Randomized, multicenter study comparing expanded polytetrafluoroethylene-covered endoprosthesis placement with percutaneous transluminal angioplasty in the treatment of superficial femoral artery occlusive disease

A Bayesian network meta-analysis for acute thrombosis after lower extremity artery endovascular treatment

BACKGROUND

Various endovascular treatment devices have been widely used in the lower extremity arterial disease (LEAD). Their patency efficiency for target lesions has been well studied and reported. Comparison of the risk of acute thrombosis events between the different endovascular treatment devices is unclear.

AIMS

To rank the risk of acute thrombosis events when bare metal stents (BMSs), covered stents (CSs), drug-eluting stents (DESs), drug-coated balloons (DCBs), and conventional percutaneous transluminal balloon angioplasty (PTA) are used to treat LEAD through Bayesian network meta-analysis.

METHODS

We performed a network meta-analysis of randomized controlled trials comparing the risk of 1-year postoperative acute thrombosis between BMSs, CSs, DESs, DCBs, and PTA for treating LEAD. Bayesian random models were used for pooled endovascular treatment modality comparisons. We ranked these treatment modalities via the Bayesian method according to their surface under the cumulative ranking curve (SUCRA) and estimated probabilities.

RESULTS

Nineteen studies (38 study arms; 2758 patients) were included. The Bayesian network ranking of treatments indicated that DCB had the lowest risk of acute thrombosis, PTA had the second-lowest risk of thrombosis, and CS, BMS, and DES had the highest risk of thrombosis. Regarding the treatment efficacy, the OR values of the loss of primary patency were significantly lower for DCB (OR = 0.44, 95% CI: 0.30-0.62), DES (OR = 0.36, 95% CI: 0.14-0.94), and CS (OR = 0.31, 95% CI: 0.18,0.56) than for PTA. When BMS was used as a reference, only the OR for CS was significantly lower (OR = 0.41, 95% CI = 0.21-0.82). Correspondingly, the Bayesian ranking of treatments from better to worse target lesion primary patency was CS, DES, DCB, BMS, and PTA.

CONCLUSION

With the available research evidence and according to the network analysis ranking, DES appears to have the highest risk of acute thrombosis and DCB appears to have the lowest risk.

Endovascular revascularization strategies for aortoiliac and femoropopliteal artery disease: a meta-analysis

AIMS

Optimal endovascular management of intermittent claudication (IC) remains disputed. This systematic review and meta-analysis compares efficacy and safety outcomes for balloon angioplasty (BA), bare-metal stents (BMS), drug-coated balloons (DCB), drug-eluting stents (DES), covered stents, and atherectomy.

METHODS AND RESULTS

Electronic databases were searched for randomized, controlled trials (RCT) from inception through November 2021. Efficacy outcomes were primary patency, target-lesion revascularization (TLR), and quality-of-life (QoL). Safety endpoints were all-cause mortality and major amputation. Outcomes were evaluated at short-term (<1 year), mid-term (1-2 years), and long-term (≥2 years) follow-up. The study was registered on PROSPERO (CRD42021292639). Fifty-one RCTs enrolling 8430 patients/lesions were included. In femoropopliteal disease of low-to-intermediate complexity, DCBs were associated with higher likelihood of primary patency [short-term: odds ratio (OR) 3.21, 95% confidence interval (CI) 2.44-4.24; long-term: OR 2.47, 95% CI 1.93-3.16], lower TLR (short-term: OR 0.33, 95% CI 0.22-0.49; long-term: OR 0.42, 95% CI 0.29-0.60) and similar all-cause mortality risk, compared with BA. Primary stenting using BMS was associated with improved short-to-mid-term patency and TLR, but similar long-term efficacy compared with provisional stenting. Mid-term patency (OR 1.64, 95% CI 0.89-3.03) and TLR (OR 0.50, 95% CI 0.22-1.11) estimates were comparable for DES vs. BMS. Atherectomy, used independently or adjunctively, was not associated with efficacy benefits compared with drug-coated and uncoated angioplasty, or stenting approaches. Paucity and heterogeneity of data precluded pooled analysis for aortoiliac disease and QoL endpoints.

CONCLUSION

Certain devices may provide benefits in femoropopliteal disease, but comparative data in aortoiliac arteries is lacking. Gaps in evidence quantity and quality impede identification of the optimal endovascular approach to IC.

Discrete Event Simulation Model for Cost-Effectiveness Evaluation of Screening for Asymptomatic Patients with Lower Extremity Arterial Disease

Lower limb ischemic disease (LEAD) affects a significant portion of the population, with most patients being asymptomatic. Patient screening is necessary because LEAD patients have an increased risk of occurrence of other cardiovascular events and manifestations of disease, in terms of leg symptoms such as intermittent claudication, critical limb ischemia, or amputation. The aim of this work was to evaluate the cost-effectiveness of screening using ABI diagnostics in asymptomatic patients and its impact on limb symptoms associated with LEAD. A discrete event simulation model was created to capture lifetime costs and effects. Costs were calculated from the perspective of the health care payer, and the effects were calculated as QALYs. A cost-effectiveness analysis was performed to compare ABI screening examination and the situation without such screening. A probabilistic sensitivity analysis and scenario analysis were carried out to evaluate the robustness of the results. In the basic setting, the screening intervention was a more expensive intervention, at a cost of CZK 174,010, compared to CZK 70,177 for the strategy without screening. The benefits of screening were estimated at 14.73 QALYs, with 14.46 QALYs without screening. The final ICER value of CZK 389,738 per QALY is below the willingness to pay threshold. Likewise, the results of the probabilistic sensitivity analysis and of the scenario analysis were below the threshold of willingness to pay, thus confirming the robustness of the results. In conclusion, ABI screening appears to be a cost-effective strategy for asymptomatic patients aged 50 years when compared to the no-screening option.

