Incidence, anatomical location, and clinical significance of compressions and fractures in infrapopliteal balloon-expandable metal stents

Surgical and Endovascular Therapies for Below-the-Knee Peripheral Arterial Disease: A Contemporary Review

Peripheral arterial disease (PAD) represents one of the most prevalent cardiovascular disease processes and carries a high burden of morbidity and mortality. Patients with chronic limb-threatening ischemia (CLTI), the most severe manifestation of PAD, have the highest rates of cardiovascular morbidity and mortality of the overall PAD population. Patients with below-the-knee (BTK) PAD have an increased propensity toward CLTI due to small-vessel caliber and the frequently comorbid conditions of end-stage renal disease and diabetes mellitus, which tend to affect small artery beds preferentially. For those with BTK PAD with CLTI, the standard of care is revascularization. Early revascularization was performed using surgical bypass. However, endovascular techniques, starting with percutaneous transluminal angioplasty and expanding to the modern armamentarium of adjunctive devices and therapies, have become standard of care for most patients with CLTI due to BTK PAD. In this review, we will discuss the modern surgical and endovascular approaches to revascularization, as well as devices that are currently in development or preapproval study for the treatment of BTK PAD.

Efficacy and Safety of Absorb Everolimus-Eluting Bioresorbable Vascular Scaffold in Peripheral Artery Disease: A Single-Arm Meta-Analysis

PURPOSE

This study aimed to evaluate the benefits and risks of patients with peripheral artery disease (PAD) treated with Absorb everolimus-eluting bioresorbable vascular scaffold (BVS) by analyzing all the published studies on the clinical characteristics of patients with PAD.

MATERIALS AND METHODS

PubMed, Embase, and the Cochrane Library were searched for relevant studies. Efficacy, safety, and basic characteristics were analyzed.

RESULTS

Four studies were included in meta-analysis, including a total number of 155 patients with PAD. The pooled overall primary patency, freedom from target lesion revascularization (TLR), symptom resolution, and wound healing were 90%, 96%, 94%, and 86%, respectively. The pooled perioperative complication and all-cause mortality were 4% and 9%, respectively. Preoperative total occlusion was detected in 43 of 192 lesions (22%). The mean lesion length was 27.26 mm. In terms of comorbidities, the pooled percentage of hypertension, hyperlipidemia, diabetes mellitus, coronary artery disease, chronic kidney disease history, and smoking were 65%, 74%, 49%, 43%, 20%, and 57%, respectively.

CONCLUSION

Among these studies, hypertension, hyperlipidemia, and diabetes mellitus were the most common comorbidities in patients with PAD. The Absorb everolimus-eluting BVS was safe and showed the favorable clinical outcomes in both patency and TLR, especially in infrapopliteal disease with heavy calcification. The conclusions of this meta-analysis still needed to be verified by more relevant studies with more careful design, more rigorous execution, and larger sample size.

Foot Revascularization Avoids Major Amputation in Persons with Diabetes and Ischaemic Foot Ulcers

The study aims to evaluate the effectiveness of foot revascularization in persons with diabetic foot ulcers (DFUs) and below-the-ankle (BTA) arterial disease. Consecutive patients referred for a new active ischaemic DFU requiring lower limb revascularization were considered. Among those, only patients with a BTA arterial disease were included. Revascularization procedures were retrospectively analysed: in the case of successful foot revascularization (recanalization of pedal artery, or plantar arteries or both) or not, patients were respectively divided in two groups, successful foot perfusion (SFP) and failed foot perfusion (FFP). Healing, minor and major amputation at 12 months of follow-up were evaluated and compared. Eighty patients (80) were included. The mean age was 70.5 ± 10.9 years, 55 (68.7%) were male, 72 (90%) were affected by type 2 diabetes with a mean duration of 22.7 ± 11.3 years. Overall 45 (56.2%) patients healed, 47 (58.7%) had minor amputation and 13 (16.2%) major amputation. Outcomes for SFP and FFP were respectively: healing (89.3 vs. 9.1%, p < 0.0001), minor amputation (44.7 vs. 78.8%, p = 0.0001), major amputation (2.1 vs. 36.3%, p < 0.0001). Failed foot revascularization resulted an independent predictor of non-healing, minor amputation, and major amputation. Foot revascularization is mandatory to achieve healing and avoid major amputation in persons with ischaemic DFU and BTA arterial disease.

Effects of external crushing forces on a novel below-the-knee vascular implant

BACKGROUND

The Tack Endovascular System^® is a novel vascular implant designed to focally treat dissections with low radial force and minimal metal burden. As there are currently no approved below-the-knee (BTK) implants in the USA, a unique, 3-stage model was developed to characterize crush deformation and fracture potential of the Tack Endovascular System in BTK arteries.

METHODS

First, 35 Tack^® implants were deployed bilaterally in the posterior tibial, anterior tibial, and peroneal arteries of 3 cadavers, and clinically relevant external forces were applied to simulate BTK crushing deformation including focal load, leg crossing, and leg bending. Intravascular ultrasound images of the implanted vessels were used to assess the magnitude of artery deformation. Outputs of the cadaver testing were input into a finite element analysis (FEA) model to determine the appropriate conditions for subsequent bench testing. Tack implants were then subjected to increasing crush forces at 30Hz for up to 650,000 cycles at 25% flat plate deformation within the worst-case FEA test condition.

