S.M.A.R.T. self-expanding nitinol stent for the treatment of atherosclerotic lesions in the superficial femoral artery (STROLL): 1-year outcomes

Navigating complexity: The Supera's triumph in femoropopliteal lesions

INTRODUCTION

The femoropopliteal sector endovascular treatment is particularly challenging due to its high tortuosity and torsional forces. Better results are still needed to ensure the long-term patency of stenting in this area. The Supera stent appears to change this paradigm.

METHODS

This single-center retrospective cohort study aims to evaluate the efficacy and safety of femoropopliteal stenting with Supera in a real-world population. Seventy-nine patients were treated between January 2015 and December 2020, and the results are reported with a median follow-up of 28 months.

RESULTS

Indications for revascularization were chronic limb-threatening ischemia with tissue loss (73.6%) or ischemic rest pain (17.7%) and claudication (7.6%). Thirty-six patients (45.6%) were classified as GLASS stage III according to the Global Limb Anatomic Staging System, with 65.8% and 30.4% in grades 3 and 4 of femoropopliteal and infrapopliteal sectors, respectively. The 36-month primary, primary-assisted, and secondary patency rates were 68.6%, 72.0%, and 79.0%, respectively, with an amputation-free survival rate of 86.6%. There was no significant difference between primary patency rates in GLASS stages I-II compared with GLASS stage III (36-month primary patency rates of 72% vs 63% respectively, p = 0.342) nor in amputation-free survival (88% vs 84%, p = 0.877). After adjusting for potential confounders, only the stent conformation significantly affected the primary patency rates, with a higher hazard of reintervention for the elongated (HR = 3.179; p = 0.36; CI 1.081-9.347) and the compressed (HR = 3.014; p = 0.42; CI 1.039-8.746) forms.

CONCLUSIONS

The 36-month patency of the Supera stents in our real-world cohort was similar to other reported series. The GLASS stage did not interfere with the stent patency, proving it is a good choice even in the most adverse anatomy patients. Only the non-nominal stent conformation affected the primary patency rates in our patients.

Association of Smoking, Diabetes, and Dialysis with the Presence of Popliteal Lesions in Femoropopliteal Artery Disease

AIM

Although recent advances in endovascular devices have markedly improved clinical outcomes of femoropopliteal endovascular therapy, lesions located in the popliteal artery are still a major challenge. This study aimed to determine the association of cardiovascular risk factors, including smoking, diabetes mellitus, and dialysis-dependent renal failure, with the location of atherosclerotic lesions in femoropopliteal artery disease.

METHODS

We used a multicenter prospective study database registering patients with symptomatic femoropopliteal artery disease undergoing drug-coated balloon treatment. The analysis included 1912 patients with de novo femoropopliteal lesions. The association of clinical characteristics with popliteal lesions was investigated using the logistic regression model. In addition, the femoropopliteal artery was divided into six segments (the proximal, middle, and distal portions of the superficial femoral artery and P1, P2, and P3 segments of the popliteal artery), and the association of clinical characteristics with the presence of atherosclerotic lesions in the respective arterial segments was investigated.

RESULTS

Smoking and dialysis-dependent renal failure showed a statistically significant inverse and positive association with the presence of popliteal lesions, respectively (adjusted odds ratio, 0.66 [95% confidence interval, 0.51-0.85] and 2.01 [1.62-2.49]; P=0.001 and P＜0.001), whereas diabetes mellitus did not (P=0.17). The subsequent per-segment analysis presented similar results.

CONCLUSIONS

Smoking was inversely associated with popliteal lesions, whereas renal failure on dialysis was positively associated in patients with symptomatic femoropopliteal artery disease who underwent drug-coated balloon treatment. Diabetes mellitus was not significantly associated.

The Interplay between Mitochondrial Dysfunction and Ferroptosis during Ischemia-Associated Central Nervous System Diseases

Cerebral ischemia, a leading cause of disability and mortality worldwide, triggers a cascade of molecular and cellular pathologies linked to several central nervous system (CNS) disorders. These disorders primarily encompass ischemic stroke, Alzheimer's disease (AD), Parkinson's disease (PD), epilepsy, and other CNS conditions. Despite substantial progress in understanding and treating the underlying pathological processes in various neurological diseases, there is still a notable absence of effective therapeutic approaches aimed specifically at mitigating the damage caused by these illnesses. Remarkably, ischemia causes severe damage to cells in ischemia-associated CNS diseases. Cerebral ischemia initiates oxygen and glucose deprivation, which subsequently promotes mitochondrial dysfunction, including mitochondrial permeability transition pore (MPTP) opening, mitophagy dysfunction, and excessive mitochondrial fission, triggering various forms of cell death such as autophagy, apoptosis, as well as ferroptosis. Ferroptosis, a novel type of regulated cell death (RCD), is characterized by iron-dependent accumulation of lethal reactive oxygen species (ROS) and lipid peroxidation. Mitochondrial dysfunction and ferroptosis both play critical roles in the pathogenic progression of ischemia-associated CNS diseases. In recent years, growing evidence has indicated that mitochondrial dysfunction interplays with ferroptosis to aggravate cerebral ischemia injury. However, the potential connections between mitochondrial dysfunction and ferroptosis in cerebral ischemia have not yet been clarified. Thus, we analyzed the underlying mechanism between mitochondrial dysfunction and ferroptosis in ischemia-associated CNS diseases. We also discovered that GSH depletion and GPX4 inactivation cause lipoxygenase activation and calcium influx following cerebral ischemia injury, resulting in MPTP opening and mitochondrial dysfunction. Additionally, dysfunction in mitochondrial electron transport and an imbalanced fusion-to-fission ratio can lead to the accumulation of ROS and iron overload, which further contribute to the occurrence of ferroptosis. This creates a vicious cycle that continuously worsens cerebral ischemia injury. In this study, our focus is on exploring the interplay between mitochondrial dysfunction and ferroptosis, which may offer new insights into potential therapeutic approaches for the treatment of ischemia-associated CNS diseases.

