Cryoplasty versus conventional balloon angioplasty of the femoropopliteal artery in diabetic patients: long-term results from a prospective randomized single-center controlled trial

Treatment of Difficult, Calcified Lesions: Plaque Modification Strategies

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

Trans-pedal access for endovascular revascularization in complex infra-popliteal lesions in critically ischemic limb: A cohort study

Background

critical limb ischemia is one of the most challenging cases we face nowadays with high risk for amputation, retrograde trans-pedal angioplasty offers an alternative technique after failure of traditional ante-grade angioplasty.

Patients and Methods

96 patients underwent trans-pedal or trans-tibial retrograde angioplasty after failure of the traditional ante-grade angioplasty with the aid of US, 21-gauge needle and 0.018 wire through sheath-less approach as a last chance for revascularization.

Results

clinical success or improvement in 77 cases (80.2%), and in other 19 cases (19.8%) there was no clinical success or improvement. The technical success was achieved in 81 cases with percentage of (84.4%), and not achieved in 15 cases (15.6%) only.

Conclusions

Retrograde Trans-pedal angioplasty is an efficient, safe, and practical procedure with a high technical success and a relatively minimal procedural adverse effect.

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retrograde trans-pedal angioplasty offers an alternative technique after failure of traditional ante-grade angioplasty.

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Retrograde Trans-pedal angioplasty is an efficient, safe, and practical procedure

Distal Bypass Versus Infrageniculate Endovascular Intervention for Chronic Limb-Threatening Ischemia

Chronic limb-threatening ischemia (CLTI) carries a high risk of amputation and warrants urgent intervention. CLTI involving the infrageniculate vessels, in particular, carries a considerably higher risk of major limb amputation. Open surgical bypass is the historical gold standard for the treatment of tibial arterial disease; however, endovascular therapy provides an attractive alternative in this high-risk patient population. In this article, we review the existing literature regarding distal bypass and infrageniculate endovascular intervention in patients with CLTI.

Overcoming ischemia in the diabetic foot: Minimally invasive treatment options

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

Infrapopliteal Artery Occlusive Disease: An Overview of Vessel Preparation and Treatment Options

Critical limb ischemia (CLI) is defined as chronic rest pain and/or the presence of tissue loss (ulcers or gangrene) in the lower extremities secondary to ischemia. CLI is a limb and potentially life-threatening disease associated with a poor prognosis with only 50% of patients being able to preserve both limbs within 12 months of diagnosis. CLI related to diabetes is often more extensive with multi-level long segmental arterial disease resulting in a 5–30-fold increased rate of amputation. As the incidence and prevalence of diabetes mellitus increases within our aging society, the rate of infrapopliteal artery occlusive disease (IPOD) and the need for intervention rises with it. The aim of this manuscript is to provide the reader with an overview of the various devices available for vessel preparation (VP) and treatment of IPOD in order to optimize patency rates, symptom resolution, healing of wounds, and minimize complications.

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.

Novel balloon technologies to minimize dissection of peripheral angioplasty

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

When Are Endovascular and Open Bypass Treatments Preferred for Femoropopliteal Occlusive Disease?

Several meta-analyses and multicenter trials have shown that chronic limb ischemia did not occur for up to 5 years in 50%–70% of patients who underwent saphenous vein grafts, with limb salvage and perioperative mortality rates of >80% and 3%, respectively. However, open surgical bypass can have limitations, including postoperative morbidity/wound complications of 10%–20% and prolonged length of hospital stay and outpatient care. Several studies have analyzed clinical outcomes for patients with critical limb ischemia treated with endovascular therapies, but they have been mainly retrospective with significant heterogeneity or were single center. Only few randomized trials have compared surgical vs. endovascular therapy. These included the Bypass vs. Angioplasty in Severe Ischemia of the Leg (BASIL) trial, with no differences found in amputation-free or overall survival rates at 1 year; however, late outcomes favored the surgical group. The Bypass or Angioplasty in Severe Intermittent Claudication (BASIC) trial concluded that the 1-year patency rates were 82% and 43% for bypass and angioplasty, respectively. The BEST Endovascular vs. Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) trial is currently enrolling patients. This review analyzed studies comparing open vs. endovascular therapy in patients with femoropopliteal disease. (This is a review article based on the invited lecture of the 45th Annual Meeting of Japanese Society for Vascular Surgery.)

