Stenting for superficial femoral artery atherosclerotic occlusion: long-term follow-up results

Recent advances in interventional devices and technology have greatly improved the results of percutaneous transluminal angioplasty (PTA), and it is now being widely used. However, it is important to obtain information regarding its results and its long-term patency. We examined the primary success rates and long-term patency in 29 limbs out of 27 patients with superficial femoral artery (SFA) occlusion who underwent PTA with self-expandable stents. Among the 29 lesions, 19 were long occlusions (>10 cm) and 10 were short (<10 cm). Overall primary success was achieved in 26 of the 29 limbs (90%). There were three unsuccessful cases in which the patients were on dialysis and had hard calcification in the arterial walls. After 3 years, primary patency, primary-assisted patency, and secondary-assisted patency were 81%, 86%, and 96%, respectively. In the case of short occlusions (<10 cm), the 3-year patency was 100%. Both the primary success rate and the long-term patency were considerably better than expected. Our results with self-expanding stents were superior to previously reported results and were not inferior to those of surgical bypass. Therefore, PTA may be considered as a good first option for the treatment of SFA occlusions.     

Balloon angioplasty versus stenting with nitinol stents in intermediate length superficial femoral artery lesions

Background : Recent randomized trials investigating stent implantation compared with balloon angioplasty for treatment of superficial femoral artery (SFA) disease have given divergent results in short (mean 5 cm) and intermediate (mean 10 cm) lesions. We reinvestigated whether primary nitinol stenting is associated with a morphologic and clinical benefit when compared with percutaneous transluminal angioplasty with optional stenting (PTA) in intermediate‐length lesions. Methods : We randomly assigned 73 patients with severe claudication or chronic limb ischemia and average 8 cm long (range 3–20 cm) SFA stenosis or occlusion to primary stent implantation (n = 34) or PTA (n = 39). Restenosis >50% and clinical outcome were assessed at 3, 6, and 12 months postintervention. Results : Average length of the treated segments was 98 ± 54 mm and 71 ± 43 mm in the stent and PTA groups (P = 0.011), respectively. In the PTA group, secondary stenting was performed in 10 of 39 patients (26%) due to a suboptimal result after balloon dilation. Restenosis rates in the stent and PTA groups were 21.9% versus 55.6% (P = 0.005) at 6 months by CT‐angiography, and 2.9% versus 18.9% (P = 0.033), 18.2% versus 50.0% (P = 0.006), and 34.4% versus 61.1% (P = 0.028) at 3, 6, and 12 months by sonography, respectively. Clinically, patients in the stent group reported a significantly higher maximum walking capacity compared with the PTA group at 6 and 12 months. Conclusion : In this randomized multicenter trial, primary stenting with a self‐expanding nitinol stent for treatment of intermediate length SFA disease resulted morphologically and clinically superior midterm results compared with balloon angioplasty with optional secondary stenting. © 2009 Wiley‐Liss, Inc.     

PTFE-covered self-expanding nitinol stents for the treatment of severe iliac and femoral artery stenoses and occlusions: final results from a prospective study.

PURPOSE: To evaluate the technical performance, safety, and 1-year clinical efficacy of polytetrafluoroethylene (PTFE)-covered nitinol stents in the treatment of atherosclerotic iliac and superficial femoral artery (SFA) disease. METHODS: The multicenter, prospective, nonrandomized COVENT study involved 98 patients (70 men; mean age 64+/-10 years) who received PTFE-covered nitinol stents in 107 arteries (60 iliac and 47 SFAs) after predilation. The average lesion length was 50 mm in the SFA and 45 mm in the iliac arteries. Postdilation was performed when necessary. Duplex ultrasound and ankle-brachial index (ABI) were performed at discharge and at 1, 6, and 12 months in follow-up. RESULTS: In total, 130 stents were placed successfully in 97 (99%) of 98 patients. One stent was misplaced during deployment and required subsequent surgical removal. The average stenosis grade was reduced from 98% to 6% in the SFAs and from 96% to 4% in the iliac arteries after covered stent placement. There was a significant rise of the mean ABI from 0.64 at baseline to 0.97 and 0.95 at 1 and 12 months, respectively (p<0.001). There were 7 primary covered stent occlusions (6.5% of 107 stented lesions: 3 not treated, 2 bypassed, 2 dilated or stented) and 5 (4.7%) recurrent in-stent occlusions (1 bypassed, 2 dilated, 2 untreated) during the 1-year follow-up. Primary patency rates were 92% at 6 months and 89.8% at 12 months for the entire cohort. Secondary patency rates were 98% and 95.6%, respectively. No statistically significant differences were observed in the primary patency rates for the SFAs (89.3% at both 6 and 12 months) versus the iliac arteries (94.3% at 6 months and 90.7% at 12 months). CONCLUSIONS: Primary implantation of PTFE-covered nitinol stents in the iliac and superficial femoral arteries is technically feasible, safe, and effective, with excellent 1-year patency.     

