Paclitaxel-Coated Balloons: Investigation of Drug Transfer in Healthy and Atherosclerotic Arteries - First Experimental Results in Rabbits at Low Inflation Pressure

The phenomenon of drug-coating embolism during lower extremity endovascular interventions with paclitaxel-coated balloon

INTRODUCTION

There is a risk of distal embolization lower extremity endovascular interventions. Possibly a drug-coating embolism caused by coating detachment from intravascular devices.

METHODS

This review focuses on providing updated information on distal embolism in endovascular revascularization of lower extremity arteries, including the use of drug-coated balloons.

RESULTS

Drug-coating embolism is a special case of distal embolization during recanalization of the arteries of the lower extremities. Preclinical studies have demonstrated embolization of drug-coated balloons during angioplasty of lower extremity arteries. However, the clinical role of drug-coating embolism is not completely clear. A 2020 meta-analysis found an increased risk of major lower extremity amputation after drug-coated balloon angioplasty in patients with critical limb ischemia. But long-term research is emerging to support the safety of using these devices. Perhaps a more thorough assessment of the quality of life and the degree of compensation of lower limb ischemia with an intraoperative assessment of the frequency of peripheral embolizations using ultrasound emboli detection, as well as microcirculation with transcutaneous oximetry and laser Doppler flowmetry of the operated lower limb will allow a more detailed study of the phenomenon of drug-coating embolism and its impact on long-term clinical outcomes.

CONCLUSION

According to the results of preclinical studies, the use of paclitaxel-coated balloons leads to an increase in the concentration of paclitaxel in distal skeletal muscles. However, paclitaxel concentration in skeletal muscle was significantly higher in first-generation DCBs. The non-target effects of drug-coating balloon are not fully understood and require further study. Understanding the phenomenon of drug-coating embolism can help physicians to better assess the patient risk and to minimize complications.

Liquid Drug Delivery Approaches for the Treatment of Occlusive Arterial Disease: A Systematic Review

OBJECTIVE

Local Liquid drug (LLD) delivery devices have recently emerged as a novel approach to treat peripheral arterial disease. This systemic review aims to identify and evaluate the clinical utility of the most commonly used delivery devices.

METHODS

A systemic review was performed using the Medical Subjects Heading terms of "drug delivery," "liquid," "local," and "cardiovascular disease" in PubMed, Google Scholar, and Scopus.

RESULTS

Four commonly used delivery devices were identified, including (1) the Bullfrog Micro-Infusion Device, (2) the ClearWay RX Catheter, (3) the Occlusion Perfusion Catheter, and (4) the Targeted Adjustable Pharmaceutical Administration. All have shown to successfully deliver liquid therapeutic into the target lesion and have exhibited favorable safety and efficacy profiles in preclinical and clinical trials. The LLD devices have the ability to treat very long or multiple lesions with a single device, providing a more economical option. The safety profile in LLD clinical studies is also favorable in view of recent concerns regarding adverse events with crystalline-paclitaxel-coated devices.

CONCLUSION

There is clear clinical evidence to support the concept of local liquid delivery to treat occlusive arterial disease.

CLINICAL IMPACT

The 'leave nothing behind' strategy has been at the forefront of the most recent innovations in the field of interventional cardiology and vascular interventions. Although drug coated balloons have overcome limitations associated with plain old balloon angioplasty and peripheral stents, recent safety concerns and cost considerations have impacted their usage. In this review, various liquid drug delivery devices are presented, showcasing their capabilities and success in both preclinical and clinical settings. These innovative liquid delivery devices, capable of targeted delivery and their ability to be re-used for multiple treatment sites, may provide solutions for current unmet clinical needs.

Endovascular Drug Delivery

Drug-eluting stents (DES) and balloons revolutionize atherosclerosis treatment by targeting hyperplastic tissue responses through effective local drug delivery strategies. This review examines approved and emerging endovascular devices, discussing drug release mechanisms and their impacts on arterial drug distribution. It emphasizes the crucial role of drug delivery in modern cardiovascular care and highlights how device technologies influence vascular behavior based on lesion morphology. The future holds promise for lesion-specific treatments, particularly in the superficial femoral artery, with recent CE-marked devices showing encouraging results. Exciting strategies and new patents focus on local drug delivery to prevent restenosis, shaping the future of interventional outcomes. In summary, as we navigate the ever-evolving landscape of cardiovascular intervention, it becomes increasingly evident that the future lies in tailoring treatments to the specific characteristics of each lesion. By leveraging cutting-edge technologies and harnessing the potential of localized drug delivery, we stand poised to usher in a new era of precision medicine in vascular intervention.

Research progress of drug eluting balloon in arterial circulatory system

The arterial circulatory system diseases are common in clinical practice, and their treatment options have been of great interest due to their high morbidity and mortality. Drug-eluting balloons, as a new type of endovascular interventional treatment option, can avoid the long-term implantation of metal stents and is a new type of angioplasty without stents, so drug-eluting balloons have better therapeutic effects in some arterial circulatory diseases and have been initially used in clinical practice. In this review, we first describe the development, process, and mechanism of drug-eluting balloons. Then we summarize the current studies on the application of drug-eluting balloons in coronary artery lesions, in-stent restenosis, and peripheral vascular disease. As well as the technical difficulties and complications in the application of drug-eluting balloons and possible management options, in order to provide ideas and help for future in-depth studies and provide new strategies for the treatment of more arterial system diseases.