Effect of expanded polytetrafluoroethylene thickness on paclitaxel release and edge stenosis in stent graft

Stent grafts have been widely used to treat lower extremity arterial stenosis or occlusion. However, there are major issues with edge stenosis and loss of patency over time. Paclitaxel-coated stent grafts have been proven to be effective in preventing edge stenosis, but the insufficient amounts of paclitaxel released may limit the effectiveness of drug-eluting stent grafts. In this study, we examined whether paclitaxel-coated expanded polytetrafluoroethylene (ePTFE) stent graft thickness influences paclitaxel release properties and inhibits edge stenosis. Low-, medium-, and high-thickness paclitaxel-coated stent grafts were prepared by varying the thickness of inner and outer ePTFE layers. Surface morphologies of the stent grafts were analyzed using a scanning electron microscope. The stent grafts were then implanted in the iliac arteries of 20 healthy swine. Twelve pigs were used to assess edge stenosis, and digital subtraction angiography was performed at day 30 (n = 4), 90 (n = 4), and 180 (n = 4). Histological evaluation of the treated arteries was also performed. Eight pigs were used for pharmacokinetic analysis, and the treated arteries were obtained at day 1 (n = 2), 30 (n = 2), 90 (n = 2) and 180 (n = 2). Scanning electron microscopy confirmed that the mean pore size of the stent grafts decreased with increasing thickness. The results of angiographic and histological evaluation demonstrated that low-thickness ePTFE-stent grafts resulted in edge stenosis and apparent intimal hyperplasia at 180 days, whereas for medium-thickness ePTFE-stent grafts, no obvious edge stenosis and intimal hyperplasia was noted in the similar time period. The results of pharmacokinetic evaluation showed that at 180 days, the paclitaxel concentration of treated arteries of the medium group was 36 ± 53 ng/g, while concentrations in the low group was not detectable. Stent grafts with increased ePTFE thickness appear to allow for more delayed release of paclitaxel compared to low-thickness ePTFEs.

Network Analysis of Endovascular Treatment Strategies for Femoropopliteal Arterial Occlusive Disease

PURPOSE

Endovascular treatment of femoropopliteal arterial diseases remains controversial. We conducted a Bayesian network meta-analysis of randomized controlled trials aiming to investigate the efficacy differences between paclitaxel- or sirolimus-eluting stents, covered stents, drug-coated balloons, bare metal stents, and percutaneous transluminal angioplasty.

METHOD

MEDLINE, Embase, Ovid, and other relevant online material were searched up to October 21, 2020. Primary endpoints were primary patency and target lesion revascularization at 6, 12, and more than 24 months.

RESULTS

Thirty-eight eligible trials included 6026 patients. In terms of primary patency, drug eluting stents were ranked as the most effective treatment based on the surface under the cumulative ranking curve values at 6 (80.6), 12 (78.4), and more than 24 months (96.5) of follow-ups. In terms of target lesion revascularization, drug eluting stents were ranked as the most effective treatment based on the surface under the cumulative ranking curve values at 6 (90.3), 12 (71.3), and more than 24 months (82.1) of follow-ups. Covered stents and bare metal stents had higher ranks in target lesion revascularization than those in primary patency. Sirolimus stents had a higher rank than paclitaxel stents.

CONCLUSION

Drug eluting stents showed encouraging results in primary patency rates and freedom from target lesion revascularization at all phases of follow-up for femoropopliteal arterial diseases. Sirolimus stents appear to be more effective in femoropopliteal segment than paclitaxel stent.

Repair of a high-flow superficial femoral arteriovenous fistula using a bell-bottom iliac limb endoprosthesis

A 50-year-old patient had presented with recalcitrant right lower extremity venous stasis ulceration, atrial fibrillation, and congestive heart failure. He had a history of a gunshot wound to the right thigh >30 years previously, which had been managed without surgery. Computed tomography angiography indicated a fistulous communication between the right superficial femoral artery and vein with massively dilated right iliofemoral venous and arterial systems. He was treated with stent-graft coverage of the superficial femoral arteriovenous fistula using a bell-bottom iliac limb endoprosthesis. This stent-graft accommodated the diameter asymmetry in the superficial femoral artery caused by the long-standing fistula and ameliorated the symptoms that had afflicted him for decades.

Inhibition of edge stenosis of endografts in swine iliac arteries by a novel endograft with biodegradable coating at both ends

Objective

This study evaluated the effectiveness and safety of a novel endograft with a biodegradable coating at both ends in preventing edge stenosis in swine iliac arteries. The biodegradable coating was composed of polylactide and paclitaxel.

Methods

Four types of endograft were implanted in the iliac arteries of healthy swine: an endograft without coating (control group) and endografts with polylactide and paclitaxel coating containing 0.1, 0.3, or 3.6 μg/mm² of paclitaxel. The edge stenosis of these endografts in swine iliac arteries was assessed using angiographic image data at 30, 90, and 180 days after the operation. After terminal angiography, histologic evaluation of the treated arteries was performed. The treated sections of iliac arteries and blood samples were obtained at 1, 7, 30, 90, and 180 days for pharmacokinetic analysis.

Results

The results of angiographic and histologic evaluation demonstrated that intimal hyperplasia contributed to edge stenosis and polylactide-paclitaxel coating effectively inhibited edge stenosis. At 30 days, edge stenosis was observed at both the proximal and distal edges of the endograft without coating. At 90 days, edge stenosis was detected for the endograft coated with 0.1 μg/mm² paclitaxel, and ectasia dilation occurred at the proximal and distal edges of the endograft coated with 3.6 μg/mm² paclitaxel. No edge stenosis or other adverse effects were observed at 90 and 180 days for the endograft coated with 0.3 μg/mm² paclitaxel. In addition, for the endograft coated with 0.3 μg/mm² paclitaxel, a pharmacokinetic analysis showed that the paclitaxel concentration of treated segments decreased from 14 264 ± 1020 ng/g at day 1 to 80 ± 70 ng/g at day 90, and 20 ± 40 ng/g at day 180. The plasma paclitaxel concentration was low at day 1 and no longer detected after 7 days.

Conclusions

Polylactide and paclitaxel coating containing 0.3 μg/mm² paclitaxel at both ends of endografts effectively and safely inhibits edge stenosis in swine iliac arteries.

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.

"Modern Endovascular Therapy"

INTRODUCTION

The past 25 years have been witness to a revolution in how vascular care is delivered. The majority of arterial and venous interventions have converted from open surgery to minimally invasive percutaneous endovascular procedures.

METHODS

This surgical innovations symposium article reviews current endovascular therapy in multiple vascular beds with a primary focus on carotid artery occlusive disease, aortic pathologies, and lower extremity arterial occlusive disease. Mesenteric arterial occlusive disease and lower extremity venous endovascular therapies are also briefly discussed. Indications for intervention, treatment examples and outcomes analysis are presented. While not reviewed in this article, endovascular therapy has also become first line in the treatment of coronary artery disease, chronic mesenteric arterial occlusive disease, superficial venous reflux, central vein occlusion, and acute venous thrombus intervention when indicated.

CONCLUSION

Endovascular therapies are used in all vascular beds to treat the full spectrum of vascular pathologies. Aneurysm disease, atherosclerotic arterial occlusive disease, acute arterial and venous thrombosis, ongoing hemorrhage, and venous reflux are among the issues which can be addressed by endovascular means. The minimally invasive nature of endovascular treatments in what is largely a very co-morbid patient cohort is an attractive method of avoiding major procedural related morbidity and mortality.

