Current approach to the diagnosis and treatment of femoral-popliteal arterial disease. A systematic review

High- Versus Low-Dose Paclitaxel-Coated Balloons for Femoropopliteal Disease: A systematic review and meta-analysis

To evaluate the comparative effectiveness of high- and low doses of paclitaxel in endovascular revascularization procedures for patients with femoropopliteal disease. The databases (Embase, PubMed, Scopus, and Web of Science) were searched for studies that had compared outcomes of high-dose and low-dose paclitaxel-coated balloons (PCBs) in the treatment of patients with femoropopliteal disease. Randomized controlled trials and nonrandomized comparative studies (eg, cohort studies and case-control studies) were eligible for inclusion. The primary outcomes of interest were patency rates, risk of restenosis, and clinically-driven target lesion revascularization (CD-TLR). Pooled effect sizes were reported as relative risk (RR) with 95% confidence intervals (CI). The analysis included 7 studies. High-dose PCB use was associated with higher patency (RR, 1.10; 95% CI, 1.00-1.21), reduced risk of restenosis (RR, 0.60; 95% CI, 0.46-0.79), and reduced need for CT-TLR (RR, 0.57; 95% CI, 0.41-0.79) compared to low-dose PCB. Rates of limb salvage (RR, 1.01; 95% CI, 0.99-1.04), freedom from major adverse limb events (RR, 1.39; 95% CI, 0.79-2.42), and overall survival (RR, 1.02; 95% CI, 0.99-1.05) were comparable in the 2 groups. There was no evidence of publication bias. High-dose PCB correlates with superior outcomes in patients with femoropopliteal disease, particularly in terms of better vascular patency, reduced restenosis risk, and lower need for target lesion revascularization, compared to low-dose PCB.

Impact of Tissue Damage and Hemodynamics on Restenosis Following Percutaneous Transluminal Angioplasty: A Patient-Specific Multiscale Model

Multiscale agent-based modeling frameworks have recently emerged as promising mechanobiological models to capture the interplay between biomechanical forces, cellular behavior, and molecular pathways underlying restenosis following percutaneous transluminal angioplasty (PTA). However, their applications are mainly limited to idealized scenarios. Herein, a multiscale agent-based modeling framework for investigating restenosis following PTA in a patient-specific superficial femoral artery (SFA) is proposed. The framework replicates the 2-month arterial wall remodeling in response to the PTA-induced injury and altered hemodynamics, by combining three modules: (i) the PTA module, consisting in a finite element structural mechanics simulation of PTA, featuring anisotropic hyperelastic material models coupled with a damage formulation for fibrous soft tissue and the element deletion strategy, providing the arterial wall damage and post-intervention configuration, (ii) the hemodynamics module, quantifying the post-intervention hemodynamics through computational fluid dynamics simulations, and (iii) the tissue remodeling module, based on an agent-based model of cellular dynamics. Two scenarios were explored, considering balloon expansion diameters of 5.2 and 6.2 mm. The framework captured PTA-induced arterial tissue lacerations and the post-PTA arterial wall remodeling. This remodeling process involved rapid cellular migration to the PTA-damaged regions, exacerbated cell proliferation and extracellular matrix production, resulting in lumen area reduction up to 1-month follow-up. After this initial reduction, the growth stabilized, due to the resolution of the inflammatory state and changes in hemodynamics. The similarity of the obtained results to clinical observations in treated SFAs suggests the potential of the framework for capturing patient-specific mechanobiological events occurring after PTA intervention.

Effectiveness of intra-arterial manometry in guiding femoral popliteal stent implantation: a prospective randomized controlled trial

BACKGROUND

Femoropopliteal artery occlusion is a prevalent peripheral arterial disease, and endovascular therapy has become the preferred treatment. Accurate assessment of balloon dilation efficacy is crucial for determining the necessity for subsequent stent implantation. This study aims to investigate the use of interlesion arterial pressure gradients as a novel approach to assess balloon dilation efficacy and guide stent implantation decisions.

METHODS

A prospective, randomized, controlled trial was conducted on 100 patients with femoropopliteal artery occlusion. Patients were randomized into a control group (n=50) and an experimental group (n=50). Stent implantation was performed in the control group according to standard indications, while the experimental group underwent stent implantation only if the mean arterial pressure gradient exceeded 10 mmHg or fractional flow reserve (FFR) fell below 0.85. Post-intervention, pressure measurements and angiography were used to evaluate residual stenosis, dissection, and pressure gradients.

RESULTS

Lesions were categorized into stent-indicated and non-indicated groups. In the non-stent-indicated lesions, the experimental group demonstrated significantly higher patency rates for lesions with pFFR < 0.85 or ΔP > 10 mmHg compared to the control group (92.9% vs. 50.0%, P=0.039). There was no significant difference in patency rates between the experimental and control groups for stent-indicated lesions.

CONCLUSION

Combining pressure measurement with angiography provides a more precise evaluation of balloon dilation efficacy and stent implantation indicators in femoropopliteal artery occlusive disease. Further research is needed to establish optimal pressure threshold values and refine treatment guidelines.

Comparative effectiveness of endovascular treatment modalities for de novo femoropopliteal lesions at long-term follow-up: A network meta-analysis of randomized controlled trials

PURPOSE

To evaluate the best endovascular treatment for de novo femoropopliteal lesions at long-term follow-up through network meta-analysis of randomized controlled trials.

METHODS

Medical databases were searched on September 17, 2023. 17 trials and 7 treatments were selected. Outcomes were primary patency, target lesion revascularization (TLR), major amputation and all-cause mortality at 3 and/or 5 years.

RESULTS

Regarding 3-year primary patency, drug-eluting stents (DES) was the best and better than balloon angioplasty (BA; odds ratio [OR], 4.96; 95% confidence interval [CI], 2.68-9.18), bare metal stents (BMS; OR, 2.81; 95% CI, 1.45-5.46), cryoplasty (OR, 6.75; 95% CI, 2.76-16.50), covered stents (CS; OR, 3.25; 95% CI, 1.19-8.87) and drug-coated balloons (DCB; OR, 2.04; 95% CI, 1.14-3.63). Regarding 5-year primary patency, DES was the best and better than BMS (OR, 2.34; 95% CI, 1.10-4.99). Regarding 3-year TLR, DES was the best and better than BA (OR, 0.24; 95% CI, 0.13-0.44). Regarding 5-year TLR, DES was the best and better than BA (OR, 0.20; 95% CI, 0.09-0.42) and balloon angioplasty with brachytherapy (OR, 0.21; 95% CI, 0.06-0.74). Regarding 3- and 5-year major amputation, DCB was the best. Regarding 3-year mortality, DES was the best and better than CS (OR, 0.09; 95% CI, 0.01-0.67).

CONCLUSIONS

DES was the best treatment regarding 3-year primary patency, TLR and mortality, and DCB was the best regarding major amputation. DES was the best treatment regarding 5-year TLR, and DCB was the best regarding primary patency and major amputation. DES and DCB should be given priority in treating femoropopliteal lesions.