Evaluation of a new paclitaxel-coated balloon catheter in an in vivo porcine peripheral venous model: Feasibility, safety, and drug deliverability

PURPOSE

To evaluate in vivo the feasibility, safety, and paclitaxel (PTX) deliverability of a newly developed non-commercially available Paclitaxel-Coated Balloon (PCB) catheter in the swine healthy peripheral vein model.

MATERIALS AND METHODS

In total 12 PCBs were deployed in 12 venous segments. Primary feasibility endpoint was the successful application of the devices to the veins of the animals. Primary efficacy endpoint was the determination of the drug content in the venous tissue at 24 h and 7 days after balloon expansion, as assessed by analysis of the vein tissue with High Performance Liquid Chromatography (HPLC) coupled with tandem mass spectrometry. Primary safety endpoint was freedom from any major adverse event. Secondary endpoint was the investigation of any independent factor affecting the primary endpoints.

RESULTS

Paclitaxel was detected in five out of six tissue samples 24 h post-intervention and five out of six tissues at 7 days following the procedure (10 tissue samples out of 12). The mean weight of tissue that was examined was 0.20604 ± 0.29822 g (range: 1.02823-0.03377 g) and the mean PTX concentration detected was 8.4 ± 13.1 μg/g (range: 0-36.1 μg/g). The average drug content detected at 24 h (17.1 ± 17.1 μg/g) was numerically superior, but non-statistically significant, compared to 7 days (3.1 ± 3.6 μg/g). An average of 33.8% of the drug remained on the balloon after retrieval. According to the multiple linear regression analysis, there was no significant correlation between transition time, PTX remaining on the balloon, time of analysis (24 h/7 days) and PTX tissue concentration. No abnormalities were noted during autopsy.

CONCLUSION

The newly developed PCB successfully delivered within the healthy venous wall a dose of Paclitaxel that inhibits neointimal hyperplasia. No safety issues were raised at short-term follow-up.

Investigating Balloon-Vessel Contact Pressure Patterns in Angioplasty: In Silico Insights for Drug-Coated Balloons

Drug-Coated Balloons have shown promising results as a minimally invasive approach to treat stenotic arteries, but recent animal studies have revealed limited, non-uniform coating transfer onto the arterial lumen. In vitro data suggested that local coating transfer tracks the local Contact Pressure (CP) between the balloon and the endothelium. Therefore, this work aimed to investigate in silico how different interventional and device parameters may affect the spatial distribution of CP during the inflation of an angioplasty balloon within idealized vessels that resemble healthy femoral arteries in size and compliance. An angioplasty balloon computational model was developed, considering longitudinal non-uniform wall thickness, due to its forming process, and the folding procedure of the balloon. To identify the conditions leading to non-uniform CP, sensitivity finite element analyses were performed comparing different values for balloon working length, longitudinally varying wall thickness, friction coefficient on the balloon-vessel interface, vessel wall stiffness and thickness, and balloon-to-vessel diameter ratio. Findings indicate a significant irregularity of contact between the balloon and the vessel, mainly affected by the balloon's unfolding and longitudinal thickness variation. Mirroring published data on coating transfer distribution in animal studies, the interfacial CP distribution was maximal at the middle of the balloon treatment site, while exhibiting a circumferential pattern of linear peaks as a consequence of the particular balloon-vessel interaction during unfolding. A high ratio of balloon-to-vessel diameter, higher vessel stiffness, and thickness was found to increase significantly the amplitude and spatial distribution of the CP, while a higher friction coefficient at the balloon-to-vessel interface further exacerbated the non-uniformity of CP. Evaluation of balloon design effects revealed that the thicker tapered part caused CP reduction in the areas that interacted with the extremities of the balloon, whereas total length only weakly impacted the CP. Taken together, this study offers a deeper understanding of the factors influencing the irregularity of balloon-tissue contact, a key step toward uniformity in drug-coating transfer and potential clinical effectiveness.

Anemia as a risk factor for restenosis in femoropopliteal arterial disease after drug-coated balloon angioplasty

OBJECTIVE

This study aimed to investigate the relationship between anemia and restenosis in patients with femoropopliteal arterial disease following drug-coated balloon (DCB) angioplasty.

METHODS

194 patients treated with DCB for femoropopliteal lesions were retrospectively analyzed for up to 12 months of follow-up between January 2017 and September 2020. Baseline clinical and procedural characteristics were compared between the anemia and non-anemia patients, and predictors of restenosis were identified using logistic regression.

RESULTS

32.5% of the patients undergoing DCB angioplasty had anemia. Patients with anemia were significantly older, with higher rates of hypertension, coronary artery disease, chronic renal insufficiency, and diabetes, and with lower rates of smoking and male gender. In the multivariate analysis, anemia was independently and significantly associated with a higher risk of restenosis (OR, 3.872; 95% CI, 1.556-9.638; P = 0.004).

CONCLUSION

Anemia is independently associated with restenosis in patients treated with DCB for femoropopliteal arterial disease. Patients with lower baseline hemoglobin might have more chances to develop restenosis at follow-up.