Meta-Analysis Comparing Endovascular Treatment Modalities for Femoropopliteal Peripheral Artery Disease

Endovascular interventions are commonly utilized for treatment of femoropopliteal peripheral artery disease. The relative efficacy of these interventions remains unclear. A Bayesian network meta-analysis was performed comparing 5 endovascular treatment modalities: balloon angioplasty (BA), bare metal stent (BMS), covered stent (CS), drug-coated balloon (DCB), drug-eluting stent (DES) for femoropopliteal peripheral artery disease. The primary efficacy end points were freedom from target lesion revascularization (TLR) and primary patency at 12 months. BA was the reference treatment. Twenty-two trials including 4,381 participants provided data on TLR. Sixteen trials including 3,691 participants provided data on primary patency. Point estimates for DCB suggested that it was the most efficacious treatment for freedom from TLR (odds ratio [OR] 4.23; 95% credible intervals [CrI] 2.43 to 7.66) followed by CS (OR 3.65; 95% CrI 1.11 to 12.55), DES (OR 2.64; 95% CrI 0.72 to 9.77), and BMS (OR 2.3; 95% CrI 1.11 to 4.76). Similarly, point estimates for primary patency were highest with DES (OR 8.93; 95% CrI 3.04, 27.14) followed by CS (OR 3.91; 95% CrI 1.18, 13.84), DCB (OR 3.32; 95% CrI 1.8, 6.25), and BMS (OR 3.5; 95% CrI 1.58, 7.99). In conclusion, DCB has the lowest need for TLR whereas DES has the highest primary patency rate. DCB, CS, and BMS were associated with significant reductions in TLR compared with BA, whereas DCB, DES, CS, and BMS were associated with significantly improved primary patency compared with BA.

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.

Comparative Effectiveness of Endovascular Treatment Modalities for De Novo Femoropopliteal Lesions: A Network Meta-analysis of Randomized Controlled Trials

Purpose: To report the results of a network meta-analysis of randomized controlled trials (RCTs) comparing multiple endovascular treatments for de novo femoropopliteal lesions. Materials and Methods: The MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials databases were systematically searched on June 1, 2019, for prospective RCTs comparing 14 treatments [ie, atherectomy, brachytherapy, cryoplasty, cutting balloons, drug-coated balloons, bare nitinol stents, drug-eluting stents (DES), covered stents (CS), and combinations] in the treatment of de novo femoropopliteal lesions. Outcomes were technical success; binary restenosis and target lesion revascularization (TLR) at 6, 12, and/or 24 months; and all-cause mortality at 12 months. Ultimately, 53 articles reporting on 45 studies (91 study arms; 5565 patients) were selected. For the technical success outcome, all types of stents, all balloons, and all atherectomy devices were aggregated in stent, balloon, and atherectomy technology groups, respectively. Results: In terms of technical success for aggregated treatment types, stent technology was the most effective treatment and was better than balloon and atherectomy technologies. In terms of binary restenosis, DES was the most effective single treatment at the 6- and 12-month follow-up and CS at the 24-month follow-up. Both DES and CS were better than the majority of other single treatments, including balloon angioplasty, cutting balloon, cryoplasty, directional atherectomy, and bare nitinol stent during all follow-up periods. In terms of TLR, DES was the second most effective single treatment and the most effective single treatment at the 6- and 12-month follow-up intervals; CS was the most effective single treatment at the 24-month follow-up. Both DES and CS were better than the majority of other single treatments. The 12-month all-cause mortality of both DES and CS were similar to other treatments, whereas cryoplasty seemed to be the least effective treatment with regard to binary restenosis and TLR. Conclusion: Both DES and CS had substantial advantages in terms of restenosis and TLR in femoropopliteal lesions and were similar to aggregate stent technology in terms of technical success. DES performed better within 12 months after operation and CS at ~24 months, but neither had much advantage in terms of mortality. In contrast, cryoplasty seemed to be a less effective treatment.

Comparative Efficacy and Safety of Endovascular Treatment Modalities for Femoropopliteal Artery Lesions: A Network Meta-analysis of Randomized Controlled Trials

PURPOSE

We conducted a network meta-analysis of randomized controlled trials comparing the efficacy and safety of multiple endovascular treatments for femoropopliteal lesions.

METHODS

Nine treatments for femoropopliteal lesions were identified. We compared major amputation and all-cause mortality at 12-month follow-ups and primary patency at 6-, 12- and 24-month follow-ups of the treatments.

RESULTS

Altogether, 26 studies (52 study arms; 4102 patients) were considered eligible. In terms of primary patency, drug-eluting stent (DES) placement was the most effective treatment at 6- and 12-month follow-ups and covered stent (CS) placement at 24-month follow-ups, whereas directional atherectomy (DA) was the least effective treatment during all follow-up periods; both DES and CS placements were better than the majority of other single treatments, including balloon angioplasty, DA, nitinol stent (NS) placement and drug-coated balloon use, during all follow-up periods. In terms of 12-month major amputation and all-cause mortality, DA was the most safe treatment, whereas NS placement was the least safe single treatment.

CONCLUSIONS

DES and CS placements have shown encouraging results in terms of primary patency for femoropopliteal lesions, DES placement performs better within 12 months after operation and CS placement at approximately 24 months, while DA seems to be less effective. DA may be better than other treatments in terms of major amputation and all-cause mortality, while NS seems to be less safe.

Ipsilateral Antegrade Angioplasty for Flush Superficial Femoral Artery Occlusion versus Open Bypass Surgery

BACKGROUND

Management of superficial femoral artery flush occlusion using the ipsilateral antegrade approach is challenging. The study aimed to assess technical feasibility, patency, and limb salvage of ipsilateral antegrade angioplasty versus surgery for this lesion in patients with lifestyle-limiting claudications and critical limb ischemia.

METHODS

Between June 2015 and March 2018, 53 patients were randomized to either ipsilateral antegrade angioplasty (n = 28) or surgical bypass (n = 25). We included patients with Trans-Atlantic Inter-Society Consensus IIB, C, or D lesions, having a patent popliteal artery. Technical success, patency, limb salvage, and major adverse events were assessed during the 12-month follow-up.