Femoro-popliteal endovascular interventions

Peripheral artery disease (PAD) is a worldwide major health challenge, and it is a strong predictor of mortality and morbidity. The advances in PAD treatment have resulted in many therapeutic options or endovascular interventions (EVIs) for endovascular revascularization if drug therapy does not lead to substantial improvement. Randomized controlled trials (RCTs) have reported the efficacy of various EVIs such as atherectomy, stents, and medicated balloons over the traditional transluminal angioplasty; however, the standard treatment for PAD remains unclear due to the lack of head-to-head comparative studies between different EVIs. Additionally, the variable outcomes between clinical trials regarding the functional capacity and quality of life (QoL) make it difficult to ascertain the superiority of one particular EVI over another. Therefore, the latest PAD clinical trials should include head-to-head comparisons between different EVIs, and this review aimed to highlight the femoro-popliteal EVIs, evidence supporting each intervention and why those EVIs are used.

Efficacy and Safety of Atherectomy Combined With Balloon Angioplasty vs Balloon Angioplasty Alone in Patients With Femoro-Popliteal Lesions: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Balloon angioplasty (BA), including drug-coated balloons (DCBs) and percutaneous transluminal angioplasty (PTA), has traditionally been used to treat femoral-popliteal lesions. However, in recent years, atherectomy (ATH) has been proposed as a complementary approach. To assess the effectiveness of ATH compared with BA alone in patients with femoral-popliteal artery lesions, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

We included RCTs that focused on patients with femoral-popliteal artery lesions and reported data on the use of ATH and BA therapy. Two reviewers conducted a literature search, refined the data, and assessed the risk of bias.

RESULTS

We included a total of 6 RCTs involving 399 patients with femoral-popliteal artery lesions. The use of ATH in combination with BA appeared to improve the patency rate at 12 months (odds ratio [OR]=2.04, 95% confidence interval [CI]=1.14-3.62). In addition, ATH with BA was associated with lower major amputation rates (MD=2.01, 95% CI=0.06-0.77, p=0.02) and a decreased likelihood of bailout stenting (OR=0.07, 95% CI=0.02-0.25, p=0.001). However, there were no statistically significant differences between the groups in terms of target lesion revascularization (TLR) at 12 months, major adverse cardiovascular events (MACEs), and distal embolization events. In addition, we performed subgroup analysis for different ATH devices and BA types.

CONCLUSIONS

Based on this meta-analysis, it can be concluded that the use of ATH in combination with BA is a safe and effective method for treating femoral-popliteal artery lesions. In addition, the patency rate at 1 year is superior to treatment with BA alone. Atherectomy also reduces the likelihood of amputation and bailout stenting. Clinicians should consider these findings when designing future RCTs and developing clinical practice guidelines.

CLINICAL IMPACT

This meta-analysis summarises a number of existing studies to advance understanding of the atherectomy devices and to reveal its potential. This new technique, when compared with drug coated balloon, shows the possibility of obtaining better clinical outcomes in femoro-popliteal lesions than drug-coated balloon alone, such as higher 12-month primary patency rates as shown in some studies. Currently, it is important to consider the appropriate technology applicable for individualised treatment. atherectomy devices seem to provide clinicians with additional options in clinical practice and to benefit patients in the future. This requires more high quality studies to explore the role and benefits of atherectomy devices in femoro-popliteal lesions.

Fluid-structure interactions of peripheral arteries using a coupled in silico and in vitro approach

Vascular compliance is considered both a cause and a consequence of cardiovascular disease and a significant factor in the mid- and long-term patency of vascular grafts. However, the biomechanical effects of localised changes in compliance cannot be satisfactorily studied with the available medical imaging technologies or surgical simulation materials. To address this unmet need, we developed a coupled silico-vitro platform which allows for the validation of numerical fluid-structure interaction results as a numerical model and physical prototype. This numerical one-way and two-way fluid-structure interaction study is based on a three-dimensional computer model of an idealised femoral artery which is validated against patient measurements derived from the literature. The numerical results are then compared with experimental values collected from compliant arterial phantoms via direct pressurisation and ring tensile testing. Phantoms within a compliance range of 1.4-68.0%/100 mmHg were fabricated via additive manufacturing and silicone casting, then mechanically characterised via ring tensile testing and optical analysis under direct pressurisation with moderately statistically significant differences in measured compliance ranging between 10 and 20% for the two methods. One-way fluid-structure interaction coupling underestimated arterial wall compliance by up to 14.7% compared with two-way coupled models. Overall, Solaris™ (Smooth-On) matched the compliance range of the numerical and in vivo patient models most closely out of the tested silicone materials. Our approach is promising for vascular applications where mechanical compliance is especially important, such as the study of diseases which commonly affect arterial wall stiffness, such as atherosclerosis, and the model-based design, surgical training, and optimisation of vascular prostheses.

Predicting 1-year in-stent restenosis in superficial femoral arteries through multiscale computational modelling

In-stent restenosis in superficial femoral arteries (SFAs) is a complex, multi-factorial and multiscale vascular adaptation process whose thorough understanding is still lacking. Multiscale computational agent-based modelling has recently emerged as a promising approach to decipher mechanobiological mechanisms driving the arterial response to the endovascular intervention. However, the long-term arterial response has never been investigated with this approach, although being of fundamental relevance. In this context, this study investigates the 1-year post-operative arterial wall remodelling in three patient-specific stented SFA lesions through a fully coupled multiscale agent-based modelling framework. The framework integrates the effects of local haemodynamics and monocyte gene expression data on cellular dynamics through a bi-directional coupling of computational fluid dynamics simulations with an agent-based model of cellular activities. The framework was calibrated on the follow-up data at 1 month and 6 months of one stented SFA lesion and then applied to the other two lesions. The calibrated framework successfully captured (i) the high lumen area reduction occurring within the first post-operative month and (ii) the stabilization of the median lumen area from 1-month to 1-year follow-ups in all the stented lesions, demonstrating the potentialities of the proposed approach for investigating patient-specific short- and long-term responses to endovascular interventions.

The Predictive Role of NLR and PLR in Outcome and Patency of Lower Limb Revascularization in Patients with Femoropopliteal Disease

BACKGROUND

Peripheral arterial disease (PAD) changes the arterial structure and function, and is the most common manifestation of the atherosclerotic process, except for the coronary and cerebral arterial systems. Inflammation is well known to have a role in the progression of atherosclerosis and, by extension, in PAD. Among the recently studied markers in the literature, we list the neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR). This study aims to analyze the preoperative role of NLR and PLR in the medium-term outcome of patients surgically revascularized for femoropopliteal disease.

METHODS

A retrospective study included patients admitted to the Vascular Surgery Clinic of the County Emergency Clinical Hospital of Târgu-Mureș, Romania, between January 2017 and December 2019, diagnosed with femoropopliteal disease and having presented an indication for surgical revascularization. The patients included in the study were classified according to the 12 months primary patency in two groups: "patency" and "nonpatency".