RESULTS

Crush deformation across all arteries ranged from 0% to 23.1%. The posterior tibial artery and large male cadaver exhibited the most vulnerability to external crush forces, while the small female model exhibited the most resistance. No fractures were observed during cadaver or bench testing.

CONCLUSIONS

This study characterized deformation forces in tibial arteries during various loading conditions. Tack implants withstood the loading conditions without fracture within the limits of this ex-vivo human vascular model and in-vitro bench testing.

Balloon Angioplasty of Infrapopliteal Arteries: A Systematic Review and Proposed Algorithm for Optimal Endovascular Therapy

Endovascular revascularization has been increasingly utilized to treat patients with chronic limb-threatening ischemia (CLTI), particularly atherosclerotic disease in the infrapopliteal arteries. Lesions of the infrapopliteal arteries are the result of 2 different etiologies: medial calcification and intimal atheromatous plaque. Although several devices are available for endovascular treatment of infrapopliteal lesions, balloon angioplasty still comprises the mainstay of therapy due to a lack of purpose-built devices. The mechanism of balloon angioplasty consists of adventitial stretching, medial necrosis, and dissection or plaque fracture. In many cases, the diffuse nature of infrapopliteal disease and plaque complexity may lead to dissection, recoil, and early restenosis. Optimal balloon angioplasty requires careful attention to assessment of vessel calcification, appropriate vessel sizing, and the use of long balloons with prolonged inflation times, as outlined in a treatment algorithm based on this systematic review. Further development of specific devices for this arterial segment are warranted, including devices for preventing recoil (eg, dedicated atherectomy devices), treating dissections (eg, tacks, stents), and preventing neointimal hyperplasia (eg, novel drug delivery techniques and drug-eluting stents). Further understanding of infrapopliteal disease, along with the development of new technologies, will help optimize the durability of endovascular interventions and ultimately improve the limb-related outcomes of patients with CLTI.

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.

Below-the-ankle arterial disease severely impairs the outcomes of diabetic patients with ischemic foot ulcers

AIM

To evaluate the impact of below-the-ankle (BTA) arterial disease in people with ischemic diabetic foot ulcers (DFUs).

METHODS

Patients with ischemic DFUs treated by a pre-set limb salvage protocol including peripheral revascularization were included. They were divided in two groups according to the involvement of BTA arteries (BTA+) or not (BTA-). Not healing, minor amputation, major amputation and mortality have been evaluated as primary outcome. Revascularization failure has been evaluated as secondary outcome.

RESULTS

The study group was composed of 272 patients, 120 (44.1%) belonging to BTA+ group and 152 (55.9%) to BTA-. After 1 year of follow-up the outcomes for BTA+ and BTA- were respectively: not healing (40.8 vs 17.8%, p < 0.0001), minor amputation (80.8 vs 20.4%, p < 0.0001), major amputation (18.3 vs 6.6%, p = 0.002), mortality (16.7% vs 10.5%, p = 0.001). The rate of revascularization failure was respectively 38.3 vs 11.2%, p < 0.0001. At the multivariate analysis BTA arterial disease resulted an independent predictor of not healing [OR 3.5 (CI 95% 2.3-6.1) p = 0.0001], minor amputation [OR 3.1 (1.5-5.9) p < 0.0001] and revascularization failure [OR 3.5 (1.9-6.3) p = 0.0001]. BTA+ patients with successful BTA revascularization showed lower rate of not healing (37.8 vs 89.1%) p < 0.0001, minor amputation (74.3 vs 91.3%) p = 0.002 and major amputation (8.1 vs 34.8%) p = 0.0003 in comparison to patients with unsuccessful BTA revascularization.

CONCLUSION

BTA arterial disease severely impairs the outcomes of diabetics with ischemic foot ulcers. BTA revascularization reduces the rate of not healing, minor and major amputation.

Current concepts regarding drug dosing for peripheral stents

Drug-eluting stent (DES) are the mainstay therapy for the treatment of coronary artery disease. Stent design and drug-elution strategies have evolved over the years leading to the last generation DES which shows optimal safety and efficacy outcome. Peripheral arteries have different mechanical and biological features and the lessons learned from the coronary field have been difficult to introduce into the development of peripheral vascular technologies. First, due to its complex biomechanical behavior the use of metallic stents is limited in some vascular segments (i.e., distal superficial fermoral artery [SFA]). Also, peripheral vascular atherosclerosis is different containing higher levels of plaque burden and calcium. Finally, peripheral arterial disease tends to be more aggressive including longer lesions and higher incidence of total chronic occlusion. In general terms, restenosis in the peripheral vascular territory is more aggressive and occurs at a later time (~12 months) requiring a different pharmacokinetic profile compared to coronary technologies. Several strategies have been evaluated in the peripheral arteries raging from the bare metal stent to the drug coated balloon and drug eluting stent with outcome varying depending on the different field of application (i.e. SFA and below-the-knee). Results coming from the clinical trial are encouraging but further studies and direct comparison among the different technologies are demanded to determine the best therapy for peripheral vascular disease.

Below-the-ankle Angioplasty: Current Evidence and Future Perspectives

Over 20 million adults in Europe suffer from peripheral arterial disease (PAD). The annual incidence of PAD is approximately 2.4%, while the annual incidence of critical limb ischaemia (CLI), the last and most severe stage of PAD, has been reported to be 0.4%. Endovascular angioplasty and/or stenting of infrapopliteal disease is, today, an established treatment for critical limb ischaemia. The main technical advantages of endovascular treatment over open bypass surgery include the possibility to revascularise more than one infrapopliteal vessels and, most importantly, to treat outflow pedal vessel disease or even reconstitute the pedal arch. Data of below-the-ankle angioplasty are beginning to sum up and the contribution of pedal arch angioplasty in limb salvage and wound healing are currently under investigation. In this review, currently available data and the future perspectives on below-the-ankle and pedal arch endovascular treatment will be presented.