RESULTS

The technical success was 100% and 89.3% in the surgical and endovascular groups, respectively (P = 0.238). At 12 months, the primary, assisted, and secondary patency rates were 72% vs. 64.5%, 78.2% vs. 74.7%, and 81.6% vs. 74.2% in the surgical versus the endovascular groups, respectively, without significant differences between both groups. Limb salvage was 88% vs. 92% in the surgical versus the endovascular group, respectively (P = 0.564). The length of hospital stay was longer in the surgical versus the endovascular group (6.24 ± 0.37 vs. 1.84 ± 0.19 days, respectively, P = 0.001). Local complications were higher in the surgical group (P = 0.046).

CONCLUSIONS

Technical success, patency, and limb salvage of endovascular approach were comparable to surgical bypass. The endovascular approach had the advantages of reduced local complications and hospitalization.

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.

Restenosis Prevention With Drug Eluting or Covered Stents in Femoropopliteal Arterial Occlusive Disease: Evidence From a Comprehensive Network Meta-analysis

BACKGROUND/OBJECTIVE

Endovascular interventions for femoropopliteal (FP) arterial diseases are limited by the development of restenosis. Current drug coated devices are capable of preventing restenosis by releasing antiproliferative agents to the vessel wall. However, default strategies for the treatment of FP diseases remain controversial. The aim of this study was to investigate the efficacy differences between drug eluting stents (DES), covered stents (CS), and other commonly used endovascular treatments in FP lesions, including drug coated balloons (DCBs), bare metal stents (BMS), and percutaneous transluminal angioplasty (PTA).

METHODS

A comprehensive network meta-analysis was conducted using data from relevant randomised control trials published up to 16 December 2018. Primary patency and target lesion revascularisation (TLR) at 12 months were set as the primary and secondary end points, respectively.

RESULTS

Twenty-eight eligible trials including 4728 patients were selected. DES was ranked as the most effective treatment in the multidimensional analysis of primary patency; however, there was no significant difference in the efficacy of DES and that of CS, DCB, and BMS. However, in short lesions (<10 cm), DES was significantly more effective than DCB (odds ratio 0.35; 95% confidence interval 0.15-0.83). Primary patency at 12 months was significantly lower with PTA. In terms of preventing TLR, DCB was ranked first, followed by DES, CS, BMS, and PTA. TLR was significantly higher with PTA than with other treatment strategies.

CONCLUSION

The findings of this network meta-analysis suggest that this is not the appropriate time to identify the best endovascular treatment strategy for the FP segment. DES is effective in maintaining mid-term patency, especially in short lesions, whereas DCB seems more suitable for clinical use.

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.

Endovascular treatment of femoro-popliteal lesions

Peripheral artery disease (PAD) is a major health concern affecting more than 200 million people worldwide and studies have shown PAD to be a strong predictor of mortality, morbidity, and disability. The management of PAD is multi-tiered and advancements in technology have given physicians more options for endovascular revascularization if medical therapy does not result in substantial improvement. Many randomized controlled trials have reported efficacy of various therapies including laser atherectomy, stent technology, and drug-coated balloons over standard percutaneous transluminal angioplasty; however, uncertainty regarding the best standard of care remains unclear because of a lack of head to head comparisons between novel therapies. Furthermore, variability in the reported clinical outcomes exists and makes it difficult to evaluate the superiority of any specific treatment modality, especially for functional capacity and quality of life. Recently established consensus definitions for clinical outcomes coupled with investigators incorporating direct comparisons within clinical trials will be crucial to establish consistent care and meaningful gain in treatment for these patients. This review will highlight the treatment modalities, literature supporting each treatment modality, and insight into why they are being used and why variation exists around the United States.

Accuracy of pre-interventional computed tomography angiography post-processing software and extravascularly calibrated devices to determine vessel diameters: comparison with an intravascularly located calibrated catheter

Background Accurate vessel sizing might affect treatment outcome of endovascular therapy. Purpose To compare accuracy of peripheral vessel diameter measurements using pre-interventional computed tomography angiography post processing software (CTA-PPS) and extravascularly located calibrated devices used during digital subtraction angiography (DSA) with an intravascular scaled catheter (SC). Material and Methods In 33 patients (28 men, mean age = 72 ± 11 years) a SC was used during DSA of the femoro-popliteal territory. Simultaneously, one scaled radiopaque tape (SRT) was affixed to the lateral thigh, one scaled radiopaque ruler (SRR) was positioned on the angiography table. For each patient, diameters of five anatomic landmarks were measured on DSA images after calibration using different scaled devices and CTA-PPS. Diameters were compared to SC (reference) and between groups of non-obese (NOB) and obese (OB) patients. Results In total, 660 measurements were performed. Compared to the reference, SRT overestimated the diameter by 1.2% (range = -10-12, standard deviation [SD] = 4.1%, intraclass correlation coefficient [ICC] = 0.992, 95% confidence interval [CI] = 0.989-0.992, P = 0.01), the SRR and CTA-PPS underestimated it by 21.3% (range = 1-47, SD = 9.4%, ICC = 0.864, 95% CI = 0.11-0.963, P = 0.08) and 3.2% (range = 17-38, SD = 9.7%, ICC = 0.976, 95% CI = 0.964-0.983, P = 0.01), respectively. Underestimation using the SRR was greatest in the proximal superficial-femoral artery (31%) and lowest at the P2 level of the popliteal artery (15%). In the NOB group, diameter overestimation of the SRT was 0.8% (range = 4-7, SD = 4.2%, B = 0.071, 95% CI = 0.293-0.435, P = 0.08) compared to the OB group of 1.6% (range = -7-4, SD = 2.9%, B = 0.010, 95% CI = 0.474-0.454, P = 0.96). Diameter underestimation of the SRR was 17.3% (range = 13-21, SD = 3.1%, B = 0.946, 95% CI = 0.486-1.405, P = 0.002) in the NOB group, 23.3% (range = 11-36, SD = 6.6%, B = 0.870, 95% CI = 0.268-1.472, P = 0.007) in the OB group. Conclusion For calibrated measurements SRT and CTA-PPS prove accurate compared to the reference, while SRR does not. Obesity has a significant impact on underestimation of diameter if SRR is used.