RESULTS

Depending on the Rutherford classification (RC), there was a higher incidence of stages II and III in the patency group and a higher incidence of stage V in the nonpatency group. Depending on the optimal cut-off value according to ROC for the 12 months primary patency, obtained from Youden's index (3.95 for NLR (82.6% sensitivity and 89.9% specificity), and 142.13 for PLR (79.1% sensitivity and 82.6% specificity)), in all high-NLR and high-PLR groups, there was a higher incidence of all adverse outcomes. Moreover, a multivariate analysis showed that a high baseline value for NLR and PLR was an independent predictor of all outcomes for all recruited patients. Furthermore, for all hospitalized patients, RC 5 was an independent predictor of poor prognosis.

CONCLUSIONS

Our findings establish that a high value of preoperative NLR and PLR determined at hospital admission is strongly predictive of primary patency failure (12 months after revascularization). Additionally, elevated ratio values are an independent predictor for a higher amputation rate and death for all patients enrolled in the study, except for mortality in RC 2, and both amputation and mortality in RC 5.

Treatment of atherosclerotic femoropopliteal artery disease with Supera interwoven nitinol stent: a real-world study in China

OBJECTIVES

To analyze the outcomes of Supera stent deployment in Chinese patients with atherosclerotic femoropopliteal artery (FPA) disease in a real-world setting.

METHODS

This retrospective cohort study collected and analyzed the medical records of 246 consecutive patients who received Supera stents for FPA disease at the China Academy of Chinese Medical Sciences Xiyuan Hospital between February 2017 and December 2019. All study patients underwent balloon angioplasty and were treated with Supera stents (Abbott Vascular, Santa Clara, CA, USA). The primary outcome was the rate of primary patency 12 months after discharge.

RESULTS

The analyses included 246 consecutive patients and 260 lesions. The mean ± SD age was 73.2±9.9 years and most patients (60.2%) were male. Of the 260 treated lesions, Supera stents were deployed in eight (3.1%) cases after previous stent fracture. Critical limb ischemia was diagnosed in 87.3% of the limbs, and 84 (32.3%) and 83 (31.5%) cases were classified as TransAtlantic Inter-Society Consensus (TASC) C and D, respectively. The majority of the lesions was in situ (80.8%) and located in the superficial femoral artery (45.0%) or the femoropopliteal artery (45.8%). The mean lesion length was 147.7 mm. Nominal deployment (-10% to 10% compression) was the most common deployment scenario (84.1%). The 1-year primary patency rate was 80.6%. Lesions that occurred as restenosis (OR = 3.34, 95% CI: 1.03-10.85, P = 0.045) or in-stent restenosis (OR = 2.88, 95% CI: 1.03-8.07, P = 0.045) were independently associated with occlusion or stenosis after stent deployment. No stent fracture was observed in the study.

CONCLUSIONS

Our study indicates that the use of Supera stents is feasible for treatment of Chinese patients with FPA disease. The long-term results reveal high primary patency.

A predictive multiscale model of in-stent restenosis in femoral arteries: linking haemodynamics and gene expression with an agent-based model of cellular dynamics

In-stent restenosis (ISR) is a maladaptive inflammatory-driven response of femoral arteries to percutaneous transluminal angioplasty and stent deployment, leading to lumen re-narrowing as consequence of excessive cellular proliferative and synthetic activities. A thorough understanding of the underlying mechanobiological factors contributing to ISR is still lacking. Computational multiscale models integrating both continuous- and agent-based approaches have been identified as promising tools to capture key aspects of the complex network of events encompassing molecular, cellular and tissue response to the intervention. In this regard, this work presents a multiscale framework integrating the effects of local haemodynamics and monocyte gene expression data on cellular dynamics to simulate ISR mechanobiological processes in a patient-specific model of stented superficial femoral artery. The framework is based on the coupling of computational fluid dynamics simulations (haemodynamics module) with an agent-based model (ABM) of cellular activities (tissue remodelling module). Sensitivity analysis and surrogate modelling combined with genetic algorithm optimization were adopted to explore the model behaviour and calibrate the ABM parameters. The proposed framework successfully described the patient lumen area reduction from baseline to one-month follow-up, demonstrating the potential capabilities of this approach in predicting the short-term arterial response to the endovascular procedure.

Trends in Utilization and Outcomes of Orbital, Laser, and Excisional Atherectomy for Lower Extremity Revascularization

PURPOSE

The aim of this study is to analyze the utilization pattern of atherectomy modalities and compare their outcomes.

MATERIALS AND METHODS

All patients undergoing atherectomy in the 2010-2016 Vascular Quality Initiative Database were identified. Utilization of orbital, laser, or excisional atherectomy was obtained. Characteristics and outcomes of patients treated for isolated femoropopliteal and isolated tibial disease by different modalities were compared.

RESULTS

Atherectomy use increased from 10.3% to 18.3% of all peripheral interventions (n = 122 938). Orbital atherectomy was most commonly used and increased from 59.4% in 2010 to 63.2% of all atherectomies in 2016, while laser atherectomy decreased from 19.2% to 13.1%. Atherectomy was mostly used for treatment of isolated femoropopliteal disease (51.1%), followed by combined femoropopliteal and tibial disease (25.8%) and isolated tibial disease (11.7%). In isolated femoropopliteal revascularization, excisional atherectomy was associated with higher rate of perforation (1.2%) compared with laser (0.4%) and orbital atherectomy (0.5%). The technical success of orbital atherectomy (96.7%) was lower compared with excisional atherectomy (98.7%). Concomitant stenting was significantly higher with laser atherectomy (43.0%) compared with orbital (27.2%) and excisional (26.1%) atherectomy. Nevertheless, there was no difference in 1-year primary patency, reintervention, major amputation, improvement in ambulatory status, or mortality. Multivariable analysis also demonstrated no difference in 1-year primary patency and major ipsilateral amputation among the modalities. In isolated tibial revascularization, there were no differences in perioperative outcomes among the modalities. Excisional atherectomy was associated with the highest 1-year primary patency (88.1%). After adjusting for confounders, excisional atherectomy remained associated with superior 1-year primary patency compared with orbital atherectomy (odds ratio [OR] = 2.59, 95% confidence interval [CI] = [1.18-5.68]), and excisional atherectomy remained associated with a lower rate of 1-year major ipsilateral amputation compared with laser atherectomy (OR = 0.29, 95% CI = [0.09-0.95]).

CONCLUSION

Atherectomy use has increased, driven primarily by orbital atherectomy. Despite significant variation in perioperative outcomes, there were no differences in 1-year outcomes among the different modalities when used for treating isolated femoropopliteal disease. In isolated tibial disease treatment, excisional atherectomy was associated with higher 1-year primary patency compared with orbital atherectomy and decreased major ipsilateral amputation rates compared with laser atherectomy. These differences warrant further investigation into the comparative effectiveness of atherectomy modalities in various vascular beds.