Multi-center feasibility study of microwave radiometry thermometry for non-invasive differential diagnosis of arterial disease in diabetic patients with suspected critical limb ischemia

AIMS

Diagnosis of vascular involvement in diabetic foot ulceration (DFU) remains challenging. We conducted a proof of concept study to investigate the feasibility of microwave radiometry (MWR) thermometry for non-invasive differential diagnosis of critical limb ischemia (CLI) in subjects with DFU.

METHODS

This prospective, multi-center, study included 80 participants, divided into four groups (group N: normal control subjects; group DN: participants with diabetes and verified neuropathic ulcers without vascular involvement; group DC: participants with diabetes and CLI and group NDC: participants with CLI without diabetes). Vascular disease was confirmed with angiography. All patients underwent MWR (RTM-01-RES:University of Bolton, UK) to record mean tissue temperatures at various pre-determined foot sites. Comparisons of temperature measurements between study groups were performed using one-way ANOVA and Dunn tests. ROC analysis was performed to determine sensitivity, specificity and cut-off value of MWR for CLI diagnosis.

RESULTS

Temperatures recorded in vicinity to the foot ulcers of participants with diabetes and CLI were similar to those with CLI without diabetes, but significantly lower than in subjects with neuropathic ulcers without vascular involvement and normal controls (group DC:29.30°C±1.89 vs. group NDC:29.18°C±1.78vs. group N:33.01°C±0.45 vs. group DN:33.39°C±1.37;P<.0001). According to ROC analysis, cut-off temperature value to diagnose CLI was <31.8°C (area under the curve: 0.984; 95% CI: 0.965-1.005;P<.001), with a sensitivity of 100.0% (95%CI: 90.26-100.0) and specificity of 88.37% (95% CI: 74.92-96.11).

CONCLUSIONS

Tissue temperatures in vicinity to ulcers were significantly lower in participants with CLI, with or without diabetes, compared to non-ischemic controls. MWR could be used for differential diagnosis of arterial ischemia in subjects with DFU.

Clinical results of single-vessel versus multiple-vessel infrapopliteal intervention

OBJECTIVE

The effects of concomitant endovascular interventions on multiple infrapopliteal vessels are not well known, and the short-term and long-term sequelae of such procedures have not been reported.

METHODS

From 2004 to 2014, 673 limbs in 528 patients underwent an infrapopliteal endovascular intervention for tissue loss (77%), rest pain (13%), stenosis of a previously treated vessel (5%), acute limb ischemia (3%), or claudication (2%). Outcomes included wound healing, RAS events (reintervention, major amputation, or stenosis [>3.5x step-up by duplex]), and mortality. Patients without an initial indication of critical limb ischemia (CLI) were excluded. Patients were characterized as having undergone either a single-vessel infrapopliteal intervention or a multiple-vessel infrapopliteal intervention.

RESULTS

Of the 673 limbs, 558 underwent a successful infrapopliteal endovascular intervention for CLI (86% for tissue loss, 14% for rest pain). During a single procedure, 503 limbs (90%) underwent a single-vessel intervention and 55 (10%) underwent a multiple-vessel intervention. Patients undergoing a single-vessel intervention more commonly underwent a prior ipsilateral endovascular procedure (17% vs 6%; P = .03) or a prior ipsilateral bypass procedure (20% vs 9%; P = .04). Kaplan-Meier analysis revealed that a RAS event ≤1 year occurred in 229 limbs (49%), with no significant difference in the 1-year rates of reintervention (22% vs 20%; P = .53), major amputation (16% vs 10%; P = .24), or stenosis (29% vs 21%; P = .25). After adjustment for baseline characteristics, multivariable regression illustrated that neither major amputation rates nor RAS events differed between patients undergoing a single-vessel vs a multiple-vessel intervention (P = .26 and P = .61, respectively).

CONCLUSIONS

Our data suggest that a multiple-vessel intervention does not improve outcomes when compared to a single-vessel intervention following infrapopliteal angioplasty for CLI.

Systematic Review and Meta-analysis of Randomized Controlled Trials of Paclitaxel-Coated Balloon Angioplasty in the Femoropopliteal Arteries: Role of Paclitaxel Dose and Bioavailability

PURPOSE

To provide a qualitative analysis and quantitative synthesis of randomized controlled trials (RCTs) investigating paclitaxel-coated balloons (PCBs) in the femoropopliteal artery.

