Meta-analysis of drug-eluting balloon angioplasty and drug-eluting stent placement for infrainguinal peripheral arterial disease

A review of the current state in neointimal hyperplasia development following endovascular intervention and minor emphasis on new horizons in immunotherapy

Endovascular strategies play a vital role in the treatment of peripheral arterial disease (PAD). However, luminal loss or restenosis after endovascular intervention remains a significant challenge. The main underlying mechanisms are negative vascular remodeling and elastic recoil in balloon angioplasty. During stenting, the main reason for this complex is neointimal proliferation. Endothelial cell injury due to endovascular intervention initiates a series of molecular events, such as overexpression of growth factors, cytokine secretion, and adhesion molecules. These induce platelet activation and inflammatory processes, which trigger the proliferation and migration of vascular smooth muscle cells into the intima, resulting in neointimal hyperplasia. During this process, PAD progression is mainly caused by chronic inflammation, in which macrophages play a central role. Of the current strategies, drug release interventions aim to suppress restenosis using antiproliferative drugs, such as sirolimus and paclitaxel, during drug release. These drugs inhibit vascular reendothelialization and reduce late in-stent restenosis. For this reason, immunotherapy can be considered an important alternative. Interventions that polarize macrophages to the M2 subtype are particularly important, as they shape the immune response in an anti-inflammatory direction and contribute to tissue repair. However, there are several challenges to overcome, such as localizing antiproliferative or polarizing agents only to areas of vascular injury. This review discusses, based on the early study observations, immunotherapeutic approaches to prevent restenosis after endovascular intervention for the treatment of PAD.

Mechano-chemo-biological Computational Models for Arteries in Health, Disease and Healing: From Tissue Remodelling to Drug-eluting Devices

This review aims to highlight urgent priorities for the computational biomechanics community in the framework of mechano-chemo-biological models. Recent approaches, promising directions and open challenges on the computational modelling of arterial tissues in health and disease are introduced and investigated, together with in silico approaches for the analysis of drug-eluting stents that promote pharmacological-induced healing. The paper addresses a number of chemo-biological phenomena that are generally neglected in biomechanical engineering models but are most likely instrumental for the onset and the progression of arterial diseases. An interdisciplinary effort is thus encouraged for providing the tools for an effective in silico insight into medical problems. An integrated mechano-chemo-biological perspective is believed to be a fundamental missing piece for crossing the bridge between computational engineering and life sciences, and for bringing computational biomechanics into medical research and clinical practice.

The current status of drug-coated devices in lower extremity peripheral artery disease interventions

Lower limb peripheral artery disease is a leading cause of cardiovascular disease morbidity and mortality. Endovascular revascularization is often indicated to improve walking function and to prevent limb loss but restenosis in the treated vessel segment remains a concern that limits the overall effectiveness of the treatment. The most promising technique to prevent restenosis is the use of drug-coated devices, and the most common drug used to coat lower limb balloon angioplasty balloons and stents is paclitaxel. A systematic review and meta-analysis in 2018 reported a possible increase in late mortality attributable to paclitaxel-coated devices. Since then, their use has been brought into question. Here, we present an update of data focusing on the efficacy and safety of paclitaxel-coated devices in lower limb treatment applications. While paclitaxel-coated devices appear to reduce restenosis rates it is still unclear how these surrogate marker improvements translate to direct patient benefits and uncertainty remains as to whether paclitaxel-coated devices confer an increased risk of long-term mortality. Available randomized clinical data is hampered by trial heterogeneity, insufficient power, potential attrition bias and the lack of a plausible mechanistic explanation. An important step forward is that the ongoing trials that were temporarily halted due to the Katsanos et al. report have now both commenced recruitment and may ultimately resolve this clinical dilemma by virtue of their larger sample sizes. Other possible ways forward are the ongoing investigation of alternative anti-proliferative coating agents and use of new sophisticated vascular imaging techniques to more clearly identify patients at risk of restenosis already in the preoperative setting.