Six-Month Angiographic and Clinical Outcomes of Therapeutic Ultrasound Pretreatment Associated With Plain Balloon Angioplasty for Below-the-Knee Lesions in Patients With Critical Limb Ischemia: A Prospective, Single-Center Pilot Study

PURPOSE

To evaluate the safety and efficacy of low-frequency, high-intensity ultrasound energy delivered via a new dedicated ultrasound catheter followed by conventional balloon angioplasty to treat calcified infrapopliteal lesions.

MATERIALS AND METHODS

A prospective, nonrandomized, single-center pilot study enrolled 12 patients (mean age 72.2±5.3 years; 8 men) with critical limb ischemia (9 Rutherford category 5 and 3 category 6) between January and November 2017. Of the 19 target lesions, 11 had severe calcification. Patients were treated with the Kapani ultrasound system before conventional balloon dilation. Primary safety endpoints included 30-day death, major target limb amputation, and target vessel acute occlusion. The main efficacy outcome was primary patency at 6 months, defined as freedom from both clinically-driven target lesion revascularization (TLR) and angiographically-defined restenosis (>50% lumen reduction).

RESULTS

Technical success (<30% residual stenosis) was achieved in all lesions without complications or stent implantation. Ultrasound energy was delivered over a mean 185.2±67.3 seconds followed by low-pressure dilation (mean 6.1±1.9 atm). Angiography confirmed primary patency at 6 months in 18 (95%) of 19 lesions. No death, TLR, or amputation was reported in follow-up. Complete ulcer healing was observed in all 12 patients at 6 months.

CONCLUSION

This pilot trial with a small number of patients suggests that low-frequency, high-intensity ultrasound energy delivery followed by plain balloon angioplasty is a safe approach to treat infrapopliteal atherosclerotic lesions. Angiographically-documented results at 6 months indicate a potential for this combined therapy in the treatment of CLI patients with calcified BTK lesions. Further studies on a larger randomized cohort are needed to confirm these positive clinical outcomes.

Current evidence of drug-elution therapy for infrapopliteal arterial disease

New and sophisticated endovascular devices, such as drug-eluting stents (DES) and drug-coated balloons (DCB), provide targeted drug delivery to affected vessels. The invention of these devices has made it possible to address the reparative cascade of arterial wall injury following balloon angioplasty that results in restenosis. DESs were first used for the treatment of infrapopliteal lesions almost 20 years ago. More recently, however, DCB technology is being investigated to improve outcomes of endovascular below-the-knee arterial procedures, avoiding the need for a metallic scaffold. Today, level IA evidence supports the use of infrapopliteal DES for short to medium length lesions, although robust evidence that justifies the use of DCBs in this anatomical area is missing. This review summarizes and discusses all available data on infrapopliteal drug-elution devices and highlights the most promising future perspectives.

Revisiting endovascular treatment in below-the-knee disease. Are drug-eluting stents the best option?

Patients with below-the-knee arterial disease are primarily individuals suffering from critical limb ischemia (CLI), while a large percentage of these patients are also suffering from diabetes or chronic renal failure or both. Available data from randomized controlled trials and their meta-analysis demonstrated that the use of infrapopliteal drug-eluting stents (DES), in short- to medium- length lesions, obtains significantly better results compared to plain balloon angioplasty and bare metal stenting with regards to vascular restenosis, target lesion revascularization, wound healing and amputations. Nonetheless, the use of this technology in every-day clinical practice remains limited mainly due to concerns regarding the deployment of a permanent metallic scaffold and the possibility of valid future therapeutic perspectives. However, in the majority of the cases, these concerns are not scientifically justified. Large-scale, multicenter randomized controlled trials, investigating a significantly larger number of patients than those already published, would provide more solid evidence and consolidate the use of infrapopliteal DES in CLI patients. Moreover, there is still little evidence on whether this technology can be as effective for longer below-the-knee lesions, where a considerable number of DES is required. The development and investigation of new, longer balloon-expanding or perhaps self-expanding DES could be the answer to this problem.

Exacerbated Peri-Stent Contrast Staining on Serial Angiography and Optical Coherence Tomography After Platinum-Chromium Everolimus-Eluting Stent Implantation for Infrapopliteal Artery Lesions

Unlike coronary arteries, little is known about peri-stent contrast staining (PSS) formation after drug-eluting stent (DES) implantation for infrapopliteal arteries. Herein, we report exacerbated PSS assessed by serial angiography and optical coherence tomography (OCT) after platinum-chromium everolimus-eluting stent (PtCr-EES) implantation for infrapopliteal artery lesions. A 68-year-old women with recurrent left critical limb ischemia was admitted to our hospital. Standard endovascular techniques were performed for the popliteal artery (POP) and tibioperoneal trunk (TPT), but residual stenosis occurred. Therefore, a 4.0 × 38-mm PtCr-EES was placed from the distal POP to TPT using OCT guidance. Ten months later, the patient was referred to our hospital due to recurrent left leg rest pain. Angiography showed severe stenosis from the distal POP to the proximal site of the stent, and diffuse in-stent restenosis (ISR). At the ISR site, stent fracture and compression were observed and vessel evaginations were newly detected on OCT. At that time, good angiographic results were obtained by conventional balloon angioplasty alone. At 6 months follow-up, recurrence of ISR was suspected on duplex ultrasonography. Angiography showed no significant ISR, but PSS had markedly exacerbated from focal type to segmental type. OCT showed exacerbated vessel evagination and in-stent thrombus. The incidence and clinical impact of PSS after DES implantation in infrapopliteal artery lesions remain unclear; therefore, careful follow-up may be needed in such cases.

