Sirolimus-eluting stents vs. bare-metal stents for treatment of focal lesions in infrapopliteal arteries: a double-blind, multi-centre, randomized clinical trial

Different drugs in drug-eluting stents for peripheral artery disease: a systematic evaluation and Bayesian meta-analysis

Drug-eluting stents (DESs) have become the first-line treatment for symptomatic peripheral arterial disease (PAD). Currently, there are many types of DESs on the market. The same type of DESs has different concentrations, and various drugs in them show uneven efficacy. The selection of DESs remains controversial. This study was aimed at comparing the long-term real-world outcomes of different DESs in the treatment of peripheral arterial occlusive disease (PAOD). The databases including Cochrane Library, Embase, and PubMed were searched with a time frame until March 25, 2023. The primary patency (PP) and target lesion revascularization (TLR) at 6 months were used as the primary endpoints. A total of 32 studies (5467 patients) were eligible. At the six-month follow-up, DES-Evero 1 ug/mm2 ranked first in terms of PP, with a significant difference from BMSs (RR [95% CI] = 1.6). DES-Siro 0.9 ug/mm2, DES-Siro 1.4 ug/mm2, DES-Siro 1.95 ug/mm2, DES-PTX 0.167 ug/mm2, DES-PTX 1 ug/mm2 and covered stents (CSs) showed significantly better PPs than BMSs. In terms of TLR, DES-Siro 0.9 ug/mm2 (0.31) ranked first, and DES-Evero 1 ug/mm2 ranked last. Among the treatment modalities for PAD, different DESs showed overall encouraging results in improving PP and TLR compared with BMSs. DES-Evero 1 ug/mm2 showed the best PP, but it had the highest reintervention rate at 6 months. Sirolimus-eluting stents were not always more effective with higher concentrations of sirolimus. Among various DESs, sirolimus-eluting stents and everolimus-eluting stents were superior to paclitaxel-eluting stents.

The Efficacy of Drug-Coated Balloons and Drug-Eluting Stents in Infrapopliteal Revascularization: A Meta-analysis

OBJECTIVE

The study aimed to compare the effectiveness of drug-coated balloon (DCB) and drug-eluting stents (DESs) to standard endovascular techniques like percutaneous transluminal angioplasty (PTA) and bare metal stent (BMS) for treating infrapopliteal artery disease.

METHODS

Including 8 DCB trials and 4 DES trials, this meta-analysis of 12 recent randomized controlled trials (RCTs) is comprehensive. We searched MEDLINE, EMBASE, Science of Web, Cochrane, and PubMed for this meta-analysis. We searched these databases for papers from their inception to February 2023. We also analyzed the references given in the listed studies and any future study that cited them. No language or publication date restrictions were applied to the 12 RCTs. The experimental group includes 8 DCB studies and 4 DES investigations, the DCB group is primarily concerned with the paclitaxel devices, whereas the DES group is preoccupied with the "-limus" devices. Key clinical outcomes in this study were primary patency and binary restenosis rates. This study's secondary outcomes are late lumen loss (LLL), clinically-driven target lesion revascularization (CD-TLR), limb amputation, and all-cause mortality. The evidence quality was assessed using Cochrane risk-of-bias. The PROSPERO registration number for this study is CRD42023462038.

FINDINGS

Only 108 of 1152 publications found satisfied qualifying criteria and contained data. All 13 RCTs have low to moderate bias. Drug-coated balloons and DESs were compared in the excluded study. The analysis comprised 2055 participants from 12 RCTs that met the inclusion criteria, including 1417 DCB patients and 638 DES patients. Drug-coated balloons outperform traditional methods in short-term monitoring of primary patency, binary restenosis, and CD-TLR. The benefits fade over time, and the 2 techniques had similar major amputation rates, mortality rates, and LLL. Drug-eluting stents outperform conventional procedures in primary patency, binary restenosis, and CD-TLR during medium-term to short-term follow-up. Comparing the 2 methods, major and minor amputations, death rate, and LLL were similar.

CONCLUSION

Comparison of DES and DCB with PTA or BMS shows that DES had better follow-up results. DCB has positive short-term results, but long-term effects differ, however, more research is needed to determine when DES and DCB should be used in medical procedures.

CLINICAL IMPACT

The provision of additional evidence to substantiate the advancement of drug-coated balloon (DCB) therapy in the treatment of lower limb arteriosclerosis obliterans, particularly in the below-the-knee area characterized by high calcium load and significant occlusion, is comparable in efficacy to conventional procedures. This finding is advantageous for the progress of interventional revascularization. The advancement and efficacy of DCB have resulted in improved treatment outcomes for medical practitioners in clinical settings. Our research incorporates the most recent randomized experiments.

Drug-Eluting Resorbable Scaffold versus Angioplasty for Infrapopliteal Artery Disease

BACKGROUND

Among patients with chronic limb-threatening ischemia (CLTI) and infrapopliteal artery disease, angioplasty has been associated with frequent reintervention and adverse limb outcomes from restenosis. The effect of the use of drug-eluting resorbable scaffolds on these outcomes remains unknown.

METHODS

In this multicenter, randomized, controlled trial, 261 patients with CLTI and infrapopliteal artery disease were randomly assigned in a 2:1 ratio to receive treatment with an everolimus-eluting resorbable scaffold or angioplasty. The primary efficacy end point was freedom from the following events at 1 year: amputation above the ankle of the target limb, occlusion of the target vessel, clinically driven revascularization of the target lesion, and binary restenosis of the target lesion. The primary safety end point was freedom from major adverse limb events at 6 months and from perioperative death.

RESULTS

The primary efficacy end point was observed (i.e., no events occurred) in 135 of 173 patients in the scaffold group and 48 of 88 patients in the angioplasty group (Kaplan-Meier estimate, 74% vs. 44%; absolute difference, 30 percentage points; 95% confidence interval [CI], 15 to 46; one-sided P<0.001 for superiority). The primary safety end point was observed in 165 of 170 patients in the scaffold group and 90 of 90 patients in the angioplasty group (absolute difference, -3 percentage points; 95% CI, -6 to 0; one-sided P<0.001 for noninferiority). Serious adverse events related to the index procedure occurred in 2% of the patients in the scaffold group and 3% of those in the angioplasty group.

CONCLUSIONS

Among patients with CLTI due to infrapopliteal artery disease, the use of an everolimus-eluting resorbable scaffold was superior to angioplasty with respect to the primary efficacy end point. (Funded by Abbott; LIFE-BTK ClinicalTrials.gov number, NCT04227899.).

Exploring the Reporting Standards of Randomised Controlled Trials Involving Endovascular Interventions for Peripheral Arterial Disease: A Systematic Review

OBJECTIVE

Endovascular technology innovation requires rigorous evaluation in high quality randomised controlled trials (RCTs). However, due to numerous methodological challenges, RCTs evaluating endovascular interventions are complex and potentially difficult to design, conduct, and report. This systematic review aimed to assess the quality of reporting of RCTs for endovascular interventions for lower limb peripheral arterial disease (PAD).

DATA SOURCES AND REVIEW METHODS

A systematic review of Medline, Embase, and the Cochrane Library databases from inception to December 2021 was performed to identify RCTs including participants with PAD undergoing any infrainguinal lower limb endovascular intervention. Study data were extracted and assessed against the Consolidating Standards of Reporting Trials extension for Non-Pharmacological Treatments (CONSORT-NPT) and the Template for Intervention Description and Replication (TIDieR) checklists. Descriptive statistics were used to summarise general study details and reporting standards of the trials.

RESULTS

After screening 6 567 abstracts and 526 full text articles, 112 eligible studies were identified, reporting on 228 different endovascular devices and techniques. Details judged sufficient to replicate the investigated intervention were provided for 47 (21%) interventions. It was unclear whether the description was reported with sufficient details in a further 56 (24%), and the description was judged inadequate in 125 (55%). Any intervention descriptions were provided for 184 (81%), with variable levels of detail (some in 134 [59%] and precise in 50 [22%]). Standardisation of intervention or some aspect of this was reported in 25 (22%) trials, but only one specified that adherence to the study protocol would be monitored.

