proximal systolic pressure) were calculated, and the relationship between these FFR values and restenosis at 12 months was investigated using receiver operating characteristic (ROC) curve analysis. Results: Poststenting FFR was significantly lower in the restenosis group (poststenting mean FFR 0.85±0.07 vs 0.93±0.05, p=0.001; poststenting systolic FFR 0.76±0.14 vs 0.87±0.08, p=0.015). The area under the ROC curve for restenosis in poststenting mean FFR was higher, but not statistically significant, than that in poststenting systolic FFR (0.84 vs 0.74, p=0.08). The best poststenting mean FFR cutoff value for predicting restenosis was 0.92 (sensitivity 0.64, specificity 0.91). The 4.5% restenosis rate at 12 months in the high (>0.92) poststenting mean FFR group was significantly lower (35.7%, p=0.008) than in the low (≤0.92) poststenting mean FFR group. Conclusion: Poststenting mean FFR is useful for predicting restenosis in SFA disease.

A randomized phase II study of Xilonix, a targeted therapy against interleukin 1α, for the prevention of superficial femoral artery restenosis after percutaneous revascularization

The purpose of this study was to evaluate an anti-interleukin 1α antibody for its ability to reduce acute postprocedural inflammation, thereby reducing neointimal hyperplasia and restenosis after superficial femoral artery (SFA) angioplasty. Restenosis of the SFA after endovascular intervention is a common problem leading to 1-year primary patency as low as 40%. These failures are primarily due to the development of neointimal hyperplasia, resulting from arterial wall inflammation. This was a randomized, phase II trial examining SFA restenosis in patients after percutaneous revascularization. Randomization occurred after successful revascularization, and patients were assigned to either the standard of care arm or the Xilonix (XBiotech USA, Inc, Austin, Tex) plus standard of care arm (N = 43). Xilonix was administered immediately after revascularization, every 2 weeks intravenously for four doses, and monthly subcutaneously until month 12. The major efficacy end points were target vessel event-free survival and incidence of major adverse cardiovascular events (MACEs). At 12 months of follow-up, MACE (43% vs 36%; P = .76) and target vessel restenosis (24% vs 27%; log-rank, P = .79) rates were not significantly different between the groups. At 3-month follow-up, which covers the intravenous dosing period, a trend toward lower incidence of restenosis (0 of 22 [0%] vs 2 of 21 [10%]; P = .14) and MACE (2 of 22 [9%] vs 5 of 21 [24%]; P = .22) was observed in the Xilonix cohort. Adverse events were equally distributed in both arms. Xilonix was well tolerated. Observed tendency to improved vessel patency with intravenous dosing suggests Xilonix could potentially represent a safe and effective therapeutic approach to preserving vessel patency.

Abstract 9689: Nitinol Stents Implantation Improves Clinical Outcome After Endovascular Therapy in Hemodialysis Patients with Superficial Femoral Artery Lesions

Background: Although endovascular therapy (EVT) has become widely performed for peripheral artery disease, high restenosis rate remains major problem after EVT to lesion of superficial femoral artery (SFA). Recently, it has been reported that nitinol stent implantation reduced restenosis in SFA after EVT in general population, however, the clinical outcome is little known in hemodialysis (HD) patients. The aim of this study was to investigate whether nitinol stent implantation improves clinical outcome after EVT to SFA lesions in HD patients. Methods: A total of 173 consecutive patients underwent nitinol stents implantation (NS group) were compared with 75 patients received stainless steel stents implantation in the preceding 5 years (SS group). We analyzed incidence of major adverse cardiovascular events (MACE) including target lesion revascurlarization (TLR), major amputation and death. To minimize the differences in both groups, a propensity-matched analysis using logistic model including male, age, traditional risk factors, critical limb ischemia (CLI) and TASC C+D lesions was performed. Each patients implanted with stainless steel stents were matched with up to two patients implanted with nitinol stents with two-digit propensity score (AUC = 0.63 using ROC analysis). Results: Baseline characteristics were comparable in both groups. On Kaplan-Meier analysis, 5-year freedom rate from MACE was higher in NS group than in SS group (51.8% vs. 24.4%, p&lt;0.0001). After adjustment, nitinol stent implantation was an independent predictor of reducing MACE [HR 0.41, 95% CI 0.25-0.65, p=0.0002]. After the propensity score matching, 106 patients in NS group and 66 patients in SS group were matched. Still, freedom from MACE was higher in NS group than in SS group (47.7% vs. 24.6%, p&lt;0.0001). Even after adjustment for other variables, implantation of nitinol stent predicted reduction of MACE (HR 0.47, 95% CI 0.28-0.79, p=0.0045). Nitinol stent implantation was also a predictor for not only preventing TLR (HR 0.35, 95%CI 0.18-0.68, p=0.0020) but also limb salvage (HR 0.26, 95%CI 0.07-0.96, p=0.043). Conclusion: Nitinol stent implantation improved clinical outcome after EVT compared to stainless steel stents in HD patients with SFA lesions.

