MISAGO 2: One-Year Outcomes After Implantation of the Misago Self-Expanding Nitinol Stent in the Superficial Femoral and Popliteal Arteries of 744 Patients

A method of assessing peripheral stent abrasiveness under cyclic deformations experienced during limb movement

Poor outcomes of peripheral arterial disease stenting are often attributed to the inability of stents to accommodate the complex biomechanics of the flexed lower limb. Abrasion damage caused by rubbing of the stent against the artery wall during limb movement plays a significant role in reconstruction failure but has not been characterized. Our goals were to develop a method of assessing the abrasiveness of peripheral nitinol stents and apply it to several commercial devices. Misago, AbsolutePro, Innova, Zilver, SmartControl, SmartFlex, and Supera stents were deployed inside electrospun nanofibrillar tubes with femoropopliteal artery-mimicking mechanical properties and subjected to cyclic axial compression (25%), bending (90°), and torsion (26°/cm) equivalent to five life-years of severe limb flexions. Abrasion was assessed using an abrasion damage score (ADS, range 1-7) for each deformation mode. Misago produced the least abrasion and no stent fractures (ADS 3). Innova caused small abrasion under compression and torsion but large damage under bending (ADS 7). Supera performed well under bending and compression but caused damage under torsion (ADS 8). AbsolutePro produced significant abrasion under bending and compression but less damage under torsion (ADS 12). Zilver fractured under all three deformations and severely abraded the tube under bending and compression (ADS 15). SmartControl and SmartFlex fractured under all three deformations and produced significant abrasion due to strut penetration (ADS 20 and 21). ADS strongly correlated with clinical 12-month primary patency and target lesion revascularization rates, and the described method of assessing peripheral stent abrasiveness can guide device selection and development. STATEMENT OF SIGNIFICANCE: Poor outcomes of peripheral arterial disease stenting are related to the inability of stents to accommodate the complex biomechanics of the flexed lower limb. Abrasion damage caused by rubbing of the stent against the artery wall during limb movement plays a significant role in reconstruction failure but has not been characterized. Our study presents the first attempt at assessing peripheral stent abrasiveness, and the proposed method is applied to compare the abrasion damage caused by Misago, AbsolutePro, Innova, Zilver, SmartControl, SmartFlex, and Supera peripheral stents using artery-mimicking synthetic tubes and cyclic deformations equivalent to five life-years of severe limb flexions. The abrasion damage caused by stents strongly correlates with their clinical 12-month primary patency and target lesion revascularization rates, and the described methodology can be used as a cost-effective and controlled way of assessing stent performance, which can guide device selection and development.

An Update on Drug-eluting Technology in Peripheral Arteries to Treat Peripheral Arterial Disease

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A Retrospective Comparative Study of Twelve-Month Clinical Outcomes for Drug-Coating Balloon Angioplasty and Stent Implantation in Treating Patients with Popliteal Obstructive Lesions

PURPOSE

Despite increased interest in treating superficial femoral and popliteal arteries with endovascular technology, there is little data regarding comparative results of different treatment modalities in the popliteal artery. It was hypothesized that to improve clinical outcomes in this segment, drug-coating balloon (DCB) angioplasty would not be inferior to stent implantation.

METHODS

The records of consecutive Chinese patients with popliteal lesions who were treated with DCB or stenting between June 2016 and February 2017 were retrospectively reviewed. The preoperative demographic, lesion characteristics and postoperative outcomes were compared and statistically analyzed. All patients were divided into different subgroups according to the degree of calcium or degree of ischemia.

RESULTS

One hundred two consecutive patients with popliteal lesions were treated with DCB or stenting and 95 (93.1%) completed a follow-up. Critical limb ischemia was present in 70.5% and occlusions were present in 61.1% of patients. DCB angioplasty was performed on 43 patients and angioplasty with primary stenting was performed on 52 patients. There was no difference in twelve-month primary patency (79.1% vs 82.7%; P = 0.687), secondary patency (95.3% vs 94.2%; P = 0.808) and amputation-free survival (93.0% vs 94.2%; P = 0.825) between the DCB group and stent groups. In patients with severe calcium, the twelve-month primary patency (61.1% vs. 79.2%; P = 0.239) and amputation-free survival (83.3% vs 87.5%; P = 0.739) did not differ between the DCB and stent groups.

CONCLUSIONS

This study demonstrates that DCB treatment in Chinese patients with popliteal atherosclerotic occlusive lesions can be associated with similar twelve-month patency and amputation-free survival compared to stenting, even in patients with severe calcification.

LEVEL OF EVIDENCE

Level 3a, Non-randomized follow-up study.

Three-Year Efficacy and Safety of the Misago Peripheral Stent for Superficial Femoral Artery Disease: Final Results from the OSPREY Trial

PURPOSE

This study evaluated the long-term outcomes of the Misago peripheral stent trial (Terumo) for atherosclerotic lesions in the superficial femoral artery (SFA) in patients with claudication.