Anti-inflammatory and antioxidative effects of gallic acid on experimental dry eye: in vitro and in vivo studies

BACKGROUND

To investigate the anti-inflammatory and antioxidative effects of gallic acid (GA) on human corneal epithelial cells (HCECs) and RAW264.7 macrophages as well as its therapeutic effects in an experimental dry eye (EDE) mouse model.

METHODS

A cell counting kit-8 (CCK-8) assay was used to test the cytotoxicity of GA. The effect of GA on cell migration was evaluated using a scratch wound healing assay. The anti-inflammatory and antioxidative effects of GA in vitro were tested using a hypertonic model (HCECs) and an inflammatory model (RAW264.7 cells). The in vivo biocompatibility of GA was detected by irritation tests in rabbits, whereas the preventive and therapeutic effect of GA in vivo was evaluated using a mouse model of EDE.

RESULTS

In the range of 0-100 μM, GA showed no cytotoxicity in RAW264.7 cells or HCECs and did not delay the HCECs monolayer wound healing within 24 h. Ocular tolerance to GA in the in vivo irritation test was good after seven days. In terms of antioxidative activity, GA significantly reduced the intracellular reactive oxygen species (ROS) in lipopolysaccharide (LPS) activated RAW264.7 macrophages and HCECs exposed to hyperosmotic stress. Furthermore, after pre-treatment with GA, the expression levels of nuclear factor E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and NADPH quinone oxidoreductase-1 (NQO-1) were significantly upregulated in RAW264.7 macrophages. GA also exhibits excellent anti-inflammatory properties. This is mainly demonstrated by the ability of GA to effectively downregulate the nuclear transcription factor-κB (NF-κB) pathway in LPS-activated RAW264.7 macrophages and to reduce inflammatory factors, such as nitric oxide (NO), interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α). In vivo efficacy testing results in a mouse model of EDE showed that GA can effectively prevent and inhibit the apoptosis of corneal epithelial cells (CECs), reduce inflammatory factors in the cornea and conjunctiva as well as protect goblet cells.

CONCLUSION

In vitro and in vivo results indicate that GA possesses potent anti-inflammatory and antioxidative properties with no apparent cytotoxicity within the range of 0-100 μM. It is a promising eye drop formulation for the effective prevention and treatment of dry eye disease (DED).

The association of calcium channel blocker with risk of adverse limb events in patients with chronic limb-threatening ischemia after endovascular treatment

Symptoms of lower-extremity artery disease (LEAD) emerge from impaired vascularization in distal circulation of the extremities. Calcium channel blockers (CCB) can improve distal circulation when used as adjunctive therapy with endovascular treatment (EVT), but few studies have evaluated that. We investigated the relationship between CCB therapy and post-EVT outcomes. Through a consecutive EVT registry, we evaluated those relationships in whole cohort and the following 2 subgroups; the patients suffered from intermittent claudication (IC) or chronic limb-threatening ischemia (CLTI), with adjusting baseline characteristics by propensity score matchings. The primary endpoints were major adverse cardiac and cerebrovascular events (MACCE, a composite endpoint of all death, nonfatal myocardial infarction, and nonfatal stroke), and major adverse limb event (MALE, a composite of major amputation, acute limb ischemia, and surgical reintervention). The group that received CCB had less MALE in whole cohort (HR 0.31; 95% confidence interval (CI) 0.20-0.47), and less MACCE and MALE in CLTI cohort (HR 0.67; 0.50-0.89 and 0.32; 0.20-0.52 respectively) compared to the group that did not receive CCB. The relationships were common in the cohorts with baseline adjustment. MACCE and MALE in IC (HR 1.01; 0.57-1.80 and 0.60; 0.25-1.45, respectively) showed no significant differences both with and without baseline adjustment. CCB use was related to fewer MACCE and MALE events in adjusted patients who underwent EVT, and the trend was more evident, especially in the adjusted CLTI cohort. This study highlights the necessity of future studies regarding CCB. Clinical Trial Registration: URL: https://www.umin.ac.jp ; Unique identifiers: UMIN000015100.

Relationship Between Neutrophil-Lymphocyte Ratio and Drug-Coated Balloon Restenosis in Patients With Femoropopliteal Arterial Disease

We investigated the relationship between neutrophil-lymphocyte ratio (NLR) and restenosis in patients with femoropopliteal arterial disease following drug-coated balloon (DCB) angioplasty. Patients (n = 120) were divided into 3 groups according to the development of restenosis and the time of restenosis occurrence. The postoperative NLR was higher in the late-restenosis group than that in the no-restenosis group (3.53 vs 2.70; p = .011). In multivariate logistic analysis, postoperative NLR was an independent predictor of late restenosis (odds ratio: 1.404, 95% confidence interval: 1.073-1.839; p = .014). The postoperative NLR cutoff value for predicting late restenosis was 2.78 with a sensitivity of 80.8% and a specificity of 53.2% (area under the ROC curve was .666 (95% CI: .541-.791, p = .010). The incidence of late restenosis in the NLR ≥2.78 group was higher than that in the NLR <2.78 group (32.3 vs 9.1%; p = .002). Postoperative NLR is independently associated with late restenosis in patients treated with DCB for femoropopliteal arterial disease.

