A prospective, multi-center study of the chocolate balloon in femoropopliteal peripheral artery disease: The Chocolate BAR registry

Below-the-Knee Endovascular Revascularization: A Position Statement

Patients with chronic limb-threatening ischemia, the terminal stage of peripheral artery disease, are frequently afflicted by below-the-knee disease. Although all patients should receive guideline-directed medical therapy, restoration of inline flow is oftentimes necessary to avoid limb loss. Proper patient selection and proficiency in endovascular techniques for below-the-knee revascularization are intended to prevent major amputation and promote wound healing. This review, a consensus among an international panel of experienced operators, provides guidance on these challenges from an endovascular perspective and offers techniques to navigate this complex disease process.

The Impact of Balloon Pre-dilatation Techniques on Drug-Coated Balloon Therapy for Femoropopliteal Artery Disease: Six-Month Results From the CIVILIAN Registry

OBJECTIVE

The purpose of this study is to compare the initial outcomes of using the Chocolate balloon pre-dilatation (CLP) and sequential enlarging angioplasty pre-dilatation (sequential balloon pre-dilation [SP]) techniques versus the conventional balloon pre-dilatation (CP) method prior to drug-coated balloon (DCB) treatment for femoropopliteal (FP) lesions.

METHODS

This was a retrospective analysis of prospectively collected data from the CIVILIAN (Clinical InVestigation of different lesIon preparation modaLIty followed by DCB in femoropopliteal Artery occlusioN disease) registry. Between March 2021 and November 2022, 3 pre-dilation techniques used prior to the DCB angioplasty were included. The study endpoint included intraoperative finial severe dissection after provisional stent placement, bailout stenting rate, the diameter of the largest pre-dilation balloon and DCB, as well as major adverse events (MAEs), including death, major limb amputation, or target vessel revascularization at 6 months.

RESULTS

During the study period, 435 limbs (429 patients) were pre-dilated before DCB treatment in FP lesions, 166 limbs were pre-dilated with Chocolate balloons, 93 limbs with sequential enlarging balloon pre-dilation technique, and 176 limbs with CP. The largest pre-dilation balloon was significantly larger in CLP and SP groups than that in the CP group (CLP 4.74±0.52 mm vs CP 4.36±0.64 mm, p<0.001; SP 4.82±0.69 mm vs CP 4.36±0.63 mm, p<0.001). A consistent result was shown in DCB diameter (CLP 4.86±0.44 mm vs CP 4.71±0.51 mm, p=0.003; SP 4.90±0.58 mm vs CP 4.71±0.51 mm, p=0.006). The bailout stenting rate was significantly lower in the CLP group than that in the CP group (18.1% vs 30.1%, p=0.011). The rates of MAEs at 6 months in the CLP and SP groups were comparable to those in the CP group (7.2% and 8.6% vs 6.3%, p>0.05). The risk for intraoperative bailout stenting rate was related to TASC D classification (3.59, 95% CI: 1.83-7.05, p<0.001), chronic total occlusion (CTO) lesion (1.82, 95% CI: 1.07-3.10, p=0.028), as well as pre-dilated with the conventional balloon (1.64, 95% CI: 1.00-2.69, p=0.048).

CONCLUSIONS

By utilizing chocolate balloon and sequential enlarging angioplasty, it becomes possible to use larger pre-dilation balloons and DCBs. In addition, the use of the chocolate balloon can significantly reduce the need for bailout stenting when compared with conventional balloons.

CLINICAL IMPACT

The utilization of a chocolate balloon and sequential enlarging angioplasty has emerged as a promising technique for angioplasty procedures. This approach allows for the use of larger pre-dilation balloons and drug-coated balloons. The use of the chocolate balloon can significantly reduce the need for bail-out stenting when compared to conventional balloons. Further research is required to determine the impact of vessel preparation techniques on the primary patency.

Advanced Endovascular Techniques for Limb Salvage

As the number of patients affected by peripheral arterial disease continues to increase, new technical approaches and devices have been developed to provide effective and durable treatment options that will lead to improved outcomes. While the mainstay of endovascular intervention remains mostly balloon-based, several innovative techniques and technologies are in development that may provide new solutions. This review highlights recent endovascular advancements in the management of chronic limb-threatening ischemia and additional adjunctive devices that are needed to improve lesion patency, reduce the need for reintervention, and lead to better patient-centered functional outcomes.