Debulking Atherectomy in the Peripheral Arteries: Is There a Role and What is the Evidence?

Traditional percutaneous balloon angioplasty and stent placement is based on mechanical plaque disruption and displacement within the arterial wall. On the contrary, transcatheter atherectomy achieves atherosclerotic plaque clearance by means of directional plaque excision or rotational plaque removal or laser plaque ablation. Debulking atherectomy may allow for a more uniform angioplasty result at lower pressures with consequently less vessel barotrauma and improved luminal gain, thereby decreasing the risk of plaque recoil and dissection that may require permanent metal stenting. It has been also argued that atherectomy may disrupt the calcium barrier and optimize drug transfer and delivery in case of drug-coated balloon applications. The authors discuss the various types of atherectomy devices available in clinical practice to date and critically appraise their mode of action as well as relevant published data in each case. Overall, amassed randomized and observational evidence indicates that percutaneous atherectomy of the femoropopliteal and infrapopliteal arteries may achieve high technical success rates and seems to lessen the frequency of bailout stenting, however, at the expense of increased risk of peri-procedural distal embolization. Long-term clinical outcomes reported to date do not support the superiority of percutaneous atherectomy over traditional balloon angioplasty and stent placement in terms of vessel patency or limb salvage. The combination of debulking atherectomy and drug-coated balloons has shown promise in early studies, especially in the treatment of more complex lesions. Unanswered questions and future perspectives of this continuously evolving endovascular technology as part of a broader treatment algorithm are discussed.

Crush Deformation of a Balloon-Expandable Stent Implanted in an Infrainguinal Bypass Graft

A 59-year-old man with critical claudication underwent left femoro-anterior bypass grafting, which was uneventful. The graft was tunneled medially across the knee, then anterior to the tibia. His symptoms recurred 1 year later and he was found to have critical stenosis of the vein graft just proximal to the anterior tibial arterial anastomosis. This was treated with scaffolded balloon angioplasty and implantation of a coronary, zotarolimus-eluting balloon-expandable stent, which was also uneventful. However, his claudication again recurred 1 year later. Diagnostic angiography revealed crush, deformation and restenosis of the balloon-expandable stent requiring surgical revision of the bypass graft.

Emerging and Future Therapeutic Options for Femoropopliteal and Infrapopliteal Endovascular Intervention

Despite recent advances in endovascular therapy for peripheral artery disease, current technologies remain limited by rates of long-term restenosis and application to complex lesion subsets. This article presents data on upcoming therapies, including novel drug-coated balloons, drug-eluting stents, bioresorbable scaffolds, novel drug delivery therapies to target arteries, techniques to limit postangioplasty dissection, and treatment of severely calcified lesions.

Drug-eluting balloons for treatment of SFA and popliteal disease - A review of current status

The endovascular treatment of atherosclerotic disease of the infra-inguinal arteries has changed significantly over the last decades. In an attempt to overcome the high restenosis rates that characterize plain balloon angioplasty and stenting using bare mate stents drug-eluting balloon technology has been applied in the treatment of lesions of the superficial femoral and popliteal artery. This paper will give an overview of the rationale and the technology of drug-eluting balloons and will review currently available data from registries and randomized controlled trials.

Endovascular Treatment of Infrapopliteal Peripheral Artery Disease

Endovascular treatment of infrapopliteal disease is focused on the treatment of patients with rest pain or critical limb ischemia (CLI) due to severe atherosclerotic disease. While the evidence base surrounding the comparative effectiveness of endovascular intervention vs. surgery is lacking, many operators have adopted an "endovascular first" approach to the treatment of infrapopliteal atherosclerotic disease due to the lower morbidity of these procedures. This manuscript reviews current data on the endovascular treatment of CLI, including a comparison of endovascular and surgical approaches, current indications for and outcomes with balloon angioplasty of infrapopliteal PAD, angiosome-guided revascularization, and emerging technologies to improve long-term vessel patency after endovascular intervention.

Long-Term Clinical Outcomes of Infrapopliteal Drug-Eluting Stent Placement for Critical Limb Ischemia in Diabetic Patients

PURPOSE

To evaluate long-term clinical outcomes of infrapopliteal drug-eluting stent (DES) placement in insulin-dependent and non-insulin-dependent diabetic patients with critical limb ischemia (CLI).

MATERIALS AND METHODS

A retrospective analysis was performed of all diabetic patients treated with infrapopliteal DES between January 2002 and September 2012. The study's primary outcome measures were patient survival and major amputation-free survival (AFS). Secondary outcome measures included technical success (defined as the creation of a straight line of blood flow to the foot arch with < 30%), identification of independent predictors of primary outcomes, infrapopliteal target limb repeat intervention-free survival, and procedure-related complications.