METHODS

PubMed, EMBASE, AMED, Scopus, CENTRAL, online content, and abstracts from international meetings were last screened in April 2015 for eligible RCTs using the PRISMA selection process. Risk of bias was assessed using the Cochrane Collaboration's tool, and quality of evidence was evaluated with the GRADE system. Outcome measures included late lumen loss (LLL) at 6 months and event rates of major limb amputations, binary lesion restenosis, and target lesion revascularization (TLR). Pooled treatment effects were analyzed in a random effects model to account for clinical heterogeneity; the outcomes are presented as the rate ratios (RRs) and their 95% confidence intervals (CIs). Extensive meta-regression was performed to analyze potential confounders. The review was registered in the PROSPERO database (CRD42015023938; www.crd.york.ac.uk/PROSPERO).

RESULTS

Eleven RCTs with 1609 subjects (1403 claudicants and 206 patients with critical limb ischemia) with medium-length femoropopliteal lesions (mean range 5.1-11.9 cm) were included. There was consistently high-quality evidence supporting the clear superiority of PCBs in terms of reduced LLL (mean difference -0.89 mm, 95% CI -1.14 to -0.64, p<0.001), less binary restenosis (RR 0.47, 95% CI 0.37 to 0.61, p<0.001), and fewer TLR events (RR 0.33, 95% CI 0.22 to 0.49, p<0.001). Major amputations were rare in both active and control arms (pooled event rate: 0.7%, 95% CI 0.3% to 1.2%). Results were stable across all potential risk modifiers and in the presence of stents as well. There was high-quality evidence that the dose of paclitaxel was related to the magnitude of the treatment effect; standard dose (3.0-μg and 3.5-μg) PCBs were significantly more effective compared with low-dose 2-μg PCB in reducing both restenosis (RR 2.1, 95% CI 1.2 to 3.4, p<0.001) and TLR (RR 2.5, 95% CI 1.9 to 3.8, p<0.001).

CONCLUSION

PCBs reduce by more than half the rates of restenosis and TLR in the femoropopliteal artery regardless of stent placement. Biologic effect size may vary according to paclitaxel bioavailability.

Combined retrograde-antegrade arterial wiring: Peroneal artery can be a bridge to cross infrapopliteal Trans Atlantic Inter Society Consensus D lesions

BACKGROUND

Percutaneous transluminal angioplasty of complex infrapopliteal lesions might be a true and complex challenge. Success rates remain suboptimal when employing standard approaches. Thus, recanalization techniques for infrapopliteal disease remain a seat of continuous evolution.

AIM OF THE STUDY

We report our results of Trans Atlantic Inter Society Consensus D infrapopliteal disease recanalization using combined antegrade-retrograde approach through peroneal artery branches.

PATIENTS AND METHODS

A total of 27 patients with infrapopliteal Trans Atlantic Inter Society Consensus D lesions underwent recanalization of at least one of the tibial arteries by combined retrograde-antegrade route using the peroneal artery normal anastomosis channels.

RESULTS

Technical success was achieved in 22 patients who were followed for 6-24 months. Healing of ischemic ulcers or spontaneous separation of ischemic gangrenous patches in 13 patients. Minor amputation in nine patients. No major amputation in the follow-up period.

CONCLUSION

Although demanding, the technique can be reserved for selected cases with failed antegrade recanalization. This technique is valuable when a proximal occlusion is not crossable, when a dissection flap or a perforation in the proximal portion of a target vessel hinders guide-wire advancement. This technique may represent a feasible endovascular option to avoid second distal puncture exhausting the landing zone of a future distal bypass.

Automated Carbon Dioxide Angiography for the Evaluation and Endovascular Treatment of Diabetic Patients With Critical Limb Ischemia

PURPOSE

To test the safety, efficacy, and diagnostic accuracy of automated carbon dioxide (CO2) angiography (ACDA) for the evaluation of diabetic patients with critical limb ischemia (CLI) and baseline renal insufficiency and compare ACDA with iodinated contrast medium (ICM) during endovascular treatment.

METHODS

From November 2014 to January 2015, 36 consecutive diabetic patients (mean age 74.8±5.8 years; 27 men) with stage ≥3 chronic kidney disease (CKD ≥3) and CLI underwent lower limb angiography with both CO2 and ICM followed by balloon angioplasty in a prospective single-center study. The primary outcome measure was the safety and efficacy of ACDA as the exclusive agent to guide angioplasty in this cohort. The secondary outcomes were the safety and diagnostic accuracy of ACDA injection as compared with ICM digital subtraction angiography (DSA) for invasive evaluation of these patients.

