Long-term Cardiovascular Morbidity, Mortality, and Reintervention after Endovascular Treatment in Patients with Iliac Artery Disease: The Dutch Iliac Stent Trial Study

Patient-specific risk factors for reintervention following primary endovascular treatment of iliac artery disease

OBJECTIVE

Predictive models for reintervention may guide clinicians to optimize selection, education, and follow-up of patients undergoing endovascular iliac revascularization. Although the impact of lesion- and device-related characteristics on iliac restenosis and reintervention risk is well-defined, data on patient-specific risk factors are scarce and conflicting. This study aimed to explore the value of patient-related factors in predicting the need for clinically driven target-vessel revascularization (CD-TVR) in patients undergoing primary endovascular treatment of iliac artery disease.

METHODS

Consecutively enrolled patients undergoing endovascular revascularization for symptomatic iliac artery disease at a tertiary vascular referral center between January 2008 and June 2020 were retrospectively analyzed. Primary and secondary outcomes were CD-TVR occurrence within 24 months and time to CD-TVR, respectively. Patients who died or did not require CD-TVR within 24 months were censored at the date of death or at 730 days, respectively. Multiple imputation was used to account for missing data in primary analyses.

RESULTS

A total of 1538 iliac interventions were performed in 1113 patients (26% females; 68 years). CD-TVR occurred in 108 limbs (74 patients; 7.0%) with a median time to CD-TVR of 246 days. On multivariable analysis, increasing age was associated with lower likelihood of CD-TVR (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.50-0.83; P = .001) and decreased risk of CD-TVR at any given time (hazard ratio [HR], 0.66; 95% CI, 0.52-0.84; P = .001). Similarly, a lower likelihood of CD-TVR (OR, 0.75; 95% CI, 0.59-0.95; P = .017) and decreased risk of CD-TVR at any given time (HR, 0.73; 95% CI, 0.58-0.93; P = .009) were observed with higher glomerular filtration rates. Lastly, revascularization of common vs external iliac artery disease was associated with lower likelihood of CD-TVR (OR, 0.48; 95% CI, 0.24-0.93; P = .030) and decreased risk of CD-TVR at any given time (HR, 0.48; 95% CI, 0.25-0.92; P = .027). No associations were observed between traditional cardiovascular risk factors (sex, hypertension, higher low-density lipoprotein cholesterol, higher hemoglobin A1c, smoking) and CD-TVR.

CONCLUSIONS

In this retrospective cohort study, younger age, impaired kidney function, and external iliac artery disease were associated with CD-TVR. Traditional markers of cardiovascular risk were not seen to predict reintervention.

The prevalent causes of death in patients with peripheral artery disease undergoing revascularisation or amputation

OBJECTIVE

Preventing untimely death in patients with peripheral artery disease (PAD) requires a detailed understanding of the predominant causes of death (COD). This literature review aims to describe how short- and long-term COD are reported in patients who had surgery for PAD.

METHODS

A literature review was conducted according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines for articles reporting specific causes of mortality in patients who had surgery for all stages of PAD. Articles were included if they reported COD after open surgical or endovascular revascularisation, or major or minor amputation for PAD. Critical appraisals were conducted according to included study types, using the Joanna Briggs Institute tools.

RESULTS

Cause of death was reported in 21 publications. Twenty were observational and one was a randomised control trial. Study size ranged from 25 to 10,505 patients. Cardiovascular disease was the most prevalent COD in perioperative periods (42.5% from 13 studies). Long-term follow-up ranged from 1 month and 7 years with 15 studies reporting cardiac related mortality as the most frequent cause of death. However, mortality from neoplasia, respiratory disease (including pneumonia and pulmonary emboli), stroke and sepsis were prevalent. Many studies were low-average quality, with few population-based observational studies.

CONCLUSION

Whilst cardiovascular COD are the most prevalent reasons for mortality in patients with PAD, the proportion of patients dying from neoplasia and respiratory disease is high. Improved reporting standards for COD in studies examining PAD are needed.

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.

Liposomal Nanocarriers Designed for Sub-Endothelial Matrix Targeting under Vascular Flow Conditions

Vascular interventions result in the disruption of the tunica intima and the exposure of sub-endothelial matrix proteins. Nanoparticles designed to bind to these exposed matrices could provide targeted drug delivery systems aimed at inhibiting dysfunctional vascular remodeling and improving intervention outcomes. Here, we present the progress in the development of targeted liposomal nanocarriers designed for preferential collagen IV binding under simulated static vascular flow conditions. PEGylated liposomes (PLPs), previously established as effective delivery systems in vascular cells types, served as non-targeting controls. Collagen-targeting liposomes (CT-PLPs) were formed by conjugating established collagen-binding peptides to modified lipid heads via click chemistry (CTL), and inserting them at varying mol% either at the time of PLP assembly or via micellar transfer. All groups included fluorescently labeled lipid species for imaging and quantification. Liposomes were exposed to collagen IV matrices statically or via hemodynamic flow, and binding was measured via fluorometric analyses. CT-PLPs formed with 5 mol% CTL at the time of assembly demonstrated the highest binding affinity to collagen IV under static conditions, while maintaining a nanoparticle characterization profile of ~50 nm size and a homogeneity polydispersity index (PDI) of ~0.2 favorable for clinical translation. When liposomes were exposed to collagen matrices within a pressurized flow system, empirically defined CT-PLPs demonstrated significant binding at shear stresses mimetic of physiological through pathological conditions in both the venous and arterial architectures. Furthermore, when human saphenous vein explants were perfused with liposomes within a closed bioreactor system, CT-PLPs demonstrated significant ex vivo binding to diseased vascular tissue. Ongoing studies aim to further develop CT-PLPs for controlled targeting in a rodent model of vascular injury. The CT-PLP nanocarriers established here show promise as the framework for a spatially controlled delivery platform for future application in targeted vascular therapeutics.