Treatment of Difficult, Calcified Lesions: Plaque Modification Strategies

Endovascular management of peripheral arterial disease is continually evolving. Most changes focus on addressing the challenges that hinder optimal patient outcomes; one of the most significant is how to best treat calcified lesions. Hardened plaque results in a variety of technical issues including impaired device delivery, decreased luminal revascularization, poor stent expansion, heightened risk of in-stent stenosis or thrombosis, and increased procedural time and cost. For this reason, plaque modification devices have been developed to mitigate this issue. This paper will describe these strategies and provide the reader with an overview of devices that can be used to treat chronically hardened lesions.

Specialty Balloons for Vessel Preparation During Infrainguinal Endovascular Revascularization Procedures: A Review of Literature

Balloon angioplasty with/without utilizing drug eluting technology or stenting constitutes the treatment of choice for a significant percentage of patients with peripheral artery disease requiring an intervention. However, in cases of diffuse disease and plaque complexity, angioplasty may lead to dissection, recoil, and/or early restenosis, making vessel preparation a key component for successful and durable endovascular revascularization outcome. This review of literature aims to present contemporary data for several commercially available specialty balloons that have been designed to minimize the arterial wall stress of conventional balloon angioplasty and facilitate technical success, as well as long-term patency.

Impact of Chocolate percutaneous transluminal angioplasty balloon on vessel preparation in drug-coated balloon angioplasty for femoropopliteal lesion

Purpose

To compare the impact of Chocolate and conventional balloons on vessel preparation in percutaneous transluminal angioplasty.

Materials and methods

This single-center retrospective study included 111 endovascular therapy consecutive cases of femoropopliteal lesions using drug-coated balloon strategy with a 1:1 pre-dilation balloon diameter between February 2020 and August 2021, divided into the Chocolate percutaneous transluminal angioplasty (n = 48) and conventional (n = 63) groups. Before the availability of Chocolate balloons in Japan (December 2020), a standard semi-compliant or non-compliant balloon was used for vessel preparation. The primary endpoint was rate of severe dissection after pre-dilatation. Secondary endpoints were angiographic percent diameter stenosis, bailout stent rate, primary patency rate, and freedom from target-lesion-revascularization rate at six months.

Results

There was no significant difference in patient and lesion characteristics. The procedural characteristics comprised balloon length 90 ± 37 and 149 ± 95 mm (P = 0.004) and inflation pressure 11 ± 3 and 16 ± 7 atm (P < 0.001) in the Chocolate and conventional groups, respectively. Regarding primary endpoint, rates of severe dissection were 4.2% and 25% (P = 0.003); regarding secondary endpoints, percent diameter stenosis was 18 ± 15% and 20 ± 17% (P = 0.409), and the rate of bailout stenting was 2.1% and 15.9% (P = 0.016) in the Chocolate and conventional groups, respectively. The primary patency rates at six months were 89.1% and 85.2% (P = 0.670), and freedom from target-lesion-revascularization rate at six months was 100% and 92.8% (P = 0.691) in the Chocolate and conventional groups, respectively.

Conclusion

Chocolate percutaneous transluminal angioplasty balloons reduce the rate of severe dissection while maintaining a sufficient dilatation effect during drug-coated balloon vessel preparation.

Endovascular Materials and Their Behavior in Peripheral Vascular Surgery

Endovascular techniques have progressively become the first option for the treatment of stenosis and occlusions of both aorto-iliac and femoro-popliteal district. The development of new technologies and new materials has broadened the applicability of the endovascular techniques, allowing the treatment of each lesion with the most suitable material. A knowledge of the behavior of endovascular materials when treating peripheral arterial disease (PAD) is, therefore, crucial for optimization of the results. Here, we aim to review the most important technical features of the actually available endovascular materials for treating PAD.

A Randomized Trial of Chocolate Touch Compared with Lutonix Drug-Coated Balloon in Femoropopliteal Lesions (The CHOCOLATE TOUCH Study)

BACKGROUND

First-generation drug-coated balloons (DCBs) have significantly reduced the rate of restenosis compared with balloon angioplasty alone; however, high rates of bailout stenting and dissections persist. The Chocolate Touch DCB is a nitinol constrained balloon designed to reduce acute vessel trauma and inhibit neointima formation and restenosis.