RESULTS

In total, 214 patients with CLI (168 men [78.5%]; mean age, 70 y ± 9) in 311 limbs, 562 arteries, and 679 lesions were treated. According to Kaplan-Meier analysis, survival rates were 90.8%, 55.5%, and 36.2%, and AFS rates were 94.9%, 90.4%, and 90.4%, respectively, at 1, 5, and 10 years. Target limb repeat intervention-free survival rates were 79.7%, 55.2%, and 49.7%, respectively, at 1, 5, and 10 years. The overall technical success rate was 97.7%. Cox multivariate analysis demonstrated that procedural failure was the only independent predictor of decreased AFS (hazard ratio [HR], 61.3; 95% confidence interval [CI], 13.8-271.9), and statin use was associated with increased survival (HR, 0.55; 95% CI, 0.31-0.98). Coronary disease (HR, 1.9; 95% CI, 1.01-3.54), dialysis (HR, 2.2; 95% CI, 1.21-4.06), and duration of diabetes (HR, 1.5; 95% CI, 1.02-2.34) were identified as independent predictors of decreased survival. Major complications occurred in four of 479 procedures (0.8%).

CONCLUSIONS

Infrapopliteal DES placement for the management of CLI in diabetic patients resulted in a 55.5% 5-year survival rate, with a 90.4% AFS at 5 and 10 years and a 50.3% repeat intervention rate at 10 years. Technical failure was associated with reduced AFS, and statin intake was associated with increased survival.

Contemporary crossing techniques for infrapopliteal chronic total occlusions

The synergism of technical refinement and advanced technology has significantly increased the popularity of infrapopliteal intervention. Since chronic total occlusion (CTO) is a common disorder among patients with symptomatic infrapopliteal artery disease, infrapopliteal CTO intervention is now evolving rapidly in the field of endovascular intervention. Guidewire crossing through the CTO is essential for a successful procedure. We review up-to-date infrapopliteal CTO crossing techniques based on the current literature.

Feasibility of endovascular recanalization of occluded infrapopliteal drug-eluting stents

PURPOSE

To investigate the safety and feasibility of percutaneous endovascular recanalization of late total occlusions of infrapopliteal drug-eluting stents (DES).

METHODS

A retrospective study investigated all 408 infrapopliteal stent procedures performed in 367 patients between January 2007 and October 2013 to identify those who underwent percutaneous reintervention for symptomatic infrapopliteal balloon-expandable DES occlusion. The search identified 49 patients with at least one infrapopliteal DES occlusion in 61 (14.9%) of 408 limbs. Seven (14.3%) patients were excluded from the analysis owing to asymptomatic status (n=6) and acute thrombotic occlusion (n=1), leaving 42 patients who underwent endovascular revascularization of occluded stents in 54 limbs. The study's primary outcomes were technical success and complication rates of endovascular recanalization, while secondary outcomes included limb salvage and the identification of factors influencing primary results.

RESULTS

Technical success was 90.7% (49/54 procedures). Technical failure was seen only in cases of stent collapse and overlapping native popliteal artery-infrapopliteal stent occlusion. According to Kaplan-Meier analysis, survival was 89.6%, 81.1%, and 73.5% at 1, 2, and 3 years, respectively, while limb salvage rates were 86.1%, 79.3%, and 72.7% at the same time points. There was 1 (1.8%) case of distal embolization. No factors influencing outcomes could be identified.

CONCLUSION

Percutaneous recanalization of infrapopliteal stent total occlusions is safe and feasible. Technical failure was noted in cases of stent deformation occurring at the pedal artery and in overlapping native popliteal artery-infrapopliteal stent occlusion.

Bioresorbable scaffolds in peripheral arterial disease

The risk of in-stent restenosis has been dramatically reduced with the use of thin-strut nitinol and balloon-expandable drug-eluting stents in the peripheral arterial territory. However, the presence of a permanent endovascular device is linked to a series of events that can lead to restenosis and stent thrombosis. Significant advances in the technology of bioresorbable materials have delivered the potential for fully bioresorbable scaffolds (BRS), which are able to mechanically support the artery wall and elute an anti-restenotic drug for a predetermined time period after which the scaffold becomes fully absorbed into the vascular wall. Currently, several vascular BRS are available, undergoing evaluation either in clinical trials or in preclinical settings. The aim of this review is to present the new developments in BRS technology, describe the mechanisms involved in the resorption process, and discuss the current and potential future prospects of this innovative treatment option for peripheral arterial disease.

Systematic review and meta-analysis of balloon angioplasty versus primary stenting in the infrapopliteal disease

OBJECTIVES

We performed a systematic review and meta-analysis of comparing balloon angioplasty and primary stenting for symptomatic infrapopliteal disease to evaluate the clinical value of primary stenting in treating infrapopliteal diseases.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed. PubMed (1984-present), ScienceDirect (1980-present), Embase (1990-present), and CBM (1988-present) databases were searched for relevant articles. Finally, 16 studies (published between 2001 and 2013) satisfying the inclusion criteria were identified. The outcome parameters were immediate technical success, 1-year primary patency rate, 1-year limb salvage rate, and 1-year target vessel revascularization (TVR)-free rate. Comparisons were made with balloon angioplasty and primary stenting, and based on the different types of stents, we divided the primary stent group into the bare metal stent (BMS) group and drug-eluting stent (DES) group.