The factors influencing the efficiency of drug-coated balloons

The drug-coated balloon (DCB) is an emerging percutaneous coronary intervention (PCI) device that delivers drugs to diseased vessels to decrease the rate of vascular stenosis. Recent clinical studies have demonstrated that DCBs tend to have both good safety and efficacy profiles, leading to extended application indications in the clinic, including in-stent restenosis (ISR) for metal stents such as drug-eluting stents (DESs), small vascular disease, bifurcation disease, large vascular disease, acute coronary syndrome (ACS), and high bleeding risk. However, some previous clinical data have suggested that DCBs performed less effectively than DESs. No studies or reviews have systematically discussed the improvement strategies for better DCB performance until now. Drug loss during the process of delivery to the target lesion and inefficient delivery of the coating drug to the diseased vascular wall are two key mechanisms that weaken the efficiency of DCBs. This review is the first to summarize the key influencing factors of DCB efficiency in terms of balloon structure and principles, and then it analyzes how these factors cause outcomes in practice based on current clinical trial studies of DCBs in the treatment of different types of lesions. We also provide some recommendations for improving DCBs to contribute to better DCB performance by improving the design of DCBs and combining other factors in clinical practice.

Editor's Choice - Risk of Major Amputation Following Application of Paclitaxel Coated Balloons in the Lower Limb Arteries: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

OBJECTIVE

There have been concerns about the long term safety of paclitaxel coated devices in the lower limbs. A formal systematic review and meta-analysis of randomised controlled trials (RCTs) was performed to examine the long term risk of major amputation using paclitaxel coated balloons in peripheral arterial disease (PAD).

METHOD

This systematic review was registered with PROSPERO (ID 227761). A broad bibliographic search was performed for RCTs investigating paclitaxel coated balloons in the peripheral arteries (femoropopliteal and infrapopliteal) for treatment of intermittent claudication or critical limb ischaemia (CLI). The literature search was last updated on 20 February 2021 without any restrictions on publication language, date, or status. Major amputations were analysed with time to event methods employing one and two stage models. Sensitivity and subgroup analyses, combinatorial meta-analysis, and a multivariable dose response meta-analysis to examine presence of a biological gradient were also performed.

RESULTS

In all, 21 RCTs with 3 760 lower limbs were analysed (52% intermittent claudication and 48% CLI; median follow up two years). There were 87 major amputations of 2 216 limbs in the paclitaxel arms (4.0% crude risk) compared with 41 major amputations in 1 544 limbs in the control arms (2.7% crude risk). The risk of major amputation was significantly higher for paclitaxel coated balloons with a hazard ratio (HR) of 1.66 (95% CI 1.14 - 2.42; p = .008, one stage stratified Cox model). The prediction interval was 95% CI 1.10 - 2.46 (two stage model). The observed amputation risk was consistent for both femoropopliteal (p = .055) and infrapopliteal (p = .055) vessels. Number needed to harm was 35 for CLI. There was good evidence of a significant non-linear dose response relationship with accelerated risk per cumulative paclitaxel dose (chi square model p = .007). There was no evidence of publication bias (p = .80) and no significant statistical heterogeneity between studies (I2 = 0%, p = .77). Results were stable across sensitivity analyses (different models and subgroups based on anatomy and clinical indication and excluding unpublished trials). There were no influential single trials. Level of certainty in evidence was downrated from high to moderate because of sparse events in some studies.

CONCLUSION

There appears to be heightened risk of major amputation after use of paclitaxel coated balloons in the peripheral arteries. Further investigations are warranted urgently.

Cilostazol as a noninferiority pharmacologic option to paclitaxel in early intimal hyperplasia inhibition after venous balloon angioplasty in a rabbit model: a preliminary study

The development of venous intimal hyperplasia (VIH) has not been fully studied. At present, there are no drugs approved for VIH inhibition; to investigate such alternatives, we aimed to compare paclitaxel with cilostazol in VIH early inhibition in a preliminary experimental model of balloon angioplasty. Twenty-eight male New Zealand rabbits were randomly divided into two groups: cilostazol (A) and paclitaxel (B), which underwent femoral vein barotrauma by a 4 mm balloon angioplasty. The VIH model was previously tested in controls obtaining an 80% increase of subintimal area (SIA) compared with veins without injury (from 0.12 mm² [standard deviation (SD), 0.05] to 0.86 mm² [SD, 0.08]). Group A received 20 mg/kg twice daily; group B angioplasty was performed with a single-dose paclitaxel-coated balloon. Seven days later rabbits were euthanized, and vein tissue samples were taken for histological analysis. The primary end point was SIA measure expressed in mm², and the anticipated difference between treatments was 0.21 mm². Other measurements were immunohistochemistry expression of hypoxia inducible factor-1 alpha, platelet derived growth factor, and smooth muscle actin, as surrogates of cell migration and oxidative stress. SIA of group A was 0.33 mm² (SD, 0.15; 95% CI, 0.24-0.42 mm²), and that of group B was 0.31 mm² (SD, 0.14; 95% CI, 0.22-0.40 mm²). Both drugs showed a reduction of 61% and 63%, respectively, in SIA, compared with controls. The difference between both drugs was 0.0193 mm² (95% CI, −0.1175 to 0.156 mm²); the statistical difference was found in hypoxia inducible factor-1 alpha expression between both groups.