MATERIALS AND METHODS

This was a prospective multicenter, single-arm, clinical trial of primary stent placement for de novo cases of SFA disease conducted in the United States and Asia. The primary endpoint was freedom from clinically driven target lesion revascularization (CD-TLR) at 36 months. Secondary outcomes were ankle-brachial index (ABI), Rutherford score, Walking Impairment Questionnaire (WIQ), a quality of life survey, and rate of device fracture.

RESULTS

A total of 276 patients (64.4% male; mean age, 69.3 ± 10.1 years) were enrolled. Freedom from CD-TLR was 78.5% (95% confidence interval [CI], 73.0%-83.0%) at 24 months and 75.4% (95% CI, 69.6%-80.2%) at 36 months. Baseline ABI was 0.7 ± 0.1 and 0.98 ± 0.20 (P < .001) at 30 days after the procedure. Baseline Rutherford score was 3.6 ± 0.6 and 1.6 ± 1.0 30 at 30 days after the procedure (P < .001). Mean (and changed) ABI and Rutherford score at 36 months compared to day 30 after the procedure were, respectively, 0.91 (-0.1 ± 0.2) and 1.5 (-0.2 ± 1.1). WIQ score at baseline was 21.49 ± 26.30 and 50.51 ± 38.49 at 30 days after the procedure ( P < .001). The mean WIQ score at 2 years was 46.65 ± 37.31 (P = .12). Stent fracture rate at 36 months was 2.0% (4 of 202 patients).

CONCLUSIONS

OSPREY (Occlusive-Stenotic Peripheral Artery Revascularization Study) 36-month data demonstrated persistent freedom from CD-TLR and sustained improvement in ABI and Rutherford score with primary stent placement for SFA lesions.

Endovascular treatment of atherosclerotic lesions in the superficial femoral artery and proximal popliteal artery using the sinus-SuperFlex-635 stent: twelve-month results from the HERO Registry

BACKGROUND

The aim of this study was to evaluate the safety and performance of the sinus-SuperFlex-635 self-expandable nitinol stent (Optimed GmbH) for the treatment of steno-occlusive lesions in the superficial femoral artery (SFA) and proximal popliteal artery (PPA).

METHODS

The prospective, multicenter, observational HERO study recruited 117 eligible patients (83 men; mean age 69.4±9.7y) from 7 centers in Belgium.

RESULTS

A total of 129 stents were successfully deployed in 121 lesions in 117 patients (100%). The patients presented with symptomatic ≥50% stenosis or chronic total occlusion (CTO) (30.6%). Mean lesion length was 71.4±56.3 mm. Moderate to severe calcification was present in 82.6% of the lesions. Acute lesion success (<30% residual stenosis) was achieved in 96.0%. There were no in-hospital serious adverse events. Duplex ultrasound-driven primary patency at 12 months was recorded in 84 of 107 (78.5%) lesions. The overall target lesion revascularization (TLR) rate was 8.4% at 12 months; the target extremity revascularization (TER) rate was 4.7%. Clinical assessment at 12 months demonstrated improvement by at least 1 Rutherford class, without the need for TLR (i.e. primary sustained clinical improvement) in 83.9% of patients and with the need for TLR in 90.6% of patients (i.e. secondary sustained clinical improvement).

CONCLUSIONS

Based on the high primary patency, low stent fracture rate and significant clinical improvement, combined with refined stent design and long stent availability, the sinus-SuperFlex-635 self-expandable nitinol stent proves its value in the treatment of complex femoropopliteal lesions.

Morphologic Changes of the Femoropopliteal Arterial Segment with Knee Flexion after Endovascular Therapy

Objective: The purpose of this study is to investigate morphologic changes of the femoropopliteal arterial segment (FPAS) with knee flexion after endovascular therapy (EVT).

Methods: From July 2012 to January 2015, EVT was performed on 12 limbs in 12 consecutive patients who had obliterative lesions in the FPAS. After the implantation of nitinol stents, angiography was performed with the knee in both extension and flexion to investigate morphologic changes of the FPAS.

Results: On angiography, the distal end of the implanted stent was placed at various distances (5–10 cm in two cases, 10–15 cm in nine cases, and 15–20 cm in one case) above the knee joint line with the knee in extension. In all cases, although the popliteal artery was highly bent with the knee in flexion, the FPAS morphology was highly variable. However, the most proximal bending point of the FPAS was about 10 cm above the knee joint line. In one case, the artery was occluded at the distal part of the stent 16 months later, probably due to EVT.

Conclusion: In EVT of the FPAS, it is important to consider the characteristics and position of the stent to prevent complications.