Endovascular Revascularization for Aortoiliac Occlusive Disease

말초동맥질환은 하지혈관을 흔히 침범하는 폐쇄성 질환이다. 대동맥-장골동맥 부위에서 이를 치료하기 위한 재개통술은 전통적으로 수술적인 접근을 통한 우회술을 근간으로 하였으며, 최근에는 국소적이고 단순한 병변들을 위주로 혈관 내 접근법을 통한 치료법이 우선 권고되고 있다. 혈관 내 접근법은 그 최소침습적인 특성으로 인하여 수술의 위험성이 높은 환자에 대해서 활용하는 것이 일반적이었으나, 근래의 다양한 기법 및 기구의 발전으로 보다 다양한 질병 상태를 가진 환자에서 활용되어 수술적인 치료에 근접하는 결과가 보고되고 있다. 이 종설에서는 말초동맥 질환에 대한 진단 및 대동맥-장골동맥 부위의 혈관 내 재개통술에 활용되는 기법 및 기구들에 대해 살펴보고 그 역할에 대해 살펴보고자 한다.

Angioplasty versus stenting for iliac artery lesions

BACKGROUND

Atherosclerosis of the iliac artery may result in a stenosis or occlusion, which is defined as iliac artery occlusive disease. A range of surgical and endovascular treatment options are available. Open surgical procedures have excellent patency rates but at the cost of substantial morbidity and mortality. Endovascular treatment has good safety and short-term efficacy with decreased morbidity, complications and costs compared with open surgical procedures. Both percutaneous transluminal angioplasty (PTA) and stenting are commonly used endovascular treatment options for iliac artery occlusive disease. A stenotic or occlusive lesion of the iliac artery can be treated successfully by PTA alone. If PTA alone is technically unsuccessful, additional stent placement is indicated. Alternatively, a stent could be placed primarily to treat an iliac artery stenosis or occlusion (primary stenting, PS). However, there is limited evidence to prove which endovascular treatment strategy is superior for stenotic and occlusive lesions of the iliac arteries. This is an update of the review first published in 2015.

OBJECTIVES

To assess the effects of percutaneous transluminal angioplasty versus primary stenting for stenotic and occlusive lesions of the iliac artery.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 24 September 2019. We also undertook reference checking and citation searching to identify additional studies.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing percutaneous transluminal angioplasty and primary stenting for iliac artery occlusive disease. We excluded quasi-randomised trials, case reports, case-control or cohort studies. We did not exclude studies based on the language of publication.

DATA COLLECTION AND ANALYSIS

Two authors independently selected suitable trials, extracted data, assessed trial quality and performed data analyses. When there was disagreement, consensus would be reached first by discussion between the two authors and, if needed, through consultation with a third author. We used GRADE criteria to assess the certainty of the evidence and presented the main results in a 'Summary of findings' table. The main outcomes of interest were technical success, complications, symptomatic improvement of peripheral arterial disease (PAD), patency, reinterventions, resolutions of symptoms and signs, and improvement in walking distance as reported by the patient.

MAIN RESULTS

We identified no new studies for this update. Previously, we identified two RCTs, with a combined total of 397 participants, as meeting the selection criteria. One study included mostly stenotic lesions (95%), whereas the second study included only iliac artery occlusions. Heterogeneity between these two studies meant it was not possible to pool the data. Both studies were of moderate methodological quality with some risk of bias relating to selective reporting and non-blinding of participants and personnel. Both studies occurred in the 1990s and techniques have since evolved. We assessed the overall certainty of the evidence to be low. We downgraded by two levels: one for risk of bias concerns and one for imprecision and indirectness. There was no evidence of a difference following percutaneous transluminal angioplasty (PTA) with selective stenting compared to primary stenting (PS) in technical success rates in either the study involving stenotic lesions (odds ratio (OR) 1.51, 95% confidence interval (CI) 0.77 to 2.99; 279 participants; low certainty evidence); or the study involving iliac artery occlusions (OR 2.95, 95% CI 0.12 to 73.90; 112 participants; low certainty evidence). In one trial, PTA of iliac artery occlusions resulted in a higher rate of major complications, especially distal embolisation (OR 4.50 95% CI 1.18 to 17.14; 1 study, 112 participants; low certainty evidence). Immediate complications were similar in the second study (OR 1.81, 95% CI 0.64 to 5.13; 1 study, 279 participants; low certainty evidence). Neither study reported on delayed complications. No evidence of a difference was seen in symptomatic improvement (OR 1.03, 95% CI 0.47 to 2.27; 1 study, 157 participants; low certainty evidence). The second study did not provide data but reported no differences. For the outcome of patency, no evidence of a difference was seen in the study involving iliac occlusion at two years (OR 1.60, 95% CI 0.34 to 7.44; 1 study, 57 participants; low certainty evidence); or the study involving stenotic lesions at two years (71.3% in the PS group versus 69.9% in the PTA group). Only one study reported on reintervention (six to eight years, OR 1.22, 95% CI 0.67 to 2.23; 1 study, 279 participants; low certainty evidence); and resolution of symptoms and signs (12 months, OR 1.14, 95% CI 0.65 to 2.00; 1 study, 219 participants; low certainty evidence), with no evidence of a difference detected in either outcome. Neither study reported on improvement in walking distance as reported by the patient.