Clinical Relevance

Although veins have a thinner middle layer compared with arteries, smooth muscle cells appear to play an important role in venous stenosis after angioplasty. The study of smooth muscle cell response after barotrauma may have clinical applications in the endovascular treatment of venous stenosis, because at the moment, there is no medication indicated to prolong patency after venous endovascular procedures, for example in May Thurner syndrome. Paclitaxel and cilostazol seem to have a promising role. Finally, the present study could inspire a research line to reduce stent placement and increase patency after venous angioplasty.

Precision delivery of liquid therapy into the arterial wall for the treatment of peripheral arterial disease

Perfusion catheters have recently emerged as a novel approach to deliver liquid anti-proliferative agents into flow obstructed arterial segments. The purpose of this study was to determine the impact of luminal delivery pressure on liquid drug penetration into the vessel wall. An ex vivo model using harvested porcine carotid arteries and a two-dimensional computational model were utilized to determine the impact of delivery pressure of liquid therapy into the arterial wall. A pig peripheral injury model determined the impact of intra-luminal delivery pressure on drug retention. Ex vivo results demonstrated that depth of fluid penetration varies from 6.93 ± 1.90% at 0 atm to 27.75 ± 6.61% penetration of the medial layer at 0.4 atm. Computational results had similar outcomes, as penetration varied between 4.4% and 22.84%. The in vivo results demonstrated significant increase in drug delivery to the arterial tissue at 0.4 atm versus 0.1 atm at 1 h (23.43 ± 13.59 ng/mg vs. 2.49 ± 1.81 ng/mg, p = 0.026) and 7 days (0.50 ± 0.39 ng/mg vs. 0.018 ± 0.023 ng/mg, p = 0.0496). The result of this study provides an innovative strategic and technical approach to enable targeted liquid therapy.

Balloon-based drug coating delivery to the artery wall is dictated by coating micro-morphology and angioplasty pressure gradients

Paclitaxel coated balloon catheters (PCB) were developed as a polymer-free non-implantable alternative to drug eluting stents, delivering similar drug payloads in a matter of minutes. While PCB have shown efficacy in treating peripheral arterial disease in certain patient groups, restenosis rates remain high and there is no class effect. To help further optimize these devices, we developed a scanning electron microscopy (SEM) imaging technique and computational modeling approach that provide insights into the coating micromorphology dependence of in vivo drug transfer and retention. PCBs coated with amorphous/flaky or microneedle coatings were inflated for 60 sec in porcine femoral arteries. Animals were euthanized at 0.5, 24 and 72 h and treated arteries processed for SEM to image endoluminal coating distribution followed by paclitaxel quantification by mass spectrometry (MS). Endoluminal surfaces exhibited sparse coating patches at 0.5 h, predominantly protruding (13.71 vs 0.59%, P < 0.001), with similar micro-morphologies to nominal PCB surfaces. Microneedle coating covered a 1.5-fold endoluminal area (16.1 vs 10.7%, P = 0.0035) owing to higher proximal and distal delivery, and achieved 1.5-fold tissue concentrations by MS (1933 vs 1298 μg/g, P = 0.1745) compared to amorphous/flaky coating. Acute longitudinal coating distribution tracked computationally predicted microindentation pressure gradients (r = 0.9, P < 0.001), with superior transfer of the microneedle coatings attributed to their amplification of angioplasty contact pressures. By 24 h, paclitaxel concentration and coated tissue areas both declined by >93% even as nonprotruding coating levels were stable between 0.5 and 72 h, and 2.7-fold higher for microneedle vs flaky coating (0.64 vs 0.24%, P = 0.0195). Tissue retained paclitaxel concentrations at 24-72 h trended 1.7-fold higher post treatment with microneedle coating compared to the amorphous/flaky coating (69.9 vs 39.9 μg/g, P = 0.066). Thus, balloon based drug delivery is critically dependent on coating micromorphologies, with superior performance exhibited by micromorphologies that amplify angioplasty pressures.

Increased mortality with paclitaxel-eluting stents is driven by lesion length

BACKGROUND

Endovascular stenting has become the first-line treatment of symptomatic peripheral artery disease of the femoropopliteal axis (FPA). Several randomized clinical trials have reported that paclitaxel-eluting stents (PESs) significantly reduce the rates of restenosis. However, a meta-analysis investigating paclitaxel-coated devices in the FPA showed a significant increase in all-cause mortality after the use of PES. The aim of this study was to compare the long-term, real-world outcomes of bare-metal stents (BMSs) and PESs for treating FPA occlusive disease.

METHODS

A retrospective review of the medical records of 296 patients who underwent FPA stenting between January 2011 and December 2017 was performed. Patients were grouped into BMS and PES groups. The primary end point was all-cause mortality. Secondary end points included limb salvage, primary patency, primary assisted patency, and secondary patency. A comparison between the two groups within TransAtlantic Inter-Society Consensus (TASC) II subgroups was also performed.

RESULTS

Of the study cohort, 101 patients (34%) received PES, whereas 195 patients (66%) underwent BMS placement. Median follow-up time was 23 months (interquartile range, 7-40 months). The 2-year all-cause mortality estimates were 12% for the PES group compared with 11.4% for the BMS group (P = .26). There were no differences in the 2-year limb salvage (90.7% vs 92%; P = .4), primary patency (78.8% vs 81.1%; P = .62), primary assisted patency (100% vs 96.5%; P = .4), and secondary patency (100% vs 98.6%; P = .26) between the PES and the BMS groups, respectively (all P > .05). These findings persisted when patients were stratified by TASC II lesions. Among patients with TASC C and D lesions, the use of PES was associated with significantly higher 2-year all-cause mortality (23.9% vs 5.1%; P = .05). After adjustment for age and other potential confounders, PES use was associated with significant increase in all-cause mortality (adjusted hazard ratio, 2.3; 95% confidence interval, 1.31-27 P = .02) in TASC C and D patients.