Agreement of duplex ultrasonography vs. computed tomography angiography for evaluation of native and in-stent SFA re-stenosis—Findings from a randomized controlled trial

BackgroundMultidetector CT angiography (CTA) is a non-invasive imaging technique for evaluation of peripheral vascular disease. CTA might be particularly useful for assessment of intermediate- and long-term morphological outcome after endovascular treatment. Validation of CTA vs. the current imaging standard, colour Doppler ultrasonography (CDUS), for quantification of native and in-stent re-stenosis in the superficial femoral artery (SFA) is required. MethodsSeventy randomized patients who underwent stent implantation (n=47) or balloon angioplasty (n=23) underwent 6-month follow-up with CDUS and CTA. CTA was compared with CDUS in both sub-groups of patients in terms of binary re-stenosis (>50% lumen narrowing) and re-occlusion. Agreement between CTA and CDUS was assessed using Kappa (κ) statistics with 95% confidence intervals, and correlation coefficients. ResultsBinary re-stenosis was detected in 16/70 (22.9%) patients by CTA and 17/70 (24.3%) patients by CDUS (κ=0.88, 95% CI: 0.80–0.96). Re-stenosis rates after balloon angioplasty were 39.1% (9/23) on CTA and CDUS (κ=0.82, 95% CI: 0.66–0.98), and after stent implantation 14.9% (7/47) on CTA and 17.0% (8/47) on CDUS (κ=0.92, 95% CI: 0.84–1.00). Re-occlusions were detected in 3/70 (4.3%) patients by both CTA and CDUS (κ=0.65; 95% CI 0.54–0.76). Significant correlations (r=0.85, p<0.001) were noted between degree of re-stenosis on CTA and peak velocity ratio on CDUS. The correlation coefficient was higher in patients after balloon angioplasty (r=0.94, p<0.001) than in patients after stent implantation (r=0.71, p<0.001). ConclusionCTA and CDUS show excellent agreement for evaluation of native and in-stent re-stenosis after endovascular treatment of SFA obstructions. CTA is an appropriate non-invasive imaging modality for follow-up after endovascular therapy.

Drug-Coated Balloons for the Prevention of Vascular Restenosis

From early in the history of percutaneous cardiovascular intervention, restenosis has been one of the most important clinical and biological measures of success, and a great deal of effort has been put into understanding the mechanisms responsible.1,2 Restenosis is the result of the interaction of a variety of mechanical and biological processes that begin immediately after balloon injury, including early vessel recoil,3,4 negative vascular remodeling,5 and excessive neointimal proliferation.5–7 The most important limitations of balloon angioplasty, abrupt vessel closure resulting from elastic recoil and occlusive plaque dissection, were effectively solved by the introduction of balloon-expandable stents.8 However, in-stent restenosis (ISR), the result of the initial injury and the vascular response to the implanted metallic prosthesis leading to excessive neointimal proliferation, remained as the most important cause of failure of these devices.9,10 Drug-eluting stents (DES) effectively reduced ISR by addressing the biological mechanisms of neointimal proliferation and have become the mainstay of the interventional treatment of coronary atherosclerotic disease.11 However, the demonstrated efficacy of DES is balanced by the small but unpredictable risk of very late stent thrombosis thought to be due to delayed vascular healing resulting from either the initial antiproliferative effect (and associated late acquired incomplete stent apposition) or a hypersensitivity reaction to the drug, polymer coating, or their combination.12,13 Moreover, beyond the coronary vasculature, there has been a paucity of effective therapies to manage restenosis after intervention. In recent years, drug-coated balloons (DCBs) have emerged as a therapeutic alternative in the interventional field.14 With this technology, short-term transfer of antiproliferative drugs to the arterial wall is achieved without the requirement of an implanted drug delivery system, thus potentially reducing the untoward effects associated with polymer-based stent technologies. In small clinical randomized trials, paclitaxel-coated balloons have been shown to be …

Nitinol stenting improves primary patency of the superficial femoral artery after percutaneous transluminal angioplasty in hemodialysis patients: A propensity-matched analysis