Efficacy and Safety of Paclitaxel-Coated Balloon Angioplasty for Dysfunctional Arteriovenous Fistulas: A Multicenter Randomized Controlled Trial

RATIONALE & OBJECTIVE

Previous studies have illustrated the potential superiority of drug-coated balloons (DCBs) in maintaining patency after initial angioplasty for arteriovenous fistula (AVF) dysfunction due to stenosis. Our trial evaluated the efficacy and safety of DCBs for preventing fistula restenosis in Chinese hemodialysis patients.

STUDY DESIGN

Multicenter, prospective, randomized, open-label, blinded end point, controlled trial.

SETTINGS & PARTICIPANTS

A total of 161 hemodialysis patients with fistula dysfunction from 10 centers in China.

INTERVENTION

Participants were randomized 1:1 to treatment with initial dilation followed by DCB angioplasty or conventional high-pressure balloon (HPB) angioplasty.

OUTCOMES

The primary end point was target lesion primary patency defined as the target lesion intervention-free survival in conjunction with an ultrasonography-measured peak systolic velocity ratio (PSVR) ≤2.0 at 6 months. The secondary end points included 1) device, technical, clinical, and procedural success; 2) major adverse events; 3) degree of target lesion stenosis at 6 months; and 4) clinically driven target lesion and target shunt revascularization within 12 months.

RESULTS

The percentage with target lesion primary patency as defined by a PSVR ≤2.0 was higher in the DCB group than in the control group (65% vs 37%, respectively; rate difference, 28% [95% CI, 13%-43%]; P <0.001) at 6 months. The target lesion and target shunt intervention-free survival of the DCB group were not superior to those of the control group at 6 months (P = 0.3 and P = 0.2, respectively) but were superior at 12 months (target lesion intervention-free survival: 73% for DCB vs 58% for control [P = 0.04]; target shunt intervention-free survival: 73% for DCB vs 57% for control [P = 0.04]). The average degree of target lesion stenoses at 6 months was not significantly different between the 2 groups (44% ± 16% for DCB vs 49% ± 18% for control; P = 0.09). There were no significant differences in major adverse events or in device, technical, clinical, or procedural success rates between the groups.

LIMITATIONS

Small sample size; short follow-up period; procedural differences between the 2 groups such as unequal inflation times and balloon lengths.

CONCLUSIONS

Compared to conventional HPB angioplasty, DCB treatment achieved superior primary patency defined using PSVR measured at 6 months and superior intervention-free survival of both the target lesion and the target shunt at 12 months without evidence of greater adverse events.

FUNDING

Funded by ZhuHai Cardionovum Medical Device Co., Ltd.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov with study number NCT02962141.

An Update on Drug-eluting Technology in Peripheral Arteries to Treat Peripheral Arterial Disease

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The SELUTION SLR™ drug-eluting balloon system for the treatment of symptomatic femoropopliteal lesions

Endovascular treatment has become first line therapy for the treatment of femoropopliteal disease. Drug-coated devices play a key role in maintaining vessel patency. In the past antiproliferative coating of drug-coated balloons (DCBs) exclusively consisted of paclitaxel. Use of limus drugs was limited by a short residency time in the vessel wall. Besides the drug, the SELUTION SLR™ drug-eluting balloon system consists of a coating formulation of four excipients. The first excipient is a biodegradable polymer (poly(lactic-co-glycolic acid)) that is intermixed with the sirolimus to form micro-reservoirs and regulates drug release via matrix degradation. This review summarizes the existing pre-clinical and clinical literature on treatment of femoropopliteal artery lesions with the SELUTION SLR DCB.

Outcomes of rotational atherectomy in complex lesions of the superficial femoral artery

BACKGROUND

The effectiveness of rotational atherectomy in the treatment of complex superficial femoral artery (SFA) lesions remains poorly defined. Outcomes of SFA lesions treated with rotational atherectomy were analyzed.

METHODS

This retrospective review assessed all patients who underwent rotational atherectomy of the SFA at a single institution between 2015 and 2018. The data of all patients were deidentified, and the study was approved by the Institutional Review Board. Informed consent was not obtained for this retrospective analysis. Main outcomes were Kaplan-Meier primary patency rate, freedom from major amputation, and 2-year survival rate. The effect of drug-coated balloon angioplasty (DCBA) on patency and time to death was investigated with univariate regression. The safety profile for atherectomy and DCBA was assessed by the 30-day incidence of major amputation and all-cause mortality.