RESULTS

A total of 3789 patients and 4339 limbs constituted our final study population. The technical success rate of balloon angioplasty was 92.29% (95% confidence interval [CI] 88.75%-94.78%). Only 2 study reported the technical failure rates as 4% and 5.2% in the primary stent group. The pooled estimates of 1-year primary patency and TVR-free rate were similarly low in the balloon angioplasty group and BMS group (primary patency: 57.65%, 95% CI 53.54%-61.67% vs 60.95%, 95% CI 48.31%-72.28%, P = .38; TVR-free rate: 73.41%, 95% CI 66.51%-80.08% vs 73.66%, 95% CI 63.58%-81.75%, P = .91). The pooled estimates of 1-year primary patency and TVR-free rate in DES group were 81.10% (95% CI 75.48%-85.67%) and 90.30% (95% CI 85.30%-93.73%), respectively, which were better than those of the BMS and balloon angioplasty groups (P < .001 for both). The pooled estimate of 1-year limb salvage in the balloon angioplasty, BMS, and DES groups was 88.61% (95% CI 85.01%-91.43%), 94.41% (95% CI 89.52%-97.1%), and 95.20% (95% CI 86.97%-98.33%), respectively (P < .001). The BMS and DES groups had higher limb salvage rates than the balloon angioplasty group (P < .001 for both comparisons). The rates of severe complications were low both in the balloon angioplasty and in the primary stent groups.

CONCLUSION

Primary BMS implantation had no advantage over balloon angioplasty in reducing restenosis or revascularization for infrapopliteal disease. Primary DES implantation seems to be a promising treatment for focal infrapopliteal lesions. Publication bias could not be ruled out, and the results should be treated with caution.

Stenting below-the-knee bifurcations with dedicated bifurcation stent BiOSS Lim - first in man case report

The best treatment strategy for below the knee bifurcation disease is not known. We present first two cases with successful implantation of dedicated coronary bifurcation sirolimus eluting stent BiOSS Lim (Balton, Poland) in complex bifurcation and trifurcation lesions of tibioperoneal trunk. Both implantations were uncomplicated with sustained short-term result at 30-day control Duplex ultrasound and remarkable clinical improvement. Our report demonstrates feasibility and short-term effectiveness of implantation of dedicated coronary bifurcation stent in below-the-knee bi- and tri-furcations.

Below-the-ankle angioplasty and stenting for limb salvage: anatomical considerations and long-term outcomes

PURPOSE

To report the long-term angiographic and clinical results in a series of below-the-ankle (BTA) angioplasty procedures and to present some biomechanical issues related to the unique anatomical geometry of the ankle.

METHODS

We performed a retrospective analysis of BTA angioplasty procedures. Clinical end points included technical success, patient mortality, salvage of the treated foot, and repeat target lesion revascularization. Imaging end points included primary patency, binary restenosis of the target lesion at the 50% threshold, and stent integrity (stent fracture, deformation, or collapse). Univariate subgroup analysis was performed.

RESULTS

In total, 40 limbs in 37 patients (age 73.5 ± 8.2 years) with critical limb ischemia were included and 42 inframalleolar lesions (4.2 ± 1.4 cm) were analyzed. Technical success was achieved in 95.2% (40 of 42). Provisional stent placement was performed in 45.2% (19 of 42). Two patients died, and two major amputations occurred up to 3 years. At 1 year, overall primary vessel patency was 50.4 ± 9.1%, lesion binary restenosis rate was 64.1 ± 8.3%, and repeat intervention-free survival was 93.6 ± 4.3% according to life table analysis of all treated lesions. Pairwise subgroup analysis showed that BTA self-expanding stents were associated with significantly higher restenosis and poorer primary patency compared to plain balloon angioplasty or sirolimus-eluting balloon-expandable stents. Significant deformation and/or fracture of balloon-expandable stents placed BTA were identified in five of 11. Dynamic imaging showed that the dorsalis pedis artery is kinked during foot dorsiflexion, whereas the distal posterior tibial artery is kinked during plantar flexion of the foot.

CONCLUSION

BTA angioplasty for critical limb ischemia treatment is safe and feasible with satisfactory long-term results. BTA stent placement must be reserved for bailout indications.

Peripheral applications of drug-coated balloons: past, present and future

Drug-coated balloon (DCB) technologies represent the latest and hottest development in the field of endovascular treatment of peripheral arterial disease. Initial experience with paclitaxel-coated balloon use in the femoral artery has demonstrated lower mid-term restenosis and superior mid-term clinical outcomes in terms of improved wound healing and reduced repeat angioplasty rates compared with standard balloon angioplasty. Many companies are presently developing and/or improving DCB catheters and therefore ongoing, technical improvements of the already existing platforms, new drugs, and innovative carriers are expected. The ongoing basic research studies and various multicenter randomized, controlled trials that are currently in progress will offer valuable scientific insights regarding the long-term effectiveness and other crucial issues, such as efficacy in various vascular beds, optimal balloon dosage, and post angioplasty antiplatelet therapy. Future applications of these devices also could include in-stent restenosis, anastomotic stenosis of surgical bypass, and benign stenoses of the central venous system. The authors envision that DCB angioplasty will evolve to a major paradigm shift in the endovascular treatment of occlusive vascular diseases.

Bifurcation stenting after failed angioplasty of infrapopliteal arteries in critical limb ischemia: techniques and short-term follow-up

OBJECTIVES

To report on the efficacy of drug eluting stents (DES) in below the knee lesions involving arterial bifurcations after failed angioplasty.

BACKGROUND

DES have become a mainstay in the treatment of below the knee lesions. However, little is known about the efficacy of DES in infrapopliteal lesions involving the arterial bifurcations. This is the first report on the endovascular treatment of below-the knee bifurcations.