Radial access for peripheral vascular intervention: the S.M.A.R.T. RADIANZ Vascular Stent System

INTRODUCTION

Radial access is the standard of care for nearly all cardiac catheterization procedures. It improves patient satisfaction, reduces the length of stay, and is associated with fewer complications. However, few devices and tools are available for the treatment of peripheral arterial disease via a transradial approach (TRA). The S.M.A.R.T. RADIANZ Vascular Stent System is among the RADIANZ suite of products, which is aimed at expanding the portfolio of devices to treat peripheral arterial disease.

AREAS COVERED

In this Expert review, the following areas will be covered: (1) Current Landscape of peripheral vascular intervention (PVI) using TRA (2) Detailed description of the S.M.A.R.T. RADIANZ Vascular Stent System. (3) Ongoing clinical trials to evaluate safety of this approach. (4) Future directions and current regulatory status.

EXPERT OPINION

TRA for PVI is a promising approach. It holds the possibility of substantially improving the care of patients with peripheral arterial disease (PAD). Numerous challenges must be overcome to realize the full potential of a radial-to-peripheral (RTP) approach. The length of devices and the small sheath size are the main constraints of this approach. The results of the ongoing RADIANCY trial will demonstrate the safety, in selected patients, of the RADIANZ suite of products.

Treatment of Long Femoropopliteal Occlusive Lesions With Self-expanding Interwoven Nitinol Stent: 24 Month Outcomes of the STELLA-SUPERA-SIBERIA Register Trial

PURPOSE

The efficacy and safety of the Supera stent in superficial femoral artery (SFA) have been reported mostly in shorter lesions with relatively low proportion of occlusions. There are little data on the effectiveness of the Supera stent in long lesions. The aim of this study was to assess the clinical safety and efficiency of the Supera stent in the treatment of long femoropopliteal occlusive lesions (Trans-Atlantic Inter-Society Consensus [TASC] C/D) in patients with symptomatic peripheral artery disease.

MATERIALS AND METHODS

The STELLA-SUPERA-SIBERIA is a prospective, single-center, single-arm study. Patients with symptomatic (Rutherford stages 3-6) de novo and TASC C/D occlusive lesions of the femoropopliteal segment were treated with Supera stent. The primary endpoint was the 12 month rate of primary sustained clinical improvement (upward shift on the Rutherford classification to a one level without the need for repeated target lesion revascularization (TLR) in surviving patients without the need for unplanned amputation). Secondary endpoints were the 24 month of primary sustained clinical improvement, MALE, limb salvage, the primary patency, the secondary patency, 24 month MACE. Follow-up included clinical examination, duplex scan, and biplane x-ray up to 24 months.

RESULTS

Between April 2019 and January 2020, 52 symptomatic patients with 55 long femoropopliteal occlusive lesions (52.7% TASC D lesions and 47.3% TASC C lesions) were treated. The mean target lesion length was 205±72 mm. All patients had total occlusions. The mean lesion length of the implanted Supera stents was 198±82 mm. At 12 and 24 months, the primary sustained clinical improvement rate was 80.2% and 63.6%, respectively. The Rutherford category assessment was significantly improved at 24 months compared with baseline (p=0.02). The primary patency rate at 12 and 24 months was 78.1% and 60.0%, respectively. At 12 and 24 months, freedom from TLR was 83.5% and 81.8%, respectively. There were no stent fractures at 24 months.

CONCLUSION

Supera Stent implantation for TASC C/D femoropopliteal lesions revascularization appears to be a safe and efficient implant given the complexity of the treated lesions. Head-to-head studies are mandatory to establish Supera Stent as an alternative tool to open surgery for long femoropopliteal lesions.

CLINICAL IMPACT

Our study indicated, that using self-expanding interwoven nitinol stent for TASC C/D femoropopliteal lesions revascularization appears to be a safe and efficient implant given the complexity of the treated lesions. Although bypass grafting is recommended for prolonged femoropopliteal lesions, open surgery is more traumatic and is associated with greater risks than endovascular procedures. Our findings suggest that the use of interwoven nitinol stents can overcome the disadvantages of traditional stents in such cases, which may help to improve patients' outcomes and reduce the risk of adverse events.

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.

Evaluation of safety and efficacy of the S.M.A.R.T.® Flex Vascular Stent System (OPEN study)

OBJECTIVES

The OPEN study evaluated the safety and efficacy of the S.M.A.R.T.® Flex Vascular Stent System in patients with femoropopliteal arterial disease.

BACKGROUND

Long-term data on endovascular treatments of femoropopliteal arterial disease are required to establish the repair durability.

METHODS

The OPEN study was a multicenter, single-arm, prospective study comparing primary safety and efficacy outcomes to performance goals (PG) developed for bare nitinol stents. Patients with symptoms due to a single, ≤180 mm length, de novo femoropopliteal arterial lesion with >70% stenosis were enrolled were enrolled and followed for 36 months. Subjects with lesions ≤150 mm served as the initial comparison cohort for the PG (other cohorts were analyzed if the PG was met).

RESULTS

257 subjects with lesions ≤180 mm were enrolled. The mean lesion length was 71 ± 46, and 52.5% had severe claudication. The primary safety endpoint (freedom from all-cause death, index limb amputation, and target lesion revascularization [TLR] through 30 days) was met in 98.8% (96.5%, 99.6%) of subjects in the comparison cohort, meeting the PG (88.0%). The primary efficacy endpoint (comparison cohort vessel patency at 12 months) was 68.4% (61.1%, 74.8%), where the lower limit of the 95% confidence interval did not meet the 66.0% PG. Freedom from TLR in the per-protocol cohort at 12-, 24-, 36-month was 84.7%, 74.6%, and 72.8%, respectively. The 24-month stent fracture rate was 4.3%, with no new fractures identified at 36 months.

CONCLUSION

The results show promising long-term safety and effectiveness for the S.M.A.R.T.® Flex Vascular Stent System in patients with femoropopliteal arterial disease.