RESULTS

Fifty-three patients (mean age, 70.2 ± 9.8 years; 73% male; 65% critical limb-threatening ischemia; 47 [90%] current or former smokers; seven [13%] with prior failed ipsilateral endovascular intervention) underwent rotational atherectomy (Jetstream; Boston Scientific, Marlborough, Mass) with mean follow-up of 543 days. Forty-six (87%) patients underwent DCBA (Lutonix; BD Bard, Covington, Ga) after atherectomy. Mean lesion length was 13.2 ± 9.0 cm. Thirty-one (58%) lesions were TransAtlantic Inter-Society Consensus C or D class. At 1-month follow-up, 39 of 45 (87%) patients experienced improvement in symptoms and Rutherford class. An improvement in ankle-brachial index was also noted in 13% of patients without improvement of symptoms, with no patients progressing to surgical bypass or major amputation. Mean ankle-brachial index increased from 0.54 ± 0.035 to 0.90 ± 0.031 at 1 month after intervention (P < .001) and remained constant out to 18 months. Mean toe pressure increased from 36 ± 3.8 mm Hg to 67 ± 4.5 mm Hg at 1 month after intervention (P < .001) and remained constant out to 18 months. Kaplan-Meier primary patency rate was 75% (95% confidence interval, 61%-85%) at 12 months and 65% (51%-77%) at 24 months. There was a trend toward improved primary patency after adjunctive DCBA compared with plain balloon angioplasty at 1 year (75% vs 43%; P = .1082). There was no significant difference in mortality between adjunctive DCBA and plain balloon angioplasty at 2 years (11% vs 0%). The 2-year incidence of major amputation in critical limb-threatening ischemia patients was 3.9% (1.2%-6.5%). One patient died and none underwent amputation within 30 days.

CONCLUSIONS

Rotational atherectomy with adjunctive DCBA of long SFA lesions has excellent long-term patency. Two-year major amputation and mortality rates are low, and the technique has an exceptional safety profile.

Paclitaxel drug-coated balloon angioplasty for the treatment of failing arteriovenous fistulas: a single-center experience

Objectives: To report our experience of angioplasty with Lutonix (Bard Peripheral Vascular, Inc., Tempe, AZ) drug-coated balloon (DCB) for the treatment of failing arteriovenous fistulas (AVF).Materials and methods: Retrospective, single-center analysis consisting of 14 patients treated with Lutonix paclitaxel DCBs in the period from July 2015 through April 2017. We analyzed technical success, clinical success, primary patency of the target lesion, primary patency of the dialysis circuit, and the rate of complications. Regular follow-up of AVF patency was realized by clinical examination and duplex ultrasonography. The Kaplan-Meier survival method was applied to determine the cumulative primary patency of the target lesion and the dialysis circuit.Results: Technical success was 100% and clinical success 92.9%. There were no major or minor complications. Cumulative target lesion primary patency after DCB was 69.2% at 6 months and 31.6% at 12 months. Cumulative vascular circuit primary patency was 61.5% at 6 months and 31.6% at 12 months.Conclusion: Compared to results reported in literature with plain old balloon angioplasty (POBA), Lutonix paclitaxel DCB angioplasty proved a short-term patency benefit in treatment of dialysis AVF stenosis.

Recent advances in endovascular treatment of peripheral arterial disease

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

Predictive value of P-selectin and endothelin-1 for vascular restenosis after interventional procedures for peripheral artery disease

Peripheral artery disease (PAD) is caused by the building up of plaques in the arteries that carry blood to the lower limbs. The present study aimed to assess the predictive value of the plasma levels of P-selectin (Ps) or endothelin-1 (ET-1) regarding the occurrence of vascular restenosis after endovascular therapy for PAD. Patients with or without vascular restenosis confirmed by computed tomography angiography after endovascular therapy between March and December 2015 (n=20 per group) were enrolled. The serum levels of Ps and ET-1 prior to the operation and at 1 h, as well as 1, 2 and 3 weeks after the operation were compared between the two groups. At 1 h after the operation, the serum levels of Ps and ET-1 were significantly increased as compared with the pre-operative levels (P<0.05). The serum levels of Ps and ET-1 at 1 h, as well as 1, 2 and 3 weeks after the operation in the restenosis group were significantly higher as compared with those in the non-stenosis group (P<0.05). However, for the non-stenosis group, the serum levels of Ps and ET-1 at 1, 2 and 3 weeks after the operation did not significantly differ from the pre-operative levels (P>0.05). The diagnostic sensitivity and specificity of the serum ET-1 levels at 1 h after the operation for predicting post-operative restenosis in PAD patients with a cut-off of 0.1089 pg/ml were 85 and 85%, respectively. In conclusion, the serum levels of Ps and ET-1 have a high predictive value for post-operative vascular restenosis after endovascular therapy for PAD patients.