Characteristics of atherosclerosis in femoropopliteal artery and its clinical relevance

Atherosclerosis is a systemic disease with different faces. Despite identical or similar pathogenetic mechanisms, atherosclerotic lesions and their clinical manifestations vary in different parts of the vascular system. Peripheral arterial disease (PAD) represents one of the most frequent clinical manifestations of atherosclerosis with predominant location in the superficial femoral artery (SFA). Morphological characteristics of atherosclerotic plaques in peripheral arteries differ from lesions in the coronary and carotid arteries. Plaques in SFA have more fibrotic components, less lipids and inflammatory cells, which makes them more stable and less prone to rupture. Factors that determine the different structure of plaques in SFA compared to coronary arteries include hemodynamic forces, vasa vasorum and calcification. Low shear stress in SFA in the adductor canal is one of the factors which determines frequent atherosclerotic lesions in this region. Lower lipid content and fewer inflammatory cells explain higher stability of SFA plaques. The specific structure of SFA plaques may require preventive and therapeutic measures, which to some extent differ from prevention of coronary atherosclerosis and may include inhibition of fibrotic proliferation in SFA plaques and calcification. Revascularization of PAD differs from procedures used in coronary arteries and requires specific technical expertise and devices.

Prognostic risk factors for loss of patency after femoropopliteal bailout stenting with dual-component stent: results from the TIGRIS Italian Multicenter Registry

PURPOSE

To identify the risk factors associated with patency loss after bailout stenting with third-generation hybrid heparin-bonded nitinol stent of the femoropopliteal segment.

METHODS

Prospective, multicenter, single-arm registry including 156 patients (50 females, mean age 72 ± 11 years) subjected, from February 2017 to December 2018, to provisional stenting with Gore Tigris vascular stent of the distal superficial femoral artery, with or without involvement of the popliteal artery, in 9 different centers. The 194 lesions, with Rutherford score ≥ 3, were stented in case of recoil, dissection or residual stenosis not responding to percutaneous trans-luminal angioplasty (PTA). The follow-up (FU) was performed with clinical evaluation and duplex ultrasound (DUS) at 1, 6 and 12 months.

RESULTS

The primary patency rate was 99(95%CI 98-100)% at 1 month, 86(80-92)% at 6 months and 81(74-88)% at-12 months. After patency loss, 13/23 (56.5%) patients were re-treated, yielding a primary assisted patency of 91(86-96)% at 6 months and 88(82-94)% at 12 months and a secondary patency of 94(90-98)% at 6 months and 90(84-95)% at 12 months. Rutherford score ≥ 4 (p = 0.03) and previous severe treatments (p = 0.01) were identified as risk factors for early patency loss during FU. The involvement of the popliteal artery was not an independent risk factor for loss of patency.

CONCLUSIONS

The bailout stenting of the femoropopliteal segment with third-generation nitinol stents is a safe and effective option in case of recoil, dissection or residual stenosis not responding to PTA. Critical limb ischemia and history of previous major treatment at the same level are significant prognostic factors for patency loss during FU.

Radial Access for Coronary Angiography Carries Fewer Complications Compared with Femoral Access: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND AIM

In patients undergoing diagnostic coronary angiography (CA) and percutaneous coronary interventions (PCI), the benefits associated with radial access compared with the femoral access approach remain controversial. The aim of this meta-analysis was to compare the short-term evidence-based clinical outcome of the two approaches.

METHODS

The PubMed, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov databases were searched for randomized controlled trials (RCTs) comparing radial versus femoral access for CA and PCI. We identified 34 RCTs with 29,352 patients who underwent CA and/or PCI and compared 14,819 patients randomized for radial access with 14,533 who underwent procedures using femoral access. The follow-up period for clinical outcome was 30 days in all studies. Data were pooled by meta-analysis using a fixed-effect or a random-effect model, as appropriate. Risk ratios (RRs) were used for efficacy and safety outcomes.

RESULTS

Compared with femoral access, the radial access was associated with significantly lower risk for all-cause mortality (RR: 0.74; 95% confidence interval (CI): 0.61 to 0.88; p = 0.001), major bleeding (RR: 0.53; 95% CI:0.43 to 0.65; p ˂ 0.00001), major adverse cardiovascular events (MACE)(RR: 0.82; 95% CI: 0.74 to 0.91; p = 0.0002), and major vascular complications (RR: 0.37; 95% CI: 0.29 to 0.48; p ˂ 0.00001). These results were consistent irrespective of the clinical presentation of ACS or STEMI.

CONCLUSIONS

Radial access in patients undergoing CA with or without PCI is associated with lower mortality, MACE, major bleeding and vascular complications, irrespective of clinical presentation, ACS or STEMI, compared with femoral access.

Transradial endovascular intervention: Results from the Radial accEss for nAvigation to your CHosen lesion for Peripheral Vascular Intervention (REACH PVI) study

BACKGROUND/PURPOSE

The transradial approach has been proposed as an alternative to traditional transfemoral access for diagnostic and therapeutic purposes in several catheterization procedures. Historically, extended length devices for lower limb endovascular interventions have been limited. The aim of this study was to investigate the acute clinical outcomes of orbital atherectomy (OA) via transradial access (TRA) for the treatment of lower extremity peripheral artery disease (PAD).

METHODS/MATERIALS

REACH PVI was a multicenter, prospective, observational study (NCT03943160) including subjects with PAD and target lesion morphology appropriate for OA. All patients were followed post-procedure through the first standard of care follow-up visit.

RESULTS

A total of 50 patients were enrolled. In most cases the indication for intervention was disabling claudication (74.0%). Overall, 50 target lesions were treated, 92.0% of lesions were femoropopliteal and 8.0% were infrapopliteal. The average lesion length was 98.3 ± 87.5 mm and 78.0% of the lesions were severely calcified. Balloon angioplasty was performed in 98.0% of target lesions, while a stent was deployed in 16.0%. Treatment success was 98.0%; in only one case the result was sub-optimal (>30% stenosis with stent placement) and a significant dissection was reported. No serious distal embolization, serious thrombus formation or serious acute vessel closure were observed intra- or post-procedurally.

CONCLUSIONS

Transradial OA followed by percutaneous transluminal angioplasty for lower extremity PAD is feasible and demonstrates a favorable safety profile. Extended length devices such as the Extended Length Orbital Atherectomy System could further facilitate transradial endovascular procedures by increasing its spectrum of application.

Short and long-term outcome after common femoral artery hybrid procedure in patients with intermittent claudication and chronic limb threatening ischemia

Background: This study aimed to evaluate the differences between the outcomes of patients with intermittent claudication (IC) and chronic limb threatening ischemia (CLTI) who underwent a hybrid procedure comprising common femoral artery endarterectomy and endovascular therapy. Patients and methods: This was a retrospective single-center study of all patients with peripheral arterial occlusive disease (PAD) who underwent the hybrid procedure between March 2007 and August 2018. The primary endpoint was primary patency after 7 years. The secondary endpoints were primary-assisted patency, secondary patency, limb salvage, and survival. Results: During the follow-up period, 427 limbs in 409 patients were treated. A total of 267 and 160 patients presented with clinical signs of IC and CLTI, respectively. The 30-day mortality was 1.4% (IC: 0% vs. CLTI: 3.8%, p=0.001). The overall 30-day major amputation rate was 1.6% (IC: 0% vs. CLTI: 4.4, p=0.001). The rates of primary and secondary patency after 7 years were 63% and 94%, respectively, in the IC group and 57% and 88%, respectively, in the CLTI group; the difference was not significant. Limb salvage (94% vs. 82%, p=0.000) and survival (58% vs. 29%, p=0.000) were significantly higher in the IC group. In a multivariate analysis, CLTI was the only risk factor for major amputation. CLTI and single vessel run-off were risk factors for death. Statin therapy was a protective factor. Conclusions: The hybrid procedure provides excellent results as a treatment option for multilevel lesions in patients with PAD. However, patients with CLTI had a shorter long-term survival and lower limb salvage rate.