Directional atherectomy and drug-coated balloon angioplasty vs. bare nitinol stent angioplasty for femoropopliteal artery lesions

Background: The present study evaluated the prognosis of directional atherectomy (DA)+drug-coated balloon (DCB) angioplasty for femoropopliteal artery lesions compared with bare nitinol stent (BNS). Patients and methods: This retrospective cohort study included patients with femoropopliteal artery lesions who underwent percutaneous endovascular surgery between January 2016 and June 2019. The primary outcome was the primary patency rate after 12, 24, and 36 months; the secondary outcomes comprised incidence of flow-limiting dissections, technical success, limb salvage, and all-cause death. Results: During the study period, 110 (44%) patients underwent DA+DCB, and 140 (56%) patients underwent bare nitinol stent (BNS). There were no differences in the 12- and 24-month patency rates of the two groups (98.2% vs. 93.6% and 68.2% vs. 60.0%, both p>.05). The 36-month primary patency rate in the DA+DCB group was significantly higher than that of the BNS group (27.3% vs. 15.7%, p=.003). The technical success rate and all-cause death were similar between groups (p>.05). Flow-limiting dissections occurred more frequently in the BNS group than in the DA+DCB group (27.9% vs. 10.9%, p=.033). After adjustment for potential confounders, such as sex, smoking, hypertension, hyperlipidemia, ABI after surgery, TASC II B, lesion length ≥15 cm, two-vessel runoff, and three-vessel runoff, the HR for primary patency rate comparing BNS to DA+DCB was 2.61 (95%CI: 1.61-4.25). Conclusions: In this retrospective cohort study, DA+DCB was associated with a higher 30-month primary patency rate and a lower flow-limiting dissection incidence than BNS.

Impact of complete revascularization on long-term clinical outcomes for patients with diabetes mellitus and coronary chronic total occlusion lesion

Diabetes mellitus (DM) is a substantial risk factor in developing coronary artery disease (CAD), coronary chronic total occlusion (CTO) lesions are discovering 10-35% in patients who underwent coronary angiography. This study compares the long-term clinical outcomes of two treatment strategies, percutaneous coronary intervention (PCI) with complete recanalization versus medication therapy (MT) with CTO lesion in DM patients with CTO. This study is a single-center, prospective, all-comer registry designed to reflect "real world" practice since 2004. Of a total of 4909 consecutive patients were diagnosed with significant CAD by coronary angiography (CAG). A total of 372 patients has DM and CTO lesions. Patients were divided into the PCI group (n = 184) and the MT group (n = 179). The primary endpoint, defined as the composite of death or myocardial infarction (MI), was compared between the two groups up to 5 years. In addition, inverse probability weighting (IPTW) analysis, derived from the logistic regression model, was performed to adjust for potential confounders. Compared to the MT group, the PCI group was associated with a significantly reduced incidence of the primary endpoint before [hazard ratio; HR 0.267, 95% confidence interval (CI) 0.116-0.614] and after (HR 0.142, 95% CI 0.032-0.629) adjusting confounding factors by IPTW. Complete revascularization by CTO-PCI with MT in DM patients should be the preferred treatment strategy compared with the MT alone strategy since it reduces the composite of death or MI up to 5 years.

A review on femoropopliteal arterial deformation during daily lives and nickel-titanium stent properties

The increasing number of studies on the behaviour of stent placement in recent decades provides a clear understanding of peripheral artery disease (PAD). The severe mechanical loads (axial tension and compression, bending, radial compression and torsion) deformation of the femoropopliteal artery (FPA) is responsible for the highest failure rate of permanent nickel-titanium (Nitinol) stents. Therefore, the purpose of this article is to review research papers that examined the deformation of the natural load environment of FPA, the properties of Nitinol and mechanical considerations. In conclusion, a better understanding of mechanical behaviour for FPA Nitinol stents contributes to increased mechanical performance and fatigue-life.

Patient-Reported Outcome Measures in Symptomatic, Non-Limb-Threatening Peripheral Artery Disease: A State-of-the-Art Review

Patient-reported outcome measures (PROMs) are health outcomes directly reported by the patient that can be used to measure the effect of disease and treatments on patient perceived well-being. This review summarizes current evidence regarding the validation of PROMs in people with symptomatic, nonlimb-threatening peripheral artery disease. A literature search was conducted to identify studies of symptomatic peripheral artery disease without limb-threatening ischemia that included PROMs and had sample sizes ≥25. PROMs were summarized along a continuum of validation using classical test theory framework and according to whether they fulfilled defined criteria for (1) content validity; (2) psychometric validation; and (3) further validation evidence base expansion. Of 2198 articles identified, 157 (7.1%) met inclusion criteria. Twenty-four PROMs in patients with symptomatic peripheral artery disease were reviewed. Among disease-specific PROMs, 8 of 15 had excellent reliability as measured by a Cronbach alpha ≥0.80. Based on established criteria for PROM responsiveness, 6 of 15 disease-specific PROMs demonstrated excellent sensitivity to change. Of these, the disease-specific peripheral artery questionnaire, vascular quality of life questionnaire, and walking impairment questionnaire met criteria for validation at each stage of the continuum. For generic (nondisease specific) PROMs, the European Quality of Life 5-Dimension and SF-36 had the most extensive evidence of validation. Evidence from this review can inform selection of PROMs aligned with scientific and clinical goals, given the variable degree of validation and potential complementary nature of the measures.