Superficial femoral artery stenting via radial access using R2P® Misago® stents: First-in-human report of the new R2P® system

A 73-year-old male with left critical limb ischemia was scheduled to undergo below-the-knee amputation. Prior to the amputation, he was referred to our institute for endovascular treatment. We inserted the new 7-Fr 150-cm-long guiding catheter, SlenGuide^®, into the external iliac artery from the right radial artery with the 7-Fr Glidesheath Slender^®. We implanted two R2P^® Misago^® stents with rapid-exchange, 200-cm-long shaft system in the stenosis of the left superficial femoral artery. This new stent system involves rapid-exchange and a long shaft system; furthermore, it is useful in transradial stenting in the superficial femoral artery.

Antithrombotic therapy after femoropopliteal artery stenting: 12-month results from Japan Postmarketing Surveillance

Objective

To investigate the effects of antithrombotic therapy on target lesion revascularisation (TLR) and major adverse cardiovascular and cerebrovascular events (MACCEs) at 12 months after femoropopliteal intervention with second-generation bare metal nitinol stents.

Methods

A total of 277 lesions in 258 limbs of 248 patients with de novo atherosclerosis in the above-the-knee femoropopliteal segment were analysed from the Japan multicentre postmarketing surveillance.

Results

At discharge, dual antiplatelet therapy (DAPT) was prescribed in 68.5% and cilostazol in 30.2% of patients. At 12 months of follow-up, prescriptions of DAPT significantly (p=0.0001) decreased to 51.2% and prescription of cilostazol remained unchanged (p=0.592) at 28.0%. Prescription of warfarin also remained unchanged (14.5% at discharge, 13.3% at 12 months, p=0.70). At 12 months, freedoms from TLR and MACCE were 89.4% and 89.7%, respectively. In a multivariate Cox proportional hazards model, neither DAPT nor cilostazol at discharge was associated with both TLR and MACCE at 12 months. However, warfarin at discharge was only independently associated with TLR at 12 months. Kaplan-Meier estimates demonstrated that warfarin at discharge yielded a significantly (p=0.013) lower freedom from TLR at 12 months than no warfarin at discharge. Freedom from TLR at 12 months by the Kaplan-Meier estimates was 77.8% (95% CI 59.0% to 88.8%) in patients with warfarin at discharge and 91.2% (95% CI 86.3% to 94.3%) in those without warfarin at discharge.

Conclusions

Clinical benefits of DAPT or cilostazol might be small in terms of TLR and MACCE at 12 months. Anticoagulation with warfarin at discharge might increase TLR at 12 months.

One-Year Clinical Outcomes following Implantation of InnovaTM Self-Expanding Nitinol Stents in Patients with Peripheral Artery Diseases Presenting Femoropopliteal Artery Lesions

Aim: Although the Innova™ self-expanding nitinol stent (Boston Scientific, Marlborough, MA) exhibits acceptable performance in long-term safety and efficacy when used for the treatment of femoropopliteal (FP) lesions, clinical outcomes following its implantation have not been systematically studied in real-world settings. We investigated the one-year clinical outcomes after implantation of Innova™ self-expanding nitinol stents for the treatment of FP lesions in real-world settings.

Methods: In this multicenter study, 481 lesions in 453 consecutive patients with peripheral artery disease (PAD) (74 ± 9 years; male, 70%; diabetes mellitus, 61%; dialysis, 27%; critical limb ischemia, 37%) who underwent endovascular therapy with the implantation of Innova™ self-expanding nitinol stents for FP lesions were analyzed from February 2016 to April 2017. The primary endpoint was one-year restenosis, whereas the secondary endpoints included one-year major adverse limb events and predictors for one-year restenosis.

Results: The mean lesion length was 18 ± 10 cm. One-year restenosis and major adverse limb event rates were 36% and 18%, respectively. Multivariate analysis revealed that the presence of diabetes mellitus (odds ratio [OR]: 1.83; 95% confidence interval [CI]: 1.07–3.13), distal reference vessel diameter (OR: 1.86; 95% CI: 1.09–3.16), spot stenting (OR: 2.27; 95% CI: 1.27–4.06), and lack of one-year cilostazol treatment (OR: 0.58; 95% CI: 0.33–1.00) were independent risk factors for one-year restenosis.

Conclusion: The current study demonstrated one-year clinical outcomes after Innova™ self-expanding nitinol stent placement for the treatment of FP lesions, including challenging cases in real-world settings.

Drug-coated balloon versus uncoated percutaneous transluminal angioplasty for the treatment of atherosclerotic lesions in the superficial femoral and proximal popliteal artery: 2-year results of the MDT-2113 SFA Japan randomized trial

OBJECTIVES

To assess the longer-term safety and efficacy of the IN.PACT Admiral (MDT-2113) drug-coated balloon (DCB) for the treatment of de novo and non-stented restenotic lesions in the superficial femoral and/or proximal popliteal arteries versus uncoated percutaneous transluminal angioplasty (PTA) in a Japanese cohort.

BACKGROUND

Although DCBs are the newest endovascular strategy for patients with peripheral artery disease presenting with femoropopliteal lesions, there remains a paucity of results in non-Caucasian populations.