Surgical management of peripheral artery pseudoaneurysm following orthopedic trauma: a report of 14 cases

PURPOSE

Purpose of this study was to report the etiology, diagnosis, surgical management, and outcome of pseudoaneurysm associated with orthopedic trauma.

METHODS

A retrospective review was conducted of all patients presenting to a Level 1 trauma center between 2013 and 2019. Clinical records were reviewed for the mechanism of primary injury, associated fracture pattern, time of presentation, site of involvement, etiology of the pseudoaneurysm, diagnosis, management, and complications. We identified 14 patients with pseudoaneurysm of peripheral arteries following orthopedic trauma.

RESULTS

The mean interval between primary injury and the manifestation of clinical symptoms was 88.5 days (range, 16-304 days). There were 3 upper limb injuries and 11 lower limb injuries. The presenting symptoms were pain associated with excessive extremity swelling in most of the patients. A significant drop in hemoglobin (mean fall- 2.9 g/dL) was noted in nine patients. Most common artery involved was the superficial branch of femoral artery and posterior tibial artery followed by the brachial artery. Fractured bone spike was the cause of injury in eight patients and iatrogenic injury in six patients. Diagnosis was confirmed by CT angiography with duplex scan in eight patients, duplex scan alone in one patient, MRI along with duplex scan in one patient. The remaining four patients were diagnosed intraoperatively. Excision of the pseudoaneurysm and ligation of the involved minor arteries was done in eight patients. Surgical repair of the major artery with critical vascular injury was done in six patients. One patient underwent secondary amputation following the anastomotic blowout.

CONCLUSION

Early diagnosis of pseudoaneurysm requires knowledge and a high index of suspicion. Surgical reconstruction of major arteries should always be done and ligation of major vessels can lead to catastrophes. Excision of pseudoaneurysm can be done when minor arteries are involved with the presence of good collateral circulation.

LEVEL OF STUDY

Level IV Study.

Impact of prior endovascular interventions on outcomes of lower limb bypass surgery: A systematic review and meta-analysis

The aim of this meta-analysis was to evaluate the mortality, amputation and complication rates in patients with peripheral lower limb arterial disease undergoing bypass surgery with or without a prior history of endovascular operation. A systematic literature screen was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines on four academic databases, Medline, Scopus, Embase and Cochrane Central Register of Controlled Trials. Out of 1,072 records, six articles involving 11,420 patients (mean age, 68.1±2.0 years) met the inclusion criteria. The findings presented a 2b level of evidence (i.e. overall evidence represents data from individual cohort study or low quality randomized controlled trials) and suggested lower mortality, amputation and complication rates for patients undergoing bypass surgery without any history of endovascular operation, compared with those with a history of prior endovascular operation. Moreover, a random-effect meta-analysis suggested a small, positive reduction in mortality (Hedge's g=0.08), amputation (Hedge's g=0.18) and complication rates (Hedge's g=0.05) for patients undergoing bypass surgery without any history of endovascular operation. Nevertheless, owing to the scarcity of high-quality data, further studies and randomized clinical trials are needed to confirm these effects.

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.

Comparative Effectiveness of Endovascular Treatment Modalities for De Novo Femoropopliteal Lesions: A Network Meta-analysis of Randomized Controlled Trials

Purpose: To report the results of a network meta-analysis of randomized controlled trials (RCTs) comparing multiple endovascular treatments for de novo femoropopliteal lesions. Materials and Methods: The MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials databases were systematically searched on June 1, 2019, for prospective RCTs comparing 14 treatments [ie, atherectomy, brachytherapy, cryoplasty, cutting balloons, drug-coated balloons, bare nitinol stents, drug-eluting stents (DES), covered stents (CS), and combinations] in the treatment of de novo femoropopliteal lesions. Outcomes were technical success; binary restenosis and target lesion revascularization (TLR) at 6, 12, and/or 24 months; and all-cause mortality at 12 months. Ultimately, 53 articles reporting on 45 studies (91 study arms; 5565 patients) were selected. For the technical success outcome, all types of stents, all balloons, and all atherectomy devices were aggregated in stent, balloon, and atherectomy technology groups, respectively. Results: In terms of technical success for aggregated treatment types, stent technology was the most effective treatment and was better than balloon and atherectomy technologies. In terms of binary restenosis, DES was the most effective single treatment at the 6- and 12-month follow-up and CS at the 24-month follow-up. Both DES and CS were better than the majority of other single treatments, including balloon angioplasty, cutting balloon, cryoplasty, directional atherectomy, and bare nitinol stent during all follow-up periods. In terms of TLR, DES was the second most effective single treatment and the most effective single treatment at the 6- and 12-month follow-up intervals; CS was the most effective single treatment at the 24-month follow-up. Both DES and CS were better than the majority of other single treatments. The 12-month all-cause mortality of both DES and CS were similar to other treatments, whereas cryoplasty seemed to be the least effective treatment with regard to binary restenosis and TLR. Conclusion: Both DES and CS had substantial advantages in terms of restenosis and TLR in femoropopliteal lesions and were similar to aggregate stent technology in terms of technical success. DES performed better within 12 months after operation and CS at ~24 months, but neither had much advantage in terms of mortality. In contrast, cryoplasty seemed to be a less effective treatment.

[Naftidrofuryl in arterial obstructive disease: A systematic revue of the literature]

INTRODUCTION

Arterial obstructive disease is a disease affecting 11 % of the general population. This prevalence is constantly increasing. Nafronyl is still prescribed despite a decreasing reimbursement rate since 2005. The objective of this study was to summarize data from the scientific literature on the efficacy and safety of nafronyl used for the treatment of peripheral arterial obstructive disease.

METHOD

A systematic review was made on EMBASE, MEDLINE and the Cochrane Library. Randomized controlled trials, systematic reviews and meta-analyses comparing naftidrofuryl with placebo were included. The main outcome was an improvement in the maximum walking distance or pain free walking distance. The quality of the reviews was analysed using a standardised reading grid. Only the best study was retained.

RESULTS

Among 193articles, one meta-analyses were selected. Naftidrofuryl improved the initial pain free walking distance by 60 % at six months, without a demonstrated increase in the risk of adverse reactions.

CONCLUSION

The efficacy of naftidrofuryl over the maximum walking distance in peripheral arterial obstructive disease appears similar to physical exercise or simvastatin.

Comparative Efficacy and Safety of Endovascular Treatment Modalities for Femoropopliteal Artery Lesions: A Network Meta-analysis of Randomized Controlled Trials

PURPOSE

We conducted a network meta-analysis of randomized controlled trials comparing the efficacy and safety of multiple endovascular treatments for femoropopliteal lesions.

METHODS

Nine treatments for femoropopliteal lesions were identified. We compared major amputation and all-cause mortality at 12-month follow-ups and primary patency at 6-, 12- and 24-month follow-ups of the treatments.