CONCLUSION

The quality of the reporting standards of RCTs investigating lower limb endovascular treatments is severely limited because the interventions are poorly described, standardised, and reported. PROSPERO registration number: CRD42022288214.

Comparation of drug-eluting stents and control therapy for the treatment of infrapopliteal artery disease: a Bayesian analysis

BACKGROUND

Critical limb-threatening ischaemia is a life-threatening disease which often combines with infrapopliteal arterial disease. Percutaneous transluminal angioplasty (PTA) is recommended as the first-line treatment for infrapopliteal arterial disease. Drug-eluting stent (DES) is another widely used option; however, its long-term therapeutic effect is controversial. The effectiveness of different DES for infrapopliteal arterial disease needs further exploration.

METHODS AND RESULTS

The PubMed, EMBASE, Cochrane Library and Clinical trials were systematically searched from inception to 1 February 2023. Literatures were included if the study was original, peer-reviewed, published in English or Chinese, and contained patients diagnosed with simple infrapopliteal arterial disease or with properly treated combined inflow tract lesions before or during the study procedure. A total of 953 patients, 504 in the DES group and 449 in the PTA/bare-metal stenting (BMS) group, from 12 randomised controlled trials were included in the meta-analysis. The results showed that DES is superior to control group for improving clinical patency, reducing the restenosis rate, and reducing the amputation rate at 6 months, 1 year, and 3 years post-treatment [at 3 years, risk ratio (RR): 1.90, 95% CI 1.23-2.93; RR: 0.87, 95% CI 0.79-0.96; RR: 0.60, 95% CI 0.36-1.00, P =0.049]. In addition, subgroup analyses suggested that DES is superior to BMS and PTA in improving clinical patency and reducing target lesion revascularisation and restenosis rates at 6-month and 1-year post-treatment. The network meta-analysis indicated that sirolimus-eluting stent was superior for improving clinical patency (at 1 year, RR: 0.23, 95% CI 0.08-0.60) and reducing the restenosis rate (at 6 months, RR: 31.58, 95% CI 4.41-307.53, at 1 year, RR: 3.80, 95% CI 1.84-8.87) significantly. However, according to the cumulative rank probabilities test, everolimus-eluting stent may have the lowest target lesion revascularisation rates and amputation rates at 1-year post-treatment (the cumulative rank probability was 77% and 49%, respectively).

CONCLUSIONS

This systematic review and network meta-analysis showed that DES was associated with more clinical efficacy than PTA/BMS significantly. In addition, sirolimus-eluting stent and everolimus-eluting stent may have better clinical benefits.

Primary results of the SAVAL randomized trial of a paclitaxel-eluting nitinol stent versus percutaneous transluminal angioplasty in infrapopliteal arteries

BACKGROUND

Effective and durable options for infrapopliteal artery revascularization for patients with chronic limb-threatening ischemia (CLTI) are limited.

METHODS

The SAVAL trial is a prospective, multicenter, randomized trial of patients with CLTI and infrapopliteal artery lesions with total lesion length ⩽ 140 mm, stenosis ⩾ 70%, and Rutherford category 4-5 assigned 2:1 to treatment with the SAVAL self-expandable paclitaxel drug-eluting stent (DES) or percutaneous transluminal angioplasty (PTA) with an uncoated balloon. The primary effectiveness endpoint was primary vessel patency (i.e., core lab-adjudicated duplex ultrasound-based flow at 12 months in the absence of clinically driven target lesion revascularization or surgical bypass of the target lesion). The primary safety endpoint was the 12-month major adverse event (MAE)-free rate; MAEs were defined as a composite of above-ankle index limb amputation, major reintervention, and 30-day mortality. The endpoints were prespecified for superiority (effectiveness) and noninferiority (safety) at a one-sided significance level of 2.5%.

RESULTS

A total of 201 patients were enrolled and randomly assigned to treatment (N = 130 DES, N = 71 PTA). Target lesion length was 68.1 ± 35.2 mm for the DES group and 68.7 ± 49.2 mm for the PTA group, and 31.0% and 27.6% of patients, respectively, had occlusions. The 12-month primary patency rates were 68.0% for the DES group and 76.0% for the PTA group (Psuperiority = 0.8552). The MAE-free rates were 91.6% and 95.3%, respectively (Pnoninferiority = 0.0433).

CONCLUSION

The SAVAL trial did not show benefit related to effectiveness and safety with the nitinol DES compared with PTA in infrapopliteal artery lesions up to 140 mm in length. Continued innovation to provide optimal treatments for CLTI is needed. (ClinicalTrials.gov Identifier: NCT03551496).

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.

A systematic review and meta-analysis of sirolimus-eluting stents for treatment of below-the-knee arterial disease

OBJECTIVE

We performed a systematic review and meta-analysis to analyze the efficacy and safety of sirolimus-eluting stents (SESs) in the treatment of below-the-knee (BTK) arterial disease.

METHODS

An electronic literature search was conducted from inception to July 24, 2021. Retrospective, prospective, and randomized studies that had used SESs to treat BTK arterial disease and had reported the primary patency, technical success, target lesion revascularization, and/or mortality were included. Meta-analyses of the proportions were conducted to derive pooled summary statistics of the outcomes. Where Kaplan-Meier curves were provided for primary patency, a meta-analysis of the individual patient data was conducted via a graphic reconstruction tool to estimate primary patency at various follow-up points. For studies comparing SESs and bare metal stents (BMSs), a two-stage meta-analysis was performed to compare the 6-month primary patency of SESs vs BMSs.

RESULTS

Ten studies across 13 publications, including 995 patients, were retrieved for analysis. In the meta-analysis of proportions, across six studies (n = 339 patients), the pooled 6-month primary patency was 87.3% (95% confidence interval [CI], 81.6%-92.1%). Across seven studies (n = 283 patients), the pooled 6-month mortality was 5.4% (95% CI, 1.4%-11.2%). An individual patient data analysis of three studies (n = 282 patients) yielded a primary patency rate of 95.2% (95% CI, 92.7%-97.8%), 82.8% (95% CI, 78.3%-87.6%), 79.8% (95% CI, 75.0%-85.0%), and 79.8% (95% CI, 75.0%-85.0%) at 6, 12, 18, and 24 months, respectively. The 12-month target lesion revascularization rate across four studies (n = 324 patients) was 9.6% (95% CI, 6.4%-13.4%). In the two-stage meta-analysis of 6-month primary patency across three studies (n = 168 patients), the use of SESs was significantly favored over BMSs (risk ratio, 1.28; 95% CI, 1.12-1.46; P < .001).

CONCLUSIONS

The overall evidence suggests that the use of SESs appears to be safe and offers favorable outcomes for BTK arterial disease compared with BMSs.

Effectiveness and Safety of Atherectomy versus Plain Balloon Angioplasty for Limb Salvage in Tibioperoneal Arterial Disease

PURPOSE

To evaluate the effectiveness and safety of atherectomy versus plain balloon angioplasty (POBA) for treatment of critical limb ischemia (CLI) due to tibioperoneal arterial disease (TPAD).

MATERIALS AND METHODS

Patients enrolled in the Vascular Quality Initiative registry who had CLI (Rutherford Class 4-6) and underwent atherectomy versus POBA alone for isolated TPAD were retrospectively identified. Of eligible patients, a cohort of 2,908 patients was propensity matched 1:1 by clinical and angiographic characteristics. The atherectomy group comprised 1,454 patients with 2,183 arteries treated, and the POBA group comprised 1,454 patients with 2,141 arteries treated. The primary study endpoint was major ipsilateral limb amputation. Secondary endpoints were minor ipsilateral amputations, any ipsilateral amputation, primary patency, target vessel reintervention (TVR), and wound healing at 12 months.