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.

Comparison of Drug-Eluting Stent with Bare-Metal Stent Implantation in Femoropopliteal Artery Disease: A Systematic Review and Meta-Analysis

BACKGROUND

This study aimed to perform a systematic review and meta-analysis of current evidence comparing the drug-eluting stent (DES) with the bare-metal stent (BMS) in the treatment of femoropopliteal artery disease (FPAD).

METHODS

All relevant articles reporting the results of DES versus BMS implantation in FPAD were systematically searched in MEDLINE, EMBASE, and Cochrane database. Randomized controlled trial (RCT), cohort, and retrospective study were all included. The efficacy end points included late lumen loss (LLL), binary restenosis, primary patency rate, freedom from target lesion revascularization (TLR), and stent fracture. Related data of the follow-up outcomes were extracted and pooled. For each end point, odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.

RESULTS

A total of 9 studies with 776 patients were included in this meta-analysis. There was no statistically significant difference between the DES and BMS groups in terms of LLL at 6 months (standard mean difference = -0.37, P = 0.07); binary restenosis at 6, 12, and 24 months (OR = 0.44, P = 0.20; OR = 0.75, P = 0.74; and OR = 0.62, P = 0.36; respectively); primary patency rate at 6, 12, and 24 months (OR = 1.18, P = 0.73; OR = 1.43, P = 0.70; OR = 1.25, P = 0.68, respectively); freedom from TLR at 12 months (OR = 1.13, P = 0.79); and stent fracture at 6 months (OR = 1.67, P = 0.38). A sensitivity analysis demonstrated that there was a significant benefit in the DES group over the BMS group in binary restenosis at 6 months (OR = 0.22, P = 0.008) after excluding a retrospective study, whereas no significant difference was observed when eliminating any other study. A subgroup analysis did not reveal any significant difference between a subgroup (sirolimus-eluting stent or paclitaxel-eluting stent) and the BMS group in FPAD.

CONCLUSIONS

According to current evidence, DES was not superior to BMS in the treatment of FPAD. Further larger RCTs are needed to provide more evidence in the comparison between DES and BMS for FPAD.

The comparative efficacy of angiosome-directed and indirect revascularisation strategies to aid healing of chronic foot wounds in patients with co-morbid diabetes mellitus and critical limb ischaemia: a literature review

BACKGROUND

Ischaemic ulcerations have been reported to persist and/or deteriorate despite technically successful revascularisations; a higher incidence of which affects patients with diabetes and critical limb ischaemia. In the context of wound healing, it is unclear if applications of the angiosome concept in 'direct revascularisation' (DR) would be able to aid the healing of chronic foot ulcerations better than the current 'best vessel' or 'indirect revascularisation' (IR) strategy in patients with co-morbid diabetes and critical limb ischaemia.

METHODS

A literature search was conducted in eight electronic databases, namely AMED, CINAHL, The Cochrane Library, ProQuest Health & Medicine Complete, ProQuest Nursing & Allied Health Source, PubMed, ScienceDirect and TRIP database. Articles were initially screened against a pre-established inclusion and exclusion criteria to determine eligibility and subsequently appraised using the Newcastle-Ottawa Scale.

RESULTS

Five retrospective studies of varying methodological quality were eligible for inclusion in this review. Critical analysis of an aggregated population (n = 280) from methodologically stronger studies indicates better wound healing outcomes in subjects who had undergone DR as compared to IR (p < 0.001; p = 0.04). DR also appears to result in a nearly twofold increase in probability of wound healing within 12 months (hazard ratio, 1.97; 95% CI, 1.34-2.90). This suggests that achieving direct arterial perfusion to the site of ulceration may be important for the healing of chronic diabetic foot ulcerations.