CONCLUSIONS

Consistent with the meta-analysis of several randomized clinical trials, the use of PES in a real-world setting was associated with a twofold increase in the risk of death. However, these findings were seen only among patients with TASC C and D lesions, who required multiple longer stents and potentially larger paclitaxel dose. There was no advantage in terms of patency in PES vs BMS in this population with extensive disease. Further studies of larger populations are required.

Kounis Syndrome after Angioplasty of the Superficial Femoral Artery with Paclitaxel-Coated Balloon

Drug-coated balloons are used widely as a form of endovascular treatment for peripheral arterial disease, to improve patency by reducing neointimal hyperplasia and restenosis. We present a rare case of acute coronary syndrome secondary to anaphylaxis after inflation of a paclitaxel-coated balloon used to treat a recurrent superficial femoral artery stenosis.

Sustained drug retention after paclitaxel-coated balloon angioplasty for superficial femoral artery disease: Follow-up intravascular imaging

A 63 year-old woman with claudication underwent endovascular therapy for diffuse stenosis of the right superficial femoral artery in our hospital. We performed paclitaxel-coated balloon angioplasty using the IN.PACT™ Admiral™ and achieved acceptable results. After 42 days, we performed follow-up optical frequency domain imaging for the right superficial femoral artery lesion treated with paclitaxel-coated balloon and observed several high-intensity regions with attenuation on the lumen surface. Sustained drug availability is a notable characteristic of paclitaxel-coated balloon. To the best of our knowledge, this is the first report on the visualization of sustained drug retention on the lumen surface using follow-up optical frequency domain imaging after paclitaxel-coated balloon angioplasty in a human patient with superficial femoral artery disease.

A universal drug delivery catheter for the treatment of infrapopliteal arterial disease using liquid therapy

OBJECTIVE

The objective of this study was to investigate the safety and feasibility of treating infrapopliteal lesions using a novel drug delivery catheter locally delivering liquid paclitaxel.

BACKGROUND

Balloon angioplasty is currently the Gold Standard to treat below-the-knee disease; however, restenosis continues to be a great challenge following these percutaneous revascularization procedures.

METHODS

The Occlusion Perfusion Catheter for Optimal Delivery of Paclitaxel for the Prevention of Endovascular Restenosis (COPPER-A) study-Below-the-Knee Cohort was a prospective, nonrandomized, multicenter, feasibility, and safety study that enrolled 35 patients at 11 participating sites. The safety endpoints at 1, 3, and 6 months were freedom from thrombosis, major amputation in the target limb and target limb related death. The efficacy endpoints were primary patency and freedom from clinically driven target lesion revascularization at 6 months.

RESULTS

All patients tolerated the procedure well with no reports of adverse procedural events. Thirty-five patients were treated with a mean lesion length of 112 ± 81.2 mm with the lesion length range of 20-286 mm. At 6-month follow-up, primary patency was 89.3% and freedom from clinically driven target lesion revascularization was 96.4%. No patients demonstrated thrombosis, major amputation in the target limb and target limb related death at the 1-, 3- and 6-months follow-up intervals.

CONCLUSIONS

The results of this multi-center study demonstrated that infrapopliteal arteries can be safely and effectively treated with liquid paclitaxel using the occlusion perfusion catheter.

Risk of Death and Amputation with Use of Paclitaxel-Coated Balloons in the Infrapopliteal Arteries for Treatment of Critical Limb Ischemia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

A formal systematic review and study-level meta-analysis of randomized controlled trials investigating treatment of the infrapopliteal arteries with paclitaxel-coated balloons compared with conventional balloon angioplasty for critical limb ischemia (CLI) was conducted. Medical databases and online content were last screened in September 2019. The primary safety and efficacy endpoint was amputation-free survival defined as freedom from all-cause death and major amputation. Target lesion revascularization (TLR) constituted a secondary efficacy endpoint. Summary effects were synthesized with a random-effects model. Some 8 randomized controlled trials with 1,420 patients (97% CLI) were analyzed up to 1 year follow-up. Amputation-free survival was significantly worse in case of paclitaxel (13.7% crude risk of death or limb loss compared to 9.4% in case of uncoated balloon angioplasty; hazard ratio 1.52; 95% confidence interval: 1.12-2.07, p = .008). TLR was significantly reduced in case of paclitaxel (11.8% crude risk of TLR versus 25.6% in control; risk ratio 0.53; 95% confidence interval: 0.35-0.81, p = .004). The harm signal was evident when examining the high-dose (3.0-3.5 μg/mm²) devices, but attenuated below significance in case of a low-dose (2.0 μg/mm²) device. Actual causes remain largely unknown, but non-target paclitaxel embolization is a plausible mechanism.