RESULTS

The median follow-up period was 507 days, the mean patient age was 69 years ± 11.7, and the mean occluded length was 6.9 cm ± 6.5. There was a trend toward higher technical success rates with atherectomy than with POBA (92.9% vs 91.0%, respectively; P = .06). The rates of major adverse events during the procedure were not significantly different. The 12-month major amputation rate was similar in the atherectomy and POBA groups (4.5% vs 4.6%, respectively; P = .92; odds ratio, 0.97; 95% CI, 0.68-1.37). There was no difference in 12-month TVR (17.9% vs 17.8%; P = .97) or primary patency (56.4% vs 54.5%; P = .64) between the atherectomy and POBA groups.

CONCLUSIONS

In a large national registry, treatment of CLI from TPAD using atherectomy versus POBA showed no significant differences in procedural adverse events, major amputations, TVR, or vessel patency at 12 months.

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.

Cost-utility analysis of early versus delayed endovascular intervention in critical limb-threatening ischemia patients with rest pain

OBJECTIVE

The prevalence of chronic limb-threatening ischemia (CLTI) and poor health outcomes are high in Germany. Serious consequences of CLTI such as amputation and mortality can be effectively prevented by the early use of evidence-based therapeutic measures such as endovascular intervention. We have developed a cost-utility analysis to compare endovascular intervention with bare metal stents (BMSs) and endovascular intervention after conservative treatment from the German payer perspective.

METHODS

A Markov model, with a 5-year time horizon and seven states, was developed: (1) intervention, (2) stable 1, (3) major amputation, (4) reintervention, (5) stable 2, (6) care, and (7) all-cause death. Transition probabilities were obtained by pooling the outcomes from multiple clinical studies. The costs were estimated using data from the German diagnosis-related group system, the German rehabilitation fund, and related literature. Health-state utilities were obtained from the reported data. The primary outcomes were the quality-adjusted life-years (QALYs) and costs.

RESULTS

Early BMS intervention after 5 years resulted in a cost of €23,913 and an increase of 2.5 QALYs per patient, and endovascular intervention with BMS after conservative treatment after 5 years resulted in a cost of €18,323 and an increase of 2 QALYs per patient. The incremental cost-effectiveness ratio was €12,438. The number of major amputations was reduced by 6%. The results of the structural, deterministic, and probabilistic sensitivity analyses were robust.

CONCLUSIONS

Early endovascular intervention with BMS resulted in more QALYs and a reduced risk of major amputation for early-stage CLTI patients. Our results showed that early endovascular intervention is very cost-effective according to World Health Organization recommended cost-effectiveness thresholds. However, the clinical decision regarding the use of early endovascular intervention should be determined by individual patient-level eligibility and the physician's judgment.

The efficacy and safety of different endovascular modalities for infrapopliteal arteries lesions: A network meta-analysis of randomized controlled trials

Background

Endovascular treatment has become the first-line therapy for infrapopliteal artery occlusive disease (IPOD), while the optimal endovascular method remains to be determined. We performed a network meta-analysis (NWM) of randomized controlled trials (RCTs) to simultaneously compare the outcomes of different endovascular modalities for IPOD.

Methods and results

The Pubmed, Embase, and Cochrane databases were used as data sources. The NWM approach used random-effects models based on the frequentist framework. In total, 22 eligible RCTs (44 study arms; 1,348 patients) involving nine endovascular modalities or combinations [balloon angioplasty (BA), drug-coated balloon (DCB), drug-eluting stent (DES), atherectomy device + BA (AD + BA), AD + DCB, balloon-expandable bare metal stent (BMS), self-expanding stent (SES), absorbable metal stents (AMS), and inorganics-coated stent (ICS)] were included. BA had a lower 12-month primary patency rate than DCB (RR 0.50, CI 0.27, 0.93) and AD + DCB (RR 0.34, CI 0.12, 0.93). AD + DCB decreased 6-month TLR compared with AMS (RR 0.15, CI 0.03, 0.90), and DES decreased it compared with BMS (RR 0.25, CI 0.09, 0.71). DCB had a lower 6-month TLR rate than AMS (RR 0.26, CI 0.08, 0.86) and BA (RR 0.51, CI 0.30, 0.89). BA had a higher 12-month TLR rate than DCB (RR 1.76, CI 1.07, 2.90). According to the value of the surface under the cumulative ranking curve (SUCRA), AD + DCB was considered the best treatment in terms of primary patency at 6 months (SUCRA = 87.5) and 12 months (SURCA = 91). AD + BA was considered the best treatment in terms of 6-month TLR (SUCRA = 83.1), 12-month TLR (SURCA = 75.8), and 12-month all-cause mortality (SUCRA = 92.5). In terms of 12-month major amputation, DES was considered the best treatment (SUCRA = 78.6), while AD + DCB was considered the worst treatment (SUCRA = 28.8). Moreover, AD + BA always ranks higher than AD + DCB in the comparison including these two combinations. Subgroup analyses of modalities without stenting did not significantly change the primary outcomes.

Conclusion

ADs showed noteworthy advantages in multiple terms for IPOD except for 12-month major amputation. AD + BA may be a better method for IPOD than AD + DCB. The efficacy and safety of ADs are worthy of further investigation.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42022331626].

Major adverse limb events in patients with femoro-popliteal and below-the-knee peripheral arterial disease treated with either sirolimus-coated balloon or standard uncoated balloon angioplasty: a structured protocol summary of the "SirPAD" randomized controlled trial

BACKGROUND

Peripheral arterial disease is a progressive atherosclerotic disease with symptoms ranging from an intermittent claudication to acute critical limb ischemia and amputations. Drug-coated balloons and stents were developed to prevent neo-intimal proliferation and restenosis after percutaneous transluminal angioplasty. Randomized controlled trials showed that drug-coated, notably paclitaxel-coated, devices reduce restenosis, late lumen loss, and the need for target lesion re-vascularization compared with uncoated ones. However, the size of these trials was too small to prove superiority for "hard" clinical outcomes. Moreover, available studies were characterized by too restrictive eligibility criteria. Finally, it remains unclear whether paclitaxel-coated balloons may impair long-term survival. Alternative drug-coated balloons, the so-called limus-based analogs, have been approved for clinical use in patients with peripheral arterial disease. By encapsulating sirolimus in phospholipid drug nanocarriers, they optimize adhesion properties of sirolimus and provide better bioavailability.

METHODS

In this investigator-initiated all-comer open-label phase III randomized controlled trial, we will evaluate whether sirolimus-coated balloon angioplasty is non-inferior and eventually superior, according to a predefined hierarchical analysis, to uncoated balloon angioplasty in adults with infra-inguinal peripheral arterial disease requiring endovascular angioplasty. Key exclusion criteria are pregnancy or breastfeeding, known intolerance or allergy to sirolimus, and participation in a clinical trial during the previous 3 months. The primary efficacy outcome is the composite of two clinically relevant non-subjective "hard" outcomes: unplanned major amputation of the target limb and endovascular or surgical target lesion re-vascularization for critical limb ischemia occurring within 1 year of randomization. The primary safety outcome includes death from all causes.

DISCUSSION

By focusing on clinically relevant outcomes, this study will provide useful information on the efficacy and safety of sirolimus-coated balloon catheters for infra-inguinal peripheral arterial disease in a representative ("all-comer") population of unselected patients. As regulatory agencies had raised safety concerns in patients exposed to paclitaxel-coated devices (versus uncoated ones), collect mortality data up to 5 years after randomization will be collected.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04238546.