RESULTS

Altogether, 26 studies (52 study arms; 4102 patients) were considered eligible. In terms of primary patency, drug-eluting stent (DES) placement was the most effective treatment at 6- and 12-month follow-ups and covered stent (CS) placement at 24-month follow-ups, whereas directional atherectomy (DA) was the least effective treatment during all follow-up periods; both DES and CS placements were better than the majority of other single treatments, including balloon angioplasty, DA, nitinol stent (NS) placement and drug-coated balloon use, during all follow-up periods. In terms of 12-month major amputation and all-cause mortality, DA was the most safe treatment, whereas NS placement was the least safe single treatment.

CONCLUSIONS

DES and CS placements have shown encouraging results in terms of primary patency for femoropopliteal lesions, DES placement performs better within 12 months after operation and CS placement at approximately 24 months, while DA seems to be less effective. DA may be better than other treatments in terms of major amputation and all-cause mortality, while NS seems to be less safe.

Women's Reproductive History and Pre-Clinical Peripheral Arterial Disease in Late Life: The San Diego Population Study

Objective: Reproductive events have been linked with increased cardiovascular risk in women, but whether they are associated with pre-clinical peripheral arterial disease (PAD) has been understudied. We evaluated associations between reproductive factors and later-life ankle-brachial index (ABI), femoral artery intima-media thickness (fIMT), and femoral plaques. Methods: Cross-sectional analysis of 707 multiethnic women who participated in a follow-up exam of the San Diego Population Study in 2007-2011. To assess associations between reproductive factors (age at menarche, parity, age at menopause, surgical menopause, hormone therapy) with ABI, and Doppler ultrasound measurements of common and superficial fIMT, linear regression was used; for femoral plaque presence, logistic regression was used. Models were adjusted for age, race/ethnicity, and cardiometabolic factors. We tested interactions of reproductive factors with menopause type (natural vs. surgical). Results: Women were on average 71 years old, and 56% were non-Hispanic White. Reproductive factors were not associated with fIMT, femoral plaque presence, or ABI. There were significant interactions between menopause type (surgical vs. natural) and oral contraceptive use (-β: 0.04, p = 0.03) for ABI, as well as between menopause type and parity (β: 0.11, p = 0.05) and age at menopause (β: 0.001, p = 0.05) for fIMT. Among women with natural menopause, oral contraceptive use was associated with higher ABI (β: 0.03, p = 0.007) and older age at natural menopause was related to greater fIMT (β: 0.009, p = 0.06). Among women with surgical menopause, nulliparity was marginally associated with greater fIMT (β: 0.33, p = 0.07). Conclusions: Reproductive history may not be independently associated with later-life lower extremity atherosclerosis in women. Studies are necessary to confirm findings and examine pregnancy-related exposures in relation to pre-clinical PAD.

Risk stratification for low extremity amputation in critical limb ischemia patients who have undergone endovascular revascularization: A survival tree analysis

Patients with peripheral artery disease (PAD) are a heterogeneous population and differ in risk of mortality and low extremity amputation (LEA), which complicates clinical decision-making. This study aimed to develop a simple risk scale using decision tree methodology to guide physicians in managing critical limb ischemia (CLI) patients who will benefit from endovascular therapy (EVT).A total of 736 patients with CLI, Rutherford classification (RC) stage ≥4, and prior successful EVT were included. Variables significantly associated with LEA by univariate analysis (P < .05) were selected and put into classification tree analysis using the Classification and Regression Tree (CART) model with a dependent variable, amputation, and depth of tree = 3. Four risk groups were generated according to the order of amputation rate. The amputation-free survival (AFS) times between groups were compared using the Kaplan-Meier curve with the log-rank test.Patients were classified as high risk for amputation (G4) (WBC counts ≥10,000/μl, and platelet-lymphocyte ratio (PLR) ≥130.337); intermediate risk group 1 (G3) (WBC < 10,000/μl and RC stage before EVT > 5); intermediate risk group 2 (G2) (WBC count ≥ 10,000/μl, and PLR < 130.337) and low-risk group (G1) (WBC < 10,000/μl, RC before EVT ≤ 5). G2, G3, and G4 risk groups had shorter AFS time (range, 58.7 to 65.5 months) than the G1 risk group (100 months) (P < .05). Risk of LEA was significantly higher in the G4, G3, and G2 groups than in the G1 group (P ≤ .05). The G4 group had the highest risk of amputation (odds ratio = 6.84, P < .001).This simple risk scale model can help healthcare professionals more easily identify and appropriately treat patients with CLI who are at different levels of risk for LEA following endovascular revascularization.

Acute Outcomes With a Novel Plaque Modification System in Real-World Femoropopliteal Lesions

Purpose:

To report outcomes of a multicenter feasibility study using the FLEX Vessel Prep (VP) System, a novel technology that facilitates plaque incision and lumen gain in stenosed or occluded femoropopliteal arteries prior to balloon angioplasty.

Materials and Methods:

Two hundred fifty-five patients (mean age 71.8±9.1 years) were treated with the FLEX VP System at 38 centers between December 2015 and November 2017. Average lesion length was 133±88 mm. Average baseline stenosis was 92%±11%; 112 (44.3%) of 253 patients presented with a chronic total occlusion. Conventional or drug-coated balloon (DCB) angioplasty was performed in all patients after vessel preparation. Vessel measurements were derived from angiograms acquired at baseline, after FLEX passage, and after subsequent ancillary procedures. Logistic regression analyses were performed to identify baseline or procedure variables that predicted the need for provisional stenting.

Results:

Average percent reduction in vessel stenosis following treatment with the FLEX VP System was 27%±17%. No flow-limiting dissection, vessel perforation, or embolization was observed; 15 (5.9%) patients had minor (type A or B) dissections. Provisional stenting was performed in 49 (19.2%) patients. Average stenosis following angioplasty ± stenting was 9.1%±7.4%; 9 (3.6%) patients had significant residual stenosis ≥30%. Logistic regression analyses found that patients with dissections, longer lesions, and those receiving conventional balloon dilation alone were most likely to undergo stenting.

Conclusion:

In a real-world patient population with long, complex femoropopliteal lesions, use of the FLEX VP System as vessel preparation for angioplasty improved acute outcomes compared to historical controls. The rate of provisional stenting was low, and no serious vessel complications were observed.

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.

Endovascular treatment of femoro-popliteal lesions

Peripheral artery disease (PAD) is a major health concern affecting more than 200 million people worldwide and studies have shown PAD to be a strong predictor of mortality, morbidity, and disability. The management of PAD is multi-tiered and advancements in technology have given physicians more options for endovascular revascularization if medical therapy does not result in substantial improvement. Many randomized controlled trials have reported efficacy of various therapies including laser atherectomy, stent technology, and drug-coated balloons over standard percutaneous transluminal angioplasty; however, uncertainty regarding the best standard of care remains unclear because of a lack of head to head comparisons between novel therapies. Furthermore, variability in the reported clinical outcomes exists and makes it difficult to evaluate the superiority of any specific treatment modality, especially for functional capacity and quality of life. Recently established consensus definitions for clinical outcomes coupled with investigators incorporating direct comparisons within clinical trials will be crucial to establish consistent care and meaningful gain in treatment for these patients. This review will highlight the treatment modalities, literature supporting each treatment modality, and insight into why they are being used and why variation exists around the United States.