CONCLUSION

Incorporating an angiosome-directed approach in the lower limb revascularisation strategy could be a very useful adjunct to a solely indirect approach, which could increase the likelihood of wound healing. With the limited data currently available, findings appear promising and merit from further investigation. Additional research to form a solid evidence base for this revised strategy in patients with co-morbid diabetes and critical limb ischaemia is warranted.

Long-Term Follow-up of the PADI Trial: Percutaneous Transluminal Angioplasty Versus Drug-Eluting Stents for Infrapopliteal Lesions in Critical Limb Ischemia

BACKGROUND

Clinical outcomes reported after treatment of infrapopliteal lesions with drug-eluting stents (DESs) have been more favorable compared with percutaneous transluminal angioplasty with a bailout bare metal stent (PTA-BMS) through midterm follow-up in patients with critical limb ischemia. In the present study, long-term results of treatment of infrapopliteal lesions with DESs are presented.

METHODS AND RESULTS

Adults with critical limb ischemia (Rutherford category ≥4) and infrapopliteal lesions were randomized to receive PTA-BMS or DESs with paclitaxel. Long-term follow-up consisted of annual assessments up to 5 years after treatment or until a clinical end point was reached. Clinical end points were major amputation (above ankle level), infrapopliteal surgical or endovascular reintervention, and death. Preserved primary patency (≤50% restenosis) of treated lesions was an additional morphological end point, assessed by duplex sonography. In total, 74 limbs (73 patients) were treated with DESs and 66 limbs (64 patients) were treated with PTA-BMS. The estimated 5-year major amputation rate was lower in the DES arm (19.3% versus 34.0% for PTA-BMS; P=0.091). The 5-year rates of amputation- and event-free survival (survival free from major amputation or reintervention) were significantly higher in the DES arm compared with PTA-BMS (31.8% versus 20.4%, P=0.043; and 26.2% versus 15.3%, P=0.041, respectively). Survival rates were comparable. The limited available morphological results showed higher preserved patency rates after DESs than after PTA-BMS at 1, 3, and 4 years of follow-up.

CONCLUSIONS

Both clinical and morphological long-term results after treatment of infrapopliteal lesions in patients with critical limb ischemia are improved with DES compared with PTA-BMS.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00471289.

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.

Incidence and clinical outcomes of the slow-flow phenomenon after infrapopliteal balloon angioplasty

OBJECTIVE

This study investigated the incidence and clinical relevance of the slow-flow phenomenon after infrapopliteal balloon angioplasty.

METHODS

This retrospective, single-center study included 161 consecutive patients with critical limb ischemia (173 limbs) who underwent endovascular treatment for infrapopliteal lesions between January 2012 and May 2015. The overall technical success rate was 88%. Of these lesions, 30 limbs presented with slow flow after angioplasty.

RESULTS

Total occlusion (90% vs 63%; P < .01) and severe calcification (43% vs 8%; P < .01) were more common in the slow-flow group. Kaplan-Meier curve analysis revealed that freedom from major amputation (60% vs 86%; log-rank, P < .01) and wound healing at 2 years (77% vs 91%; log-rank, P = .03) were significantly less common in the slow-flow group. Univariate Cox proportional hazard analysis identified Rutherford class 6 (hazard ratio [HR], 6.4; 95% confidence interval [CI], 2.8-15.8; P < .01), the slow-flow phenomenon (HR, 3.9; 95% CI, 1.6-8.9; P < .01), and hemodialysis (HR, 3.2; 95% CI, 1.2-11.1; P = .02) as independent predictors of major amputation and Rutherford class 6 (HR, 0.3; 95% CI, 0.2-0.6; P < .01), the slow-flow phenomenon (HR, 0.5; 95% CI, 0.3-0.9; P = .02), and pedal arch (HR, 1.6; 95% CI, 1.0-2.5; P = .04) as predictors of wound healing.

CONCLUSIONS

The slow-flow phenomenon after infrapopliteal balloon angioplasty occurred in 18.6% of limbs. This phenomenon may result in poor outcomes.