AUTHORS' CONCLUSIONS

There is insufficient evidence to make general conclusions about the effects of percutaneous transluminal angioplasty versus primary stenting for stenotic and occlusive lesions of the iliac artery. Data from one study indicate that primary stenting in iliac artery occlusions may result in lower distal embolisation rates (low certainty evidence). The evidence in this review, based on two studies, was assessed as low certainty, with downgrading decisions based on limitations in risk of bias, imprecision and indirectness. More studies are required to strengthen our confidence in the results.

Iliac Artery Intervention

Endovascular revascularization for aortoiliac occlusive disease (AIOD) is now considered first-line therapy for patients with claudication and critical limb ischemia and in asymptomatic patients in whom large-bore access is required (eg, mechanical circulatory support or transcatheter aortic valve replacement). The authors review the data supporting endovascular therapy for AIOD, indications and contraindications for AIOD revascularization, as well as the procedural techniques required to safely perform endovascular therapy in this vascular bed. They review prevention and management of the major complications that can occur during these procedures. Finally, they discuss postprocedural management to maintain patency and optimize patient outcomes.

Real-world outcomes of endovascular treatment in a non-selected population with peripheral artery disease - prospective study with 2-year follow-up

Background: The study aimed to evaluate the outcomes of percutaneous transluminal angioplasty (PTA) in lower-extremity peripheral artery disease (PAD) patients. Patients and methods: A multi-centre, observational study was performed with 32 German and Austrian centres contributing data to the PTA registry. Data of 1,781 patients with lower-leg and pelvic PAD who were suitable for endovascular PTA treatment were contributed from participating centres. Data from 1,533 patients are reported here (1,055 male and 478 female). This study did not have exclusion criteria. Quality of life (QOL) questionnaire (EQ-5D) scores, Rutherford classification, mortality, patency rate and details of major adverse cardiovascular events were collected at 6-, 12-, 18-, and 24-month follow ups. Results: PTA with/without stenting achieved 90.3 %, 86.5 %, 82.7 %, and 71.9 % technical success (recanalisation achieving ≥ 70 % patency, no evidence of embolisation, recoiling or dissection) in iliac, femoral, popliteal, and below-the-knee arteries, respectively. Procedural/postprocedural complications occurred in 142 (9.3 %, 1 death) and 74 (4.8 %) patients. QOL, mobility, self-care, activity, and pain/discomfort scores improved (p < 0.01), anxiety/depression was insignificantly improved. During follow-up, 409 (26.7 %) patients were hospitalised for PAD, 281 (18.3 %) required reintervention, and 145 (9.5 %) died or needed amputation (n = 49; 3.2 %). Multivariate analysis demonstrated poorer outcomes in patients with comorbidities. Conclusions: PTA with/without stenting is effective, safe, and widely applicable, with few complications. It improves QOL, but not anxiety/depression.

Patient doses in endovascular and hybrid revascularization of the lower extremities

OBJECTIVE:

Hybrid surgical methods such as remote endarterectomy and endovascular revascularization are fluoroscopy-guided procedures successfully replacing conventional open surgery for treatment of peripheral artery disease (PAD). The aim of this study was to: (1) evaluate the dose parameters describing exposure of patients undergoing endovascular or hybrid revascularization of the lower limb (below the inguinal ligament); (2) compare the data available in the literature with the evaluations of patients' dose values and related factors for patients undergoing such procedures; (3) examine the correlation of doses with certain parameters; (4) estimate the peak skin dose and assess the potential for radiation-induced skin injuries during the procedures.

METHODS:

Data for 259 patients were extracted retrospectively and analyzed. The procedures were grouped by type of intervention, vascular approach, and level of complexity. The analyses included the correlation of dose values with the operating team.

RESULTS:

The air kerma-area product (KAP) and fluoroscopy time (FT) values greatly varied depending on the procedure type but also among patients undergoing the same procedure. The type of vascular access has the largest impact on patients' doses. The KAP and FT values for brachial artery were: 347 Gy.cm² and FT: NA; for contralateral common femoral artery (CFA) approach: 207 Gy.cm² and 153 s; e.g. significantly higher than for ipsilateral CFA: 96 Gy.cm² and 78 s; for hybrid surgery: 77 Gy.cm² and 41 s; and for ipsilateral retrograde popliteal approach: 61 Gy.cm² and 53 s. The same tendency is observed for the peak skin dose (PSD) values: the highest are for brachial artery (2053 mGy) and contralateral CFA (1325 mGy) approach, followed by the ipsilateral CFA (748 mGy), hybrid surgery (649 mGy), and ipsilateral retrograde popliteal approach (566 mGy).

CONCLUSION:

Registered dose values and FT for the different procedures do not exceed the International Atomic Energy Agency (IAEA) proposed trigger values for patients' follow-up for radiation-induced skin injuries. The type of vascular access has the highest negative impact on radiation dose levels and resultant KAP, PSD, and FT values. There is a significant increase of the dose values with increase of the number of inserted stents and the level of complexity. This should be considered in planning, especially for patients who undergo multiple diagnostic and therapeutic procedures.