BioMimics 3D vascular stent system for femoropopliteal interventions

Background: The MIMICS-3D study aimed to assess the safety and effectiveness of the BioMimics 3D Vascular Stent System for the treatment of symptomatic femoropopliteal artery disease in a real-world patient population. Patients and methods: Consecutive participants who were scheduled for implantation of the BioMimics 3D stent were enrolled in the prospective, observational, multicenter study. The primary effectiveness outcome was freedom from clinically driven target lesion revascularization at 12 months and the primary safety outcome was a composite of major adverse events comprising death, major target limb amputation, or clinically driven target lesion revascularization at 30 days. Outcomes through 24 months are reported. Results: A total of 507 patients (70±10 years, 65.5% male sex) were enrolled and treated with the study stent. 24.0% had critical limb-threatening ischemia, lesion length was 127±92 mm, and 56.8% of lesions were totally occluded. The Kaplan-Meier (KM) estimate of freedom from clinically driven target lesion revascularization at twelve-months was 90.6% (95% CI: 87.9%-93.3%) and the 30-day primary safety outcome occurred in 1.2% (95% CI: 0.5%-2.7%) of participants. At 24 months, clinical improvement was achieved in 86.6% and the KM estimate of freedom from clinically driven target lesion revascularization was 82.8% (95% CI: 79.4%-86.4%). The KM estimate of freedom from loss of primary patency according to PSVR >2.4 was 78.6% (95% CI: 74.7%-82.4%). Survival distribution functions regarding primary patency were lower with long lesions (>150 mm; log-rank p<0.001) but did not differ significantly between participants with or without critical limb-threatening ischemia (log-rank p=0.07). Conclusions: Endovascular treatment of atherosclerotic femoropopliteal lesions with the BioMimics 3D Vascular Stent System is efficacious and safe in a real-world setting.

Endovascular treatment of femoro-popliteal disease with the Supera stent: results of a multicenter study

Background: Even though many types of stents have been tested in superficial femoral artery (SFA) and popliteal artery (PA), most of these devices have provided an unsatisfactory outcome, probably due their unsuitable anatomical and physiological characteristics. The Supera peripheral stent (Abbott Vascular, Santa Rosa, CA, USA) is a braided interwoven nitinol device specifically designed for treating atherosclerotic lesions of the femoro-popliteal segment. The aim of this multicenter retrospective study was to describe the effectiveness of Supera stents in the management of femoral-popliteal atherosclerotic lesions and to critically analyze our findings in the context of current and past literature.

Design and methods: In this study we enrolled only patients who satisfied the inclusion criteria: i) patients affected by chronic obstructive arterial disease (COAD) grade II, as per Rutherford classification; ii) patients treated with endovascular revascularization and Supera stent implantation in the femoro-popliteal axis. We retrospectively analyzed the Doppler Ultra-sound (US) follow- up at 12-24 and 36 months to detect the vascular occlusions. The primary patency, primary patency assisted and TLR were described statistically analyzed by survival analysis and the demographic data, clinical data, device safety following stenting were described as frequency and mean value.

Results: 105 endovascular procedures on 99 patients for femoro-popliteal stenting with Supera were performed in four Italian hospitals. The median follow-up was 39 months (range 6-72), with primary patency rate of 83.1%, 74.3% and 69.5% at 12, 24 and 36 months after the procedure. The primary patency assisted was 89.9%, 76.8% and 73.4% in the same period, while the freedom from TLR values were 92.7%, 91.5% and 89.5% at 12, 24 and 36 months after the procedure, respectively. The mortality rate recorded at 12 months from the Supera implantation was 2.8% (3 out of 99 patients enrolled).

Conclusions: Our data were in agreement with the current literature, showing the non-inferiority Supera stent in relation to the other stent available. Supera stent showed an excellent safety, effectiveness profile and high durability for the treatment of PAD patients with femoro-popliteal artery disease.

A critical appraisal of registry-based objective performance goals in peripheral arterial disease

The multidisciplinary Superficial Femoral Artery-Popliteal EvidencE Development (SPEED) Study Group, under the auspices of the Registry Assessment of Peripheral Interventional Devices (RAPID) partnership, recently published objective performance goals for peripheral vascular interventions in the femoropopliteal arteries. Retrospective outcomes from the Vascular Quality Initiative provided the sole study data source. Strengths and weaknesses of this landmark effort are examined. Critical concerns include the substantial risks of ascertainment bias, flawed end point selection, sparse and variable capture of midterm follow-up data, and lack of expected discrimination between treatment modalities. The current Vascular Quality Initiative registry data thus appear insufficiently robust for the generation of objective performance goals and practice benchmarks; suggestions for redesign are provided. The impact of the statutory framework of the US Food and Drug Administration on device approval pathways and the maturation of an evidence-based approach to peripheral vascular intervention is explored.

Impact of chronic outward force on arterial responses of proximal and distal of long superficial femoral artery stent

BACKGROUND

Self-expanding nitinol stent (SENS) implantation is commonly oversized in the superficial femoral artery (SFA), and leads to chronic outward force (COF) and in-stent restenosis (ISR). This study aimed to investigate the impact of COF of oversizing SENS on ISR of SFA.

METHODS

In patients with implanted SENS in SFA, intimal hyperplasia especially between proximal segment and distal segment was evaluated by quantitative angiography, and the impact of COF on mid-term angiographic outcomes was investigated. In addition, porcine model with implanted SENS was used to evaluate the impact of COF on angiographic and histopathologic outcomes at 1 month. Excised stented arteries were evaluated by histopathologic analysis.

RESULTS

We analyzed 65 SENS in 61 patients with follow-up angiography at 6 months to 1 year. The baseline diameter was 6.8 ± 0.71 mm and length were 97.0 ± 33.8 mm for the SENS. The ratio of the diameter of the stent to the reference vessel was 1.3 ± 0.24 at the proximal portion and 1.53 ± 0.27 at the distal portion (P < 0.001). In the long SFA stent, stent-to-vessel ratio was significantly higher in the distal stent than in the proximal stent (1.3 ± 0.2 vs. 1.55 ± 0.25, P = 0.001). ISR incidence was higher at the distal stent (37.3% vs 52.6%, P = 0.029). All 11 pigs survived for 4 weeks after SENS implantation. The vessel diameter was 4.04 ± 0.40 mm (control group) vs 4.45 ± 0.63 mm (oversized group), and the implanted stent diameter was 5.27 ± 0.46 mm vs. 7.18 ± 0.4 mm (P = 0.001). The stent-to-vessel diameter ratio was 1.31 ± 0.12 versus 1.63 ± 0.20 (P < 0.001). After 4 weeks, restenosis % was 29.5 ± 12.9% versus 46.8 ± 21.5% (P = 0.016). The neointimal area was 5.37 ± 1.15 mm² vs. 8.53 ± 5.18 mm² (P = 0.05). The restenosis % was 39.34 ± 8.53% versus 63.97 ± 17.1% (P = 0.001).