RESULTS

ACDA safely and effectively guided angioplasty in all patients without complications. Transcutaneous oxygen pressure improved from 11.8±6.3 to 58.4±7.6 mm Hg (p<0.001). There were no complications related to ACDA during diagnostic imaging and no significant changes in the estimated glomerular filtration rate from baseline to 24 hours (44.7±13.3 vs 47.0±0.8 mL/min/1.73 m(2); nonsignificant). The diagnostic accuracy of CO2 was 89.8% (sensitivity 92.3%; specificity 75%; positive predictive value 95.5%; negative predictive value 63.1%). There was no statistically significant difference in the qualitative diagnostic accuracy between the media (p=0.197).

CONCLUSION

ACDA is an accurate, safe, and effective technique that can be utilized to guide endovascular interventions in diabetics with CLI and baseline CKD ≥3. Larger multicenter randomized studies are needed to validate these results.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Cryoplasty versus angioplasty in the treatment of arterial restenosis in an experimental model of atherosclerosis in rabbits

Cryoplasty may reduce the incidence of post-angioplasty restenosis in peripheral atherosclerotic arteries. Our study is looking to investigate the mid-term effects (4 weeks) of an FDA-approved cryoplasty catheter (PolarCath(®), Boston Scientific) compared to a conventional angioplasty catheter using a hypercholesterolemic rabbit model of arterial restenosis based on diet plus vessel injury. Thirty-six normolipidemic, 3-month old male New Zealand White rabbits were used. Balloon angioplasty was performed on left external iliac arteries on day 1. Animals were fed with a hypercholesterolemic diet for 60 days. On day 120, three groups of animals were established: conventional PTA (percutaneous transluminal angioplasty) was applied on the PTA group; the CRY group was treated with the PolarCath(®) cryoplasty system and no treatment was given to a control (CTR) group. A broad variety of atheromatous lesions were observed 30 days after treatment, presenting significant differences between groups. Most of the complicated lesions were found in the CRY group, while advanced and early lesions were more often appreciated in the CTR and PTA groups, respectively. The histomorphometric evaluation of the arteries showed significant differences between the CRY group and the other two groups, with the highest percentage of IEM (internal elastic membrane) injury, vascular stenosis and ratio intima/media being registered on animals treated with cryoplasty. Intravascular cryotherapy induces complicated lesions in arterial walls 30 days after treatment in a hypercholesterolemic rabbit model based on diet plus vessel injury. Cryoplasty leads to the production of severe fibrosis and mineralisation and stenosis compared to a conventional angioplasty.

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.

Initial experience with ticagrelor in patients with critical limb ischemia and high on-clopidogrel platelet reactivity undergoing complex peripheral endovascular procedures

PURPOSE

To investigate the safety and efficacy of ticagrelor in patients with critical limb ischemia (CLI) and high on-clopidogrel platelet reactivity (HCPR) undergoing complex, limb-salvage, peripheral endovascular procedures (PEP).

MATERIALS AND METHODS

The study included consecutive patients with HCPR undergoing PEP for CLI. HCPR was defined as platelet reaction units (PRU) >234 as assessed by the VerifyNow P2Y12 assay. Patients with HCPR were prescribed ticagrelor, 180/90 mg twice daily, and aspirin, 100 mg daily, for 6 months and ticagrelor, 180/90 mg twice daily, thereafter. Primary safety outcome was total major bleeding, and primary efficacy outcome was the composite of cardiovascular death and major amputation. Secondary outcomes included the level of platelet inhibition achieved and target limb revascularization (TLR)-free survival rate.

RESULTS

In total, 37 CLI patients with 40 limbs were investigated. Mean follow-up period was 11.3 ± 5.0 months (range 6-21). The mean treated lesion length was 229.2 ± 71.4 mm in the femoropopliteal axis and 179.3 ± 83.9 mm in the infrapopliteal arteries. No major or minor bleeding was detected. There were four periprocedural minor adverse events (10.8%), and in two cases (5.6%) ticagrelor was discontinued. In all patients, ticagrelor achieved platelet inhibition lower than the cut-off value. Mean PRU during clopidogrel therapy was 308.4 ± 41.8 (range 257-422) versus 67.0 ± 52.8 (range 2-189) when switched to ticagrelor; p < 0.0001. Kaplan-Meier estimated primary efficacy outcome and TLR-free survival rates were 92.0 and 67.3% at 12 months, respectively.

CONCLUSION

In this series of CLI patients with HCPR undergoing complex PEP, initial experience with ticagrelor was proven safe and efficient because it resulted in sufficient platelet inhibition and satisfactory clinical results without major complications.