ADVANCES IN KNOWLEDGE:

This study gives a systematic understanding for patient radiation exposure in endovascular and hybrid revascularization of the lower extremities, thus far absent in the literature.

The promoted delivery of RRM2 siRNA to vascular smooth muscle cells through liposome-polycation-DNA complex conjugated with cell penetrating peptides

Peripheral vascular disease (PVD) is a prevalent vascular disease that affect a large number of patients. The establishment of optimal treatments to mitigate the intimal hyperplasia (IH)-induced restenosis would help relieve the health burden of the PVD. Ribonucleotide reductase M2 (RRM2) is critical to cellular migration and proliferation. We have previously demonstrated that suppression of RRM2 expression could substantially inhibit hepatocellular carcinoma cell proliferation and migration. We hereby developed RRM2 small interfering RNA (siRNA)-loaded cell penetrating peptides-conjugated liposome-polycation-DNA complex (LPD) (RRM2-CLPD), aiming to inhibit the migration and proliferation of vascular smooth muscle cells (VSMCs) crucial for IH. RRM2-CLPD is of a small size (∼150 nm) and high siRNA encapsulation efficiency (∼90%). Further, we demonstrated that RRM2-CLPD could significantly inhibited RRM2 gene and protein expression by ∼80%. Notably, RRM2-CLPD was able to effectively bind to VSMCs, resulting in significant cellular proliferation and migration inhibition. Taken together, RRM2-CLPD represent a very promising treatment for IH.

Improving the efficacy of liposome-mediated vascular gene therapy via lipid surface modifications

BACKGROUND

We have previously defined mechanisms of intimal hyperplasia that could be targets for molecular therapeutics aimed at vascular pathology. However, biocompatible nanocarriers are needed for effective delivery. Cationic liposomes (CLPs) have been demonstrated as effective nanocarriers in vitro. However, in vivo success has been hampered by cytotoxicity. Recently, neutral PEGylated liposomes (PLPs) have been modified with cell-penetrating peptides (CPPs) to enhance cellular uptake. We aim to establish CPP-modified neutral liposomes as viable molecular nanocarriers in vascular smooth muscle cells.

METHODS

CLPs, PLPs, and CPP-modified PLPs (R8-PLPs) were assembled with short interfering RNA (siRNA) via ethanol injection. Characterization studies determined liposomal morphology, size, and charge. siRNA encapsulation efficiency was measured via RiboGreen assay. Vascular smooth muscle cells were exposed to equal lipid/siRNA across all groups. Rhodamine-labeled liposomes were used to quantify cell association via fluorometry, live/dead dual stain was used to measure cytotoxicity, and gene silencing was measured by quantitative polymerase chain reaction.

RESULTS

R8-PLPs exhibited increased encapsulation efficiency equivalent to CLPs. PLPs and R8-PLP-5 mol% and R8-PLP-10 mol% had no cytotoxic effect. CLPs demonstrated significant cytotoxicity. R8-PLP-5 mol% and R8-PLP-10 mol% exhibited increased cell association versus PLPs. R8-PLP-10 mol% resulted in significant gene silencing, in a manner dependent on lipid-to-siRNA load capacity.

CONCLUSIONS

The negligible cytotoxicity and enhanced cellular association and gene silencing capacity exhibited by R8-PLPs reveal this class of liposomes as a candidate for future applications. Further modifications for optimizing R8-PLPs are still warranted to improve efficacy, and in vivo studies are needed for translational development. However, this could prove to be an optimal nanocarrier for vascular gene therapeutics.

First-in-Human Experience With the Gore Balloon-Expandable Covered Endoprosthesis in Iliac Artery Occlusive Disease

Purpose: To report the first-in-human iliac artery experience of a new balloon-expandable covered endoprosthesis. Methods: A prospective, single-center pilot study recruited 30 symptomatic patients (mean age 64 years; 18 men) to evaluate the safety and early efficacy of the new Gore balloon-expandable covered endoprosthesis for the treatment of de novo or restenotic common and/or external iliac artery lesions. According to protocol, up to 2 discrete lesions could be treated with a maximum total treated length ≤110 mm. Follow-up included clinical evaluation with duplex ultrasound at 1, 6, and 12 months. Data are presented through 12-month follow-up. The primary safety endpoint was a composite of device- or procedure-related death, myocardial infarction, or amputation in the treated leg within 30 days of the index procedure. Multiple performance outcomes were also evaluated. Results: The primary 30-day safety endpoint was 0%. Per-subject estimates of primary patency, freedom from target lesion revascularization, and freedom from target vessel revascularization were 100% at 1 and 6 months and 96.6% at 12 months. Estimates of assisted primary and secondary patency were both 100% at 12 months. Freedom from major adverse events at 12 months was 100%. Most patients experienced improvements in Rutherford category, ankle-brachial index, and functional status that were sustained to 12 months. Conclusion: This positive first-in-human experience with the Gore balloon-expandable covered endoprosthesis suggests this device will have an important role in the management of aortoiliac occlusive disease.

Endovascular Treatment of Iliac Occlusive Disease: Review and Update

Use of endovascular interventions for arterial occlusive lesions continues to increase. With the evolution of the technology supporting these therapeutic measures, the results of these interventions continue to improve. In general, a comparison of techniques for revascularization of iliac occlusive diseases shows similar initial technical success rates for open versus percutaneous transluminal angioplasty. Angioplasty is often associated with lower periprocedural morbidity and mortality rates. Conversely, surgery frequently provides greater long-term patency, although late failure of percutaneous therapies may occur but still can be treated successfully with reintervention. The perpetual buildup of experience with angioplasty and stenting will eventually characterize its role in the management of occlusive disease. This review outlines the current consensus and applicability of endovascular management of iliac occlusive diseases.