Drug-eluting stents versus bare metal stents following rotational atherectomy for heavily calcified coronary lesions: late angiographic and clinical follow-up results

OBJECTIVES: To study the effectiveness of drug-eluting stents following rotablation of severely calcified lesions. BACKGROUND: Drug-eluting stents are increasingly showing promising results in complex lesions and high-risk patients. Heavily calcified stenoses have not been adequately studied, and form a challenge both for the immediate and late outcomes. METHODS: Single-center prospective study among 27 patients treated by rotablation followed by a drug-eluting stent implantation for angiographically heavily calcified lesions, compared with a historical control of 34 patients treated by rotablation followed by bare stent implantation for the same indication. The primary endpoint was the late lumen loss at 9 months; secondary endpoints were binary restenosis and major adverse cardiac events at 9 months. A 2-year follow-up directed to death and myocardial infarction was added. RESULTS: Both groups were comparable regarding baseline and procedural characteristics. Angiographic success was 100% for both groups. At 9 months, there was a significant difference in the late lumen loss (0.11 +/- 0.7 mm in the DES group and 1.11 +/- 0.9 mm in the BMS group, P = 0.001). This difference was manifest in the clinical event rates at late follow-up (combined incidence of death due to any cause, MI, and TLR was 7.4% in the DES group and 38.2% in the BMS group; P = 0.004). At 2 years, there were 5 deaths in each group (P = 0.5) and 2 infarctions in the BMS group versus none in the DES group (P = 1.0). CONCLUSION: The combination of rotablation and drug-eluting stent implantation (Rota-DES) has a favorable effect on clinical and angiographic outcomes at 9 months when treating heavily calcified lesions compared to rotablation followed by bare metal stent implantation. No safety concerns are observed at 2 years.     

Drug-eluting stents compared with thin-strut bare stents for the reduction of restenosis: a prospective, randomized trial.

AIM: Drug-eluting stents have considerably reduced restenosis. Their relative merits have been assessed on the basis of comparisons made with control bare stents with thick struts. However, increased strut thickness negatively affects restenosis. No direct comparisons between drug-eluting stents and bare stents with thin struts have been performed. The aim of this study was to evaluate the relative efficacy of sirolimus-eluting stents (Cypher) as compared with that of bare stents with thin struts (BeStent 2). METHODS AND RESULTS: A total of 500 patients with coronary artery disease were randomly assigned to receive a Cypher stent or BeStent. The primary endpoint was angiographic restenosis defined as a stenosis diameter > or = 50% at 6-month angiographic follow-up. The secondary endpoint was the need for target vessel revascularization (TVR) during the year following the procedure. Follow-up angiography was performed in 81.8% of the patients. Patients treated with Cypher stents had a lower angiographic restenosis rate [8.3 vs. 25.5%, relative risk, 0.33 (95% confidence interval, 0.19-0.56), P<0.001] and a lower incidence of TVR [7.2 vs. 18.8%, relative risk, 0.38 (0.22-0.66), P<0.001]. For smaller vessels (< 2.8 mm), the angiographic restenosis rates were 7.0% with the Cypher stent and 34.2% with the BeStent (P<0.001). For larger vessels (> or = 2.8 mm), angiographic restenosis rates were 10.0% with the Cypher stent and 13.1% with the BeStent (P=0.52). CONCLUSION: The drug-eluting stent, Cypher, is associated with a significantly lower risk of restenosis compared with the bare thin-strut BeStent. The advantage of the Cypher stent is vastly reduced in large vessels.     