Although percutaneous transluminal angioplasty (PTA) has become a common therapeutic standard for peripheral artery disease (PAD), high restenosis rates in the superficial femoral artery (SFA) remain a major problem. Nitinol stent implantation is reported to reduce restenosis in SFA after PTA in the general population; however, little is known about whether the nitinol stent improves primary patency after PTA in hemodialysis patients who are at higher risk of revascularization failure. The aim of this study was to clarify the effects of nitinol stent implantation for primary patency in SFA after PTA in hemodialysis patients with PAD. Eighty consecutive hemodialysis patients (167 SFA lesions) who underwent PTA with nitinol stents from January 2006 to January 2008 were compared with 64 hemodialysis patients (128 SFA lesions) who received stainless steel stents in the preceding 2 years. In the follow-up study to 2 years, incidence of restenosis, amputation, and all-cause mortality were analyzed. End points between the groups were examined with the Kaplan-Meier and log-rank methods. Prognostic values for end points were calculated by a Cox univariate analysis and Cox multivariable regression models. To statistically minimize the differences in each stent group, a propensity-matched analysis was also performed using the model including male gender, age, diabetes, hypertension, hyperlipidemia, smoking, incidence of ulcer/gangrene, and TransAtlantic Inter-Society Consensus (TASC) type C+D. The 2-year primary patency rate was 58% in the nitinol group vs 42% in the stainless steel group (hazard ratio [HR], 0.58; 95% confidence interval [CI], 0.39-0.84; P = .0045), despite a higher prevalence of TASC C+D lesion in the nitinol group (68% vs 49%, P = .0014). In 108 lesions matched after propensity score analysis, the primary patency for 2 years was 64% in the nitinol group vs 42% in the stainless steel group (HR, 0.39; 95% CI, 0.24-0.65; P = .0003). Cox multivariate models showed nitinol stent (HR, 0.42; 95% CI, 0.25-0.73; P = .002), age (HR, 1.04; 95% CI, 1.01-1.08; P = .031), and incidence of ulcer/gangrene (HR, 2.35; 95% CI, 1.17-4.75; P = .017) were independent predictors of restenosis. These data suggest that nitinol stent implantation improves primary patency in SFA after PTA compared with the stainless steel stent, even in hemodialysis patients with PAD.

Beta endovascular brachytherapy using CO2-filled centering catheter for treatment of recurrent superficial femoropopliteal artery disease

Recurrent disease (restenosis) after endovascular treatment of the superficial femoral artery (SFA) remains a major problem. We evaluated the efficacy of beta-endovascular brachytherapy using the CORONA centering catheter in patients with SFA restenosis in a single-arm Phase II trial. A total of 28 patients (mean age 70 years; 16 female, 12 male) with recurrent SFA stenosis were treated, and in-stent restenosis was present in 17 patients (61%). Brachytherapy was performed with strontium-90 beta source using a 7-French CO(2)-filled one-segment centering catheter. New stents had to be applied in two cases. Mean interventional length was 129 mm (range 20-240 mm). A dose of 14 Gy in vessel radius (postinterventional) plus 2 mm was applied in 24 patients and 18.4 Gy in four patients. Treatment time was 7 min 32 s per radiation segment. No major adverse events occurred. Patients were followed by ankle-brachial index and duplex sonography for a median of 42 months. Cumulative restenosis rates at 1, 2, and 3 years were 9%, 28%, and 40%, respectively. Target vessel revascularization was performed in seven cases (25%). In comparison to literature data, the treatment of SFA restenosis with beta brachytherapy may improve long-term patency.

Atherosclerotic Peripheral Vascular Disease Symposium II

Percutaneous intervention for peripheral artery disease has evolved from balloon angioplasty for simple focal lesions to multimodality techniques that enable treatment of severe arterial insufficiency. This technological expansion comes without a standard approach or algorithm, which makes the decision-making process more subjective than objective. Nevertheless, clinical tools are available that can have a favorable effect on patient care, and these promote usage. So, when are standard endovascular techniques (such as balloon and stents) good enough, and when are the latest advances (eg, atherectomy, drug-eluting stents) more appropriate? This section will address these questions for acute limb ischemia (ALI) and chronic critical limb ischemia (CLI). It will also delineate the problem of restenosis, particularly of the superficial femoral artery (SFA), and describe treatment alternatives. The discussion will review the role of drug-eluting stents, atherectomy devices, reentry catheters, and brachytherapy, as well as their potential complications and appropriate remedies. Treatment algorithms for aortoiliac and infrainguinal disease are provided in Figures 1 through 3⇓⇓. Figure 1. Treatment algorithm for acute lower-limb ischemia. *Short infusion of thrombolytic therapy proximal to occlusion can be used to facilitate wire traversal. Figure 2. Simplified treatment algorithm for symptomatic aortoiliac disease in patients deemed candidates for revascularization. In patients with multilevel disease, the aortoiliac segment should be addressed first. TASC indicates TransAtlantic Inter-Society Consensus; AI, aortoiliac; PTA, percutaneous transluminal angioplasty; PE, physical examination; ABI, ankle-brachial index; and U/S, ultrasound. Figure 3. Simplified treatment algorithm for symptomatic infrainguinal peripheral arterial disease, assuming concomitant aortoiliac disease has been treated and the patient is an acceptable candidate for revascularization. *Alternative therapies to PTA include cryotherapy, atherectomy (directional, rotational, ablative), and cutting balloon. †Alternative stent options include stent (graft, balloon expanding, and self expanding) and drug-eluting stent. PTA indicates percutaneous transluminal angioplasty; TASC, TransAtlantic Inter-Society Consensus; PE, physical examination; …