Endovascular treatment of high-risk peripheral vascular occlusive lesions: a review of current evidence and emerging applications of intravascular lithotripsy, atherectomy, and paclitaxel-coated devices

Endovascular treatment of peripheral arterial disease has evolved and expanded rapidly over the last 20 years. New technologies have increased the diversity of devices available and have made it possible to approach even the most challenging and high-risk lesions using endovascular techniques. In this review, we examine the clinical evidence available for several categories of endovascular devices available to treat peripheral arterial disease, including intravascular lithotripsy, atherectomy, and drug-coated devices. The best application for some technologies, such as intravascular lithotripsy and atherectomies, have yet to be identified. In contrast, drug-coated devices have an established role in patients at high risk for long-term failure, but have been the subject of much controversy, given recent concerns about possible adverse effects of paclitaxel. Future investigation should further assess these technologies in patients with complex disease using updated staging systems and outcomes with direct clinical relevance, such as functional improvement, wound healing, and freedom from recurrent symptoms.

Overcoming ischemia in the diabetic foot: Minimally invasive treatment options

As the global burden of diabetes is rapidly increasing, the incidence of diabetic foot ulcers is continuously increasing as the mean age of the world population increases and the obesity epidemic advances. A significant percentage of diabetic foot ulcers are caused by mixed micro and macro-vascular dysfunction leading to impaired perfusion of foot tissue. Left untreated, chronic limb-threatening ischemia has a poor prognosis and is correlated with limb loss and increased mortality; prompt treatment is required. In this review, the diagnostic challenges in diabetic foot disease are discussed and available data on minimally invasive treatment options such as endovascular revascularization, stem cells, and gene therapy are examined.

Comprehensive Assessment of Current Management Strategies for Patients With Diabetes and Chronic Limb-Threatening Ischemia

Chronic limb-threatening ischemia (CLTI) is the most severe form of peripheral artery disease. It is estimated that 60% of all nontraumatic lower-extremity amputations performed annually in the United States are in patients with diabetes and CLTI. The consequences of this condition are extraordinary, with substantial patient morbidity and mortality and high socioeconomic costs. Strategies that optimize the success of arterial revascularization in this unique patient population can have a substantial public health impact and improve patient outcomes. This article provides an up-to-date comprehensive assessment of management strategies for patients afflicted by both diabetes and CLTI.

Retrograde Revascularization of Tibial Arteries in Patients with Critical Limb Ischemia: Plantar-Arch Versus Transpedal Approach

PURPOSE

To compare retrograde plantar-arch and transpedal-access approach for revascularization of below-the-knee (BTK) arteries in patients with critical limb ischemia (CLI) after a failed antegrade approach.

MATERIALS AND METHODS

Retrospectively we identified 811 patients who underwent BTK revascularization between 1/2014 and 1/2020. In 115/811 patients (14.2%), antegrade revascularization of at least 1 tibial artery had failed. In 67/115 (58.3%), patients retrograde access to the target vessel was achieved via the femoral access and the plantar-arch (PLANTAR-group); and in 48/115 patients (41.7%) retrograde revascularization was performed by an additional retrograde puncture (TRANSPEDAL-group). Comorbidities, presence of calcification at pedal-plantar-loop/transpedal-access-site, and tibial-target-lesion was recorded. Endpoints were technical success (PLANTAR-group: crossing the plantar-arch; TRANSPEDAL-group: intravascular placement of the pedal access sheath), procedural success [residual stenosis <30% after plain old balloon angioplasty (POBA)], and procedural complications limb salvage and survival. Correlations between calcification at access site/tibial-target-lesion and technical/procedural-success were tested.

RESULTS

Technical success was achieved in 50/67 (75%) patients of the PLANTAR-group and in 39/48 (81%) patients of the TRANSPEDAL-group (p=0.1). Procedural success was obtained in 23/67 (34%) patients of the PLANTAR-group and in 25/48 (52%) patients of the TRANSPEDAL-group (p=0.04). In 14/49 (29%) cases with calcification at the pedal-plantar loop, technical success was not achieved (p=0.04), and in 33/44 (75%) patients with calcification at the tibial-target-lesion, procedural success was not attained (PLANTAR-group) (p=0.026). In the TRANSPEDAL-group, correlations between calcification at access site/tibial-target-lesion and technical/procedural-success were not observed (p=0.2/p=0.4). In the PLANTAR-group, minor complications occurred in 13/67 (19%) and in the TRANSPEDAL-group in 4/48 patients (8%) (p=0.08). Limb salvage at 12 (18) months was 90% (82%) (PLANTAR-group; 95%CI 15.771-18.061) and 84% (76%) (TRANSPEDAL-group; 95%CI 14.475-17.823) (Log-rank p=0.46). Survival at 12 (18) months was 94% (86%) (PLANTAR-group; 95%CI 16.642-18.337) and 85% (77%) (TRANSPEDAL; 95%CI 14.296-17.621) (Log-rank p=0.098).

CONCLUSION

Procedural success was significantly higher using the transpedal-access approach. Calcifications at pedal-plantar loop and target-lesion significantly influenced technical/procedural failure using the plantar-arch approach. No significant difference between both retrograde techniques in terms of feasibility, safety, and limb salvage/survival was found.

Use of drug-eluting stents in patients with critical limb ischemia and infrapopliteal arterial disease: a real-world single-center experience

BACKGROUND

Although no drug-eluting stent (DES) has been approved by the Food and Drug Administration to treat infrapopliteal arterial disease, several industry-sponsored trials have reported the outcomes with the use of paclitaxel or sirolimus DESs. To the best of our knowledge, only one study to date has reported on the use of everolimus DESs for infrapopliteal arterial disease. In the present study, we analyzed the clinical outcomes with everolimus DESs in our real-world, single-center experience.

METHODS

A total of 107 limbs with critical limb threatening ischemia (98 patients; 118 lesions) treated with DESs (Xience; Abbott Vascular, Santa Clara, Calif) were analyzed. The postoperative early outcomes, major adverse limb events (above the ankle limb amputation or major intervention at 1 year), and major adverse events (death, amputation, target lesion thrombosis or reintervention) were analyzed. Kaplan-Meier analysis was used to estimate the primary patency rates (using duplex ultrasound), amputation-free rates, and amputation-free survival rates.

RESULTS

Of the 118 lesions treated, 33% were in the anterior tibial artery, 28% were in the tibioperoneal (TP) artery, 21% were in the posterior tibial artery, 8% were in the peroneal artery, 5% were in the TP/posterior tibial artery, 4% were in the TP artery/PA, and 1% were in the TP/anterior tibial artery. The mean lesion length was 41 mm, and 59% were totally occluded (41% stenotic). The mean follow-up was 18.5 months (range, 1-70 months). The overall postoperative complication rate was 11% (2% major amputations), with 2% mortality. Late symptom improvement of one or more Rutherford category was obtained in 71%. The major adverse events rate at 30 days and 1 year was 12% and 45%, respectively. The major adverse limb events rate at 1 year was 15%. The overall primary patency rate was 42%. The primary patency rate at 1, 2, and 3 years was 57%, 45%, and 33%, respectively. The major amputation-free and overall amputation-free survival rates were 87%, 80%, and 77% and 76%, 65%, and 61% at 1, 2, and 3 years, respectively.

CONCLUSIONS

The clinical outcomes after DES (Xience; Abbott Vascular) for infrapopliteal lesions were somewhat satisfactory at 1 year but inferior to the previously reported outcomes, especially at 3 years. Further data with long-term follow-up are needed.

Atherectomy and Drug-Coated Balloon Angioplasty for the Treatment of Long Infrapopliteal Lesions: A Randomized Controlled Trial

[Figure: see text].