METHODS

Patients with claudication or ischemic rest pain (Rutherford class 2-4) and superficial femoral or popliteal disease (≥70% stenosis) were randomized 1:1 to Chocolate Touch or Lutonix DCB at 34 sites in the United States, Europe, and New Zealand. The primary efficacy endpoint was DCB success defined as primary patency at 12 months (peak systolic velocity ratio <2.4 by duplex ultrasound without clinically driven target lesion revascularization in the absence of clinically driven bailout stenting). The primary safety endpoint was freedom from major adverse events at 12 months, a composite of target limb-related death, major amputation, or re-intervention. Both primary endpoints were tested for non-inferiority, and if met, sequential superiority testing for efficacy followed by safety was prespecified. An independent clinical event committee, angiographic and duplex ultrasound core laboratories blinded to treatment allocation reviewed all endpoints.

RESULTS

A total of 313 patients were randomized to Chocolate Touch (n=152) versus Lutonix DCB (n=161). Follow-up at 1 year was available in 94% of patients. Mean age was 69.4±9.5 years, the average lesion length was 78.1±46.9 mm, and 46.2% had moderate-to-severe calcification. The primary efficacy rates of DCB success at 12 months was 78.8% (108/137) with Chocolate Touch and 67.7% (88/130) with Lutonix DCB (difference 11. %; 95% confidence interval [CI] 0.6-21.7), meeting non-inferiority (P_{non-inferiority}<0.0001) and sequential superiority (P_superiority=0.04). The primary safety event rate was 88.9% (128/144) with Chocolate Touch and 84.6% (126/149) with Lutonix DCB (P_{non-inferiority}<0.001, P_superiority=0.27).

CONCLUSIONS

In this prospective, multicenter, randomized trial, the second-generation Chocolate Touch DCB met both non-inferiority endpoints for efficacy and safety and was more effective than Lutonix DCB at 12 months for the treatment of femoropopliteal disease.

An update on vessel preparation in lower limb arterial intervention

Background

Plain balloon angioplasty has traditionally been used to treat lower limb arterial disease but can be limited by significant residual stenosis, vessel recoil, dissection, and by late restenosis. Appropriate vessel preparation may significantly improve short and long-term outcomes. We aim to give an overview of some of the devices currently available, or under investigation, for vessel preparation in the lower limb.

Main text

Vessel preparation devices include those that remove plaque (atherectomy devices) and those that modify plaque.

The four groups of plaque removing atherectomy devices are defined by their plaque removal method: Directional, rotational orbital and excimer laser are categories of devices investigated for plaque modification.

Intravascular lithotripsy devices generate sonic pulsatile pressure waves that pass into the vessel wall cracking calcified plaques whilst sparing soft tissue. This enables dilatation of calcified lesions at low pressure by conventional balloons and enables full stent expansion.

Other balloon based vessel preparation devices were designed to modify plaque and produce more controlled, lower pressure luminal expansion without major dissections and potentially with less recoil than conventional angioplasty balloons. Scoring balloons have a helical nitinol element attached to the balloon that scores plaque facilitating uniform luminal enlargement. Further specialty balloons have been developed in recent years, including the Chocolate, Phoenix and Serranator balloons. Finally, the temporary Spur self-expanding retrievable nitinol stent has a series of radially aligned spurs that are driven into the vessel wall by post-dilatation, potentially improving drug delivery.

Conclusion

Lesion specific vessel preparation aims to improve both short and long term outcomes through improved penetration of anti-proliferative drug, maximising luminal gain, reducing the need for stent placement and minimising intimal injury. Some forms of vessel preparation appear to improve short term outcomes; long-term outcomes remain uncertain. An overview of some of the multiple devices available for vessel preparation is presented.

Vessel Preparation Is Essential to Optimize Endovascular Therapy of Infrainguinal Lesions

Symptomatic peripheral arterial disease management involves medical treatment and interventional procedures. Intermittent claudication and critical limb threatened ischemia (CLTI) should be individually considered with specific outcomes and procedures. When intervention is required, an endovascular approach is usually the first-line option. Plain balloon angioplasty was previously used to dilate clinically significant femoropopliteal lesions with variable results. However, over recent years, the use of self-expanding nitinol stents has enabled treatment of long lesions, yielding significantly improved clinical results. Drug-eluting technology has also exhibited a capacity to limit in-stent restenosis and to drive target revascularization. Nevertheless, calcifications and elastic recoil of the arterial wall remain risk factors for early restenosis and failure. Therefore, vessel preparation using specific devices is required to modify vessel compliance and debulk obstructive calcification. In this short review, we provide an overview of the options for gaining lumen before stenting or dilation using drug-coated balloons.