Drug-coated balloon angioplasty for dialysis access fistula stenosis

Maintaining vascular access patency represents a tremendous challenge in hemodialysis patients. Although "native" arteriovenous fistula (AVF) is currently recommended as primary vascular access, neointimal hyperplasia stenoses frequently develop, with a risk for AVF thrombosis and vascular access loss. For years, first-line treatment of AVFs stenoses has been percutaneous transluminal angioplasty, generally with high-pressure or cutting uncoated balloons. However, restenosis and reintervention rates remain incredibly high and occur, according to recent studies, in up to 60% and 70% of patients at 6 and 12 months, respectively. Drug-coated balloons delivering paclitaxel at the angioplasty site have proved their superiority in the treatment of coronary and peripheral arterial stenoses. Paclitaxel reduces neointimal hyperplasia and drug-coated balloons, therefore, it represents an attractive option for AVF stenoses. Because data are scarce, the aim of this paper was to review the concepts and current results of drug-coated balloons in AVF stenosis management.

Drug-eluting balloon angioplasty versus uncoated balloon angioplasty for peripheral arterial disease of the lower limbs

BACKGROUND

Atherosclerotic peripheral arterial disease (PAD) can lead to disabling ischemia and limb loss. Treatment modalities have included risk factor optimization through life-style modifications and medications, or operative approaches using both open and minimally invasive techniques, such as balloon angioplasty. Drug-eluting balloon (DEB) angioplasty has emerged as a promising alternative to uncoated balloon angioplasty for the treatment of this difficult disease process. By ballooning and coating the inside of atherosclerotic vessels with cytotoxic agents, such as paclitaxel, cellular mechanisms responsible for atherosclerosis and neointimal hyperplasia are inhibited and its devastating complications are prevented or postponed. DEBs are considerably more expensive than uncoated balloons, and their efficacy in improving patient outcomes is unclear.

OBJECTIVES

To assess the efficacy of drug-eluting balloons (DEBs) compared with uncoated, nonstenting balloon angioplasty in people with symptomatic lower-limb peripheral arterial disease (PAD).

SEARCH METHODS

The Cochrane Vascular Trials Search Co-ordinator (TSC) searched the Specialised Register (last searched December 2015) and Cochrane Register of Studies (CRS) (2015, Issue 11). The TSC searched trial databases for details of ongoing and unpublished studies.

SELECTION CRITERIA

We included all randomized controlled trials that compared DEBs with uncoated, nonstenting balloon angioplasty for intermittent claudication (IC) or critical limb ischemia (CLI).

DATA COLLECTION AND ANALYSIS

Two review authors (AK, TA) independently selected the appropriate trials and performed data extraction, assessment of trial quality, and data analysis. The senior review author (DKR) adjudicated any disagreements.

MAIN RESULTS

Eleven trials that randomized 1838 participants met the study inclusion criteria. Seven of the trials included femoropopliteal arterial lesions, three included tibial arterial lesions, and one included both. The trials were carried out in Europe and in the USA and all used the taxane drug paclitaxel in the DEB arm. Nine of the 11 trials were industry-sponsored. Four companies manufactured the DEB devices (Bard, Bavaria Medizin, Biotronik, and Medtronic). The trials examined both anatomic and clinical endpoints. There was heterogeneity in the frequency of stent deployment and the type and duration of antiplatelet therapy between trials. Using GRADE assessment criteria, the quality of the evidence presented was moderate for the outcomes of target lesion revascularization and change in Rutherford category, and high for amputation, primary vessel patency, binary restenosis, death, and change in ankle-brachial index (ABI). Most participants were followed up for 12 months, but one trial reported outcomes at five years.There were better outcomes for DEBs for up to two years in primary vessel patency (odds ratio (OR) 1.47, 95% confidence interval (CI) 0.22 to 9.57 at six months; OR 1.92, 95% CI 1.45 to 2.56 at 12 months; OR 3.51, 95% CI 2.26 to 5.46 at two years) and at six months and two years for late lumen loss (mean difference (MD) -0.64 mm, 95% CI -1.00 to -0.28 at six months; MD -0.80 mm, 95% CI -1.44 to -0.16 at two years). DEB were also superior to uncoated balloon angioplasty for up to five years in target lesion revascularization (OR 0.28, 95% CI 0.17 to 0.47 at six months; OR 0.40, 95% CI 0.31 to 0.51 at 12 months; OR 0.28, 95% CI 0.18 to 0.44 at two years; OR 0.21, 95% CI 0.09 to 0.51 at five years) and binary restenosis rate (OR 0.44, 95% CI 0.29 to 0.67 at six months; OR 0.38, 95% CI 0.15 to 0.98 at 12 months; OR 0.26, 95% CI 0.10 to 0.66 at two years; OR 0.12, 95% CI 0.05 to 0.30 at five years). There was no significant difference between DEB and uncoated angioplasty in amputation, death, change in ABI, change in Rutherford category and quality of life (QoL) scores, or functional walking ability, although none of the trials were powered to detect a significant difference in these clinical endpoints. We carried out two subgroup analyses to examine outcomes in femoropopliteal and tibial interventions as well as in people with CLI (4 or greater Rutherford class), and showed no advantage for DEBs in tibial vessels at six and 12 months compared with uncoated balloon angioplasty. There was also no advantage for DEBs in CLI compared with uncoated balloon angioplasty at 12 months.