Management of Infrapopliteal Arterial Disease: Critical Limb Ischemia

According to the TransAtlantic Inter-Society Consensus Document on Management of Peripheral Arterial Disease, "there is increasing evidence to support a recommendation for angioplasty in patients with critical limb ischemia and infrapopliteal artery occlusion." Management of infrapopliteal artery disease starts with diagnosis using modern preprocedural noninvasive and invasive imaging. Interventionalists need to learn the role of chronic total occlusion cap analysis and collateral zone recognition in angiosome-directed interventions for management of critical limb ischemia and be familiar with equipment and device selection and a stepwise approach for endovascular interventions. Interventionalists need to know which crossing tools to use to successfully cross-complex chronic total occlusion caps.

An overview of optimal endovascular strategy in treating the femoropopliteal artery: mechanical, biological, and procedural factors

Treatment of the femoropopliteal (FP) artery remains a challenge to the endovascular specialist. Long-term patency is low with a high rate of target lesion revascularization. The true patency rate varies considerably between studies partly because there is a lack of uniform performance criteria and reporting standards in peripheral arterial interventions. Literature review supports three principles that emerge as important components of an optimal strategy in treating the FP artery: (1) improving vessel compliance and subsequently less dissections and bailout stenting, (2) reducing smooth muscle cell proliferation, and (3) protecting outflow vessels from distal embolization. In this overview, we examine current data that support the validity of this strategy.

Endovascular techniques in limb salvage: cutting, cryo, brachy, and drug-eluting balloons

The complex pathophysiology response to injury of the lower-extremity arteries has prompted the development of several unique balloon technologies to overcome initial technical failures and short-term intimal hyperplasia. Cryoplasty alters the cellular and mechanical properties of the vessel wall during angioplasty. Cutting balloons incise the wall, preventing elastic recoil and allowing expansion of the lumen at a lower pressure, thus limiting barotrauma. Drug-eluting balloons actively transfer inhibitory compounds to the wall during the initial therapy, while brachytherapy balloons allow for localized delivery of radiation to inhibit the proliferative response seen after angioplasty. These platforms provide unique means to enhance immediate and short-term results and also reduce stent usage in the lower extremity.

Clopidogrel responsiveness in patients undergoing peripheral angioplasty

PURPOSE

To investigate the incidence and clinical significance of platelet responsiveness in patients receiving clopidogrel after peripheral angioplasty procedures.

MATERIALS AND METHODS

This prospective study included patients receiving antiplatelet therapy with clopidogrel 75 mg after infrainguinal angioplasty or stenting and who presented to our department during routine follow-up. Clopidogrel responsiveness was tested using the VerifyNow P2Y12 Assay. Patients with residual platelet reactivity units (PRU) ≥ 235 were considered as nonresponders (NR group NR), whereas patients with PRU < 235 were considered as normal (responders [group R]). Primary end points were incidence of resistance to clopidogrel and target limb reintervention (TLR)-free survival, whereas secondary end points included limb salvage rates and the identification of any independent predictors influencing clinical outcomes.

RESULTS

In total, 113 consecutive patients (mean age 69 ± 8 years) with 139 limbs were enrolled. After clopidogrel responsiveness analysis, 61 patients (53.9 %) with 73 limbs (52.5 %) were assigned to group R and 52 patients (46.1 %) with 66 limbs (47.5 %) to group NR. Mean follow-up interval was 27.7 ± 22.9 months (range 3-95). Diabetes mellitus, critical limb ischemia, and renal disease were associated with clopidogrel resistance (Fisher's exact test; p < 0.05). According to Kaplan-Meier analysis, TLR-free survival was significantly superior in group R compared with group NR (20.7 vs. 1.9 %, respectively, at 7-year follow-up; p = 0.001), whereas resistance to clopidogrel was identified as the only independent predictor of decreased TLR-free survival (hazard rate 0.536, 95 % confidence interval 0.31-0.90; p = 0.01). Cumulative TLR rate was significantly increased in group NR compared with group R (71.2 % [52 of 73] vs. 31.8 % [21 of 66], respectively; p < 0.001). Limb salvage was similar in both groups.

CONCLUSION

Clopidogrel resistance was related with significantly more repeat interventions after peripheral angioplasty procedures.

Cryoplasty for peripheral arterial disease

BACKGROUND

Percutaneous balloon angioplasty is an endovascular technique for restoring blood flow through an artery that has become narrowed or blocked by atherosclerosis. Narrowing of the artery following angioplasty (restenosis) is the major cause of long-term failure. Cryoplasty offers a different approach to improving long-term angioplasty results. It combines the dilation force of balloon angioplasty with cooling of the vessel wall. This systematic review evaluated cryoplasty in peripheral arterial disease and provides focus for further research in the field. This is an update of a review first published in 2007.