Sirolimus-Eluting Stents versus the Superficial Femoral Artery: Second Round

RESTENOSIS remains a major limitation of femoropopliteal interventions, despite technologic advances in numerous endovascular strategies. Percutaneous transluminal angioplasty has been only modestly successful in the treatment of atherosclerotic disease of the superficial femoral artery (SFA), with 1-year patency rates of 41%–85% depending on lesion length, presence of diabetes, and distal runoff (1–6). Vascular stents are effective in rescuing suboptimal angioplasty results. However, the impact of femoropopliteal stent placement is still compromised by neointimal hyperplasia, and multiple studies have shown no improvement in lasting patency after primary stent placement compared with angioplasty alone (1,7–9). Newer generations of nitinol self-expanding stents appear to have a positive impact on femoropopliteal patency, but this has not been confirmed in a randomized setting (10–12). Drug-eluting stents have revolutionized the treatment of coronary artery disease. In the first human application of this breakthrough technology, minimal in-stent angiographic restenosis was observed in 28 patients 2 years after implantation of sirolimus-eluting stents in coronary arteries (13). These results were confirmed in a randomized study that included 238 patients (14). At 6-month angiographic follow-up, none of the patients had in-stent restenosis in the sirolimus-eluting stent group, compared with 26.6% in the bare stent group. With use of the same technology, inhibition of in-stent restenosis was also reproduced in a study that included 850 patients with complex coronary lesions consisting of a high percentage of diabetic patients and patients with longer lesions (15). At 8-month angiographic follow-up, the in-stent restenosis rates were 3.2% versus 35.4% in the sirolimus and bare stent groups, respectively. It was hypothesized that these impressive results could be obtained in the femoropopliteal segment by applying the same technology. The first human evaluation of drugeluting stents for the treatment of obstructive SFA disease (average length of 85 mm 57) included 36 patients randomized to receive treatment with bare versus sirolimus-eluting S.M.A.R.T. stents (Cordis, Warren, NJ) (16). The 6-month angiographic follow-up revealed a larger in-stent mean lumen diameter of 4.95 mm in the sirolimus group, versus 4.31 mm in the bare stent group (P .05). The lower 6-month binary restenosis rate (0 vs 23.5%) and the lower mean in-stent percent diameter stenosis (22.6% vs 30.9%) observed in the sirolimus-eluting stent group were not significant as a result of the small sample size. It was later learned that a subgroup of five patients who had received a slow-release drug coating within the sirolimus-eluting stent group had less restenosis than patients in the fast-eluting sirolimus and bare stent groups at 9 and 18-month duplex follow-ups. The SIROCCO I study showed the feasibility and safety of the use of a drugeluting self-expandable stent platform, but it also suggested that slow-eluting stents could reduce SFA restenosis. Based on these results, the SIROCCO II extension trial, presented in this issue of JVIR, was conducted in 57 additional patients randomized to receive treatment with the slow-release form of sirolimus-eluting and bare S.M.A.R.T. stents (17). Because stent fractures were detected in six patients who had received at least three overlapping stents in the SIROCCO I study (16), a maximum of two stents per patient was allowed in the SIROCCO II study (17) to treat lesions with an average length of 81.5 mm 41.2. Although there was a trend toward better performance of sirolimus-eluting stents, the 6-month angiographic follow-up revealed no significant difference between treatment groups in any of the variables: the in-stent mean lumen diameter values were 4.94 mm 0.69 versus 4.76 mm 0.54, the binary restenosis rates were zero versus 7.7%, and the late loss values were 0.038 0.64 versus 0.68 0.97 in the sirolimus and bare stent groups, respectively. In addition, 18-month duplex follow-up data presented at the 2004 Annual Meeting of the Cardiovascular and Interventional Radiology Society of Europe revealed a 20.7% binary restenosis rate in the sirolimus group (six stenoses and no occlusions in 29 paFrom the Department of Radiology, Centre Hospitalier de l’Universite de Montreal, Notre-Dame Hospital, 1560 Sherbrooke East, Montreal, Quebec, Canada H2L 4M1. Address correspondence to V.L.O.; E-mail: voliva@sympatico.ca