Recent advances in endovascular treatment of peripheral arterial disease

As associated co-morbidities have transformed over time, the evaluation and management of peripheral arterial disease have evolved as well. New classification systems have been created to better understand the severity of a patient’s condition and the risk of amputation. These classifications include the Wound, Ischemia, and Foot Infection (WIfI) and Global Anatomic Staging System (GLASS) classification systems. Through the utility of these systems, a patient’s disease can be appropriately staged and managed with medical, endovascular, or surgical therapies or a combination of these. Endovascular therapies specifically have grown with the explosion of new technologies. There are numerous options for patients with disease amenable to endovascular therapy. In this review article, we discuss a number of these different endovascular therapies as well as the new classification systems.

Novel balloon technologies to minimize dissection of peripheral angioplasty

INTRODUCTION

Percutaneous transluminal angioplasty (PTA) currently remains the endovascular treatment of choice in a large percentage of patients suffering from peripheral artery disease (PAD). However, the mechanism of angioplasty itself can cause some extent of arterial dissection leading to early vessel restenosis/reocclusion. Current endovascular imaging studies have reported a higher rate of arterial dissection than previously reported in literature and advocated the correlation of dissection with poor patency. Thus, there is the need of developing devices to minimize dissection and bailout stenting.

AREAS COVERED

The present review focuses on newly-developed balloon angioplasty technologies designed to minimize arterial wall distress and consequently the rate of dissections. Available literature regarding three new specialty balloons is being reviewed, highlighting their value and limitations. Authors' future perspective about the benefits of utilizing specialty balloons towards a metal free and dissection free future is also provided.

EXPERT OPINION

By understanding the mechanism of angioplasty and thus developing devices which cause minimal or no arterial wall distress, the rate of dissections and bailout stenting can be minimized and long-term clinical outcomes of endovascular therapy can be optimized.

Is vessel prep necessary before treating the superficial femoral artery?

The standard of care for treating symptomatic peripheral arterial disease has been percutaneous transluminal angioplasty with or without stenting over the last couple of years. This endovascular treatment of claudicants or patients with critical limb ischemia has increased in numbers and has even surpassed open surgery. Our daily practice has evolved to an endovascular-first approach, especially in the femoropopliteal region, being the most frequently treated vessel. However, neointimal hyperplasia and elastic recoil leading to target lesion restenosis or occlusion after initial successful treatment is not uncommon. In recent years, drug-eluting technologies on balloons or stents have been investigated as a potential solution for this problem with excellent results compared to plain-old balloon angioplasty. Nonetheless in the majority of those trials, the bailout stenting rate increased with lesion complexity, albeit it in long or heavily calcified lesions due to flow-limiting dissections, elastic recoil or the calcium barrier preventing adequate drug uptake. There is a need for vessel preparation in order to ameliorate drug delivery, especially in complex lesions. Multiple devices are available to prepare even the most challenging lesions for drug uptake or stenting, by achieving maximal luminal gain and by minimizing dissections. This review aims to give an overview of the most common modalities for vessel preparation in the superficial femoral artery beside plain old balloon angioplasty together with an overview of the current literature of each device in the superficial femoral artery.

Dissections After Infrainguinal Percutaneous Transluminal Angioplasty: A Systematic Review and Current State of Clinical Evidence