METHODS

IN.PACT SFA Japan is an independently-adjudicated, prospective, multicenter, randomized, single-blinded trial. Endpoints through 2 years included primary patency and a composite safety endpoint of freedom from device- and procedure-related death through 30 days, freedom from target limb major amputation and freedom from clinically-driven target vessel revascularization at 24 months.

RESULTS

One hundred patients were assigned by 2:1 randomization to treatment with the IN.PACT Admiral DCB (n = 68) or PTA (n = 32). The groups were well-matched at baseline. Mean lesion length for the DCB and PTA groups were 9.15 ± 5.85 and 8.89 ± 6.01 cm (P = 0.838), respectively. Patients treated with DCB exhibited superior 24-month primary patency compared to PTA (79.8% vs. 46.9%; log rank P < 0.001). The 24-month clinically driven target lesion revascularization rate was 9.1% for DCB versus 20.7% for PTA (P = 0.177). There were no device- or procedure-related deaths, major amputations, or thromboses in either group.

CONCLUSIONS

Two-year results from IN.PACT SFA Japan demonstrated persistently superior patency and low CD-TLR rates through 2 years when compared to uncoated PTA in Japanese patients. These data are consistent with other IN.PACT DCB trials.

Nitinol Self-Expanding Stents for the Treatment of Obstructive Superficial Femoral Artery Disease: Three-Year Results of the RELIABLE Japanese Multicenter Study

Objective: To assess the use of a nitinol stent to treat symptomatic stenoses or occlusions of the native superficial femoral artery (SFA).

Materials and Methods: Seventy-four patients were treated at 12 Japanese sites. The primary endpoint, freedom from target-limb failure (TLF), was a composite of device- or procedure-related death, target-limb amputation, target-vessel revascularization (TVR), or restenosis compared to an objective performance goal (OPG) at 12 months. Secondary endpoints, including primary patency, freedom from TVR/target-lesion revascularization (TLR), improvements in clinical parameters, and major adverse events (MAEs) were evaluated through 36 months.

Results: The mean overall lesion length was 80.7±38.9 mm (mean stented length: 98.8±46.1 mm). Freedom from TLF was 81.2% (p<0.001 compared to OPG) with a Kaplan–Meier estimate of 84.2% [95% confidence interval (95%CI) 73.3%, 90.9%] at 12 months. Primary patency was 71.0% at 12 months and 67.8% at 36 months. A total of 94.7% of patients improved by at least one Rutherford category and 70.2% of patients improved ankle–brachial indices ≧0.10 from baseline to 36 months. Freedom from TVR/TLR (Kaplan–Meier) was 90% at 12 months and 79.5% at 36 months. Four MAEs were reported; none were found to be device or procedure related.

Conclusion: A self-expanding stent was used safely to treat stenotic and occlusive lesions of the SFA in a Japanese patient population. The composite endpoint, freedom from TLF, was superior to an historical control at one year, with low rates of revascularization and good functional and clinical outcomes through three years.

Endovascular Interventions for Femoropopliteal Peripheral Artery Disease: A Network Meta-Analysis of Current Technologies

PURPOSE

To use network meta-analysis (NMA) to determine the optimal endovascular strategy for management of femoropopliteal peripheral artery disease (PAD) given the lack of multiple prospective randomized trials to guide treatment decisions.

MATERIALS AND METHODS

NMA is a new meta-analytic method that permits comparisons among any 2 therapies by combining results of a collection of clinical trials conducted in the same or similar patient population. NMA was used to analyze data from 15 randomized controlled trials (RCTs) and 10 prospective, multicenter, single-arm trials (combined evidence [CE] NMA) that evaluated target lesion revascularization (TLR) for 5 endovascular strategies: bare metal stent (BMS), polymer-covered metal stent (CMS), drug-eluting stent (DES), drug-coated balloon (DCB) and percutaneous transluminal angioplasty (PTA).

RESULTS

The RCT and CE NMAs included 2,912 (6,091) patients with 3,151 (6,786) person-years of follow-up. In the CE NMA, DCB provided a statistically significant 68% reduction in TLR compared with PTA and a statistically significant 53% reduction in TLR compared with BMS. BMS, CMS, and DES provided reductions in TLR of 33%, 48%, and 58% compared with PTA, with statistical significance achieved for CMS and DES. The significant reductions in TLR for DCB compared with PTA and BMS were replicated in the RCT NMA.

CONCLUSIONS

This NMA demonstrated that DCB provided better reduction in TLR rates compared with PTA and BMS.

Retrospective Multicenter Comparison of S.M.A.R.T. CONTROL and MISAGO Stents in Treatment of Femoropopliteal Lesions

PURPOSE

To compare primary patency between MISAGO (Terumo Corporation, Tokyo, Japan) and S.M.A.R.T. CONTROL (Cordis Corporation, Miami Lakes, Florida), second-generation and first-generation nitinol stents, in femoropopliteal lesions.