OBJECTIVES

To assess the efficacy of, and complications associated with, cryoplasty for maintaining patency in the iliac, femoropopliteal and crural arteries in the short and medium term.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched October 2012) and CENTRAL (2012, Issue 10). Trial databases were searched for ongoing or unpublished studies. We also searched the reference lists of relevant articles.

SELECTION CRITERIA

All randomised controlled trials in which participants with peripheral arterial disease (PAD) of the lower limbs, or lower limb bypass graft stenoses, were randomised to cryoplasty with or without another procedure versus a procedure without cryoplasty were considered. This included trials where all participants received angioplasty and the randomisation was for cryoplasty versus no cryoplasty and trials where cryoplasty was used as an adjunct to conventional treatment (for example stenting) against a control.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed, assessed and selected trials, extracted data and assessed risk of bias.

MAIN RESULTS

Seven trials (six primary cryoplasty and one adjunctive cryoplasty trial) with a combined total of 478 patients were included in this review. The trials reported patency and restenosis either by participant, lesion or vessel location. Follow-up ranged from 30 days to three years.Target lesion patency measured at various time points in two primary cryoplasty trials showed no statistically significant difference between the treatment groups. The adjunctive cryoplasty study showed that cryoplasty was associated with improved patency only at six months (OR 5.37, 95% CI 1.09 to 26.49, n = 90).Restenosis measured per patient (two primary cryoplasty trials) showed no statistically significant difference between the treatments. Restenosis measured by lesion (two primary cryoplasty trials) showed a statistically significant difference only within 24 hours of the procedure (OR 0.08, 95% CI 0.04 to 0.18, n = 192) favouring cryoplasty.Need for re-intervention was not significantly different in primary cryoplasty trial participants (per participant: OR 0.27, 95% CI 0.05 to 1.52, n = 241, I(2) = 89%; per lesion: OR 0.59, 95% CI 0.06 to 5.69, n = 307, I(2) = 94%). The adjunctive cryoplasty trial did not report on need for intervention.Immediate success of procedure (within 24 hours) was not significantly different in primary cryoplasty trial participants (per participant: OR 1.63, 95% CI 0.14 to 19.55, n = 340, I(2) = 95%; per lesion: OR 1.81, 95% CI 0.19 to 17.36, n = 397, I(2) = 90%). The adjunctive cryoplasty trial reported 100% success.Limb loss, deaths from all causes and the risk of complications immediately after treatment showed no statistically significant differences between the treatments.

AUTHORS' CONCLUSIONS

The benefit of cryoplasty over conventional angioplasty cannot be established as the number of randomised controlled trials is small and their quality is not sufficiently high. The technical success and primary patency rates seen in these trials are inconsistent and do not necessarily suggest a future role for cryoplasty in the treatment of PAD, but they cannot be reliably interpreted. Currently there are insufficient data to support the routine use of cryoplasty over conventional balloon angioplasty in the treatment of PAD.

Cost-effectiveness analysis of enhancements to angioplasty for infrainguinal arterial disease

Background

The aim was to perform an economic evaluation of the cost-effectiveness of endovascular enhancements to percutaneous transluminal balloon angioplasty (PTA) with bail-out bare metal stents for infrainguinal peripheral arterial disease.

Methods

The following interventions were considered: PTA with no bail-out stenting, PTA with bail-out drug-eluting stents, drug-coated balloons, primary bare metal stents, primary drug-eluting stents, endovascular brachytherapy, stent-grafts and cryoplasty. A discrete-event simulation model was developed to assess the relative cost-effectiveness of the interventions from a health service perspective over a lifetime. Populations of patients with intermittent claudication (IC) and critical leg ischaemia (CLI) were modelled separately. Univariable and probabilistic sensitivity analyses were undertaken. Effectiveness was measured by quality-adjusted life-years (QALYs).

Results

For both patient populations, the use of drug-coated balloons dominated all other options by having both lower lifetime costs and greater effectiveness. For willingness-to-pay thresholds between £0 and £100 000 per additional QALY, the probability of drug-coated balloons being cost-effective was at least 58·3 per cent for patients with IC and at least 72·2 per cent for patients with CLI. Sensitivity analyses showed that the results were robust to different assumptions regarding the clinical benefits attributable to the interventions.