CONCLUSIONS

COF is an important cause of restenosis in the distal portion of the SFA stent. Optimal sizing of the SFA stent is important to reduce the incidence of restenosis. Therefore, COF was an important factor of restenosis following distal SFA stenting.

Assessing health-related quality of life among patients with peripheral artery disease: A review of the literature and focus on patient-reported outcome measures

Peripheral artery disease (PAD) is a progressive atherosclerotic disease associated with high rates of morbidity and mortality. Symptomatic PAD typically presents with claudication, and symptom severity strongly associates with reduced health-related quality of life (HRQoL). Existing treatment strategies for PAD are aimed at reducing symptom severity and improving functional outcomes. However, there is a need to incorporate patient-reported outcome measures (PROMs) into PAD treatment and research in order to provide more patient-centered care. This review will discuss the impact of PAD on HRQoL, existing PROMs available to assess PAD-related HRQoL, utilization of PROMs in research studies and registries, and challenges and solutions related to the integration of PROMs into research and clinical settings.

Femoral-popliteal peripheral artery disease: From symptom presentation to management and treatment controversies

Peripheral artery disease (PAD) is a common condition with increasing prevalence domestically and worldwide. Patients with PAD have a poor prognosis, as PAD is associated with high rates of myocardial infarction, ischemic stroke, and cardiovascular disease death. The primary symptom of PAD, claudication, significantly reduces quality of life and functional status and is associated with depression. In addition to several advances in medications for PAD over the last decade, endovascular device therapy has seen a significant breakthrough in the form of paclitaxel-coated devices (PCDs), which significantly reduce rates of restenosis relative to non-PCDs, a finding which has been demonstrated in numerous randomized clinical trials. After their introduction to the market in 2012 (paclitaxel-eluting stents) and 2014 (paclitaxel-coated balloons) their use surged as they replaced non-PCDs and were designated the first-line endovascular therapy by society guidelines. This trend was abruptly reversed, however, after a meta-analysis of summary-level data was published in December of 2018 that reported an elevated mortality associated with PCDs compared with non-PCDs 2-5 years after treatment. This meta-analysis has been criticized for considerable methodological flaws. The Food and Drug Administration conducted a review and concluded that insufficient data existed to make a definitive statement regarding the safety of PCDs. They called for restriction of the use of PCDs to the highest-risk patient populations. At the same time, the FDA deemed pursuing new RCTs to better evaluate PCDs unfeasible due to the high numbers of patients and long follow-up time that would be required. In this setting, real-world data emerged as a powerful source of information for the evaluation of PCDs. Real-world data offers advantages over randomized-controlled trials including expeditious access to and analysis of data and the availability of large numbers of patients. Several retrospective observational studies demonstrate no difference in long-term all-cause mortality in patients treated with PCDs relative to those treated with non-PCDs. This paclitaxel controversy has illustrated the critical role that real-world data is assuming in long-term safety monitoring of medical devices.

Treatment of Femoropopliteal Lesions With the BioMimics 3D Vascular Stent System: Two-Year Results From the MIMICS-2 Trial

PURPOSE

To report the safety and effectiveness outcomes through 2 years of the BioMimics 3D Vascular Stent System in the treatment of symptomatic patients with atherosclerotic femoropopliteal disease.

MATERIALS AND METHODS

The tubular, nitinol BioMimics 3D stent, which was designed to impart a helical shape to the arterial segment, was implanted in 271 patients (mean age 68.4±9.5 years; 180 men) with de novo femoropopliteal lesions enrolled at 43 investigational sites [31 US (n=162), 6 German (n=78), and 6 Japanese (n=31)] in the prospective, single-arm MIMICS-2 investigational device exemption trial (ClinicalTrials.gov identifier NCT02400905) between June 2015 and October 2016. Mean lesion length was 81.2±38.4 mm, 30.0% of patients had total occlusions, and 45.9% had moderate to severe calcification. Primary safety and effectiveness endpoints were compared at 1 year with prespecified objective performance goals (OPGs) set by the VIVA Physicians organization. Outcomes through 2 years are reported.

RESULTS

The primary effectiveness endpoint of 12-month primary stent patency was met by 182 of 249 patients (73.1%, 95% CI 67.3% to 78.2%), exceeding the OPG of 66%. The primary safety endpoint of 30-day freedom from major adverse events (MAEs) was met in 268 of 269 patients (99.6%, 95% CI 97.7% to 100%), exceeding the OPG of 88%. Kaplan-Meier estimates of freedom from loss of primary patency were 83.1% at 12 months and 70.2% at 24 months, freedom from MAEs estimates were 86.9% at 12 months and 79.2% at 24 months, and freedom from clinically-driven target lesion revascularization estimates were 88.0% at 12 months and 83.0% at 24 months. At 24 months, 88.2% of patients showed improvement of ≥1 Rutherford category; the ankle-brachial index was >0.9 for 64.4% vs 11.3% at baseline. There were no cases of stent fracture.

CONCLUSION

Through 24 months, the BioMimics 3D Vascular Stent System provided safe and effective treatment for femoropopliteal lesions in patients with symptomatic peripheral artery disease.

Recent Update on Peripheral Arterial Endovascular Therapy for Peripheral Arterial Occlusive Disease

Endovascular treatment is effective for symptomatic peripheral arterial disease (PAD). Following recent device improvements, favorable long-term outcomes have been achieved in iliac arteries as well as small arteries such as the femoral and popliteal arteries. This paper outlines the history and recent advances in endovascular treatment of peripheral vascular diseases as well as the characteristics and usage of devices. The history and the advances in endovascular treatment of peripheral vascular disease have been parallel, with the development of devices such as catheters and stents. Accordingly, endovascular treatment is now recommended in guidelines as the first-line for PAD.