[The modern principles of management of intermittent claudication]

Number of patients with peripheral arterial disease, despite various national public health programs, remains high and has no steady downward trend over the past few decades. Despite recent advances in drug therapy, сonservative approach in the management of peripheral arterial disease is often neglected by vascular surgeons. However, vast majority of patients with intermittent claudication, who receive comprehensive conservative treatment, including risk factor modification, exercise and drug therapy, may get significant improvement in quality of life by partial or complete relief of symptoms related to the disease. Patients strictly adhering to medical recommendations has favorable prognosis and progression of disease to the stage of critical limb ischemia is very unlikely. Noncompliant patients and those who continue smoking in particular, often experience progression of symptoms related to the disease. That may result in the need for surgical intervention aiming to prevent or delay the onset of critical limb ischemia.

Percutaneous versus surgical management of lower extremity peripheral artery disease

Lower extremity peripheral artery disease (PAD) is highly prevalent and can manifest as intermittent claudication or, in the most advanced form, critical limb ischemia. Revascularization, which can be accomplished by an endovascular or surgical approach, is performed to improve quality of life or, in severe cases, for limb salvage. Over the past decade, percutaneous catheter-based techniques have improved such that acute procedural success is high even in complex anatomy. Patency rates have also increased with the use of atherectomy devices and drug-eluting stents. Often, patients with PAD have comorbidities that increase the risk of cardiovascular complications with surgical procedures. These factors have led to the adoption of an endovascular first strategy with surgical management reserved for selected patients. This review focuses on the most current clinical trials of endovascular therapy for PAD. In addition, older but relevant studies comparing endovascular and surgical approaches and contemporary surgical trials are presented for reference.

Angioplasty versus stenting for iliac artery lesions

BACKGROUND

Atherosclerosis of the iliac artery may result in a stenosis or occlusion, which is defined as iliac artery occlusive disease. A range of surgical and endovascular treatment options are available. Open surgical procedures have excellent patency rates but at the cost of substantial morbidity and mortality. Endovascular treatment has good safety and short-term efficacy with decreased morbidity, complications and costs compared with open surgical procedures. Both percutaneous transluminal angioplasty (PTA) and stenting are commonly used endovascular treatment options for iliac artery occlusive disease. A stenotic or occlusive lesion of the iliac artery can be treated successfully by PTA alone. If PTA alone is technically unsuccessful, additional stent placement is indicated. Alternatively, a stent could be placed primarily to treat an iliac artery stenosis or occlusion (primary stenting, PS). However, there is limited evidence to prove which endovascular treatment strategy is superior for stenotic and occlusive lesions of the iliac arteries.

OBJECTIVES

To assess the effects of percutaneous transluminal angioplasty versus primary stenting for stenotic and occlusive lesions of the iliac artery.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched April 2015) and Cochrane Register of Studies (CRS) (2015, Issue 3). The TSC searched trial databases for details of ongoing and unpublished studies.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing percutaneous transluminal angioplasty and primary stenting for iliac artery occlusive disease. We excluded quasi-randomised trials, case reports, case-control or cohort studies. We excluded no studies based on the language of publication.

DATA COLLECTION AND ANALYSIS

Two authors (JB, NA) independently selected suitable trials. JB and HJ independently performed data extraction and trial quality assessment. When there was disagreement, consensus would be reached first by discussion among both authors and, if still no consensus could be reached, through consultation with BF.

MAIN RESULTS

We identified two RCTs with a combined total of 397 participants as meeting the selection criteria. One study included mostly stenotic lesions (95%), whereas the second study included only iliac artery occlusions. Both studies were of moderate methodological quality with some risk of bias relating to selective reporting and non-blinding of participants and personnel. The overall quality of evidence was low due to the small number of included studies, the differences in study populations and definitions of the outcome variables. Due to the heterogeneity among these two studies it was not possible to pool the data. Percutaneous transluminal angioplasty (PTA) with selective stenting and primary stenting (PS) resulted in similar improvement in the stage of peripheral arterial occlusive disease according to Rutherford's criteria, resolution of symptoms and signs, improvement of quality of life, technical success of the procedure and patency of the treated vessel. Improvement in walking distance as reported by the patient, measured claudication distance, ulcer healing, major amputation-free survival and delayed complications (> 72 hours) were not reported in either of the studies. In one trial, PTA of iliac artery occlusions resulted in a significantly higher rate of major complications, especially distal embolisation. The other trial showed a significantly higher mean ankle brachial index (ABI) at two years in the PTA group (1.0) compared to the mean ABI in the PS group (0.91); mean difference (MD) 0.09 (95% confidence interval (CI) 0.04 to 0.14; P value = 0.001, analysis performed by review authors). However, at other time points there was no difference. We consider it unlikely that this difference is attributable to the study procedure, and also believe this difference may not be clinically relevant.

AUTHORS' CONCLUSIONS

There is insufficient evidence to assess the effects of PTA versus PS for stenotic and occlusive lesions of the iliac artery. From one study it appears that PS in iliac artery occlusions may result in lower distal embolisation rates. More studies are required to come to a firm conclusion.