Viral Induced Oxidative and Inflammatory Response in Alzheimer's Disease Pathogenesis with Identification of Potential Drug Candidates: A Systematic Review using Systems Biology Approach

Alzheimer's disease (AD) is genetically complex with multifactorial etiology. Here, we aim to identify the potential viral pathogens leading to aberrant inflammatory and oxidative stress response in AD along with potential drug candidates using systems biology approach. We retrieved protein interactions of amyloid precursor protein (APP) and tau protein (MAPT) from NCBI and genes for oxidative stress from NetAge, for inflammation from NetAge and InnateDB databases. Genes implicated in aging were retrieved from GenAge database and two GEO expression datasets. These genes were individually used to create protein-protein interaction network using STRING database (score≥0.7). The interactions of candidate genes with known viruses were mapped using virhostnet v2.0 database. Drug molecules targeting candidate genes were retrieved using the Drug- Gene Interaction Database (DGIdb). Data mining resulted in 2095 APP, 116 MAPT, 214 oxidative stress, 1269 inflammatory genes. After STRING PPIN analysis, 404 APP, 109 MAPT, 204 oxidative stress and 1014 inflammation related high confidence proteins were identified. The overlap among all datasets yielded eight common markers (AKT1, GSK3B, APP, APOE, EGFR, PIN1, CASP8 and SNCA). These genes showed association with hepatitis C virus (HCV), Epstein- Barr virus (EBV), human herpes virus 8 and Human papillomavirus (HPV). Further, screening of drugs targeting candidate genes, and possessing anti-inflammatory property, antiviral activity along with a suggested role in AD pathophysiology yielded 12 potential drug candidates. Our study demonstrated the role of viral etiology in AD pathogenesis by elucidating interaction of oxidative stress and inflammation causing candidate genes with common viruses along with the identification of potential AD drug candidates.

An Experimental Study of Paclitaxel Embolisation During Drug Coated Balloon Angioplasty

OBJECTIVE

Drug coated balloons (DCB) improve the patency of femoropopliteal angioplasty but their use in infrapopliteal lesions is debateable as paclitaxel (PTX) particle embolisation has been suspected in some trials. The aim of this study was to compare experimentally five DCBs in terms of distal embolism of PTX.

METHODS

Twenty-five New Zealand rabbits were divided into five groups according to the DCB used: Lutonix (Bard), In.Pact (Medtronic), Passeo-18 Lux (Biotronik), Ranger (Boston Scientific), and Stellarex (Spectranetics) (n = 5 in each group). After ligation of the right common iliac artery, a 4 × 40 mm DCB was inflated in the infrarenal aorta for 180 seconds. Rabbits were euthanised two hours after inflation of the DCB. The infrarenal aorta, a blood sample and three left hind leg muscles (tensor fasciae latae [TFL], vastus lateralis [VL], and tibialis anterior [TA] muscles) were harvested for blind measurement of PTX concentrations and histological analysis (PTX emboli count).

RESULTS

In the TA muscle (the most distal), concentrations of PTX were significantly lower for the Ranger (0.067 ng/mg) than for the Lutonix (0.342 ng/mg; p = .008), In.Pact (0.370 ng/mg; p = .012), and Passeo-18-Lux (0.160 ng/mg; p = .021) DCBs. Similarly, concentrations of PTX were significantly lower for the Passeo-18-Lux than for the In.Pact (p = .028). Concentrations of PTX were not significantly different between DCBs in the TFL and VL muscles. Concentrations of PTX were found to be significantly higher in the plasma and lower in the aorta and on the DCBs after use of Lutonix compared with the four other DCBs. Histological analysis revealed evidence of embolised PTX crystals in small arterioles of all muscle tissue samples without any significant difference between the DCBs.

CONCLUSIONS

This study suggests some differences regarding distal embolisation profiles between the five assessed DCBs. Although clinical implications remain to be demonstrated, the present results may have implications when choosing a DCB, especially in a critical limb ischaemia setting.

Risk of Death Following Application of Paclitaxel-Coated Balloons and Stents in the Femoropopliteal Artery of the Leg: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background Several randomized controlled trials ( RCT s) have already shown that paclitaxel-coated balloons and stents significantly reduce the rates of vessel restenosis and target lesion revascularization after lower extremity interventions. Methods and Results A systematic review and meta-analysis of RCT s investigating paclitaxel-coated devices in the femoral and/or popliteal arteries was performed. The primary safety measure was all-cause patient death. Risk ratios and risk differences were pooled with a random effects model. In all, 28 RCT s with 4663 patients (89% intermittent claudication) were analyzed. All-cause patient death at 1 year (28 RCT s with 4432 cases) was similar between paclitaxel-coated devices and control arms (2.3% versus 2.3% crude risk of death; risk ratio, 1.08; 95% CI, 0.72-1.61). All-cause death at 2 years (12 RCT s with 2316 cases) was significantly increased in the case of paclitaxel versus control (7.2% versus 3.8% crude risk of death; risk ratio, 1.68; 95% CI, 1.15-2.47; -number-needed-to-harm, 29 patients [95% CI , 19-59]). All-cause death up to 5 years (3 RCT s with 863 cases) increased further in the case of paclitaxel (14.7% versus 8.1% crude risk of death; risk ratio, 1.93; 95% CI , 1.27-2.93; -number-needed-to-harm, 14 patients [95% CI , 9-32]). Meta-regression showed a significant relationship between exposure to paclitaxel (dose-time product) and absolute risk of death (0.4±0.1% excess risk of death per paclitaxel mg-year; P<0.001). Trial sequential analysis excluded false-positive findings with 99% certainty (2-sided α, 1.0%). Conclusions There is increased risk of death following application of paclitaxel-coated balloons and stents in the femoropopliteal artery of the lower limbs. Further investigations are urgently warranted. Clinical Trial Registration URL : www.crd.york.ac.uk/PROSPERO . Unique identifier: CRD 42018099447.