Evolution of stents for the treatment of femoral artery lesions

Endovascular treatment and stent implantation in the superficial femoral artery have been proposed for over 20 years. However, the first experiments with stainless stents were relatively disappointing. The first improvement consisted in the introduction of nitinol self-expanding stents. This technology allowed an initial improvement of clinical performances, but the first generation of nitinol stents demonstrated a relatively high rate of fractures. Better knowledge of the femoral artery biomechanics and advances in technology allowed to propose a second generation of nitinol stents with improved flexibility, which decreased the rates of fracture. In-stent restenosis related to neointimal hyperplasia has also led to the development of new concepts to improve patency rates after stenting of the femoral artery: drug-eluting stents (coated-stents), biodegradable stents, and covered stents. These technologies will help to treat more complex lesions of the femoral artery in the future, with comparable results to those obtained with femoropopliteal bypasses, but we are still waiting for results of ongoing studies.     

Drug-eluting stents for treatment of focal infrapopliteal lesions

We have investigated the role of drug-eluting stents on patency rates after treatment of focal infrapopliteal lesions in patients with intermittent claudication and critical limb ischemia. Reports indicate that drug-eluting stents reduce the risk of restenosis after percutaneous infrapopliteal artery revascularization. A Pub Med, EMBASE, Cochrane database review search of non-randomized studies investigating patency rates, target lesion revascularisation rates, limb salvage rates and mortality rates in an up to 3-year follow-up period after drug-eluting stent placement was conducted. In addition, preliminary results of randomized studies comparing drug-eluting stents with bare-metal stents and plain balloon angioplasty in treatment of focal infrapopliteal lesions were included in this review. A total of 1039 patients from 10 non-randomized and randomized studies were included. Most commonly used drug-eluting stents were sirolimus-eluting. The mean follow-up period was 12.6 (range 8 - 24). The mean 1-year primary patency rate was 86 ± 5 %. The mean target lesion revascularization rate and limb salvage rate was 9.9 ± 5 % and 96.6 %±4 %, respectively. Results from non-randomized and preliminary results from prospective, randomized trials show a significant advantage for drug-eluting stents in comparison to plain balloon angioplasty and bare-metal stents concerning target lesion patency and in parts target lesion revascularisation. No trial reveals an advantage for drug-eluting stents with regard to limb salvage and mortality.     

Multislice computed tomographic angiography versus digital subtraction angiography in the follow-up of nitinol stents in the superficial femoral artery.

PURPOSE: To compare quantitative and qualitative parameters obtained from digital subtraction angiography (DSA) with multislice computed tomographic angiography (MSCTA) in the follow-up of superficial femoral artery (SFA) stents. METHODS: Thirteen patients who had SMART stents implanted in the SFA were examined systematically with DSA and MSCTA (16-row scanner) at 6 months. Quantitative analysis and morphological assessment were performed on DSA images by an independent core laboratory, while the MSCTA images were analyzed by 2 radiologists in consensus. DSA measurements included stent length, minimal lumen diameter and reference diameter at mid stent and 5 mm either side of the stent, and percentage of stenosis. For MSCTA images, lumen area and the minimum, maximum, and mean diameters were also recorded. The images were analyzed qualitatively for diameter stenosis (<50%, 50% to 70%, 71% to 99%, and occlusion), bends, fractures, and calcifications. RESULTS: There were no statistical differences between lengths of stented segments, diameter measurements, or percentages of stenosis from DSA and MSCTA images. The Bland-Altman method showed good agreement between the 2 methods of measurement. MSCTA detected in-stent proliferation with a diameter stenosis <50% in all 13 cases diagnosed on DSA (there was no stenosis >50%). There were no bends or stent fractures on either set of images. The agreement between DSA and MSCTA for the presence and grading of calcifications was moderate (kappa=0.5). CONCLUSION: MSCTA provided quantitative and qualitative data comparable with DSA in the analysis of SFA nitinol stents.     

One-year follow-up after implantation of the EverFlex nitinol stent in long lesions of the superficial femoral artery

For treatment of complex superficial femoral artery lesions, suitable stent devices are required. The present study details the first long-term results with the long EverFlex nitinol stent. Forty-one EverFlex stents were implanted in 32 patients with either superficial femoral artery occlusions (n = 20) or stenoses (n = 12); mean lesion length was 13.3 cm (range = 8.0-39.0). Patients presented with clinical stage Fontaine IIb (n = 27), III (n = 4), or IV (n = 1). Stent lengths were 10 cm (n = 18), 12 cm (n = 6), or 15 cm (n = 17). Follow-up after 2 months indicated primary and secondary patency rates of 96.9% (n = 31) and 100% (n = 32); ABI improved from 0.57 to 0.91 (P < .001). After 1 year, revascularization was performed in 6 patients (18.8%). Primary and secondary patency rates were 81.3% (n = 26) and 93.8% (n = 30). In this first long-term evaluation, the long EverFlex nitinol stent achieves excellent clinical results after implantation into complex superficial femoral artery lesions.     