Conclusion

The use of drug-coated balloons represents a cost-effective alternative to the use of PTA with bail-out bare metal stents.

Systematic review and meta-analysis of additional technologies to enhance angioplasty for infrainguinal peripheral arterial occlusive disease

Background

There are several additional techniques designed to enhance conventional percutaneous transluminal balloon angioplasty (PTA). This systematic review assessed current evidence on the clinical effectiveness of additional techniques for infrainguinal peripheral arterial occlusive disease (PAD).

Methods

Relevant electronic databases, including MEDLINE, were searched in May 2011. The population comprised participants with symptomatic PAD undergoing endovascular treatment for disease distal to the inguinal ligament. Interventions were additional techniques compared with conventional PTA. Main outcome measures were restenosis and need for reintervention. Randomized clinical trials (RCTs) of clinical effectiveness were assessed for quality and data were extracted. Where appropriate, meta-analysis was undertaken to produce risk ratios (RRs).

Results

Forty RCTs were selected. Meta-analysis showed a significant benefit in reducing restenosis rates at 6 months for self-expanding stents (RR 0·49) and drug-coated balloons (RR 0·40), and at 12 months for endovascular brachytherapy (RR 0·63). There was also evidence that use of a stent-graft significantly reduced restenosis compared with PTA, as did drug-eluting stents compared with bare-metal stents. Meta-analysis showed that use of drug-coated balloons was associated with significantly lower reintervention rates than PTA alone at 6 months (RR 0·24) and 24 months (RR 0·27) of follow-up. There was also evidence of significantly lower reintervention rates for self-expanding stents at 6 months. Other techniques did not show significant treatment effects for restenosis or reintervention.

Conclusion

The conclusions of this review should be tempered by small sample sizes, lack of clinical outcome measures and differing outcome definitions, making direct comparison across trials difficult. However, self-expanding stents, drug-eluting stents and drug-coated balloons appeared to be the most promising technologies worthy of future study.

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

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

Endovascular management of the arteria profunda femoralis: long-term angiographic and clinical outcomes

PURPOSE

This study was designed to investigate the long-term angiographic and clinical outcomes of percutaneous transluminal angioplasty (PTA) of the arteria profunda femoralis (PFA), in a series of patients suffering from critical limb ischemia (CLI) or severe intermittent claudication (IC).

METHODS

Our department's database was searched to identify patients who underwent PTA or bail-out stenting of the PFA. Among the study's inclusion criteria were Rutherford categories 3-6 and ≥70% stenosis of the PFA. Only de novo stenotic lesions were assessed. Primary endpoints were technical success, angiographic lesion primary patency, angiographic binary in-lesion restenosis, and target lesion recanalization (TLR) rates. Secondary endpoints included patient survival, limb salvage, and complication rates. Patient's baseline demographics, lesion, and procedural details were analyzed.

RESULTS

Between 2001 and 2011, 20 consecutive patients (17 males) with a mean age of 73 ± 9 (range 53-87) years underwent PTA or bail-out stenting in 23 PFA lesions. Critical limb ischemia was the indication in eight of 20 patients (40%). The mean lesion length was 31 ± 9.5 mm. The procedural technical success was 100% (23/23), whereas mean time angiographic and clinical follow-up was 26.8 ± 24.6 months. According to the Kaplan-Meier analysis, primary patency and binary restenosis rate were 95 and 86.1% respectively up to 8 years follow-up. No TLR procedures were performed. The 8-year patient survival and limb salvage rates were 87.5 and 84.7% respectively.

CONCLUSIONS

PTA or stenting of focal, stenotic, PFA lesions, in patients suffering from CLI or IC, exhibit high long-term primary patency rates, as well as low binary restenosis and TLR rates. Large, multicenter studies are required to validate these results.

Pilot trial of cryoplasty or conventional balloon post-dilation of nitinol stents for revascularization of peripheral arterial segments: the COBRA trial

OBJECTIVES

The purpose of this study is to compare post-dilation strategies of nitinol self-expanding stents implanted in the superficial femoral artery of diabetic patients with peripheral arterial disease.

BACKGROUND

Endovascular treatment of superficial femoral artery disease with nitinol self-expanding stents is associated with high rates of in-stent restenosis in patients with diabetes mellitus.

METHODS

We conducted a prospective, multicenter, randomized, controlled clinical trial of diabetic patients to investigate whether post-dilation of superficial femoral artery nitinol self-expanding stents using a cryoplasty balloon reduces restenosis compared to a conventional balloon. Inclusion criteria included diabetes mellitus, symptomatic peripheral arterial disease, and superficial femoral artery lesions requiring implantation of stents>5 mm in diameter and >60 mm in length. Primary endpoint was binary restenosis at 12 months, defined as ≥2.5-fold increase in peak systolic velocity by duplex ultrasonography.