Relationship Between Postoperative Neutrophil-Lymphocyte Ratio and 6-Month Primary Patency of Percutaneous Transluminal Angioplasty in Femoropopliteal disease With Drug-Coated and Uncoated Balloons

We investigated the relationship of postoperative neutrophil-lymphocyte ratio (NLR) with 6-month primary patency of percutaneous transluminal angioplasty (PTA) in femoropopliteal disease using drug-coated balloon (DCB) or uncoated balloon (UCB). This retrospective study included 106 patients who received DCB (n = 44) or UCB (n = 62). The postoperative NLR was lower in the DCB group than that in the UCB group (2.60 vs 3.23; P = .004), and 6-month primary patency rate was significantly higher in DCB group than that in the UCB group (77.3% vs 53.2%; P = .011). Multivariate logistic analysis showed that the postoperative NLR was an independent predictor of 6-month primary patency after PTA in patients with femoropopliteal disease (odds ratio: 1.589, 95% confidence interval: 1.078-2.343; P = .019). The cutoff value of postoperative NLR was 3.05 for prediction of 6-month primary patency, with a sensitivity of 64.1% and specificity of 65.7%. The 6-month primary patency rate in the NLR ≤3.05 group was higher than that in the NLR >3.05 group (75.9% vs 47.9%; P = .003). In conclusion, DCB may improve early primary patency by inhibiting inflammation. A higher postoperative NLR was associated with early restenosis.

Coating and Pharmacokinetic Evaluation of Air Spray Coated Drug Coated Balloons

Drug coated balloons (DCB) are becoming the standard-care treatment for peripheral arterial disease (PAD). DCB use excipients to transfer and retain anti-proliferative drugs, such as paclitaxel. Excipients thus play a vital role in the design and function of DCB, however methods to coat balloons with excipients and anti-proliferative drugs remain unknown. The goal of this study was to thus develop an approach to coat and evaluate DCB for various excipients. An air sprayer method was developed to deposit paclitaxel and various excipients onto non-coated commercially available angioplasty balloons. The coating of the angioplasty balloons was evaluated for drug deposition and coating efficiency using high performance liquid chromatography tandem mass spectrometry. Drug transfer and retention of the coated angioplasty balloons into arterial segments were evaluated ex vivo using harvested pig arteries in a pulsatile flow bioreactor. The air sprayer method successfully delivered varying excipients including bovine serum albumin (BSA), urea and iohexol. The air spray method was configured to coat four angioplasty balloons simultaneously with paclitaxel and iohexol with an average paclitaxel load of 4.0 ± 0.70 µg/mm². The intra-day (within) and inter-day (between) coating precisions, defined as relative standard deviation (RSD), was 17.2 and 15.5%, respectively. Ex vivo deployment of iohexol-paclitaxel DCB yielded an arterial paclitaxel concentration of 123.4 ± 44.68 ng/mg (n = 3) at 1 h, 126.7 ± 25.27 ng/mg (n = 3) at 1 day, and 12.9 ± 12.88 ng/mg (n = 3) at 7 days. This work provides proof-of-concept of a quick, inexpensive approach to coat commercially available angioplasty balloons with paclitaxel and various excipients.

Decorin gene upregulation mediated by an adeno-associated virus vector increases intratumoral uptake of nab-paclitaxel in neuroblastoma via inhibition of stabilin-1

The availability of effective medication for the treatment of refractory or recurrent neuroblastoma remains limited. This study sought to investigate the effects of increased decorin (DCN) expression on the intratumoral uptake of nab-paclitaxel as a potential novel approach to NB. Correlation between the clinical characteristics of neuroblastoma and the expression of DCN, secreted protein acidic and rich in cysteine (SPARC) and stabilin-1 was evaluated. The anticancer effect of recombinant adeno-associated virus-DCN (rAAV-DCN) was assessed in vivo and in vitro. And the effect of rAAV-DCN on the intratumoral uptake of paclitaxel was also studied in neuroblastoma-grafted nude mice. Overall, 12.5%, 17.7%, and 71.9% of the tumors stained positive for DCN, SPARC and stabilin-1 respectively and correlated to age, stage and N-MYC status in 96 children and adolescents with neuroblastoma. Transfected neuroblastoma cells stably expressed DCN, with in vivo and in vitro studies demonstrating rAAV-DCN sensitized the anticancer effect of nab-paclitaxel. Systemic rAAV-DCN in neuroblastoma-grafted nude mice inhibited stabilin-1, up-regulated SPARC, and increased the intratumoral uptake of paclitaxel. Macrophage depletion or anti-stabilin-1 monoclonal antibody increased the intratumoral uptake of nab-paclitaxel and its anticancer effects to a degree comparable to that achieved by systemic rAAV-DCN. The systemic administration of rAAV-DCN up-regulates DCN in neuroblastoma and accelerates the intratumoral uptake of nab-paclitaxel by inhibiting stabilin-1 mediated SPARC degradation.