Edge Stenosis After Covered Stenting for Long Superficial Femoral Artery Occlusive Disease: Risk Factor Analysis and Prevention With Drug-Coated Balloon Angioplasty

Purpose: To report a retrospective analysis of risk factors for edge restenosis after Viabahn stent-graft treatment of superficial femoral artery (SFA) occlusive disease and determine any protective effect of drug-coated balloons (DCBs) used at the time of stent-graft implantation. Methods: Between October 2011 and July 2016, 110 patients (mean age 73.3±7.6 years; 78 men) were treated with the Viabahn stent-graft for long SFA occlusions. Thirty-eight (34.5%) patients had DCB reinforcement at the distal edge of the stent-graft. For analysis, the population was divided into groups of no edge stenosis patients (n=88; mean lesion length 22.4±4.2 cm) and edge stenosis patients (n=22; mean lesion length 23.5±5.7 cm). The clinical outcomes, ankle-brachial indices, computed tomography angiography findings, and patency were compared at a minimum of 12 months. Logistic regression analysis was employed to determine risk factors for edge stenosis; the results are presented as the odds ratio (OR) and 95% confidence interval. Results: No differences in clinical or procedural characteristics were identified except the higher incidence of diabetes (p=0.008) and greater need for retrograde access (p=0.033) in the edge stenosis group. DCB reinforcement reduced the incidence of edge stenosis (p=0.021) and target lesion revascularization (TLR; p=0.010) and resulted in a significantly higher 1-year primary patency rate (92.1% vs 76.4%, p=0.042). However, multivariate analysis revealed only poor distal runoff (OR 0.31, 95% CI 0.11 to 0.83, p=0.020) as a predictor of edge stenosis. Conclusion: The risk of edge stenosis after Viabahn implantation was higher in patients with poor distal runoff. DCB reinforcement over the distal edge reduced edge stenosis, decreased 1-year TLR, and improved 1-year primary patency.

Self-expanding nitinol stents of high versus low chronic outward force in de novo femoropopliteal occlusive arterial lesions (BIOFLEX-COF trial): study protocol for a randomized controlled trial

Background

Self-expanding nitinol stents must be oversized at least by a minimal amount to ensure contact with the vessel wall and prevent migration. Once the stent is deployed it exerts a continuous force upon the vascular wall, termed chronic outward force (COF). Animal studies have found an increased neointimal hyperplasia in stents with high oversizing and thus high COF. Data about correlation between COF and neointimal hyperplasia in humans are currently lacking. The objective of the BIOFLEX-COF trial is to prospectively investigate differences in formation of intimal hyperplasia at 1 and 2 years after implantation of nitinol stents with high versus low COF in de novo femoropopliteal occlusive arterial lesions.

Methods

The BIOFLEX-COF trial is a prospective, quantitative, randomized study. Eighty subjects with symptomatic peripheral arterial lesions eligible for endovascular stent implantation will be enrolled and randomly assigned to either a high COF group (LifeStent Flexstar, Bard Peripheral Vascular Inc., Tempe, AZ, USA) or low COF group (Pulsar, Biotronik AG, Bülach, Switzerland) using an online randomization program to generate a random 1:1 group allocation (block randomization). After implantation and dilatation, COF at every 2 mm along the stent axis will be calculated from the actual stent diameter versus its nominal diameter.

There will be two follow-up evaluations at 12 and 24 months. Primary endpoint is the amount of in-stent neointima at 1 year, assessed by contrast-enhanced CT angiography (CTA). In the control examinations, stent diameter and true lumen diameter will be measured on DICOM images every 2 mm along the stent axis to quantify the relative amount of in-stent restenosis.

Secondary objectives are the amount of in-stent neointima at 2 years, device- and procedure-related adverse events and target lesion revascularization (TLR) rate.

The scheduled time for recruitment is 2 years. Recruitment is expected to be complete in October 2017.

Discussion

This trial is the first to prospectively investigate the influence of COF on stent patency. If successful, the results will aid in a more precise selection of stent type and size in a given target vessel.

The present study is challenging in that it compares two different self-expanding nitinol stents head-to-head against each other. To optimize the power of this study, traditional binary outcome parameters such as TLR and restenosis at Doppler ultrasound were dropped as primary endpoints. Instead, the amount of neointima inside the stent accessed by CTA was selected as (continuous) outcome parameter.

Trial registration

ClinicalTrials.gov Identifier: NCT03097679. Date of registration: 14 March 2017 (retrospectively registered).

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2338-0) contains supplementary material, which is available to authorized users.

Endovascular Interventions for Femoropopliteal Peripheral Artery Disease: A Network Meta-Analysis of Current Technologies

PURPOSE

To use network meta-analysis (NMA) to determine the optimal endovascular strategy for management of femoropopliteal peripheral artery disease (PAD) given the lack of multiple prospective randomized trials to guide treatment decisions.

MATERIALS AND METHODS

NMA is a new meta-analytic method that permits comparisons among any 2 therapies by combining results of a collection of clinical trials conducted in the same or similar patient population. NMA was used to analyze data from 15 randomized controlled trials (RCTs) and 10 prospective, multicenter, single-arm trials (combined evidence [CE] NMA) that evaluated target lesion revascularization (TLR) for 5 endovascular strategies: bare metal stent (BMS), polymer-covered metal stent (CMS), drug-eluting stent (DES), drug-coated balloon (DCB) and percutaneous transluminal angioplasty (PTA).

RESULTS

The RCT and CE NMAs included 2,912 (6,091) patients with 3,151 (6,786) person-years of follow-up. In the CE NMA, DCB provided a statistically significant 68% reduction in TLR compared with PTA and a statistically significant 53% reduction in TLR compared with BMS. BMS, CMS, and DES provided reductions in TLR of 33%, 48%, and 58% compared with PTA, with statistical significance achieved for CMS and DES. The significant reductions in TLR for DCB compared with PTA and BMS were replicated in the RCT NMA.

CONCLUSIONS

This NMA demonstrated that DCB provided better reduction in TLR rates compared with PTA and BMS.

2-Year Results of Paclitaxel-Coated Balloons for Long Femoropopliteal Artery Disease: Evidence From the SFA-Long Study

OBJECTIVES

The aim of this study was to appraise 2-year outcomes after percutaneous transluminal angioplasty of long femoropopliteal artery disease using paclitaxel-coated balloons (PCBs).

BACKGROUND

Percutaneous transluminal angioplasty with PCBs for TransAtlantic Inter-Society Consensus types C and D femoropopliteal artery disease has provided favorable results ≤12 months but no prospective studies performed longer term follow-up assessment.

METHODS

Consecutive patients with Rutherford class 2 to 4 disease due to femoropopliteal lesions >15 cm long were prospectively enrolled in a multicenter study. The primary study endpoint was primary patency (i.e., freedom from the combined endpoint of clinically driven target lesion revascularization and >50% restenosis in the treated lesion as appraised by a duplex ultrasound peak systolic velocity ratio of >2.4) at 24 months. Secondary endpoints included major adverse events (the composite of death, target limb amputation, thrombosis at the target lesion, or clinically driven nontarget lesion revascularization), changes in Rutherford class, and quality of life ≤24 months post-procedure.