[Current Strategy in Endovascular Management for Below-the-Knee Arterial Lesions]

The below-the-knee arterial tree is the thinnest of all the leg vessels and is an important path for blood flow to the foot. Hence, lesions including stenosis, especially obstruction, may lead to critical limb ischemia which represents the most severe clinical manifestation of peripheral arterial disease. It is characterized by the presence of ischemic rest pain, ischemic lesions, or gangrene attributable to the objectively proven arterial occlusive disease. Typically, the atherosclerotic disease process involving the below-the-knee arterial tree is diffuse in the majority of patients. The cornerstone of therapy is vascular reconstruction and limb salvage. Revascularization should be attempted whenever technically possible, without delay, in patients presenting critical limb ischemia and when the clinical status is not hopelessly non-ambulatory. Therefore, endovascular treatment can become the gold standard for the full range of patients including below-the-knee, limiting the clinical role of the classically trained surgeons.

Antegrade and retrograde in-stent tibial artery chronic total occlusion recanalization with double kiss crush (DK crush) stenting of previous stent

Below the knee (BTK) peripheral arterial disease often presents with critical limb ischemia (CLI) clinically with involvement of more than one tibial vessels. Drug eluting stent (DES) technology for treatment of BTK disease has shown promising long-term durable results; however, currently only coronary DESs are available for application in the United States. Although coronary bifurcation stenting techniques are backed by extensive data in literature, there is a scarcity of data for the treatment of tibial bifurcation disease. Bifurcation angles in the tibials are similar to those in the coronaries and therefore the same two stent bifurcation technique can be applied in BTK disease. Double Kiss crush (DK crush) stenting has superior outcomes when compared to provisional or culotte stenting in randomized coronary trials (based on Medina classification). We present a case of BTK CLI with tibial bifurcation chronic total occlusion treated with two stent DK crush technique using coronary DES.

Everolimus eluting bioresorbable vascular scaffolds for infrapopliteal critical limb ischemia: Moving beyond grasping at metal straws

Consistent and durable patency and clinical benefit after initially successful infrapopliteal percutaneous balloon transluminal angioplasty (PTA) for critical limb ischemia remains an unmet need. Permanently implanted metallic stents for suboptimal initial infrapopliteal PTA results also have limited patency and clinical results as well as other drawbacks. In 48 critical limb ischemia patients with infrapopliteal lesions < 50 mm length, everolimus eluting bioresorbable vascular scaffolds (EEBVS) achieved 90% primary patency and freedom from clinically driven target lesion revascularization at 2 years follow-up with no late scaffold thrombosis.

Outcomes of endovascular treatment for infrapopliteal peripheral artery disease based on the updated TASC II classification

We retrospectively analyzed all endovascular procedures of infrapopliteal arterial lesions (n = 383) performed in 270 patients at our institution between December 2008 and January 2018. The overall technical success rate was 97% and yielded 98% for stenoses (n = 214) and 95% for occlusions (n = 169). Trans-Atlantic Inter-Society Consensus (TASC II) classification had no impact on success rates (TASC A + B vs C + D; 96.5% vs 96.9%, p = 0.837). Freedom from clinically driven target lesion revascularization (TLR) after 6 and 12 months was 88.3% and 77.2%. TLR was comparable for TASC A to C lesions and no difference was observed comparing groups of moderately complex TASC A/B lesions and more complex TASC C/D lesions (TASC A + B vs C + D; 78.5% vs 74.2%, p = 0.457). Freedom from TLR was significantly lower in very complex TASC D lesions (TASC A + B + C vs D; 79.7% vs 42.5%, p < 0.001). Multivariate analysis identified TASC D lesions (hazard ratio D/A: 1.5; overall p = 0.002), Fontaine class III and IV (hazard ratio III or IV/IIa or IIb: 2.4; p = 0.041), and occlusive lesions (hazard ratio occlusion/stenosis: 2.4; p = 0.026) as predictors for TLR. In conclusion, endovascular therapy for infrapopliteal artery disease was safe and accompanied with a promising long-term outcome.

Two-year follow-up of bioresorbable vascular scaffolds in severe infra-popliteal arterial disease

OBJECTIVES

To assess the safety, efficacy, and durability of the Absorb bioresorbable vascular scaffold in predominantly complex, infra-popliteal lesions for the management of chronic limb ischemia at two-year clinical follow-up. Bioresorbable vascular scaffold are biodegradable scaffolds that provide short-term vascular support before undergoing intravascular degradation. A recent trial reported excellent 36-month vessel patency rates in simple infrapopliteal arterial lesions treated with Absorb bioresorbable vascular scaffold.

METHODS

This single-center, retrospective study evaluated the use of the Absorb bioresorbable vascular scaffold (everolimus impregnated poly-L-lactic scaffold) in patients with infra-popliteal peripheral arterial disease (PAD) with respect to safety (thrombosis and TIMI bleeding), technical success, and freedom from clinically driven target vessel failure at 24 months.

RESULTS

31 patients (51.6% male) with a median age of 67 years with predominantly advanced infra-popliteal disease were treated with 49 bioresorbable vascular scaffold in 41 vessels. The mean stenosis was 94% (80-100), with 49% of lesions being chronic thrombotic occlusions. No scaffold thrombosis or peri-procedural bleeding was observed. Procedural success was achieved in all patients; 93.5% of patients experienced freedom from clinically driven target vessel failure at 24 months, driven by one revascularization and one amputation. Primary patency was 96.7% at 12 months and 87.1% at 24 months. All patients were alive at 12 and 24 months.

CONCLUSIONS

At 24 months, our study found that patients with predominantly advanced infra-popliteal PAD who were treated with Absorb bioresorbable vascular scaffold reported improved clinical status and a low and durable rate of clinically driven target vessel failure extending out to 24 months.

Asia-Pacific Consensus Statement on the Management of Peripheral Artery Disease: A Report from the Asian Pacific Society of Atherosclerosis and Vascular Disease Asia-Pacific Peripheral Artery Disease Consensus Statement Project Committee

BACKGROUND

Peripheral artery disease (PAD) is the most underdiagnosed, underestimated and undertreated of the atherosclerotic vascular diseases despite its poor prognosis. There may be racial or contextual differences in the Asia-Pacific region as to epidemiology, availability of diagnostic and therapeutic modalities, and even patient treatment response. The Asian Pacific Society of Atherosclerosis and Vascular Diseases (APSAVD) thus coordinated the development of an Asia-Pacific Consensus Statement (APCS) on the Management of PAD.

OBJECTIVES

The APSAVD aimed to accomplish the following: 1) determine the applicability of the 2016 AHA/ACC guidelines on the Management of Patients with Lower Extremity Peripheral Artery Disease to the Asia-Pacific region; 2) review Asia-Pacific literature; and 3) increase the awareness of PAD.

METHODOLOGY

A Steering Committee was organized to oversee development of the APCS, appoint a Technical Working Group (TWG) and Consensus Panel (CP). The TWG appraised the relevance of the 2016 AHA/ACC PAD Guideline and proposed recommendations which were reviewed by the CP using a modified Delphi technique.

RESULTS

A total of 91 recommendations were generated covering history and physical examination, diagnosis, and treatment of PAD-3 new recommendations, 31 adaptations and 57 adopted statements. This Asia-Pacific Consensus Statement on the Management of PAD constitutes the first for the Asia-Pacific Region. It is intended for use by health practitioners involved in preventing, diagnosing and treating patients with PAD and ultimately the patients and their families themselves.

10-Year Paclitaxel Dose-Related Outcomes of Drug-Eluting Stents Treated Below the Knee in Patients with Chronic Limb-Threatening Ischemia (The PADI Trial)

Purpose

Recently, two meta-analyses concluded that there appears to be an increased risk of long-term mortality of paclitaxel-coated balloons and stents in the superficial femoral and popliteal artery, and paclitaxel-coated balloons below the knee. In this post hoc study of the PADI Trial, we investigated the long-term safety of first-generation paclitaxel-coated drug-eluting stents (DES) below the knee and the dose–mortality relationships of paclitaxel in patients with chronic limb-threatening ischemia (CLI).