Exercise-induced calf muscle hyperemia: quantitative mapping with low-dose dynamic contrast enhanced magnetic resonance imaging

Peripheral artery disease (PAD) in the lower extremities often leads to intermittent claudication. In the present study, we proposed a low-dose DCE MRI protocol for quantifying calf muscle perfusion stimulated with plantar flexion and multiple new metrics for interpreting perfusion maps, including the ratio of gastrocnemius over soleus perfusion (G/S; for assessing the vascular redistribution between the two muscles) and muscle perfusion normalized by whole body perfusion (for quantifying the muscle's active hyperemia). Twenty-eight human subjects participated in this Institutional Review Board-approved study, with 10 healthy subjects ( group A) for assessing interday reproducibility and 8 healthy subjects ( group B) for exploring the relationship between plantar-flexion load and induced muscle perfusion. In a pilot group of five elderly healthy subjects and five patients with PAD ( group C), we proposed a protocol that measured perfusion for a low-intensity exercise and for an exhaustion exercise in a single MRI session. In group A, perfusion estimates for calf muscles were highly reproducible, with correlation coefficients of 0.90-0.93. In group B, gastrocnemius perfusion increased linearly with the exercise workload ( P < 0.05). With the low-intensity exercise, patients with PAD in group C showed substantially lower gastrocnemius perfusion compared with elderly healthy subjects [43.4 (SD 23.5) vs. 106.7 (SD 73.2) ml·min^-1·100 g^-1]. With exhaustion exercise, G/S [1.0 (SD 0.4)] for patients with PAD was lower than both its low-intensity level [1.9 (SD 1.3)] and the level in elderly healthy subjects [2.7 (SD 2.1)]. In conclusion, the proposed MRI protocol and the new metrics are feasible for quantifying exercise-induced muscle hyperemia, a promising functional test of PAD. NEW & NOTEWORTHY To quantitatively map exercise-induced hyperemia in calf muscles, we proposed a high-resolution MRI method shown to be highly reproducible and sensitive to exercise load. With the use of low contrast, it is feasible to measure calf muscle hyperemia for both low-intensity and exhaustion exercises in a single MRI session. The newly proposed metrics for interpreting perfusion maps are promising for quantifying intermuscle vascular redistribution or a muscle's active hyperemia.

Intravascular ultrasound guided directional atherectomy versus directional atherectomy guided by angiography for the treatment of femoropopliteal in-stent restenosis

BACKGROUND

The aim of this study was to compare 1-year outcomes for patients with femoropopliteal in-stent restenosis using directional atherectomy guided by intravascular ultrasound (IVUS) versus directional atherectomy guided by angiography.

METHODS AND RESULTS

This was a retrospective analysis for patients with femoropopliteal in-stent restenosis treated with IVUS-guided directional atherectomy versus directional atherectomy guided by angiography from a single center between March 2012 and February 2016. Clinically driven target lesion revascularization was the primary endpoint and was evaluated through medical chart review as well as phone call follow up.

CONCLUSIONS

Directional atherectomy guided by IVUS reduces clinically driven target lesion revascularization for patients with femoropopliteal in-stent restenosis.

Swirling Flow and Wall Shear: Evaluating the BioMimics 3D Helical Centerline Stent for the Femoropopliteal Segment

The BioMimics 3D self-expanding nitinol stent represents a strategy for femoropopliteal intervention that is alternative or complementary to deployment of drug-coated stents or balloons. Whereas conventional straight stents reduce arterial curvature and disturb blood flow, creating areas of low wall shear, where neointimal hyperplasia predominantly develops, the helical centerline geometry of the BioMimics 3D maintains or imparts arterial curvature, promotes laminar swirling blood flow, and elevates wall shear to protect against atherosclerosis and restenosis. In the multicenter randomized MIMICS trial, treatment of femoropopliteal disease with the BioMimics 3D (n = 50) significantly improved 2-year primary patency (log-rank test p = 0.05) versus a control straight stent (n = 26), with no cases of clinically driven target lesion revascularization between 12 and 24 months (log-rank test p = 0.03 versus controls). In geometric X-ray analysis, the BioMimics stent was significantly more effective in imparting a helical shape even when the arterial segment was moderately to severely calcified. Computational fluid dynamics analysis showed that average wall shear was significantly higher with the helical centerline stent (1.13 ± 0.13 Pa versus 1.06 ± 0.12 Pa, p = 0.05). A 271-patient multicenter international MIMICS-2 trial and a 500-patient real-world MIMICS-3D registry are underway.

Optimal Ultrasound Criteria for Grading Stenosis of the Superficial Femoral Artery

This retrospective study determined the duplex ultrasound scanning criteria for detecting 50%-69% and 70%-99% stenosis of the superficial femoral artery (SFA). Examinations of 278 limbs in 185 patients with peripheral arterial disease were performed. Duplex ultrasound scanning was used to measure the diameter of the vascular lumen, the peak systolic velocity (PSV) at the stenotic segment of the SFA (PSV_st), the segment proximal to the stenosis (PSV_pro) and the popliteal artery (PSV_pop, distal to the stenosis). The ratios PSV_st/PSV_pro and PSV_st/PSV_pop were calculated. Receiver operator characteristic curves were plotted, with digital subtraction angiography as the reference. PSV_st and PSV_st/PSV_pop had the highest diagnostic value for stenosis. Cut-off thresholds were: for 50%-69% stenosis, PSV_st ≥ 210 cm/s, PSV_st/PSV_pop ≥ 2.5, with PSV_st the better parameter; for 70%-99% stenosis, PSV_st ≥ 275 cm/s, PSV_st/PSV_pop ≥ 4.0, with PSV_st/PSV_pop superior. PSV_st/PSV_pop may be a better parameter than PSV_st/PSV_pro for diagnosing SFA stenosis.

New Innovations in Drug-Eluting Stents for Peripheral Arterial Disease

PURPOSE OF REVIEW

The purpose of this paper was to provide a review of the burden of peripheral arterial disease; to examine older therapies and their limitations; and especially to highlight new treatment innovations as well as the data supporting their use.

RECENT FINDINGS

Building on the success of paclitaxel in the prevention of restenosis in the peripheral circulation, the newest generation drug-eluting stent is presented, which combines paclitaxel with a polymer-allowing the drug to be eluted slowly over 12 months. The positive results of the pilot MAJESTIC study led to the ongoing IMPERIAL trial. Limited data of bioresorbable scaffolds in above and below-the-knee applications are also reviewed. Endovascular therapy of peripheral arterial disease has had many advances in the preceding two decades. However, drug-eluting stent technology has had the greatest impact to date and holds great promise for the future.

Treatment of Superficial Femoral Artery Restenosis

PURPOSE

To determine the predictors of restenosis, major adverse limb events (MALEs), postoperative death (POD), and all-cause mortality after repeat endovascular treatment of superficial femoral artery (SFA) restenosis.