Percutaneous endovascular treatment of peripheral arterial disease in Germany

PURPOSE

The general distribution of balloon angioplasty, stenting and other endovascular interventions in treating peripheral arterial disease (PAD) is unclear.

METHODS AND RESULTS

We used national statistics (DRG statistics) published by the Federal Statistical Office including data from almost all hospitals in Germany to calculate the rates and types of lower extremity endovascular procedures in 2012. In 2012 150,503 peripheral endovascular procedures were documented in Germany. The predominant procedures were percutaneous transluminal angioplasty (PTA) with 86.0% followed by thrombolysis with 7.2% and thrombectomy with 2.9%. In 50,092 (33.3%) of all peripheral endovascular procedures performed in the lower limb arteries a stent was placed: 66.7% in iliac, 34.3% in femoro-popliteal and 9.7% in cruro-pedal procedures. From these 50,092 procedures DES were coded in 3063 (6.1%) and covered stents in 1841 (3.7%). The highest rate of covered stents was placed in the aorta (8.6%) but the highest rate of DES was in the cruro-pedal arteries (23.1%).

CONCLUSION

Pure PTA is still the most frequently performed procedure in peripheral arteries and in only one third of all procedures was a stent placed in Germany in 2012.

Iliac arteries: how registries can help improve outcomes

There are many publications reporting excellent short and long-term results with endovascular techniques. Patients included in trials are often highly selected and may not represent real world practice. Registries are important to interventional radiologists for several reasons; they reflect prevailing practice and can be used to establish real world standards of care and safety profiles. This information allows individuals and centers to evaluate their outcomes compared with national norms. The British Iliac Angioplasty and Stenting (BIAS) registry is an example of a mature registry that has been collecting data since 2000 and has been reporting outcomes since 2001. This article discusses the evidence to support both endovascular and surgical intervention for aortoiliac occlusive disease, the role of registries, and optimal techniques for aortoiliac intervention.

Management of Atherosclerotic Aortoiliac Occlusive Disease

Development of aortoiliac occlusive disease (AIOD) is associated with classic risk factors for atherosclerotic disease such as hyperlipidemia, hypertension, diabetes, or smoking. Risk factor modification, smoking cessation, and prevention of cardiovascular events remain the cornerstones of AIOD management. Symptom improvement and limb loss prevention are considered secondary goals of therapy. Continuous technological advances, new devices, as well as new revascularization techniques are constantly changing the landscape of AIOD management. Surgical interventions, which were considered a gold standard therapy for nearly 50 years, currently give way to newer and less invasive endovascular techniques.

Gender-specific risk factors for peripheral artery disease in a voluntary screening population

Background

Women have high rates of peripheral artery disease (PAD) despite fewer cardiovascular disease (CVD) risk factors, compared to men. We sought to determine the gender‐specific prevalence of low ankle brachial index (ABI) and the relationship to C‐reactive protein (CRP) levels and CVD risk factors in the Life Line Screening population.

Methods and Results

Between April 2005 and August 2011, 133 750 women and 71 996 men had ABI and CRP measured at a Life Line Screening Center. Women were slightly older than men, whereas men were more likely to be current smokers, have diabetes mellitus (DM), and coronary artery disease (CAD) (P<0.001 for each). Women were more likely to have ABI≤1.0, compared to men (26.6% versus 14.4%, respectively; P<0.001), as well as ABI≤0.9 (4.1% women versus 2.6% men; P<0.001). Women had higher median CRP levels (1.94 mg/L; interquartile range [IQR], 0.89, 4.44 mg/L), compared to men (1.35 mg/L; IQR, 0.73, 2.80 mg/L; P<0.001). Men and women shared similar risk factors for ABI≤0.9, including older age, black race, smoking, DM, hypertension, hypercholesterolemia, CAD, and elevated CRP levels. In an adjusted model, there were significant interactions between gender and age (P<0.001), CRP (P<0.001), CAD (P=0.03), and DM (P=0.06) with ABI as the outcome. The associations between age, CRP, CAD, and DM with ABI≤0.9 were stronger in men than in women.

Conclusions

Women participating in the Life Line Screening had higher CRP levels and a higher prevalence of PAD, compared to men. Neither higher CRP levels nor conventional CVD risk factors explained the excess prevalence of PAD in women.

Peripheral artery disease. Part 2: medical and endovascular treatment

The treatment of peripheral artery disease (PAD) focuses on risk factor modification, cardiovascular event reduction, limb viability, and symptom improvement. Hypertension, hyperlipidemia, and diabetes mellitus should all be controlled to recommended target levels, and smoking cessation is vital. Antiplatelet therapies, such as aspirin or clopidogrel, should be administered in all patients unless contraindicated. Whenever possible, patients who present with claudication should be offered a regimen comprised of both medical and exercise therapy, which often results in substantial improvement in symptoms. For patients presenting with more-advanced disease, such as acute limb ischemia, critical limb ischemia, and severely-limiting symptoms of PAD, revascularization is often necessary. As a result of the rapid evolution in endovascular revascularization technology and expertise, many patients with PAD can be treated percutaneously. Therefore, in this Review, we will focus on medical therapy and endovascular revascularization of patients with PAD, with reference to surgical bypass in specific clinical scenarios.

Endovascular stents for intermittent claudication

BACKGROUND

Endovascular stents have been suggested as a means to improve the patency of arteries after angioplasty in patients with intermittent claudication. This is an update of a Cochrane review published in 2002.