Materials and Methods

The PADI Trial compared paclitaxel-coated DES with percutaneous transluminal angioplasty with bail-out bare-metal stents (PTA ± BMS) in patients with CLI treated below the knee. Follow-up was extended to 10 years after the first inclusion, and survival analyses were performed. In addition, dose-related mortality and dose per patient weight-related mortality relations were examined.

Results

A total of 140 limbs in 137 patients were included in the PADI Trial. Ten years after the first inclusion, 109/137 (79.6%) patients had died. There was no significant difference between mortality in the DES group compared with the PTA ± BMS group (Log-rank p value = 0.12). No specific dose-related mortality (HR 1.00, 95% CI 0.99–1.00, p = 0.99) or dose per weight mortality (HR 1.05, 95% CI 0.93–1.18, p = 0.46) relationships were identified in the Cox-proportional Hazard models or by Kaplan–Meier survival analyses.

Conclusions

There is a poor 10-year survival in both paclitaxel-coated DES and PTA ± BMS in patients with CLI treated below the knee. No dose-related adverse effects of paclitaxel-coated DES were observed in our study of patients with CLI treated below the knee.

Level of Evidence

The PADI Trial: level 1, randomized clinical trial

Electronic supplementary material

The online version of this article (10.1007/s00270-020-02602-6) contains supplementary material, which is available to authorized users.

Mortality in patients undergoing revascularization with paclitaxel eluting devices for infrainguinal peripheral artery disease: Insights from a network meta-analysis of randomized trials

OBJECTIVES

We aimed to evaluate whether paclitaxel eluting devices increased the risk of death in patients undergoing revascularization for infrainguinal peripheral artery disease using network meta-analyses.

METHODS

PUBMED and EMBASE were searched through April 2020 for randomized trials in patients with infrainguinal peripheral artery disease who underwent revascularization with or without a paclitaxel eluting device (balloon/stent). Short-term mortality defined as death at 6-12 months, and long-term mortality defined as death at >12 months after revascularization.

RESULTS

Our search identified 57 eligible randomized controlled studies enrolling a total of 9,362 patients comparing seven revascularization strategies (balloon angioplasty vs. bare metal stent vs. covered stent vs. paclitaxel eluting stent vs. other drug eluting stent vs. paclitaxel-coated balloon vs. bypass surgery). Overall, paclitaxel eluting stent and paclitaxel-coated balloons did not increase short-term mortality (eg, vs. balloon angioplasty: paclitaxel-coated balloon OR [95% CI] 1.21 [0.88-1.66], p = .24; paclitaxel eluting stent OR [95%CI] 1.01 [0.63-1.63], p = .97, respectively). In addition, paclitaxel eluting stent did not show significant increase in long-term mortality (eg, vs. balloon angioplasty: OR [95%CI] 1.06 [0.70-1.59], p = .79). However, paclitaxel-coated balloon showed significant increase in long-term mortality compared to balloon angioplasty and bypass (vs. balloon angioplasty: OR [95% CI] 1.48 [1.06-2.07], p = .021; vs. bypass: OR [95%CI] 1.73 [1.05-2.84], p = .031, respectively).

CONCLUSIONS

In this meta-analysis of randomized trials, there was no significant increase in mortality with paclitaxel eluting stent, but there was increased risk of long-term mortality in paclitaxel-coated balloon for the treatment of infrainguinal peripheral artery disease.

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.

Cost-Effectiveness of Drug-Eluting Stents for Infrapopliteal Lesions in Patients with Critical Limb Ischemia: The PADI Trial

PURPOSE

Drug-eluting stents (DES) improve clinical and morphological long-term results compared to percutaneous transluminal angioplasty (PTA) with bailout bare metal stenting (BMS) in patients with critical limb ischemia (CLI) and infrapopliteal lesions (PADI trial). We performed a cost-effectiveness analysis of DES compared to PTA ± BMS in cooperation with Dutch health insurance company VGZ, using data from the PADI trial.

MATERIALS AND METHODS

In the PADI trial, adults with CLI (Rutherford category ≥ 4) and infrapopliteal lesions were randomized to receive DES with paclitaxel or PTA ± BMS. Seventy-four limbs (73 patients) were treated with DES and 66 limbs (64 patients) with PTA ± BMS. The costs were calculated by using the mean costs per stent multiplied by the mean number of stents used per patient (€750 × 1.8 for DES vs €250 × 0.3 for PTA ± BMS). These costs were compared with the costs of major amputation (€16.000) and rehabilitation (first year €15.750, second year €7.375 and third year €3.600).

RESULTS

The 5-year major amputation rate was lower in the DES group (19.3% vs 34.0% for PTA ± BMS; p = 0.091). In addition, the 5-year amputation-free survival and event-free survival were significantly higher in the DES group (31.8% vs 20.4%, p=0.043; and 26.2% vs 15.3%, p=0.041, respectively). After 1 year, the cost difference per patient between DES and PTA ± BMS is €1.679 in favor of DES and €2.694 after 3 years.

CONCLUSION

In our analysis, DES are cost-effective due to the higher hospital costs of amputation and rehabilitation in the PTA ± BMS group.

LEVEL OF EVIDENCE

Level 1b, analysis based on clinically sensible costs and randomized controlled trial.

The role of precise imaging with intravascular ultrasound in coronary and peripheral interventions

Angiography remains a widely utilized imaging modality during vascular procedures. Angiography, however, has its limitations by underestimating the true vessel size, plaque morphology, presence of calcium and thrombus, plaque vulnerability, true lesion length, stent expansion and apposition, residual narrowing post intervention and the presence or absence of dissections. Intravascular ultrasound (IVUS) has emerged as an important adjunctive modality to angiography. IVUS offers precise imaging of the vessel size, plaque morphology and the presence of dissections and guides interventional procedures including stent sizing, assessing residual narrowing and stent apposition and expansion. IVUS-guided treatment has shown to yield superior outcomes when compared to angiography-only guided therapy. The cost-effectiveness of the routine use of IVUS during vascular procedures needs to be further studied.

Global Vascular Guidelines on the Management of Chronic Limb-Threatening Ischemia

GUIDELINE SUMMARY

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

Global vascular guidelines on the management of chronic limb-threatening ischemia

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

A Network Meta-analysis of Randomized Controlled Trials Comparing Treatment Modalities for Infrapopliteal Lesions in Critical Limb Ischemia

BACKGROUND

We aimed to conduct a network meta-analysis of randomized controlled trials comparing treatment modalities for infrapopliteal lesions in critical limb ischemia.

METHODS

Five treatments for infrapopliteal lesions in critical limb ischemia were recognized. We compared primary patency, target lesion revascularization (TLR), major amputation at the 12-month follow-up, and technical success rate of the treatment modalities.

RESULTS

Altogether, 11 studies (22 study arms; 1,330 patients) were considered eligible. The drug-eluting balloon (DEB) significantly increased primary patency compared with balloon angioplasty (BA; odds ratio [OR] 9.02, 95% confidence interval [CI] 3.18-25.55), the bare metal stent (BMS; OR 14.39, 95% CI 4.33-47.87), and the drug-eluting stent (DES; OR 3.70, 95% CI 1.20-11.11). The DES significantly increased primary patency compared with BA (OR 2.42, 95% CI 1.57-3.74) and BMS (OR 3.86, 95% CI 2.24-6.65). DES significantly increased the technical success rate compared with BA (OR 11.78, 95% CI 1.42-97.59). According to the value of the surface under the cumulative ranking curve (SUCRA), DEB was considered the best treatment in terms of primary patency (SUCRA = 99.7) and TLR (SUCRA = 70.7), and DES was considered the best treatment in terms of technical success rate (SUCRA = 90.6) and major amputation (SUCRA = 85.9).

CONCLUSIONS

DEB has shown encouraging results in terms of primary patency for infrapopliteal lesions in critical limb ischemia; furthermore, DEB may be better than other treatments in terms of TLR. DES may be better than other treatments in terms of technical success and major amputation. In contrast, BA and BMS seem to be less effective treatment options.