Purpose: To systematically review the literature and extract information on the definitions, prevalence, implications, and treatment of dissections after infrainguinal balloon angioplasty, with a goal of summarizing current data and identifying gaps in knowledge to help direct future research. Materials and Methods: A systematic review was performed according to the PRISMA guidelines. Medline (PubMed), Scopus, and Cochrane CENTRAL databases were reviewed for prospective and retrospective studies reporting dissection identification, characterization, incidence, severity, and/or outcomes after infrainguinal balloon angioplasty up to January 30, 2019. The electronic search resulted in 288 studies. From these, 153 full-text articles were assessed, and 51 published from 1964 to 2018 were selected as relevant to this systematic review. Because of the significant between-study differences in lesion characteristics, reporting methods, and lack of core laboratory adjudication, the findings were summarized from each study, but the results were not pooled. Results: The mechanism of percutaneous transluminal angioplasty (PTA) consists of adventitial stretching, medial necrosis, and controlled dissection or plaque fracture. PTA-induced dissections can precipitate pathological high and low shear hemodynamic defects and have been implicated as a contributing factor in procedural complications as well as restenosis at the treatment site. The development of significant dissection after PTA often leads to the use of adjunctive therapies, including stent placement. Despite the ubiquitous nature of dissection after balloon angioplasty (incidence 7.4% to 84%), limited data are available to categorize dissections in the peripheral arteries and direct subsequent treatments to improve vessel patency. With the increased utilization of drug-coated balloon angioplasty, understanding the outcomes of postangioplasty dissection has become increasingly important, as the decision to treat dissections with additional strategies has therapeutic and economic implications. Conclusion: All post-PTA dissections in the femoropopliteal arteries may benefit from a treatment approach that ensures optimal hemodynamics with long-term durability in treated lesions. Further understanding the importance of postangioplasty dissections, along with the development of new technologies, will help optimize the patency of endovascular interventions.

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.

PRELUDE Prospective Study of the Serranator Device in the Treatment of Atherosclerotic Lesions in the Superficial Femoral and Popliteal Arteries

Purpose: To evaluate the safety and efficacy of the Serranator Alto PTA Serration Balloon Catheter in subjects with peripheral artery disease in the superficial femoral and popliteal arteries. Materials and Methods: A prospective, multicenter, single-arm feasibility study enrolled 25 patients (mean age 66 years; 18 men) to evaluate Serranator inflation and postinflation effects under monitoring by independent core laboratories. Inclusion criteria were claudication or ischemic rest pain, de novo lesions or native artery restenosis, >70% stenosis, lesion length <10 cm, and a reference vessel diameter of 4 to 6 mm. Chronic total occlusions (CTO) up to 6 cm in length were allowed (n=8). The primary safety endpoint was 30-day major adverse events. Primary efficacy outcome was device success with final diameter stenosis <50%. The secondary objective was to confirm the presence of serrations across the lesions using optical coherence tomography (OCT) or intravascular ultrasound (IVUS) following treatment in a subset of 10 subjects. Follow-up evaluations were conducted at 30 days and 6 months. Results: Technical success of device delivery and retrieval was 100%. The primary safety endpoint was met, with no patients experiencing a major adverse event in the first 30 days. Pretreatment stenosis of 88% was reduced to 23%. One stent was implanted for grade D dissection in a CTO. The core laboratory–adjudicated primary patency was 100% at 1 month and 64% at 6 months. Serrations were confirmed in all 10 OCT/IVUS images reviewed by the core laboratory. The Rutherford category showed significant and sustained improvement at 6 months. Conclusion: The Serranator is a safe and efficacious angioplasty balloon catheter system. This new design provides an exciting potential for optimizing vessel preparation and aiding drug delivery.

Recanalization of bilateral axillaris/brachialis artery occlusion in a patient with Takayashu arteritis: First case report on using a novel drug-coated nitinol "chocolate" balloon catheter

When fibrosis develops in Takayasu arteritis (TA), endovascular treatment may become necessary. A 63-year-old woman with TA underwent PTA with a nitinol-structured (chocolate-like) drug-coated balloon (C-DEB PTA). She remained in remission for >1 year. The case may foster research into the use of C-DEB PTA in TA.

The evidence to support the use of focal force balloon technology to improve outcomes in the treatment of lower extremity arterial occlusive disease

Despite recent advances in endovascular therapy of lower extremity atherosclerotic disease, mainly driven through drug eluting balloon angioplasty, treatment of complex lesions remains challenging. Drug-eluting balloons work less well in heavily calcified lesions and in particular long lesions often require bail-out stenting. Lesion preparation, as a stand-alone treatment or before delivering antiproliferative therapy or scaffolding, has gained increased recognition in recent years. Focal force or other specialty balloons are designed to prepare complex lesions to improve acute technical success and, ideally, long term patency of the vessel. There are numerous dedicated balloons on the market that use different modes of action to prepare the lesions. The current review focuses on mechanistic insights and the evidence behind those specialty balloons.