MATERIALS AND METHODS

This multicenter, retrospective study included 240 cases with MISAGO stent implantation and 1,265 cases with S.M.A.R.T. stent implantation. The S.M.A.R.T. group had more Trans-Atlantic Inter-Society of Consensus (TASC) II class C/D lesions (53% vs 41%, P = .001) and smaller reference vessel diameter (RVD) (5.3 mm ± 0.9 vs 5.5 mm ± 0.9, P < .001).

RESULTS

Kaplan-Meier estimates of 2-year primary patency after S.M.A.R.T. and MISAGO stent implantation were 67% and 55% (P = .007). Interaction analysis revealed that TASC II classification and RVD had a significant influence on the association of MISAGO versus S.M.A.R.T. stents with the outcome. The study population was stratified according to TASC II classification and RVD, and MISAGO and S.M.A.R.T. stents were compared after propensity score matching. There was no significant difference in 2-year patency between the 2 stents in the subgroup with TASC II class A/B and RVD ≥ 5 mm (S.M.A.R.T. 82% ± 4 vs MISAGO 74% ± 5, P = .480). MISAGO stents had lower primary patency than S.M.A.R.T. stents in cases with TASC II class C/D or RVD < 5 mm (S.M.A.R.T. 62% ± 6 vs MISAGO 25% ± 6, P = .015).

CONCLUSIONS

S.M.A.R.T. and MISAGO stents had similar patency in simple lesions, but MISAGO stents had lower patency than S.M.A.R.T. stents in more complex lesions.

[Stent-assisted recanalization of femoropopliteal arterial occlusive disease. Influence of stent design on patency rates]

BACKGROUND

Despite enormous technical progress the results of endovascular treatment of the femoropopliteal vasculature are unsatisfactory and its role is still controversially discussed. In the past decade numerous new stent designs have come onto the market but it is unclear whether they have benefits with respect to patency rates.

OBJECTIVES

Comparison of published data on patency rates and target lesion revascularization rates after use of different stent designs in the femoropopliteal vasculature.

MATERIAL AND METHODS

Analysis of 25 published studies and registries from 2006 to 2015 for classical open-cell stents, interwoven stents and partially or fully covered stents.

RESULTS AND CONCLUSION

The published data are heterogeneous and comparative studies for different stent designs are completely missing. Over the past decade the patency rates after femoropopliteal stenting could be improved. According to available data stenting of short lesions < 5 cm does not show any benefit compared to isolated balloon angioplasty. Primary stenting is now recommended for intermediate and longer lesions > 6.4 cm. Due to the heterogeneity of published data a clear benefit for a specific stent design is not obvious; however, data for interwoven stents are promising and show a tendency towards improved patency, at least for certain lesions. Randomized controlled comparative trials are needed to confirm this result.

Efficacy of intravascular ultrasound in femoropopliteal stenting for peripheral artery disease with TASC II class A to C lesions

PURPOSE

To investigate whether use of intravascular ultrasound (IVUS) improves primary patency following nitinol stenting for TASC II (TransAtlantic Inter-Society Consensus) A-C femoropopliteal lesions.

METHODS

Using a retrospective multicenter database of 1198 limbs from 965 patients (695 men; mean age 72±9 years) with TASC II A-C lesions (28% critical limb ischemia) treated by provisional stenting from April 2004 to December 2011, primary patency rate was compared between 234 propensity score-matched pairs with vs. without IVUS use.

RESULTS

IVUS was used in 22% (n=268) of the overall population. It was more likely to be used in cases with generally more complicated femoropopliteal lesions (e.g., more severe TASC II class, longer lesion length, and narrower reference diameter). Analysis of the 234 propensity score-matched pairs (mean follow-up 1.9±1.5 years; 142 events) revealed higher 5-year primary patency with than without IVUS use (65%±6% vs. 35%±6%, p<0.001). IVUS resulted in significantly better assisted primary patency (p<0.001), secondary patency (p=0.004), freedom from any reintervention (p<0.001), freedom from any adverse limb event (p<0.001), and event-free survival (p<0.001).

CONCLUSION

IVUS use in femoropopliteal stenting for TASC II A-C lesions appears to be associated with higher primary patency rate.

Intravascular Ultrasound Measurements After Drug-Eluting Stent Placement in Femoropopliteal Lesions

Purpose:

To investigate the relationship between postprocedure intravascular ultrasound (IVUS) findings and restenosis after placement of drug-eluting stents (DES) for femoropopliteal lesions.

Methods:

Between July 2012 and May 2013, DES were placed in 64 patients with 88 de novo femoropopliteal lesions. In 40 patients (mean age 74.2±9.4 years; 27 men), DES were placed in 50 lesions under IVUS guidance, and restenosis was monitored for 1 year. All patients were symptomatic (Rutherford 2–6), and 17 patients (43%) suffered from critical limb ischemia. IVUS findings after stenting were compared for patients with vs without restenosis, which was defined as a peak systolic velocity ratio >2.4 on duplex ultrasonography or >50% diameter stenosis on angiography.