OBJECTIVES

The null hypothesis to be tested by this review is that for individuals with claudication the use of an endovascular stent, in addition to percutaneous transluminal angioplasty, does not improve symptoms of life-style limiting claudication when compared to percutaneous angioplasty alone.

SEARCH STRATEGY

For this update the Cochrane Peripheral Vascular Diseases Group searched their Specialised Register (last searched August 2009) and the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (last searched 2009, Issue 3).

SELECTION CRITERIA

Randomised trials comparing angioplasty alone versus angioplasty with endovascular stents in patients with intermittent claudication.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted the data. Only published trial data were used but unpublished data were sought for the update. Effectiveness was measured by the pre-defined primary outcome measures restenosis or reocclusion rates and maximum walking distance.

MAIN RESULTS

Two studies were included involving a total of 104 participants. Both studies included only individuals with femoro-popliteal disease. They compared angioplasty and stenting with the Palmaz stent against angioplasty alone. Although one study showed a slight statistical advantage in arterial patency after angioplasty alone, this was not found when the two studies were combined. No differences in the secondary outcomes were detected in either study.

AUTHORS' CONCLUSIONS

The small number of relevant studies identified together with the small sample sizes and methodological weaknesses severely limit the usefulness of this review in guiding practice. The results from larger multicentre trials are needed.

Review: Peripheral Arterial Disease and Diabetes: A Clinical Update

Peripheral arterial disease is characterized by a gradual reduction in blood to the extremities secondary to atherosclerosis. In diabetes, the pattern of atherosclerotic occlusion typically shows a propensity toward the infrapopliteal vessels. Additionally, impairment of the microcirculation manifests in diminished vasoreactivity and a functional ischemia that is not always correctable with surgery. However, when a nonhealing wound is complicated by peripheral arterial disease, revascularization is paramount to wound healing. Revascularization can be accomplished through traditional bypass surgery or newer endovascular interventions, such as angioplasty and stenting. These less invasive techniques of revascularization offer the advantages of quicker recovery and lower morbidity but durability may be compromised. Ultimately, the choice of revascularization procedure should be based on the clinical characteristics of the atherosclerotic lesion along with the individual patient history.

[Peripheral arterial disease. Diagnosis and therapy according to current guidelines]

Guidelines conduce to establish consistent standards of therapy and contribute to the orientation and safeguard of the attending physician. Peripheral arterial disease (PAD) may be classified according to its stage as intermittent claudication, chronic critical limb ischemia or acute limb ischemia. Since these diseases are common and life-threatening, current guidelines are of major interest for the attending physician, not least because of forensic reasons. This overview describes the current principles of diagnosis and therapy as well as recent developments in peripheral endovascular intervention. Current national and international guidelines, particularly the Transatlantic Intersociety Consensus (TASC), were taken into account.

Non-invasive cardiac assessment in high risk patients (The GROUND study): rationale, objectives and design of a multi-center randomized controlled clinical trial

Background

Peripheral arterial disease (PAD) is a common disease associated with a considerably increased risk of future cardiovascular events and most of these patients will die from coronary artery disease (CAD). Screening for silent CAD has become an option with recent non-invasive developments in CT (computed tomography)-angiography and MR (magnetic resonance) stress testing. Screening in combination with more aggressive treatment may improve prognosis. Therefore we propose to study whether a cardiac imaging algorithm, using non-invasive imaging techniques followed by treatment will reduce the risk of cardiovascular disease in PAD patients free from cardiac symptoms.

Design

The GROUND study is designed as a prospective, multi-center, randomized clinical trial. Patients with peripheral arterial disease, but without symptomatic cardiac disease will be asked to participate. All patients receive a proper risk factor management before randomization. Half of the recruited patients will enter the 'control group' and only undergo CT calcium scoring. The other half of the recruited patients (index group) will undergo the non invasive cardiac imaging algorithm followed by evidence-based treatment. First, patients are submitted to CT calcium scoring and CT angiography. Patients with a left main (or equivalent) coronary artery stenosis of > 50% on CT will be referred to a cardiologist without further imaging. All other patients in this group will undergo dobutamine stress magnetic resonance (DSMR) testing. Patients with a DSMR positive for ischemia will also be referred to a cardiologist. These patients are candidates for conventional coronary angiography and cardiac interventions (coronary artery bypass grafting (CABG) or percutaneous cardiac interventions (PCI)), if indicated. All participants of the trial will enter a 5 year follow up period for the occurrence of cardiovascular events. Sequential interim analysis will take place. Based on sample size calculations about 1200 patients are needed to detect a 24% reduction in primary outcome.

Implications

The GROUND study will provide insight into the question whether non-invasive cardiac imaging reduces the risk of cardiovascular events in patients with peripheral arterial disease, but without symptoms of coronary artery disease.

Trial registration

Clinicaltrials.gov NCT00189111

Current status of heroic limb salvage for critical limb ischemia

The treatment of chronic lower extremity peripheral arterial disease is in a state of flux. During the past decade, vascular surgeons have assumed the responsibility for the endovascular care of patients needing vascular intervention. Once surgeons began performing these procedures, a change in attitude toward angioplasty resulted in an "endovascular explosion" and an overall reassessment of the traditional approaches to critical limb ischemia. Our current method of assessing outcomes is also in a state of flux. The original measure of procedural success, reconstruction patency, has been found to be a poor predictor of both patient palliation and functional success. A shift toward determining more accurate, patient-oriented outcome measures is ongoing. Until then, evidence would suggest that there are patients with such severe medical comorbidities, which include impaired ambulatory ability at presentation, that the benefits of revascularization seem to be insignificant. As our patient population ages and our healthcare system continues to fail financially, economic rationing motivated by lack of evidence-based data to the contrary may dictate that these patients are best served by primary limb amputation.