RESULTS

A total of 105 patients (age 68 ± 9 years; 81.9% men) successfully treated with PCBs were included (treated lesion length was 251 ± 71 mm; 49.5% total occlusions). The 24-month follow-up data were available in 98 patients; they showed a primary patency rate of 70.4%, with major adverse events occurred in 10 patients (10.2%, 5 non-procedure-related deaths) and persistently significant clinical benefits in Rutherford class (51% of asymptomatic patients at 24 months).

CONCLUSIONS

PCBs benefits on primary patency and target vessel revascularization satisfactorily extend over 24 months in patients undergoing percutaneous transluminal angioplasty for symptomatic femoropopliteal disease.

Angiographic classification of patterns of restenosis following femoropopliteal artery intervention: A proposed scoring system

OBJECTIVES

To propose a classification system for characterizing angiographic femoropopliteal artery restenosis patterns associated with common endovascular modalities.

BACKGROUND

Peripheral artery disease is a worldwide issue affecting millions of people. Despite a myriad of endovascular technologies available to treat peripheral artery disease of the femoropopliteal arteries, restenosis remains a common failure mode. Characterizing common patterns of restenosis is important to discern the potential impact of baseline patient, lesion, and procedural characteristics, as well as treatment modalities on either the primary success or the failure patterns associated with restenosis.

METHODS

Studies included in the analysis were from previous core laboratory-adjudicated femoropopliteal artery disease trials and registries reflecting a wide array of treatment modalities.

RESULTS

From the subjects enrolled and analyzed, there were 403 total angiograms for analysis and adjudication. Target lesion revascularization images of the 32 validation cases were evaluated for index treated length, diameter stenosis, and lesion morphology characteristics. The following lesion types are proposed: Type 1 "Focal" pattern, which may be "Edge Proximal" or "Edge Distal" depending on location; a Type 2 "Multifocal" pattern which may also exhibit edge restenosis, but may also be "Edge Bilateral"; a Type 3 "Moderate" pattern and a Type 4 "Diffuse" pattern; and finally, a Type 5 "Occlusion".

CONCLUSIONS

A classification system that enables healthcare professionals to anticipate and describe failures following the index procedure, thereby impacting the choice of options for retreatment, may facilitate consistency and standardization within the heterogeneous field of endovascular device treatments for the femoropopliteal artery.

Durability of the Viabahn stent graft after axillary artery pseudoaneurysm exclusion

Pseudoaneurysm formation caused by iatrogenic arterial injury during a regional anesthetic block is a rare complication. We report a case of a 56-year-old male patient who developed an axillary artery pseudoaneurysm caused by brachial plexus block performed for an upper extremity dialysis access operation. Successful repair of this pseudoaneurysm was achieved with endovascular stent graft exclusion. The repaired axillary artery with the stent graft remained patent after 10 years of follow-up. The successful long-term patency of this treatment and a strategy to potentially avoid this complication are discussed.

Collateral artery pathways of the femoral and popliteal artery

BACKGROUND

The role of collateral artery circulation in the lower limb is under debate but clinically relevant, particularly when using covered stents for occlusive disease. Covered stents seem to outperform nitinol stents in extensive disease, but collaterals could be essential in case of acute thrombosis. In the present study, we describe the collateral pathways of the deep and superficial femoral artery (DFA, SFA) and the popliteal artery (PA), observed in human cadavers.

METHODS

Ten fresh frozen cadaver legs were selected. The SFA and DFA were separately cannulated and injected with a different colored latex mixture simultaneously. After curing of the latex, the circulation was dissected thus visualizing the main arteries and their collateral vessels. The process was photographed and recorded, and collateral pathways were analyzed using a standardized vessel segmentation. The upper leg was divided in three regions, that is, the femoral triangle (F), the adductor canal (H), and the popliteal fossa (P) that, in turn, were split in three segments (1, 2, and 3, from proximal to distal).

RESULTS

Overall, 113 collateral vessels were found; 69 originated from the DFA, 34 from the SFA, and 10 from the PA. The majority of collaterals originating from the DFA terminated in the SFA (57%). Fifty-six of 113 collaterals (50%) ended in either the distal adductor channel (H3) or the proximal PA (P1). Another 28 collateral arteries (25%) had their origin in this segment (H3, P1) and mostly connected to the P2 and P3 segments. Forty-three collaterals of the DFA and H3 segment had a direct or indirect connection to below the knee muscles.

CONCLUSIONS

The majority of collaterals originate from the DFA, and the greater part of all collaterals has a connection with the H3-P1 segment. This observation may have clinical implications in the planning of endovascular procedures.

Early Post-Registry Experience With Drug-Eluting Stents in the Superficial Femoral Artery

OBJECTIVE

Restenosis remains the primary failure mode after stent placement in the superficial femoral artery (SFA). Drug-eluting technology aims to reduce intimal hyperplasia and subsequent stent failure, improving durability for endovascular management of SFA occlusive disease. We present our early experience with the Cook Zilver PTX stent.

METHODS

We retrospectively reviewed a prospectively collected database of patients undergoing placement of the Cook Zilver PTX stent for SFA or popliteal disease since its availability to our institution in October 2013. Patients treated with additional non-PTX stents were excluded. Patient demographics, comorbidities, concomitant procedures, TASC classification, procedural details, and follow-up were reviewed.

RESULTS

Thirty-one limbs in 30 patients were treated with Zilver PTX stents, 5 limbs were excluded for concomitant use of non-PTX stents, leaving 26 limbs in 26 patients for analysis. Indications for intervention were claudication in 17 (65.4%), rest pain in 1 (3.8%), and tissue loss in 8 (30.8%). A median of 2 PTX stents per limb was used to treat a mean length of 14.2 ± 11 cm with technical success of 100%. Concomitant inflow (N = 4) or atherectomy (N = 2) interventions were performed in 23%. Sixty-nine percent of lesions were TASC C (N = 7) or D (N = 11) and 42% were total occlusions. Over a mean 20-week follow-up, 2 occlusions were noted (mean 27 weeks), one was treated with surgical bypass and the other with endovascular salvage. Limb salvage in the series was 92.3% with 2 patients requiring major amputations for infected, non-healing wounds, despite patent stents.

CONCLUSION

On mean 20-week follow-up, we have seen 92.3% primary patency and 96.2% secondary patency. A larger number of patients and longer follow-up will be required to determine the true real-world efficacy of this drug-eluting device, but early experience is encouraging and warrants continued trial.

An Update on Methods for Revascularization and Expansion of the TASC Lesion Classification to Include Below-the-Knee Arteries: A Supplement to the Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II): The TASC Steering Comittee(.)

The Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC) guidelines were last updated in 2007 (TASC II) and represented the collaboration of international vascular specialties involved in the management of patients with peripheral arterial disease (PAD). Since the publication of TASC II, there have been innovations in endovascular revascularization strategies for patients with PAD. The intent of this publication is to provide a complete anatomic lower limb TASC lesion classification, including the infrapopliteal segment, and an updated literature review of new endovascular techniques and practice patterns employed by vascular specialists today.

An Update on Methods for Revascularization and Expansion of the TASC Lesion Classification to Include Below-the-Knee Arteries: A Supplement to the Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II)

The Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC) guidelines were last updated in 2007 (TASC II) and represented the collaboration of international vascular specialties involved in the management of patients with peripheral arterial disease (PAD). Since the publication of TASC II, there have been innovations in endovascular revascularization strategies for patients with PAD. The intent of this publication is to provide a complete anatomic lower limb TASC lesion classification, including the infrapopliteal segment, and an updated literature review of new endovascular techniques and practice patterns employed by vascular specialists today.

An Update on Methods for Revascularization and Expansion of the TASC Lesion Classification to Include Below-the-Knee Arteries

The Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC) guidelines were last updated in 2007 (TASC II) and represented the collaboration of international vascular specialties involved in the management of patients with peripheral arterial disease (PAD). Since the publication of TASC II, there have been innovations in endovascular revascularization strategies for patients with PAD. The intent of this publication is to provide a complete anatomic lower limb TASC lesion classification, including the infrapopliteal segment, and an updated literature review of new endovascular techniques and practice patterns employed by vascular specialists today.

Endovascular intervention for peripheral artery disease

Advances in endovascular therapies during the past decade have broadened the options for treating peripheral vascular disease percutaneously. Endovascular treatment offers a lower risk alternative to open surgery in many patients with multiple comorbidities. Noninvasive physiological tests and arterial imaging precede an endovascular intervention and help localize the disease and plan the procedure. The timing and need for revascularization are broadly related to the 3 main clinical presentations of claudication, critical limb ischemia, and acute limb ischemia. Many patients with claudication can be treated by exercise and medical therapy. Endovascular procedures are considered when these fail to improve quality of life and function. In contrast, critical limb ischemia and acute limb ischemia threaten the limb and require more urgent revascularization. In general, endovascular treatments have greater long-term durability for aortoiliac disease than femoral popliteal disease. Infrapopliteal revascularization is generally reserved for critical and acute limb ischemia. Balloon angioplasty and stenting are the mainstays of endovascular therapy. New well-tested innovations include drug-eluting stents and drug-coated balloons. Adjunctive devices for crossing chronic total occlusions or debulking plaque with atherectomy are less rigorously studied and have niche roles. Patients receiving endovascular procedures need a structured surveillance plan for follow-up care. This includes intensive treatment of cardiovascular risk factors to prevent myocardial infarction and stroke, which are the main causes of death. Limb surveillance aims to identify restenosis and new disease beyond the intervened segments, both of which may jeopardize patency and lead to recurrent symptoms, functional impairment, or a threatened limb.

Effectiveness of Viabahn in the Treatment of Superficial Femoral Artery Occlusive Disease

Purpose: To evaluate the effectiveness of the Viabahn stent-graft in the treatment of superficial femoral artery (SFA) occlusive disease. Methods: A systematic review and meta-analysis of published studies was performed to evaluate the efficacy of the Viabahn for SFA lesions. Studies were stratified according to controlled vs uncontrolled design and analyzed using random-effects models. Outcomes are reported as the risk ratio (RR) and 95% confidence interval (CI). Four prospective randomized controlled trials, one retrospective controlled study, and 9 uncontrolled studies were identified. Results: In controlled studies, primary patency with the Viabahn was superior to other interventions at 1 year (RR 0.63, 95% CI 0.49 to 0.82, p<0.001) and ankle-brachial index (ABI) improvement was greater at 6 months (mean difference 0.05, 95% CI 0.01 to 0.09, p=0.01) compared with other interventions. Subgroup analysis demonstrated a lower incidence of stent fracture in lesions with >15-cm stented lengths. In uncontrolled studies, ABI improvement was consistently superior at all measurement points during follow-up. Conclusions: Current evidence suggests that the Viabahn stent-graft is a safe and effective option for symptomatic SFA lesions. Prospective multicenter randomized controlled trials with long-term follow-up are needed to confirm the sustained efficacy of the Viabahn device.

Hyperglycemia has no effect on development of restenosis after percutaneous transluminal angioplasty (PTA) in a diabetic rabbit model

It is well known that hyperglycemia is a trigger of atherosclerosis in patients with diabetes mellitus. However, the role of hyperglycemia in restenosis remains unclear. In this study, we investigated the effects of hyperglycemia on restenosis. Stenosis was evaluated in two sets of diabetic rabbit models: i) diabetic restenosis versus nondiabetic restenosis and ii) diabetic atherosclerosis versus nondiabetic atherosclerosis. Our results indicated that there was no difference in rates of stenosis between the diabetic and the nondiabetic groups in restenosis rabbit models. However, the incidence of stenosis was significantly higher in the diabetic atherosclerosis group compared with the nondiabetic atherosclerosis group. Similarly, the intima-media thickness and cell proliferation rate were significantly increased in the diabetic atherosclerosis group compared with the nondiabetic atherosclerosis group, but there was no difference between the diabetic restenosis and the nondiabetic restenosis groups. Our results indicate that hyperglycemia is an independent risk factor for atherosclerosis, but it has no evident effect on restenosis. These findings indicate that the processes of atherosclerosis and restenosis may involve different pathological mechanisms.

Treating femoropopliteal disease: established and emerging technologies

The femoropopliteal artery is the most common site of disease in patients with peripheral arterial disease and presents some of the greatest challenges for interventional radiology. Many patients can be managed with medical treatment combined with supervised exercise alone. However, a significant proportion, especially those suffering from severe intermittent claudication or critical limb ischemia, will require some form of endovascular or surgical revascularization procedure. During the past few years an endovascular-first approach has gained support from all vascular specialties. Today, even complex lesions can be treated successfully with an endovascular approach. Unfortunately, the unique bio-mechanical properties of this vascular segment have limited long-term patency rates and clinical value of the endovascular options. In this review, the authors discuss the methods and techniques for treatment of femoropopliteal lesions and review the current evidence for commercially available devices on patency outcomes following successful recanalization.