Results:

Ten patients (14 lesions) developed restenosis, while 30 patients (36 lesions) did not. There were no significant differences in the frequency of diabetes or dialysis between the 2 groups. Female patients were predominant in the restenosis group (p<0.003). There were no significant differences of the percentage of TransAtlantic Inter-Society Consensus C/D lesions or stent edge dissection. Multivariate analysis indicated that cilostazol use [odds ratio (OR) 0.13; p=0.046], distal lumen cross-sectional area (CSA) (OR 0.86; p=0.035), and axial symmetry index (OR 0.60; p=0.045) were independent predictors of restenosis. Using receiver operator characteristic analysis, the best cutoff values of the distal lumen CSA and axial symmetry index for predicting restenosis were 17.1 cm2 and 0.6, respectively.

Conclusion:

IVUS guidance of DES placement in femoropopliteal lesions can offer useful predictors of restenosis at 1 year. The utility of distal lumen CSA and the axial symmetry index in the prediction of restenosis after femoropopliteal DES placement should be confirmed in a larger cohort.

Bare metal stent versus paclitaxel eluting stent for intermediate length femoropopliteal arterial lesions (BATTLE trial): study protocol for a randomized controlled trial

BACKGROUND

Currently, endovascular treatment is indicated to treat femoropopliteal lesions ≤15 cm. However, the Achilles' heel of femoropopliteal endovascular repair remains restenosis. Paclitaxel eluting stents have shown promising results to prevent restenosis in femoropopliteal lesions compared to percutaneous transluminal angioplasty. A recently released prospective registry using a newer generation of self-expandable nitinol stents (Misago®; Terumo Corp., Tokyo, Japan) supports primary bare metal stenting as a first-line treatment for femoropopliteal lesions. To date, no studies have been designed to compare bare metal stents to paclitaxel eluting stents for the treatment of femoropoliteal lesions. The BATTLE trial was designed to compare paclitaxel eluting stents (Zilver® PTX®) and a last generation bare self-expandable nitinol stents (Misago® RX, Terumo Corp., Tokyo, Japan) in the treatment of intermediate length femoropopliteal lesions (≤14 cm).

METHODS/DESIGN

A prospective, randomized (1:1), controlled, multicentric and international study has been designed. One hundred and eighty-six patients fulfilling the inclusion criteria will be randomized to one of the two assessments of endovascular repair to treat de novo femoropopliteal lesions ≤14 cm in symptomatic patients (Rutherford 2 to 5): bare stent group and paclitaxel eluting stent group. The primary endpoint is freedom from in-stent restenosis at 1 year defined by a peak systolic velocity index >2.4 (restenosis of >50%) at the target lesion and assessed by duplex scan. Our main objective is to demonstrate the clinical superiority of primary stenting using Zilver® PTX® stent system versus bare metal self-expandable stenting in the treatment of femoropopliteal lesions in patients with symptomatic peripheral arterial disease.

DISCUSSION

This is the first randomized and controlled study to compare the efficacy of bare metal stents and paclitaxel eluting stents for the treatment of femoropopliteal lesions. It may clarify the indication of stent choice for femoropopliteal lesions of intermediate length.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT02004951. 3 December 2013.

4-French-compatible endovascular material is safe and effective in the treatment of femoropopliteal occlusive disease: results of the 4-EVER trial

PURPOSE

To report the 1-year results of a prospective multicenter trial to evaluate the safety and efficacy of treating symptomatic femoropopliteal occlusive disease using 4-F-compatible materials and no closure device.

METHODS

The non-randomized 4-EVER trial (4-F endovascular treatment approach to infrainguinal disease) was conducted at 5 European hospitals (ClinicalTrials.gov identifier NCT01413139). The protocol mandated the use of only 4-F sheaths, self-expanding nitinol stents (Astron Pulsar or Pulsar-18 stent), and balloons from a single manufacturer. Between June 2010 and June 2011, 120 symptomatic patients (82 men; mean age 71±9.7 years, range 47-90), primarily claudicants, treated for 120 femoropopliteal lesions (>90% TASC A/B) were enrolled. The mean lesion length was 71.0±45.9 mm. Follow-up evaluations were scheduled on day 1 and at 1, 6, 12, and 24 months. A duplex ultrasound was performed on all follow-up visits to determine vessel patency (primary outcome measure at 1 year), and biplanar radiography was performed at 12 and 24 months to assess stent fracture.