Drug-eluting stents in the treatment of intermediate lesions: pooled analysis from four randomized trials.

OBJECTIVES: To address the safety and efficacy of drug-eluting stents (DES) in the treatment of intermediate lesions, we performed a pooled analysis of four randomized DES versus bare-metal stent (BMS) trials and assessed outcomes among patients with intermediate lesions. BACKGROUND: Before the introduction of DES, intermediate coronary lesions were commonly managed based on physiologic or anatomic assessment of lesion severity. The DES may challenge this paradigm. METHODS: The study population involved 167 of 2,478 randomized patients (6.7%) with intermediate lesions (diameter stenosis <50% [mean 44%] by quantitative coronary angiography) from the Sirolimus-coated Bx Velocity Balloon Expandable Stent in the Treatment of Patients with De Novo Coronary Artery Lesions (SIRIUS), TAXUS-IV, and the First and Second First Use to Underscore Restenosis Reduction with Everolimus (FUTURE-I and -II) trials. End points examined included early (in-hospital and 30-day) and late (1-year) major adverse cardiac events (MACE), including cardiac death, myocardial infarction (MI), target vessel revascularization (TVR), stent thrombosis, and follow-up angiographic restenosis. RESULTS: Patients with intermediate lesions randomized to DES versus BMS had low rates of 30-day MACE (1.1% vs. 4.0% respectively; p = 0.22). At one-year follow-up, patients treated with DES versus BMS had similar rates of cardiac death (0% vs. 2.7%, respectively; p = 0.11) and MI (3.4% vs. 5.4%; p = 0.49) but markedly lower rates of TVR (3.4% vs. 20.3%; p = 0.0004), MACE (5.6% vs. 25.4%; p = 0.0003), and binary angiographic restenosis (1.8% vs. 34.0%; p < 0.0001). No patient in either group developed stent thrombosis. CONCLUSIONS: Compared with BMS, treatment of intermediate lesions with DES appears safe and results in a marked reduction in clinical and angiographic restenosis. The efficacy of DES may require a reevaluation of current treatment paradigms for intermediate lesions.     

Functional and clinical outcomes of nitinol stenting with and without abciximab for complex superficial femoral artery disease: a randomized trial.

OBJECTIVE: To evaluate the effect of glycoprotein IIb/IIIa inhibition during nitinol stenting, of superficial femoral occlusive disease. BACKGROUND: Stent implantation in the superficial femoral artery has been associated with suboptimal results while Glycoprotein IIb/IIIa inhibitors have shown improved procedural results during coronary intervention. We evaluated abciximab infusion during (Smart Stent) implantation in superficial femoral obstructions. METHODS: We conducted a randomized placebo controlled trial. The two primary end points include: (1) 9-month restenosis defined as a decrease in ankle brachial index and in-stent duplex ultrasound restenosis: (2) adverse events defined as death (30 days) or repeat revascularization within 9 months. RESULTS: Twenty-seven patients were randomized to abciximab and 24 patients to control (placebo). The primary end point of cumulative restenosis occurred in 15.4% of patients administered abciximab and in 12% administered placebo (P = 0.873). The primary restenosis endpoint in diabetics and total occlusions were similar at 14.3% and 15.4% respectively. The composite end point of 30-day mortality and 9-month revascularization occurred in 5.8% abciximab and 0% (P = 0.274) placebo with no 30-day deaths. Graded treadmill time and Rutherford class were all significantly improved in both groups, but the abciximab group did not appear to demonstrate any identifiable effect. CONCLUSION: (Smart Stent) nitinol stenting of the superficial femoral artery was associated with favorable functional outcomes at 9 months. Adjunctive abciximab did not appear to demonstrate any identifiable effect.     