METHODS

11 patients with critical lower limb ischemia and complex infrapopliteal atherosclerotic disease underwent provisional DES placement in infrapopliteal bifurcation lesions. Clinical and angiographic follow-up data were prospectively collected in all patients.

RESULTS

Technical success was achieved in all cases. After 6 months, the two vessel primary patency (2VPP) rate was 54.5% and the 1VPP rate was 81.8%. Between baseline and the follow-up, mean ankle-brachial index increased from 0.31 ± 0.10 to 0.68 ± 0.16, and mean Rutherford-Becker class decreased from 4.73 ± 0.20 to 3.00 ± 1.41 (P < 0.001 for both comparisons).

CONCLUSIONS

Bifurcation stenting techniques, that are described for the coronary arteries can be also performed in the infrapopliteal arteries. However, early reocclusion was frequent in this case series, when stenting was performed in a bail-out setting. If balloon angioplasty alone leads to no sufficient results in bifurcation lesions, a single stent strategy could also be considered.

Nitric oxide donors for cardiovascular implant applications

In an era of increased cardiovascular disease burden in the ageing population, there is great demand for devices that come in to contact with the blood such as heart valves, stents, and bypass grafts that offer life saving treatments. Nitric oxide (NO) elution from healthy endothelial tissue that lines the vessels maintains haemostasis throughout the vasculature. Surgical devices that release NO are desirable treatment options and N-diazeniumdiolates and S-nitrosothiols are recognized as preferred donor molecules. There is a keen interest to investigate newer methods by which NO donors can be retained within biomaterials so that their release and kinetic profiles can be optimized. A range of polymeric scaffolds incorporating microparticles and nanomaterials are presenting solutions to current challenges, and have been investigated in a range of clinical applications. This review outlines the application of NO donors for cardiovascular therapy using biomaterials that release NO locally to prevent thrombosis and intimal hyperplasia (IH) and enhance endothelialization in the fabrication of next generation cardiovascular device technology.

Endovascular treatment of critical ischemia in the diabetic foot: new thresholds, new anatomies

This review discusses the role of endovascular treatment in diabetic patients with critical limb ischemia (CLI). Angioplasty of the femoropopliteal region achieves similar technical success and limb salvage rates in diabetic and nondiabetic patients. Angioplasty in as many as possible tibial vessels is accompanied by more complete and faster ulcer healing as well as better limb salvage rates compared to isolated tibial angioplasty. Targeted revascularization of a specific vessel responsible for the perfusion of a specific ulcerated area is a promising new approach: it replaces revascularization of the angiographically easiest-to-access tibial vessel, even if this is not directly responsible for the perfusion of the ulcerated area, by revascularization of area-specific vascular territories. In conclusion, the endovascular approach shows very high efficacy in ulcer healing for diabetic patients with CLI. Larger prospective studies are now needed to estimate the long-term results of this approach.

Preservation of aortic arch branches using chimney and sandwich stent grafts

PURPOSE

To share our hybrid endovascular experiences using chimney or sandwich stent grafts for acute aortic arch pathologies.

METHODS

Hybrid procedures for a distal aortic arch aneurysm and an ascending anastomotic aortic aneurysm rupture were reported. Right to left common carotid and left axillar artery bypasses were located. Covered stents were inserted into the inominate artery, with the flow-proximal end located in the ascending (standard chimney) or the descending aortic stent graft (retrograde sandwich).

RESULTS

Both cases had no signs of brain ischemia. Aneurysms are decreasing in size.

CONCLUSION

Chimney and sandwich techniques were technically feasible in the complex and acute situations.

Below-the-knee drug-eluting stents and drug-coated balloons

Endovascular procedures have evolved to the mainstream treatment of choice for revascularization of infrapopliteal obstructive disease, especially in patients suffering from critical limb ischemia and multiple comorbidities. However, standard balloon angioplasty is limited by the potential of a suboptimal acute outcome due to elastic recoil and/or flow-limiting dissection, followed by neointimal hyperplasia and progressive vascular restenosis even in the case of bare-metal stent use. Drug-eluting stents and drug-coated balloons are emerging endovascular technologies with the promise of significant inhibition of vessel restenosis and improved clinical outcomes. The current review outlines the drug-eluting properties of those instruments and summarizes the currently available clinical data. The authors critically appraise the current status and also provide a glimpse of the near future of endovascular below-the-knee treatments.

Randomized comparison of everolimus-eluting versus bare-metal stents in patients with critical limb ischemia and infrapopliteal arterial occlusive disease

OBJECTIVE

Critical limb ischemia, the most severe form of peripheral arterial disease, results in extremity amputation if left untreated. Endovascular recanalization of stenotic or occluded infrapopliteal arteries has recently emerged as an effective form of therapy, although the duration of patency is typically limited by restenosis. Recently, it has been suggested that drug-eluting stents originally developed for the coronary arteries might also be effective in preventing restenosis in the infrapopliteal arteries. This prospective, randomized, controlled clinical trial tested the hypothesis that treatment of infrapopliteal arterial occlusive lesions with an everolimus-eluting stent (Xience V) would provide superior patency to treatment with a bare-metal stent (Multi-Link Vision).

METHODS

A sample size of 140 patients was planned to be enrolled at five European investigative sites. The primary end point was arterial patency at 12 months, defined as the absence of ≥50% restenosis based on quantitative analysis of contrast angiography.