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.

Flexible and Expandable Robot for Tissue Therapies - Modeling and Design

OBJECTIVE

Implantable technologies should be mechanically compliant with the tissue in order to maximize tissue quality and reduce inflammation during tissue reconstruction. We introduce the development of a flexible and expandable implantable robotic (FEIR) device for the regenerative elongation of tubular tissue by applying controlled and precise tension to the target tissue while minimizing the forces produced on the surrounding tissue.

METHODS

We introduce a theoretical framework based on iterative beam theory static analysis for the design of an expandable robot with a flexible rack. The model takes into account the geometry and mechanics of the rack to determine a trade-off between its stiffness and capability to deliver the required tissue tension force. We empirically validate this theory on the benchtop and with biological tissue.

RESULTS

We show that FEIR can apply the required therapeutical forces on the tissue while reducing the amount of force it applies to the surrounding tissues as well as reducing self-damage.

CONCLUSION

The study demonstrates a method to develop robots that can change size and shape to fit their dynamic environment while maintaining the precision and delicacy necessary to manipulate tissue by traction.

SIGNIFICANCE

The method is relevant to designers of implantable technologies. The robot is a precursor medical device for the treatment of Long-Gap Esophageal Atresia and Short Bowel Syndrome.

Paclitaxel-Coated Balloon vs Uncoated Balloon Angioplasty for Treatment of In-Stent Restenosis in the Superficial Femoral and Popliteal Arteries: The COPA CABANA Trial

Purpose: To investigate the efficacy and sustainability of drug-coated balloon (DCB) treatment of femoropopliteal in-stent restenosis (ISR). Materials and Methods: An investigator-initiated, prospective, multicenter, 1:1 randomized study enrolled 88 patients for treatment of ISR with DCB (n=47; mean age 68.3±9.6 years; 26 men) or uncoated balloon (n=41; mean age 67.6±10.2 years; 26 men) angioplasty ( ClinicalTrials.gov identifier NCT01594684). Additionally, the protocol provided for an observational arm composed of patients from either randomized arm who experienced recurrent ISR ≥30 days after the index treatment. Redo treatment consisted of 2 DCBs sequentially inflated at the same location (double dose therapy). The majority of patients (66, 78%) had Rutherford category 3 ischemia. The mean lesion length was 140 mm; a third (27, 31%) were total occlusions. The primary endpoint was angiographic late lumen loss (LLL) at 6 months evaluated by an independent core laboratory. Results: Twenty-two patients (7 DCB +15 uncoated) were treated for recurrence with fully overlapping double DCB angioplasty. Six-month LLL was lower after DCB (0.34±1.12 mm) treatment than after angioplasty with an uncoated balloon (1.58±1.10 mm, p<0.001). At the 12-month follow-up, target lesion revascularization (TLR) was performed in 18 (49%) of 37 patients in the uncoated group, 6 (14%) of 43 patients in the single-dose DCB group (p=0.001), and no patients from the recurrent ISR group. At ~2 years after treatment, a remarkable number (14/27, 52%) of TLRs were recorded in the single-dose DCB group. Conclusion: Treatment with DCBs resulted in significantly less 6-month LLL and fewer TLRs up to 24 months than treatment with uncoated balloons. The double dose for treating recurrent ISR did not cause recognizable adverse events or require TLR up to 24 months.

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.

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.

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.

Validating Fatigue Safety Factor Calculation Methods for Cardiovascular Stents

Evaluating risk of fatigue fractures in cardiovascular implants via nonclinical testing is essential to provide an indication of their durability. This is generally accomplished by experimental accelerated durability testing and often complemented with computational simulations to calculate fatigue safety factors (FSFs). While many methods exist to calculate FSFs, none have been validated against experimental data. The current study presents three methods for calculating FSFs and compares them to experimental fracture outcomes under axial fatigue loading, using cobalt-chromium test specimens designed to represent cardiovascular stents. FSFs were generated by calculating mean and alternating stresses using a simple scalar method, a tensor method which determines principal values based on averages and differences of the stress tensors, and a modified tensor method which accounts for stress rotations. The results indicate that the tensor method and the modified tensor method consistently predicted fracture or survival to 107 cycles for specimens subjected to experimental axial fatigue. In contrast, for one axial deformation condition, the scalar method incorrectly predicted survival even though fractures were observed in experiments. These results demonstrate limitations of the scalar method and potential inaccuracies. A separate computational analysis of torsional fatigue was also completed to illustrate differences between the tensor method and the modified tensor method. Because of its ability to account for changes in principal directions across the fatigue cycle, the modified tensor method offers a general computational method that can be applied for improved predictions for fatigue safety regardless of loading conditions.

Long-term clinical and quality of life outcomes after stenting of femoropopliteal artery stenosis: 3-year results from the STROLL study

OBJECTIVES

To evaluate the clinical and health status outcomes of patients undergoing superficial femoral artery (SFA) revascularization using the Shape Memory Alloy Recoverable Technology (S.M.A.R.T.®) nitinol self-expanding stent through 3 years of follow-up.

BACKGROUND

Limited long-term data are available describing the durability of benefits after femoropopliteal revascularization.

METHODS

In a multicenter, prospective, core-lab adjudicated study, 250 subjects with de novo or restenotic femoropopliteal arterial lesions were treated with the S.M.A.R.T.® stent. The primary endpoint of target vessel patency, a composite of ultrasound-assessed patency and freedom from clinically driven target lesion revascularization (TLR), was evaluated through 3 years. Secondary endpoints included stent fracture and health status. Health status was measured using generic and disease-specific instruments, including the Peripheral Artery Questionnaire (PAQ).