AUTHORS' CONCLUSIONS

Based on a meta-analysis of 11 trials with 1838 participants, there is evidence of an advantage for DEBs compared with uncoated balloon angioplasty in several anatomic endpoints such as primary vessel patency (high-quality evidence), binary restenosis rate (moderate-quality evidence), and target lesion revascularization (low-quality evidence) for up to 12 months. Conversely, there is no evidence of an advantage for DEBs in clinical endpoints such as amputation, death, or change in ABI, or change in Rutherford category during 12 months' follow-up. Well-designed randomized trials with long-term follow-up are needed to compare DEBs with uncoated balloon angioplasties adequately for both anatomic and clinical study endpoints before the widespread use of this expensive technology can be justified.

Techniques in Vascular and Interventional Radiology Drug Delivery Technologies in the Superficial Femoral Artery

Peripheral arterial disease (PAD) affects over 8 million people in the United States alone. Although great strides have been made in reducing the burden of cardiovascular disease the prevalence of PAD is expected to rise with the age of global population. PAD characterized by narrowing of arterial blood can be asymptomatic or cause limb threatening claudication. It has been classically treated with bypass, but these techniques have been supplanted by endovascular therapy. Plain old balloon angioplasty has been successful in helping revascularize lesions, but its effect has not been durable because of restenosis. This prompted the creation of several technologies aimed at reducing restenosis. These advances slowly improved outcomes and the durability of endovascular management. Among the main tools used in current endovascular practice are drug-delivery devices aimed at inhibiting the inflammatory and proliferative pathways that lead to restenosis. This article examines the current drug-delivery technologies used in the superficial femoral artery.

Drug-eluting balloon catheters for lower limb peripheral arterial disease: the evidence to date

A significant proportion of patients with severe lower limb peripheral arterial disease require revascularization. Over the past decade, an endovascular-first approach even for complex disease has gained widespread use among vascular specialists. An important limitation of percutaneous transluminal balloon angioplasty or stenting remains the occurrence of restenosis. Drug-coated balloons have emerged as an exciting technology developed to overcome the limitations of standard balloon angioplasty and stenting. Drug-eluting devices inhibit neointimal growth of vascular smooth muscle cells with the potential of preventing restenosis. This review provides a synopsis of the up-to-date evidence on the role of drug-coated balloons in the treatment of lower limb peripheral arterial disease. Bibliographic searches were conducted using MEDLINE, EMBASE, and the Cochrane Library electronic database. Eleven randomized clinical trials, two systematic reviews, and a published registry providing the best available evidence were identified. Current evidence suggests that angioplasty with drug-coated balloon is reliable, safe, and efficient in increasing patency rates and reducing target lesion revascularization and restenosis. However, it remains unknown whether these improved results can translate into beneficial clinical outcomes, as current randomized clinical trials have failed to demonstrate a significant benefit in limb salvage and mortality. Further randomized trials focusing on clinical and functional outcomes of drug-eluting balloons and on cost versus clinical benefit are required.