RESULTS

Seventy-four patients, with 90 stented superficial femoral artery lesions, were randomly assigned to post-dilation using cryoplasty (n=45 lesions) or conventional balloons (n=45 lesions). Mean lesion length was 148±98 mm, mean stented length was 190±116 mm, mean stent diameter was 6.1±0.4 mm, and 50% of the lesions were total occlusions. Post-dilation balloon diameters were 5.23±0.51 mm versus 5.51±0.72 mm in the cryoplasty and conventional balloon angioplasty groups, respectively (p=0.02). At 12 months, binary restenosis was significantly lower in the cryoplasty group (29.3% vs. 55.8%, p=0.01; odds ratio: 0.36, 95% confidence interval: 0.15 to 0.89).

CONCLUSIONS

Among diabetic patients undergoing implantation of nitinol self-expanding stents in the superficial femoral artery, post-dilation with cryoplasty balloon reduced binary restenosis compared to conventional balloon angioplasty. (Study Comparing Two Methods of Expanding Stents Placed in Legs of Diabetics With Peripheral Vascular Disease [COBRA]; NCT00827853).

PolarCath cryoplasty enhances smooth muscle cell apoptosis in a rabbit iliac artery model: an experimental in vivo controlled study

PURPOSE

To in vivo investigate the histological response after single and double cryoplasty therapy in a rabbit iliac artery model.

MATERIALS AND METHODS

In total, 40 New Zealand White rabbits underwent percutaneous transluminal angioplasty of the iliac artery using either PolarCath balloon or a conventional angioplasty balloon of equal diameter. Arterial injury, inflammatory response and smooth muscle cells (SMC) apoptosis with the TUNEL (Terminal deoxynucleotidyl transferase dUTP Nick End Labeling) immunohistochemical assay were analyzed. Rabbits were divided between single or double balloon inflation and histological results were compared between cryoplasty and control angioplasty both at 30 min and 72 h.

RESULTS

Arterial injury and wall inflammation scores were low and similar between cryoplasty and control groups after single and double balloon inflation. Compared to conventional balloon angioplasty, Polarcath cryoplasty demonstrated superior SMC apoptosis after single inflation at 30 min [12.0±1.2 cells/(0.025 mm)2 vs 7.0±1.5 cells/(0.025 mm)(2), p=0.002], single inflation at 72 h [9.0±1.0 cells/(0.025 mm)(2) vs 5.4±1.4 cells/(0.025 mm)(2), p=0.001], double inflation at 30 min [11.6±1.5 cells/(0.025 mm)(2) vs 6.8±1.4 cells/(0.025 mm)(2), p=0.001] and double inflation at 72h [9.2±0.8 cells/(0.025 mm)(2) vs 5.0±0.7 cells/(0.025 mm)(2), p=0.001]. There were no significant differences in apoptosis between single and double cryoplasty application at 30 min and 72 h.

CONCLUSION

Cryoplasty demonstrated superior rates of SMC apoptosis at 30 min and 72 h and was associated to relatively low arterial injury and inflammation scores. An immediate second PolarCath inflation did not achieve superior apoptosis.

Angioplasty for Treatment of Isolated Below-the-Knee Arterial Stenosis in Patients With Critical Limb Ischemia

Objective: To report our experience in patients with critical limb ischemia (CLI) due to isolated below-the-knee (BTK) arterial lesions. Methods: Between 1992 and 2009, we performed 2747 peripheral angioplasties, while 2.8% (78 of 2747) were only BTK and were included in the present study. Results: Mean age was 70.2 ± 11 years, 58.4% had diabetic, 85.7% were smokers, and 20.8% had chronic renal failure. Baseline Rutherford class: 50 patients with class IV and 27 with class V to VI. Angiographic and clinical success were 97.4% and 90.91%, respectively. At 30 days, there were no deaths, 2 patients had acute vessel closure and 2 major amputation. At long-term follow-up (22.4 ± 9.6 months), there were 7 unrelated deaths (10%), 5 amputations (7.1%), 3 reinterventions (4.2%), while 16 patients remained symptomatic. Overall amputation and amputation plus claudication-free survival were 90% and 70%, respectively. Conclusion: Endovascular treatment of BTK lesions represents a safe and effective treatment option to patients with CLI.