RESULTS

At 3-year follow-up, Kaplan-Meier estimated target vessel patency was 72.7%, freedom from clinically driven TLR was 78.5%, and the incidence of stent fracture was 3.6%. The PAQ summary score was markedly impaired at baseline (mean 37.3 ± 19.6 points) and improved substantially at 1 month (mean change from baseline of 31.4 points, 95% CI: 28.5-34.3; P < 0.001). Disease-specific health status benefits assessed by the PAQ were largely preserved through 3 years of follow-up (mean change from baseline, 28.0 points, 95% CI: 24.3-31.7; P < 0.0001).

CONCLUSIONS

In patients undergoing revascularization for moderately complex SFA disease, use of the self-expanding S.M.A.R.T® stent was associated with a high rate of target vessel patency through 3 years and led to substantial and sustained health status benefits.

Nitinol Stents in the Femoropopliteal Artery: A Mechanical Perspective on Material, Design, and Performance

Endovascular stenting has matured into a commonly used treatment for peripheral arterial disease (PAD) due to its minimally invasive nature and associated reductions in short-term morbidity and mortality. The mechanical properties of the superelastic Nitinol alloy have played a major role in the explosion of peripheral artery stenting, with modern stents demonstrating reasonable resilience and durability. Yet in the superficial femoral and popliteal arteries, even the newest generation Nitinol stents continue to demonstrate clinical outcomes that leave significant room for improvement. Restenosis and progression of native arterial disease often lead to recurrence of symptoms and reinterventions that increase morbidity and health care expenditures. One of the main factors thought to be associated with stent failure in the femoropopliteal artery (FPA) is the unique and highly dynamic mechanical environment of the lower limb. Clinical and experimental data demonstrate that the FPA undergoes significant deformations with limb flexion. It is hypothesized that the inability of many existing stent designs to conform to these deformations likely plays a role in reconstruction failure, as repetitive movements of the leg and thigh combine with mechanical mismatch between the artery and the stent and result in mechanical damage to both the artery and the stent. In this review we will identify challenges and provide a mechanical perspective of FPA stenting, and then discuss current research directions with promise to provide a better understanding of Nitinol, specific features of stent design, and improved characterization of the biomechanical environment of the FPA to facilitate development of better stents for patients with PAD.

Novel Nitinol Stent for Lesions up to 24 cm in the Superficial Femoral and Proximal Popliteal Arteries: 24-Month Results From the TIGRIS Randomized Trial

PURPOSE

To evaluate the safety and effectiveness of the TIGRIS stent for lesions up to 24 cm in the superficial femoral and proximal popliteal arteries (SFA/PPA).

METHODS

This prospective, multicenter, randomized study enrolled 274 subjects at 36 sites in the United States and Europe. Subjects were randomly assigned in a 3:1 ratio to treatment with the TIGRIS stent (n=197; mean age 66.7±9.28 years; 141 men) or LifeStent (n=70; mean age 67.9±8.87 years; 49 men). The primary safety endpoint was 30-day freedom from major adverse events (MAE). The primary efficacy endpoint was primary patency at 12 months. Secondary endpoints included target lesion revascularization (TLR) and stent fracture. Clinical success and quality of life were also assessed.

RESULTS

Mean lesion length (107.6 vs 117.9 mm, p=0.29), procedure success (99.5% vs 97.1%, p=0.17), and freedom from MAE (99.5% vs 100%, p>0.99) were similar for the TIGRIS and control groups, respectively. Likewise, there was no difference in primary patency at 12 months (60.6% vs 63.2%, p=0.73) or 24 months (56.3% vs 50.2%, p=0.60) or in TLR at the same time points (76.6% vs 80.6%, p=0.49; 70.5% vs 67.2%, p=0.85). There were no differences in the changes in Rutherford category or the ankle/brachial index through 24 months. The rate of stent fracture was lower for TIGRIS compared with LifeStent (0% vs 32.7%, p<0.001).

CONCLUSION

The TIGRIS stent and LifeStent were similarly effective for the treatment of lesions in the SFA and PPA. The high flexibility and zero fracture rate associated with the TIGRIS stent make this device favorable for use in high-flexion arteries.

1-Year Results of Paclitaxel-Coated Balloons for Long Femoropopliteal Artery Disease: Evidence From the SFA-Long Study

OBJECTIVES

The aim of this study was to appraise 1-year outcomes after percutaneous treatment of long femoropopliteal artery disease using paclitaxel-coated balloons.

BACKGROUND

Percutaneous transluminal angioplasty with paclitaxel-coated balloons for TransAtlantic Inter-Society Consensus types A and B femoropopliteal artery disease has provided favorable results.

METHODS

Consecutive patients with Rutherford class 2 to 4 disease due to femoropopliteal lesions >15 cm long and with 4- to 7-mm reference vessel diameter were prospectively enrolled in a multicenter study. The primary study endpoint was primary patency at 12 months. Secondary endpoints included major adverse events (the composite of death, major target limb amputation, thrombosis at the target lesion site, or clinically driven non-target lesion target vessel revascularization), changes in Rutherford class, ankle-brachial index, and quality of life up to 24 months post-procedure.

RESULTS

A total of 105 patients (mean age 68 ± 9 years, 81.9% men) treated with paclitaxel-coated balloons and provisional stenting were enrolled, and final procedural success was obtained in all. The mean treated lesion length was 251 ± 71 mm, including 63.4% moderate to severely calcified lesions and 49.5% total occlusions. The bailout stent rate was 10.9%. Follow-up after 12 months was obtained in 101 patients (96.2%), showing that primary patency was maintained in 84 (83.2%), and major adverse events had occurred in 7 (6.2%), with persistently significant clinical benefits in Rutherford class.

CONCLUSIONS

Paclitaxel-coated balloons are associated with favorable functional and clinical outcomes at 1 year in patients with long femoropopliteal artery disease requiring percutaneous revascularization. (Drug Eluting Balloon [DEB] and Long Lesions of Superficial Femoral Artery [SFA] Ischemic Vascular Disease [DEB-SFA-LONG]; NCT01658540).

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.

2-Year Results of Paclitaxel-Coated Balloons for Long Femoropopliteal Artery Disease: Evidence From the SFA-Long Study

OBJECTIVES

The aim of this study was to appraise 2-year outcomes after percutaneous transluminal angioplasty of long femoropopliteal artery disease using paclitaxel-coated balloons (PCBs).