MATERIALS AND METHODS

This was a retrospective review of 440 patients with 518 SFA lesions who were treated between January 2002 and October 2011. Ninety-six limbs were treated for restenosis with bare metal stents (BMSs) or percutaneous transluminal angioplasty (PTA), of which 28 limbs developed another restenosis requiring a third procedure. The interaction measured in this study was between the second and third intervention. Predictors of SFA patency, MALEs, POD, and all-cause mortality after SFA restenosis treatment were identified.

RESULTS

Patients who were treated with BMSs (n = 51) had similar rates of restenosis compared with patients who were treated with PTA (n = 45) (hazard ratio [HR] 1.40; 95% confidence interval [CI] 0.68-2.90; P = .37). Patients in the BMS group who took statins had a significantly lower risk of restenosis than patients who did not take statins (HR 0.13; 95% CI 0.04-0.41; P < .001). Stage 4-5 chronic kidney disease (CKD) (n = 12) was associated with a significantly higher risk of MALE + POD (HR 6.17; 95% CI 1.45-26.18; P = .014) and all-cause mortality (HR 2.83; 95% CI 1.27-6.33; P = .01). Clopidogrel was protective against all-cause mortality (HR 0.41; 95% CI 0.20-0.80; P = .01).

CONCLUSIONS

Patients in the BMS group who took statins at the time of intervention had a significantly lower risk of developing restenosis. Stage 4-5 CKD was a risk factor for MALE + POD and all-cause mortality, while clopidogrel decreased all-cause mortality risk.

The acute effects of lower limb intermittent negative pressure on foot macro- and microcirculation in patients with peripheral arterial disease

Background

Intermittent negative pressure (INP) applied to the lower leg and foot increases foot perfusion in healthy volunteers. The aim of the present study was to describe the effects of INP to the lower leg and foot on foot macro- and microcirculation in patients with lower extremity peripheral arterial disease (PAD).

Methods

In this experimental study, we analyzed foot circulation during INP in 20 patients [median (range): 75 (63-84yrs)] with PAD. One leg was placed inside an air-tight vacuum chamber connected to an INP-generator. During application of INP (alternating 10s of -40mmHg/7s of atmospheric pressure), we continuously recorded blood flow velocity in a distal foot artery (ultrasound Doppler), skin blood flow on the pulp of the first toes (laser Doppler), heart rate (ECG), and systemic blood pressure (Finometer). After a 5-min baseline sequence (no pressure), a 10-min INP sequence was applied, followed by 5-min post-INP (no pressure). To compare and quantify blood flow fluctuations between sequences, we calculated cumulative up-and-down fluctuations in arterial blood flow velocity per minute.

Results

Onset of INP induced an increase in arterial flow velocity and skin blood flow. Peak blood flow velocity was reached 3s after the onset of negative pressure, and increased 46% [(95% CI 36–57), P<0.001] above baseline. Peak skin blood flow was reached 2s after the onset of negative pressure, and increased 89% (95% CI 48–130), P<0.001) above baseline. Cumulative fluctuations per minute were significantly higher during INP-sequences compared to baseline [21 (95% CI 12–30)cm/s/min to 41 (95% CI 32–51)cm/s/min, P<0.001]. Mean INP blood flow velocity increased significantly ~12% above mean baseline blood flow velocity [(6.7 (95% CI 5.2–8.3)cm/s to 7.5 (95% CI 5.9–9.1)cm/s, P = 0.03)].

Conclusion

INP increases foot macro- and microcirculatory flow pulsatility in patients with PAD. Additionally, application of INP resulted in increased mean arterial blood flow velocity.

Laser Atherectomy for the Treatment of Peripheral Arterial Disease

BACKGROUND

The aim of the study was to investigate the clinical results of laser atherectomy in the treatment of peripheral arterial disease.

METHODS

Retrospective analysis of consecutive patients underwent laser atherectomy at a single institution during a 7-year period by vascular surgeons and interventional cardiologists in a tertiary university-affiliated hospital. Clinical data were retrieved from patient charts and hospital electronic medical records along with the associated arteriograms.

RESULTS

A total of 461 lesions in 343 limbs were treated in 300 patients with a mean age of 70 years. The indication was critical limb ischemia (CLI) with rest pain or tissue loss in 227 (66%) of interventions and claudication in 116 (34%). All procedures included an associated balloon angioplasty, while stenting was performed in 33%. Technical success was achieved in 99% with only 2 (<1%) cases with an acute procedure-related complication requiring surgical intervention. At a mean follow-up of 28 months (range, 1-87 months; median 24 months), 156 patients (45%) became asymptomatic or achieved significant clinical improvement (resolution of tissue loss or rest pain), 60 (17%) remained with CLI, 30 (9%) had a major proximal amputation, and 18 (5%) had a minor amputation. Freedom from major amputation was 90% at 5 years by life-table analysis. Univariate statistical analysis demonstrated the risk of a major amputation to be associated with diabetes, hemodialysis, and tissue loss (P < 0.05 to P < 0.005), while multivariate logistic regression analysis indicated diabetes to be overwhelmingly important (RR: 4.84; 95% confidence interval [CI]: 1.1-21.3; P < 0.05). In a similar manner, multivariate analysis indicated dialysis (RR: 2.46; 95% CI: 1.01-5.98; P < 0.05) and CLI (RR: 2.27; 95% CI: 1.42-3.65; P < 0.01) were associated with higher likelihood for lack of clinical improvement. There was no difference in major amputation rates between surgeons and interventional cardiologists (RR: 1.5; 95% CI: 0.7-2.1; P < 0.1) although it was 3 times more likely for the patients treated by surgeons to suffer from CLI (odds ratio: 3.2; 95% CI: 1.9-5.4; P < 0.0001).

CONCLUSIONS

Laser atherectomy is a safe and useful adjunct in limb salvage. Diabetics have much higher probability of requiring a proximal amputation, while those on dialysis and with CLI are least likely to gain clinical benefit.

Comparing velocity and fluid shear stress in a stenotic phantom with steady flow: phase-contrast MRI, particle image velocimetry and computational fluid dynamics

OBJECT

This study aims to validate phase-contrast magnetic resonance imaging (PC-MRI) measurements of a steady flow through a severe stenotic phantom using particle image velocimetry (PIV) and computational fluid dynamics (CFD).

MATERIALS AND METHODS

The study was performed in an axisymmetric 87 % area stenosis model using an inlet Reynolds number (Re) of 160, corresponding to a jet Re of 444. Velocity patterns and estimated fluid shear stresses from three modalities were analyzed and compared qualitatively and quantitatively.

RESULTS

Visual analysis via contour subtraction and Bland-Altman plots showed good agreement for flow velocities and less agreement for maximum shear stress (MSS). The Pearson's coefficients of correlation between PC-MRI and PIV were 0.97 for the velocity field and 0.82 for the MSS. The corresponding parameters between PC-MRI and CFD were 0.96 and 0.84, respectively.

CONCLUSION

Findings indicate that PC-MRI can be implemented to estimate velocity flow fields and MSS; however, this method is not sufficiently accurate to quantify the MSS at regions of high shear rate.