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.

The use of drug-eluting stents in infrapopliteal arteries: an updated systematic review and meta-analysis of randomized trials

INTRODUCTION

Endovascular treatment below-the-knee is safe and effective but limited by poor patency. Coronary drug-eluting stents (DES) may play a role in providing mechanical scaffolding and deliver anti-proliferative drug to the site of vascular barotrauma to reduce the incidence of restenosis. Our aim was to evaluate and compare the use of contemporary DES with standard endovascular-therapies for atherosclerotic disease of infrapopliteal arteries.

EVIDENCE ACQUISITION

We performed a meta-analysis of randomized controlled trials comparing DES with conventional treatment for symptomatic peripheral artery disease (search date 30 August 2017). The primary endpoint was primary patency. Secondary endpoints were freedom from target lesion revascularization (TLR), major amputation, sustained Rutherford class improvement and mortality.

EVIDENCE SYNTHESIS

We identified 7 trials enrolling 801 randomly assigned patients (392 DES, 409 control). At the median follow-up of 12-months DES improved rates of primary patency (OR 3.49, 95%CI 2.38-5.12, I2=0%, P<0.00001), freedom from TLR (OR 2.19, 95%CI 1.30-3.69, I2=38%, P=0.003), major amputation (OR 0.56, 95%CI 0.31-0.99, I2=0%, P=0.049), and Rutherford class improvement (OR 1.62, 95%CI 1.01-2.59, I2=65%, P=0.046), but not mortality (OR 1.05, 95%CI 0.68-1.62; I2 =0%, P=0.91) compared to control. Subgroup analysis of primary patency favoured DES coated in sirolimus analogues compared to paclitaxel (Test for subgroup differences, Chi2=6.51, df=1, P=0.01, I2=84.6%).

CONCLUSIONS

At midterm follow-up DES significantly improved rates of primary patency, re-intervention, Rutherford class improvement and major amputation for the treatment of atherosclerotic disease of infrapopliteal arteries compared to control therapy, with no effect on patient survival. Stents coated in sirolimus analogues were more effective than paclitaxel.

Rapamycin: A Bacteria-Derived Immunosuppressant That Has Anti-atherosclerotic Effects and Its Clinical Application

Atherosclerosis (AS) is the leading cause of stroke and death worldwide. Although many lipid-lowering or antiplatelet medicines have been used to prevent the devastating outcomes caused by AS, the serious side effects of these medicines cannot be ignored. Moreover, these medicines are aimed at preventing end-point events rather than addressing the formation and progression of the lesion. Rapamycin (sirolimus), a fermentation product derived from soil samples, has immunosuppressive and anti-proliferation effects. It is an inhibitor of mammalian targets of rapamycin, thereby stimulating autophagy pathways. Several lines of evidence have demonstrated that rapamycin possess multiple protective effects against AS through various molecular mechanisms. Moreover, it has been used successfully as an anti-proliferation agent to prevent in-stent restenosis or vascular graft stenosis in patients with coronary artery disease. A thorough understanding of the biomedical regulatory mechanism of rapamycin in AS might reveal pathways for retarding AS. This review summarizes the current knowledge of biomedical mechanisms by which rapamycin retards AS through action on various cells (endothelial cells, macrophages, vascular smooth muscle cells, and T-cells) in early and advanced AS and describes clinical and potential clinical applications of the agent.

Angioplasty versus stenting for infrapopliteal arterial lesions in chronic limb-threatening ischaemia

BACKGROUND

Chronic limb-threatening ischaemia (CLTI) is a manifestation of peripheral arterial disease (PAD) that includes chronic ischaemic rest pain or ischaemic skin lesions, ulcers, or gangrene for longer than two weeks. The severity of the disease depends on the extent of arterial stenosis and the availability of collateral circulation. Treatment for CLTI aims to relieve ischaemic pain, heal ischaemic ulcers, prevent limb loss, improve quality of life, and prolong survival. CLTI due to occlusive disease in the infrapopliteal arterial circulation (below-knee circulation) can be treated via an endovascular technique by a balloon opening the narrowed vessel, so called angioplasty, with or without the additional deployment of a scaffold made of metal alloy or other material, so called stenting. Endovascular interventions in the infrapopliteal vasculature may improve symptoms in patients with CLTI by re-establishing in-line blood flow to the foot. Controversy remains as to whether a balloon should be used alone to open the vessel, or whether a stent should also be deployed.

OBJECTIVES

To determine the efficacy and safety of percutaneous transluminal angioplasty (PTA) alone versus PTA with stenting of infrapopliteal arterial lesions (anterior tibial artery, posterior tibial artery, fibular artery (formerly known as peroneal artery), and common tibioperoneal trunk) for patients with chronic limb-threatening ischaemia (CLTI).

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, and AMED databases, as well as World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 25 June 2018. We applied no language restrictions.

SELECTION CRITERIA

We planned to include randomised or quasi-randomised controlled trials comparing PTA versus PTA with a stent and including patients aged 18 years or over with CLTI. We defined CLTI as Fontaine stage III (ischaemic rest pain) and IV (ischaemic ulcers or gangrene) or consistent with Rutherford category 4 (ischaemic rest pain), 5 (minor tissue loss), and 6 (major tissue loss), with stenotic (> 50% luminal loss) or occluded infrapopliteal artery, including tibiofibular trunk, anterior tibial artery, posterior tibial artery, and fibular artery. We included all types of stents irrespective of design (e.g. bare-metal, drug-eluting, bio-absorbable).

DATA COLLECTION AND ANALYSIS

Two review authors (CC-TH and GNCK) independently selected suitable trials, assessed trial quality, and extracted data. An additional third review author (MLvD) assessed trial quality and, when necessary, acted as arbiter for study selection and data extraction. Outcomes included technical success of the procedure, procedural complications, patency, major amputation, and mortality. We assessed the quality of evidence using the GRADE approach.

MAIN RESULTS

We included in the review seven trials with 542 participants. One trial randomised limbs to undergo PTA alone or PTA with stent placement, and the remaining studies randomised participants. Five trials with 476 participants show that the technical success rate was greater in the stent group than in the angioplasty group (odds ratio (OR) 3.00, 95% confidence interval (CI) 1.14 to 7.93; 476 lesions; 5 studies; I² = 23%). Meta-analysis of three eligible trials with 456 participants did not show a clear difference in short-term (within six months) patency between infrapopliteal arterial lesions treated with PTA and those treated with PTA and stenting (OR 0.88, 95% CI 0.37 to 2.11; 456 lesions; 3 studies; I² = 77%). Results also did not show clear differences between treatment groups in procedure complication rate (OR 0.87, 95% CI 0.01 to 53.60; 360 participants; 5 studies; I² = 85%), rate of major amputations at 12 months (OR 1.34, 95% CI 0.56 to 3.22; 306 participants; 4 studies; I² = 0%), and rate of mortality at 12 months (OR 0.71, 95% CI 0.43 to 1.17; 497 participants; 6 studies; I² = 0%). Heterogeneity between studies was high for the outcomes procedure complications and primary patency. The overall methodological quality of the trials included in this review was moderate due to selection and performance bias. Studies used different regimens for pretreatment and post-treatment antiplatelet/anticoagulant medication. We downgraded the certainty of the overall evidence for all outcomes by one level to moderate due to inconsistency of results across studies and large confidence intervals (small numbers of trials and participants).