RESULTS

Stents were successfully implanted in all patients: an Astron Pulsar stent in 70 (58.3%) lesions and a Pulsar-18 stent in 46 (38.3%); 4 (3.3%) patients had both stents implanted for flow-limiting dissection after predilation. No closure devices were used; the mean manual compression time was 8.1 minutes (2-15). Four (3.3%) patients developed significant hematoma at the puncture site, but none required surgical repair. The overall 12-month primary patency rate was 81.4%: 85.2% for the Astron Pulsar and 73.4% for the Pulsar-18 (p=0.236). Freedom from target lesion revascularization at 12 months for the entire cohort was 89.3%.

CONCLUSION

Compared to published historical data for superficial femoral artery type A/B lesion stenting using 6-F devices, the 4-F devices applied in this trial showed similar patency at 12 months, fewer access site complications, and shorter manual compression times, supporting the supposition that 4-F endovascular treatment is safe and effective.

12-month primary patency rates of contemporary endovascular device therapy for femoro-popliteal occlusive disease in 6,024 patients: beyond balloon angioplasty

BACKGROUND

Endovascular approach to superficial femoral artery (SFA) disease, the most common cause of symptomatic peripheral arterial disease, remains fraught with high failure rates. Newer devices including second-generation nitinol stents, drug-coated stents, drug-coated balloons, covered stents, cryo-therapy, LASER, and directional atherectomy have shown promising results. Clinical equipoise still persists regarding the optimal selection of devices, largely attributable to the different inclusion criteria, study population, length of lesions treated, definition of "patency" and "restenosis," and follow-up methods in the pivotal trials.

METHODS

A prospective protocol was developed. We performed a literature search using PubMed from January 2006 to November 2013. Published articles including endovascular interventions in SFA or popliteal arteries with reported 12-month "primary patency" or "binary restenosis" rates as endpoints were included.

RESULTS

We identified 6,024 patients in 61 trials reporting 12-month primary patency rates in patients with femoropoliteal disease. Primary patency rates were (weighted average) 77.2% for nitinol stents, 68.8% for covered stents, 84% for drug eluting stents, 78.2% for drug eluting/coated balloon, 60.7% for cryoballoon, 51.1% for LASER atherectomy, 63.5% for directional atherectomy and 70.2% with a combination of endovascular devices.

CONCLUSION

The most frequently used endovascular devices yielded various 12-month primary patency rates ranging from 51% to 85%. The increased variation in inclusion criteria, length, and complexity of lesions between studies does not allow direct comparison between them. Larger randomized trials in specific patient populations comparing those modalities is needed before we can make safe recommendation of the superiority of one device over the other.

Direct stent puncture technique for intraluminal stent recanalization in the superficial femoral and popliteal arteries in-stent occlusion: outcomes from a prospective clinical analysis of diabetics with critical limb ischemia

PURPOSE

To evaluate the efficacy and safety of "Direct Stent Puncture" technique for intraluminal stent recanalization in the femoro-popliteal segments.

METHODS AND MATERIALS

A cohort of diabetics who had symptomatic in-stent occlusion of the superficial femoral or popliteal arteries underwent endovascular recanalization. After antegrade failure, direct stent puncture technique was performed. The primary end-point was to efficacy assessment, intended as technical success and clinical improvement. The secondary end-point was safety assessment, intended as free of complication rate.

RESULTS

Fifty-four patients (37 men; 73.6±8.5 years) underwent direct stent puncture technique, after several unsuccessful antegrade attempts to cross the occluded stent. Technical success for intraluminal stent recanalization was achieved in 53/54 (98.2%) of cases and failed in 1/54 (1.8%). Clinical improvement was obtained in 51/54 (94.4%) of cases, with regression of the clinical symptoms and improvement of the TcPO2, from 3±18 mmHg to 43±11 mmHg after 15 days (p<0.001). Free of complications rate was 92.5%. In 2/54 (3.7%) of cases distal embolization occurred, in 1/54 (1.9%) case a sudden vessel thrombosis was diagnosed after 12 hours and in 1/54 (1.9%) case hematoma at the stent puncture site was observed.

CONCLUSIONS

Direct Stent Puncture technique is an efficacy and safety option for intraluminal stent recanalization in the femoro-popliteal segment in-stent occlusion.

Evaluation of the 4-French Pulsar-18 Self-expanding Nitinol Stent in Long Femoropopliteal Lesions

PURPOSE

To evaluate the patency and the freedom of target lesion revascularization of the 4-French Pulsar-18 self-expandable (SE) nitinol stent for the treatment of long femoropopliteal occlusive disease in a two-center, prospective, all-comers registry with a follow-up period of 12 months.

METHODS

This registry enrolled 36 patients with symptomatic femoropopliteal long lesions for recanalization and implantation of the 4-French Pulsar-18 SE nitinol stent. Routine follow-up examination including duplex ultrasound was performed after 6 and 12 months. Primary patency was defined as no binary restenosis on duplex ultrasound (Peak systolic velocitiy ration (PSVR) <2.5) and no target lesion revascularization was performed within 12 months’ follow-up. No drug-eluting devices were allowed in this registry.