Contemporary Management of Femoral Popliteal Revascularization

Symptomatic peripheral artery disease of the femoral popliteal segment can be treated by surgical and endovascular revascularization, but controversy exists about the best approach. Conventional approaches to revascularization have focused on lesion anatomy to decide on bypass versus endovascular treatment, but advances in endovascular therapy make an endovascular-first approach increasingly feasible-either as a single approach or as an adjunct to short-segment bypass (ie, hybrid procedure). In this review, we discuss the medical, endovascular, and surgical treatment of femoral popliteal revascularization with a special emphasis on advances in percutaneous therapy.

Effectiveness of a new exercise program after lower limb arterial blood flow surgery in patients with peripheral arterial disease: a randomized clinical trial

OBJECTIVE

The aim of this study was to evaluate the effectiveness of a supervised exercise program (SEP) plus at home nonsupervised exercise therapy (non-SET) on functional status, quality of life (QoL) and hemodynamic response in post-lower-limb bypass surgery patients.

RESULTS

One hundred and seventeen patients were randomized to an intervention (n = 57) or a control group (n = 60). A new individual SEP was designed for patients with peripheral arterial disease (PAD) and applied to the studied subjects of the intervention group who also continued non-SET at home, whereas those assigned to the control group received just usual SEP according to a common cardiovascular program. The participants of the study were assessed by a 6-min walking test (6 MWT), an ankle-brachial index (ABI), and the Medical Outcomes Study Short Form-36 (SF-36) of QoL at baseline, at 1 and 6 months after surgery. A significant improvement was observed in the walked distance in the intervention group after 6 months compared with the control group (p < 0.001). The intervention group had significantly higher QoL score in the physical and mental component of SF-36 (p < 0.05).

CONCLUSIONS

A 6-month application of the new SEP and non-SET at home has yielded significantly better results in walking distance and QoL in the intervention group than in the controls.

Increasing role of interventional cardiologists for peripheral vascular disease

Improvements in the design of endovascular devices and technical skills of interventionalists have opened new possibilities for patients with a wide range of peripheral vascular diseases. In lower extremity peripheral artery disease, percutaneous treatments have become the predominant revascularization strategy for simple and complex lesions. Newer generations of stents and drug-coated balloons have demonstrated strong potential in the treatment of femoropopliteal and infrainguinal diseases. One of the most dramatic advances in the recent past has been endovascular repair of thoracic and abdominal aortic aneurysms, which has become the preferred approach in lieu of open surgical repair. Contemporary trials have established the safety and effectiveness of carotid stenting in selected patients with severe stenosis. Endovascular treatments for venous occlusive disease have long been underutilized, but their effectiveness is being increasingly recognized. This review covers new endovascular procedures performed by interventional cardiologists for peripheral vascular diseases.

12-month primary patency rates of contemporary endovascular device therapy for femoro-popliteal occlusive disease in 6,024 patients: beyond balloon angioplasty

BACKGROUND

Endovascular approach to superficial femoral artery (SFA) disease, the most common cause of symptomatic peripheral arterial disease, remains fraught with high failure rates. Newer devices including second-generation nitinol stents, drug-coated stents, drug-coated balloons, covered stents, cryo-therapy, LASER, and directional atherectomy have shown promising results. Clinical equipoise still persists regarding the optimal selection of devices, largely attributable to the different inclusion criteria, study population, length of lesions treated, definition of "patency" and "restenosis," and follow-up methods in the pivotal trials.

METHODS

A prospective protocol was developed. We performed a literature search using PubMed from January 2006 to November 2013. Published articles including endovascular interventions in SFA or popliteal arteries with reported 12-month "primary patency" or "binary restenosis" rates as endpoints were included.

RESULTS

We identified 6,024 patients in 61 trials reporting 12-month primary patency rates in patients with femoropoliteal disease. Primary patency rates were (weighted average) 77.2% for nitinol stents, 68.8% for covered stents, 84% for drug eluting stents, 78.2% for drug eluting/coated balloon, 60.7% for cryoballoon, 51.1% for LASER atherectomy, 63.5% for directional atherectomy and 70.2% with a combination of endovascular devices.

CONCLUSION

The most frequently used endovascular devices yielded various 12-month primary patency rates ranging from 51% to 85%. The increased variation in inclusion criteria, length, and complexity of lesions between studies does not allow direct comparison between them. Larger randomized trials in specific patient populations comparing those modalities is needed before we can make safe recommendation of the superiority of one device over the other.

Bayesian network meta-analysis of nitinol stents, covered stents, drug-eluting stents, and drug-coated balloons in the femoropopliteal artery

OBJECTIVE

Several randomized controlled trials (RCTs) have shown the superiority of some of these technologies over balloon angioplasty, but direct comparisons between these treatment options are lacking. The authors conducted a network meta-analysis of RCTs comparing bare nitinol stents, covered nitinol stents, paclitaxel- or sirolimus-eluting stents (PES or SES), and paclitaxel-coated balloons (PCB) with plain balloon angioplasty or with each other in the femoropopliteal artery (PROSPERO registry: CRD42013004845).

METHODS

Sixteen RCTs comprising 2532 patients with 4227 person-years of follow-up were analyzed on an intention-to-treat basis. Bayesian random effects Poisson and binomial models were used for mixed treatment comparisons (WinBUGS). Clinical heterogeneity was accounted for by incorporating a meta-regression model on trial-specific baseline risk. End points included technical success, vascular restenosis, target lesion revascularization, and major amputations. Pairwise odds ratios and rate ratios (ORs and RRs) of absolute treatment effects were calculated, and the probabilities of each treatment being best are reported. Summary estimates are reported as the posterior median and associated credible intervals (CrIs) that serve the same purpose as confidence intervals in the context of the Bayesian framework. Extensive sensitivity, meta-regression, and network consistency analyses were performed to evaluate heterogeneity.

RESULTS

Technical success was highest with covered stents (pooled OR, 13.6; 95% CrI, 3.3-31.1, probability best 82%) followed by uncovered stents (pooled OR, 7.0; 95% CrI, 2.6-129, probability best 18%) when compared with balloon angioplasty (reference treatment). Vascular restenosis was lowest with PES (RR, 0.43; 95% CrI, 0.16-1.18, probability best 45%) followed by PCB (RR, 0.43; 95% CrI, 0.26-0.67, probability best 42%). Target lesion revascularization was lowest with PCB (RR, 0.36; 95% CrI, 0.23-0.55, probability best 56%) followed by PES (RR, 0.42; 95% CrI, 0.16-1.06, probability best 33%). Major amputations were rare in all treatment and control groups (pooled amputation rate of 0.7 events per 100 person-years).

CONCLUSIONS

Immediate technical success is better with the use of covered stents, whereas paclitaxel-eluting stents and paclitaxel-coated balloons offer the best long-term results in the femoropopliteal artery.