BACKGROUND

Percutaneous transluminal angioplasty with PCBs for TransAtlantic Inter-Society Consensus types C and D femoropopliteal artery disease has provided favorable results ≤12 months but no prospective studies performed longer term follow-up assessment.

METHODS

Consecutive patients with Rutherford class 2 to 4 disease due to femoropopliteal lesions >15 cm long were prospectively enrolled in a multicenter study. The primary study endpoint was primary patency (i.e., freedom from the combined endpoint of clinically driven target lesion revascularization and >50% restenosis in the treated lesion as appraised by a duplex ultrasound peak systolic velocity ratio of >2.4) at 24 months. Secondary endpoints included major adverse events (the composite of death, target limb amputation, thrombosis at the target lesion, or clinically driven nontarget lesion revascularization), changes in Rutherford class, and quality of life ≤24 months post-procedure.

RESULTS

A total of 105 patients (age 68 ± 9 years; 81.9% men) successfully treated with PCBs were included (treated lesion length was 251 ± 71 mm; 49.5% total occlusions). The 24-month follow-up data were available in 98 patients; they showed a primary patency rate of 70.4%, with major adverse events occurred in 10 patients (10.2%, 5 non-procedure-related deaths) and persistently significant clinical benefits in Rutherford class (51% of asymptomatic patients at 24 months).

CONCLUSIONS

PCBs benefits on primary patency and target vessel revascularization satisfactorily extend over 24 months in patients undergoing percutaneous transluminal angioplasty for symptomatic femoropopliteal disease.

Angiographic classification of patterns of restenosis following femoropopliteal artery intervention: A proposed scoring system

OBJECTIVES

To propose a classification system for characterizing angiographic femoropopliteal artery restenosis patterns associated with common endovascular modalities.

BACKGROUND

Peripheral artery disease is a worldwide issue affecting millions of people. Despite a myriad of endovascular technologies available to treat peripheral artery disease of the femoropopliteal arteries, restenosis remains a common failure mode. Characterizing common patterns of restenosis is important to discern the potential impact of baseline patient, lesion, and procedural characteristics, as well as treatment modalities on either the primary success or the failure patterns associated with restenosis.

METHODS

Studies included in the analysis were from previous core laboratory-adjudicated femoropopliteal artery disease trials and registries reflecting a wide array of treatment modalities.

RESULTS

From the subjects enrolled and analyzed, there were 403 total angiograms for analysis and adjudication. Target lesion revascularization images of the 32 validation cases were evaluated for index treated length, diameter stenosis, and lesion morphology characteristics. The following lesion types are proposed: Type 1 "Focal" pattern, which may be "Edge Proximal" or "Edge Distal" depending on location; a Type 2 "Multifocal" pattern which may also exhibit edge restenosis, but may also be "Edge Bilateral"; a Type 3 "Moderate" pattern and a Type 4 "Diffuse" pattern; and finally, a Type 5 "Occlusion".

CONCLUSIONS

A classification system that enables healthcare professionals to anticipate and describe failures following the index procedure, thereby impacting the choice of options for retreatment, may facilitate consistency and standardization within the heterogeneous field of endovascular device treatments for the femoropopliteal artery.

Diagnosis, classification, and treatment of femoropopliteal artery in-stent restenosis

In-stent restenosis is a pervasive challenge to the durability of stenting for the treatment of lower extremity ischemia. There is considerable controversy about the criteria for diagnosis, indications for treatment, and preferred algorithm for addressing in-stent restenosis. This evidence summary seeks to review existing information on strategies for the treatment of this difficult problem.

Stent placement in the superficial femoral and proximal popliteal arteries with the innova self-expanding bare metal stent system

OBJECTIVES

The SuperNOVA trial was designed to evaluate performance of the Innova Vascular Self-Expanding Stent System (Boston Scientific, Marlborough, MA) for treating lesions in the femoropopliteal arteries.

METHODS

Patients with chronic lower limb peripheral artery disease (Rutherford category 2, 3, or 4) and atherosclerotic lesions in the native superficial femoral and/or proximal popliteal artery (lengths 30-190 mm) were enrolled in this single-arm, multinational study. Major adverse events (MAEs) were defined as all-cause death through 1 month, target limb major amputation, and target lesion revascularization (TLR). Vessel primary patency was defined as core laboratory-adjudicated duplex ultrasonography-derived peak systolic velocity ratio ≤2.4 in the absence of TLR, surgical bypass of the target lesion, or major amputation of the target limb. Primary safety and efficacy endpoints were evaluated at 12 months, with follow-up through 24 months also reported.

RESULTS

SuperNOVA patients (N = 299; mean age 67.4 ± 9.7 years, 74% men, 41% with diabetes) had a mean lesion length of 93.2 mm. The MAE-free rate was 99.7% at 30 days, 85.8% at 12 months, and 77% at 24 months. Kaplan-Meier estimates of primary patency and TLR-free rates were 68.7% and 78.0%, respectively, at 24 months. Clinical improvements were sustained through 2 years, with 80% of patients displaying no or minimal symptoms (Rutherford category 0-1) at 24 months.

CONCLUSIONS

In the SuperNOVA study, the Innova Stent System demonstrated an excellent safety profile and acceptable clinical outcomes despite the challenging anatomical characteristics of the lesions. © 2017 Wiley Periodicals, Inc.

Targeting oxidative stress for the treatment of ischemic stroke: Upstream and downstream therapeutic strategies

Excessive oxygen and its chemical derivatives, namely reactive oxygen species (ROS), produce oxidative stress that has been known to lead to cell injury in ischemic stroke. ROS can damage macromolecules such as proteins and lipids and leads to cell autophagy, apoptosis, and necrosis to the cells. This review describes studies on the generation of ROS, its role in the pathogenesis of ischemic stroke, and recent development in therapeutic strategies in reducing oxidative stress after ischemic stroke.

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.