AUTHORS' CONCLUSIONS

Trials show that the immediate technical success rate of restoring luminal patency is higher in the stent group but reveal no clear differences in short-term patency at six months between infrapopliteal arterial lesions treated with PTA with stenting versus those treated with PTA without stenting. We ascertained no clear differences between groups in periprocedural complications, major amputation, and mortality. However, use of different regimens for pretreatment and post-treatment antiplatelet/anticoagulant medication and the duration of its use within and between trials may have influenced the outcomes. Limited currently available data suggest that high-quality evidence is insufficient to show that PTA with stent insertion is superior to use of standard PTA alone without stenting for treatment of infrapopliteal arterial lesions. Further studies should standardise the use of antiplatelets/anticoagulants before and after the intervention to improve the comparability of the two treatments.

Atherectomy in below-the-knee endovascular interventions: One-year outcomes from the XLPAD registry

BACKGROUND

Use of atherectomy for the treatment of peripheral arterial disease (PAD) is increasing as an adjunctive treatment to either conventional or drug-coated balloon angioplasty. There is limited data on atherectomy outcomes in below-the-knee (BTK) endovascular interventions.

METHODS

Data from the multicenter Excellence in Peripheral Artery Disease (XLPAD) registry (NCT01904851) were analyzed to examine predictors of atherectomy use and its associated 1-year patency rate. We analyzed 518 BTK procedures performed between January 2005 and December 2016.

RESULTS

Overall a total of 518 BTK procedures were treated in 430 patients, and 43% of interventions used atherectomy. African American patients were less likely (13% vs 25%; |standard residual| = 3.41) to be treated with atherectomy. Use of atherectomy was lower in chronic total occlusive (CTO) lesions (48% vs 58%; P = 0.02). There were no significant associations of baseline comorbidities, critical limb ischemia (CLI), ankle-brachial index, number of BTK vessel run-off, or vessel location with atherectomy use. Compared with patients without atherectomy, use of atherectomy was associated with lower incidence of repeat target limb intervention at 1 year after adjusting for age, CLI, in-stent restenosis, heavy calcification, presence of diffuse disease, and CTO lesion traits (Hazard Ratio 0.41, 95% confidence interval 0.23-0.72; P < 0.01).

CONCLUSIONS

Compared with no atherectomy, use of atherectomy in BTK interventions is associated with lower rates of 1-year repeat target limb revascularization. These findings require confirmation in prospective, randomized clinical studies.

Three-Year Results of the Absorb Everolimus-Eluting Bioresorbable Vascular Scaffold in Infrapopliteal Arteries

Purpose: To investigate the midterm performance of the everolimus-eluting Absorb bioresorbable vascular scaffold (BVS) for the treatment of symptomatic infrapopliteal atherosclerotic disease. Methods: A single-center study prospectively enrolled 48 symptomatic patients (mean age 82.1±8.0 years; 27 men) between September 2013 and February 2018 to evaluate the Absorb everolimus-eluting BVS system in distal popliteal and tibial lesions. Mean lesion length was 20.1±10.8 mm. Following predilation, up to 2 BVS were implanted in target lesions in 55 limbs. Clinical and duplex ultrasound follow-up was performed at 1, 3, 6, 12, 24, 36, and 48 months to determine 30-day morbidity and midterm Kaplan-Meier estimates of binary restenosis, clinically-driven target lesion revascularization (CD-TLR), amputation, and mortality. Results: Seventy-one scaffolds were implanted to treat 61 lesions. Technical success was achieved in all patients, with no amputation, death, or target limb bypass surgery within 30 days of the index procedure. There was 1 early thrombotic occlusion of 2 BVS in a previously anticoagulated patient not given antiplatelet medication after the procedure. During a mean follow-up of 24.0±15.3 months, 11 (23%) patients died; the remaining 37 were available for follow-up. Binary restenosis (50%–75%) was detected in 6 (8%) scaffolds. Primary patency estimates at 12, 24, and 36 months were 92.2%, 90.3%, and 81.1%; freedom from CD-TLR estimates were 97.2%, 97.2%, and 87.3% at the same time points. No late scaffold thrombosis has been observed. The majority of the 55 limbs (51, 93%) were clinically improved; 4 (7%) were unchanged. Thirty-six (92%) of 39 limbs treated for tissue loss achieved complete wound healing, with no major amputation (limb salvage 100%). Conclusion: Midterm follow-up demonstrates excellent safety, patency, and freedom from CD-TLR rates using the Absorb bioresorbable vascular scaffold below the knee.

Outcomes of infrapopliteal angioplasty for limb salvage based on the updated TASC II classification

PURPOSE

We aimed to evaluate limb salvage, defined as freedom from major amputation, and to identify predictors of major amputation in patients with infrapopliteal peripheral arterial disease (PAD) based on the updated 2015 TASC II anatomic classification treated by percutaneous transluminal angioplasty (PTA).

METHODS

This was a retrospective study of infrapopliteal PTA procedures performed for PAD over a 4-year period. Patient demographics, medical comorbidities, risk factors, angiographic imaging, technical details, and clinical follow-up were analyzed to determine limb salvage rates, technical success, and all-cause mortality. Predictors of major amputation following PTA were identified.

RESULTS

A total of 112 patients were treated by infrapopliteal PTA. Most lesions consisted of TASC C (44%) and D (34%) categories, were over 10 cm in length, and were occlusive and heavily calcified (89%). Overall technical success was 75%, with limb salvage rates of 77% at 1 year and 65% at 3 years following PTA. Smoking, previous stroke or cardiovascular events, and anticoagulation use were associated with an increased risk of major amputation following PTA.

CONCLUSION

PTA of complex infrapopliteal PAD is associated with good intermediate term limb salvage rates.

Critical limb ischemia update and the evolving role of drug-elution technologies

INTRODUCTION

Critical limb ischemia (CLI) is a prevalent condition associated with cardiovascular mortality and limb loss. Areas covered: This review discusses the epidemiology of CLI, revascularization options, and drug-elution therapies. Expert commentary: Drug-eluting stents (DES) and drug-coated balloons (DCB) improve patency rates in the femoropopliteal segment, and are generally used as first-line therapies. For below-knee disease, angioplasty is the default strategy unless lesions are focal whereby DES can be used to reduce restenosis risk.

New Innovations in Drug-Eluting Stents for Peripheral Arterial Disease

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Experience With the Absorb Everolimus-Eluting Bioresorbable Vascular Scaffold in Arteries Below the Knee: 12-Month Clinical and Imaging Outcomes

OBJECTIVES

The aim of this study was to investigate the midterm performance of an everolimus-eluting, bioresorbable vascular scaffold (Absorb, Abbott Vascular, Santa Clara, California) for the treatment of focal tibial and distal popliteal lesions.

BACKGROUND

Drug-eluting stents are used below the knee to improve technical success and durability, but the ongoing presence of a permanent metal scaffold may have deleterious effects on the local vessel.

METHODS

Tibial and distal popliteal angioplasty with scaffold placement was performed using an everolimus-eluting, bioresorbable scaffold (Absorb). Clinical and ultrasound follow-up was performed at 1, 3, 6, 12, and 24 months to detect binary restenosis and evaluate safety, restenosis, and clinical improvement.

RESULTS

Thirty-eight limbs in 33 patients were treated for critical limb ischemia (68.4%) or severe claudication (31.6%). Fifty scaffolds were used to treat a total of 43 lesions, with a mean length of 19.2 ± 11.6 mm. During a mean follow-up period of 12.0 ± 3.9 months, 5 patients died, and all others were available for follow-up. Among the 38 treated limbs, clinical improvement was present in 30 (79%). Binary restenosis was detected in 3 of 50 scaffolds (6%). Using the Kaplan-Meier method, rates of primary patency were 96% and 84.6% at 12 and 24 months, respectively, and rates of freedom from clinically driven target lesion revascularization were 96% and 96% at 12 and 24 months, respectively. Complete wound healing occurred in 64% of those treated for tissue loss, with no major amputation and a limb-salvage rate of 100%.

CONCLUSIONS

Twelve-month follow-up demonstrated excellent safety, patency, and freedom from target lesion revascularization using the Absorb bioresorbable vascular scaffold below the knee.