RESULTS

Average lesion length of the femoropopliteal segment was 182.3 ± 51.8 mm. Mean stent implantation length was 181.5 ± 35.4 mm. Total occlusion was present in 46 of the 48 (95.8%) treated lesions. Involvement of popliteal segment I–III was present in 3 (6.3%) lesions. The primary patency after 6 and 12 months was 87.5% and 85.4%, respectively. The clinically driven overall freedom from target lesion revascularization (fTLR) was 89.6% after 6 months and 87.5% after 12 months. ABI, pain-free walking distance and Rutherford category, all improved significantly (P < 0.001) after 6 and 12 months. The primary patency rate in patients with diabetes (P = 0.18) and renal insufficiency (P = 0.3) was not significantly lower as compared to the overall primary patency.

CONCLUSIONS

In this two-center, all-comers registry, the use of the Pulsar-18 SE nitinol stent for endovascular intervention of femoropopliteal disease with a mean lesion length of 182.3 ± 51.8 mm showed promising primary patency and fTLR rates after 6 and 12 months. Diabetes and renal insufficiency had no negative impact on the patency rate.

SUMMIT registry: one-year outcomes after implantation of the EPIC self-expanding nitinol stent in the femoropopliteal segment

PURPOSE

To evaluate the efficacy and safety of the EPIC self-expanding nitinol stent in patients with femoropopliteal occlusive disease.

METHODS

The prospective, multicenter, nonrandomized SUMMIT study (ClinicalTrials.gov identifier NCT01336101) enrolled 100 patients (76 men; mean age 67.6 years) with symptomatic de novo femoropopliteal disease undergoing angioplasty and subsequent implantation of EPIC stents from April 2011 to October 2011. The mean lesion length was 69.5±40.5 mm; 29 of the lesions were total occlusions. Clinical examination and duplex sonography were prospectively performed after 6 and 12 months. The primary endpoint was in-stent restenosis as assessed by duplex ultrasound (peak systolic velocity ratio ≥2.5). Further outcome measures were patency rates, improvement in the Rutherford category and ankle-brachial index (ABI), as well as stent integrity based on plain radiography.

RESULTS

A residual stenosis <30% was achieved in all procedures. The primary patency rates were 96.8% after 6 months and 85.1% at 1 year. The secondary patency rates were 97.9% and 91.2% at the same intervals. The 1-year binary >50% restenosis rate was 15.7%. Freedom from target lesion revascularization at 1 year was 92.3%. Between baseline and the 12-month follow-up, the mean ABI increased from 0.73 to 0.96, and the mean Rutherford category decreased from 2.9 to 1.0 (p<0.001 for both comparisons). Plain radiographs from 86 patients at the 12-month examination confirmed the absence of stent fractures.

CONCLUSION

The outcome of the SUMMIT registry demonstrates that the EPIC self-expanding nitinol vascular stent is a safe and effective device for treating peripheral artery disease in the femoropopliteal segment.

Stent Placement Versus Balloon Angioplasty for the Treatment of Obstructive Lesions of the Popliteal Artery

Background—

Stenting has been shown to improve patency after femoral artery revascularization compared with balloon angioplasty. Limited data are available evaluating endovascular treatment for obstructive lesions of the popliteal artery.

Methods and Results—

This prospective, randomized, multicenter trial compared primary nitinol stent placement to percutaneous transluminal balloon angioplasty in patients with peripheral artery disease Rutherford-Becker class 2 to 5 who had a de novo lesion in the popliteal artery. The primary study end point was 1-year primary patency, defined as freedom from target-lesion restenosis (luminal narrowing of ≥50%) as detected by duplex ultrasound. Secondary end points included target-lesion revascularization rate and changes in Rutherford-Becker class. Provisional stent placement was considered target-lesion revascularization and loss of primary patency. Two hundred forty-six patients were included in this trial. The mean target-lesion length was 42.3 mm. One hundred ninety-seven patients were available for the1-year follow-up. The 1-year primary patency rate was significantly higher in the group with primary nitinol stent placement (67.4%) than in the percutaneous transluminal balloon angioplasty group (44.9%, P =0.002). Target-lesion revascularization rates were 14.7% and 44.1%, respectively ( P =0.0001); however, when provisional nitinol stent placement was not considered target-lesion revascularization and loss in patency, no significant differences prevailed between the study groups (67.4% versus 65.7%, P =0.92 for primary patency). Approximately 73% of patients in the percutaneous transluminal balloon angioplasty group and 77% in the nitinol stent group showed an improvement of ≥1 Rutherford-Becker class ( P =0.31).

Conclusions—

Primary nitinol stent placement for obstructive lesions of the popliteal artery achieves superior acute technical success and higher 1-year primary patency only if provisional stenting is considered target-lesion revascularization. Provisional stenting as part of a percutaneous transluminal balloon angioplasty strategy has equivalent 1-year patency and should be preferred over primary stenting.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00712309.