Evolving standard in the treatment of coronary artery disease. Drug-eluting stents

Coronary stent implantation is the predominant method of percutaneous coronary interventions (PCI). This is to be attributed to the ease of use beside the better short and long term clinical outcome as compared to balloon angioplasty. Nevertheless, improvements in operator skill and stent technology together with better use of adjunctive pharmacological therapy have contributed to the improvement in clinical outcome. However, the main limitation of coronary stenting is still represented by in-stent restenosis (ISR) with an estimated rate of 17-32%. Thus, compared to coronary bypass surgery, the major adverse cardiac events following stent implantation are still higher and mainly represented by the need for re-intervention. The advent of drug eluting stents (DES) has led the experts to predict that with DES there will be little or no difference between PCI and coronary bypass surgery in terms of long-term outcome leading to a further expansion of indications. The clinical trial programs of the 2 available DES for clinical use (sirolimus-eluting stent, SES - Cypher and paclitaxol-eluting stent - Taxus) have been able to demonstrate the safety and clinical efficacy of both. Nevertheless, off-label use in patients on high risk for restenosis confirmed these data. At least for SES as was demonstrated by 2 "real world" registries. Thus, the introduction of DES represents a remarkable evolution for new standards in coronary artery disease treatment and offers hope to those patients considered to be "high risk" such as diabetics, patients with ISR, diffuse disease in whom surgery was previously the only therapeutic option. This paper will discuss the main results of the clinical trial programs of the DES (mentioned above) available for clinical use in the present time and analyze technical and procedural aspects which could affect long term outcome.     

Drug-eluting stents versus bare metal stents in ST elevation myocardial infarction: from evidence to practice

In 2001, drug-eluting stents (DES) were introduced as a strategy to decrease restenosis and need for re-intervention. As the utilization of DES grew in general practice, there was considerable use of DES in "off-label" patients not evaluated in the initial randomized clinical trials. Single-center and large registry studies were able to demonstrate that the clinical efficacy of DES persisted even in patient subgroups not included in the initial clinical trials. These observations provided support for evaluating DES in STEMI patients. We will consider the evidence that evaluates the relative safety and efficacy of DES compared to BMS in STEMI patients, as well as address practical issues faced in the routine clinical care of these patients.     

Covered versus bare self-expanding stents for endovascular treatment of carotid artery stenosis: a stopped randomized trial.

PURPOSE: To investigate whether filter-protected carotid artery stenting (CAS) using a covered self-expanding stent reduces the risk of cerebral embolization. METHODS: Fourteen asymptomatic patients (13 men; median age 77 years, IQR 73-83) were enrolled in a randomized pilot trial comparing the rates of cerebral microembolism during and after filter-protected CAS using either a self-expanding covered (n=8) or a bare (n=6) carotid stent. Transcranial Doppler (TCD) monitoring was done during and for 90 minutes after the procedure. Diffusion-weighted magnetic resonance imaging (DW-MRI) was performed before and 24 hours after CAS. Patients were followed for 6 months for neurological events and occurrence of restenosis. RESULTS: A significant reduction in ipsilateral microembolic signals by TCD was observed with the covered (median 1, IQR 0-4) versus the bare stent (median 6, IQR 3-8; p=0.043). Comparison of the preprocedural and 24-hour postprocedural DW-MRI images showed no new ipsilateral lesions but 1 new lesion in the contralateral hemisphere in the covered stent group, resulting in an overall 7% (95% CI 0%-20%) rate of new ischemic lesions. No neurological complications occurred up to 6 months. Restenosis (>70%) occurred in 3 (38%) of 8 patients with the covered versus none of the bare stents (p=0.21). The trial was stopped when the third restenosis of a covered stent was detected. CONCLUSION: Self-expanding covered stents potentially reduce the risk of cerebral microembolism during and after carotid stenting. However, the problem of in-stent restenosis has to be resolved before these devices can be considered for further investigation.     

Drug-eluting stents: caution and concerns for long-term outcome

Recent publications on drug-eluting stents (DES) report a significant reduction in restenosis rates as compared to bare metal stents in patients mostly with single vessel disease. We have recently observed however, late stent thrombosis following CYPHER DES implantation. The patient developed a hypersensitivity reaction around stent struts limited to the polymer with aneurysmal dilatation and extensive inflammation of the arterial wall in the absence of vascular healing. This incidence promotes a cautionary view and perhaps supports the use of DES only in high-risk patients.