Quality improvement guidelines for endovascular treatment of iliac artery occlusive disease

Endovascular therapy is the treatment of choice for type A and the preferred treatment for type B lesions. In selective patients, this type of treatment can be applied in type C and even type D lesions. Ipsilateral femoral, contralateral femoral, and brachial approach and both the intraluminal and subintimal space can be used for successful recanalization. The application of stents has improved the immediate hemodynamic and probably long-term clinical results of iliac percutaneous transluminal angioplasty. However, the superiority of primary or direct stenting over selective stenting has not been proven yet. The choice of stent type depends on lesion morphology and location but otherwise there is insufficient evidence to support the use of a particular stent design. There is insufficient evidence to justify routine use of covered stents. All patients should receive antiaggregant therapy following endovascular recanalization of iliac arteries. There is no consensus regarding prophylaxis with antibiotics in iliac recanalization procedures.

Endovascular therapies for peripheral arterial disease: an evidence-based review

Peripheral arterial disease is one manifestation of systemic atherosclerosis. The prevalence of peripheral arterial disease increases with the age of the population. It is important to remember the significant association of coincident coronary artery disease, which is the major cause of mortality in these patients. Remarkable technological advances in the past decade, along with patient preference, have shifted revascularization strategies from traditional open surgical approaches toward lower-morbidity percutaneous endovascular treatments. The availability of stents, more than any other advance, has fueled the growth of catheter-based procedures by improving the safety, durability, and predictability of percutaneous revascularization.

Remote endarterectomy for occlusive iliac and superficial femoral artery disease

Today's patients increasingly desire a low-risk procedure with rapid return to functional status following surgery. Many patients actively seek a minimally invasive option. During the last decade, minimally invasive surgical and radiological procedures emerged from their infancy to become an integral part of the treatment strategy in both peripheral arterial occlusive disease and aneurysmal arterial disease. The trend towards restoration of luminal patency, using the vessel itself as a conduit, can also be termed restorative intervention. As radiological percutaneous transluminal angioplasty has thus far proven unsuccessful in the long term for iliac and femoropopliteal occlusive lesions exceeding 10 cm, a new endovascular surgical procedure has been developed. A modification to the original ringstripper, used in semiclosed endarterectomy, was made to enable the technique of remote endarterectomy.

Dutch Iliac Stent Trial: Long-term Results in Patients Randomized for Primary or Selective Stent Placement

PURPOSE

To determine long-term results of the prospective Dutch Iliac Stent Trial.

MATERIALS AND METHODS

The study protocol was approved by local institutional review boards. All patients gave written informed consent. Two hundred seventy-nine patients (201 men, 78 women; mean age, 58 years) with iliac artery disease were randomly assigned to undergo primary stent placement (143 patients) or percutaneous transluminal angioplasty (PTA) with selective stent placement in cases in which the residual mean pressure gradient was greater than 10 mm Hg across the treated site (136 patients). Before and at 3, 12, and 24 months and 5-8 years after treatment, all patients underwent assessment, which included duplex ultrasonography (US), ankle-brachial index (ABI) measurement, Fontaine classification of symptoms, and completion of the Rand 36-Item Health survey for quality-of-life assessment. Treatment was considered successful for symptoms if symptoms increased at least one Fontaine grade, for ABI if ABI increased more than 0.10, for patency if peak systolic velocity ratio at duplex US was less than 2.5, and for quality of life if the RAND 36-Item Health Survey score increased more than 15 points. Effects of both treatments on symptoms, quality of life, patency, and ABI were compared by using survival analyses.

RESULTS

Patients who underwent PTA and selective stent placement had better improvement of symptoms (hazard ratio [HR], 0.8; 95% confidence limits [CLs]: 0.6, 1.0) than did patients treated with primary stent placement, whereas ABI (HR, 0.9; 95% CLs: 0.7, 1.3), iliac patency (HR, 1.3; 95% CLs: 0.8, 2.1), and score for quality of life for nine survey dimensions did not support a difference between treatment groups.

CONCLUSION

Patients treated with PTA and selective stent placement in the iliac artery had a better outcome for symptomatic success compared with patients treated with primary stent placement, whereas data about iliac patency, ABI, and quality of life did not support a difference between groups.

Lower extremity arterial occlusive disease: Role of percutaneous revascularization

Percutaneous endovascular interventions for peripheral arterial disease are indicated in carefully selected patients with favorable anatomy and associated clinical symptoms. Although endovascular therapy appears to be hemodynamically equivalent to other modalities in isolated iliac disease, this does not appear to be the case for infrainguinal disease, particularly when the disease is diffuse and extensive. Such disease in these beds can often be treated surgically, although there is an increasing role for percutaneous therapies, particularly in patients at higher surgical risk. Catheter-based therapy should be considered an integral part of comprehensive medical therapy in patients with lower extremity peripheral arterial disease. Embarking on an endovascular approach to therapy should involve a frank physician-patient discussion of the risks, benefits, and durability of the proposed procedure tailored to anatomic locale and patient-specific factors.