RESULTS

Between March of 2008 and September of 2009, 74 patients were treated with Xience V and 66 patients were treated with Vision. After 12 months, the primary patency rate after treatment with Xience V was 85% compared with 54% after treatment with Vision (P = .0001). Treatment with Xience V significantly reduced mean in-stent diameter stenosis (21% ± 21% vs 47% ± 27%; P < .0001) and mean in-stent late lumen loss (0.78 ± 0.63 vs 1.41 ± 0.89 mm; P = .001). There were no differences in the percentage of patients receiving a designation of Rutherford class 0 or 1 at the 12-month follow-up visit (56% for Vision, vs 60% for Xience V; P = .68). Major extremity amputations were rare in both groups (two for Vision and one for Xience V). The use of the Xience V stent significantly reduced the need for repeat intervention: freedom from target lesion revascularization was 91% for Xience V vs 66% for Vision (P = .001).

CONCLUSIONS

Treatment of the infrapopliteal occlusive lesions of critical limb ischemia with everolimus-eluting stents reduces restenosis and the need for reintervention compared with bare metal stents.

Stent-assisted below-the-ankle angioplasty for limb salvage

PURPOSE

To report the clinical outcome of stent-assisted below-the-ankle angioplasty for limb salvage in the setting of critical limb ischemia (CLI).

METHODS

A retrospective single-center study was conducted of 40 critical ischemic limbs in 31 patients (mean age 67 ± 8 years, range 46-94) undergoing below-the-ankle stent-assisted angioplasty between April 2006 and April 2009. Coronary bare metal stents were implanted in cases of failed balloon angioplasty due to significant recoil, flow-limiting dissection, abrupt closure, or repeat early reocclusion.

RESULTS

Technical success was 93% (37 limbs), with 3 failures to cross the occlusive lesions. Acute or subacute occlusion was evident in 9 (23%) limbs. The number of runoff vessels increased significantly (p < 0.001) from 0.6 ± 0.8 to 1.8 ± 0.8. During a clinical follow-up of 19.3 ± 11.4 months (range 1-48), the number of repeat interventions for limb salvage was 2.2 ± 1.6 (range 1-9), and a total of 1.6 ± 0.9 stents (range 1-3) were implanted in 8 dorsalis pedis arteries. Acute or subacute stent thrombosis after stenting was observed in 2 of these, and symptomatic in-stent restenosis was detected in 4, which were all treated by repeat intervention. At 6, 12, and 24 months, the freedom from repeat intervention was 39.6%, 39.6%, and 35.2%, respectively. Amputation-free survival was 80.0%, 69.7%, and 62.7%, and limb salvage was 94.7%, 91.4%, and 82.1% at the same time points. Patient survival rates were 77.4%, 71.0%, and 71.0%, respectively. During a mean follow-up of 13.4 ± 12.7 months (range 1-31 months) in 7 of the 8 stented arteries, all examined stents were deformed: stent compression was evident in 5 and stent fracture in 5. However, 7 limbs undergoing dorsalis pedis artery stenting showed complete wound healing; 1 limb had a resistant wound in the heel.

CONCLUSION

Stent-assisted below-the-ankle angioplasty produced a satisfactory clinical outcome but with the need for repeat intervention. Thus, further refinement in endovascular technology is mandatory to reduce the need for repeat interventions and to resolve stent deformity issues.

Contemporary Management of Infrapopliteal Peripheral Arterial Disease

Peripheral arterial disease (PAD) is a common manifestation of atherosclerotic vascular disease and the incidence of infrapopliteal PAD continues to rise in the population. The historical experience with surgical and endovascular interventions for infrapopliteal stenosis was disappointing as operators experienced high rates of early technical failures and procedural complications, coupled with high rates of restenosis in this vascular territory when compared with more proximal vascular beds. While patients with infrapopliteal PAD may be asymptomatic, the majority would ultimately develop intermittent claudication or may also present with critical limb ischemia. In this article, we review the current literature, and discuss some of the technical aspects of endovascular therapy in this vascular bed. We also emphasize the importance of adjunctive evidence-based therapies such as antiplatelet agents, statins, and lifestyle modification such as smoking cessation in this particularly high-risk cohort to optimize clinical outcomes.

Outcome analysis of infrapopliteal percutaneous transluminal angioplasty and bypass graft surgery with nonreversed saphenous vein for individuals with critical limb ischemia

OBJECTIVE

To compare the results of percutaneous transluminal angioplasty (PTA) and bypass graft surgery (BGS) for the treatment of infrapopliteal lesions in individuals presenting with critical limb ischemia (CLI).

METHOD

A total of 48 infrapopliteal PTAs and 50 infrapopliteal BGS were compared retrospectively. All grafts used nonreversed saphenous vein in a single length as a substitute.

RESULTS

Secondary patency and limb salvage rates in 24 months for the surgical group were 64.7% and 73.2%, respectively. For PTA group, these values were 63.7% and 68.2%, without differences between groups (log rank; P = .45 and .39, respectively). Bypass graft surgery presented better results of secondary patency (72.9% vs 57.1%) and limb salvage (83.5% vs 53.6%) than PTA for patients with Transatlantic Inter-Society Consensus (TASC) D lesions (P = .04 and P = .01, respectively).

CONCLUSIONS

Both BGS and PTA provided similar results of patency and limb salvage for individuals with infrapopliteal atherosclerotic disease presenting with CLI. Bypass graft surgery had better results than PTA when TASC D lesions were present.