Transcatheter interventions for the treatment of peripheral atherosclerotic lesions: part I

Endovascular treatment of Takayasu arteritis in a middle-aged woman with syncope and limb claudication: a case report

Takayasu arteritis (TA) is a disease that causes inflammation and stenosis of medium to large blood vessels. We report a case of a 50-year-old female patient with newly developed hypertension, syncope, and claudication of the extremities. Total occlusion of the left subclavian artery at the origin was found and significant stenosis of the right common iliac artery was revealed by hemodynamic analysis. She was successfully treated with percutaneous angioplasty for multiple peripheral arterial diseases and was finally diagnosed with TA. In consultation with a rheumatologist, medical treatment for TA was initiated, the patient's hypertension disappeared, and her claudication symptoms improved.

Three-Year Real-World Outcomes of Interwoven Nitinol Supera Stent Implantation in Long and Complex Femoropopliteal Lesions

BACKGROUND

Peripheral artery disease (PAD) remains a major issue in modern societies and affects more than 200 million people around the world. Endovascular methods have been evaluated to be safe and effective in limb salvage. The Supera is able to withstand increased compression, biomechanical stress and to have higher radial force. The objective of this study is to evaluate performance, durability and 3-year patency of Supera stent implantation in severe femoropopliteal disease.

METHODS

A retrospective real-world analysis was performed with consideration of 77 patients that had a Supera stent implanted with femoropopliteal atherosclerotic disease at a single center. Among the 77 individuals, 92 Supera stents were implanted. Analysis of patients' demographics, lesions characteristics, reintervention rates and patency rates was performed.

RESULTS

The median follow-up was 33 months and ranged from 0 to 84 months. Chronic limb-threatening ischemia was observed among 43 patients. Mean lesion length was 152.8 ± 94.6 mm. Chronic total occlusions were observed in a majority of lesions. Overall, primary patency rates at 6, 12, 24 and 36 months were 85.0%, 73.6%, 59.2% and 53.2%, respectively.

CONCLUSIONS

The Supera stent is effective in the management of long and complex lesions. The results of patency rates were evaluated to be worse among lesions extending to the popliteal artery.

Quantitative model for assessment of lower-extremity perfusion in patients with diabetes

BACKGROUND

Although diabetic and atherosclerotic vascular diseases have different pathophysiological mechanisms, the screening methods currently used for diabetic lower-extremity vascular diseases are mainly based on the evaluation methods used for atherosclerotic vascular diseases. Thus, assessment of microvascular perfusion is of great importance in early detection of lower-extremity ischemia in diabetes.

PURPOSE

This cross-sectional study aimed to develop a quantitative model for evaluating lower-extremity perfusion.

METHODS

We recruited 57 participants (14 healthy participants and 43 diabetes patients, of which 16 had lower-extremity arterial disease [LEAD]). All participants underwent technetium-99 m sestamibi (99mTc-MIBI) scintigraphy and ankle-brachial index (ABI) examination. We derived two key perfusion kinetics indices named activity perfusion index (API) and basal perfusion index (BPI). This study was registered in ClinicalTrials.gov (URL: https://www.

CLINICALTRIALS

gov, NCT02752100).

RESULTS

The estimated limb perfusion values in our lower-extremity perfusion assessment (LEPA) model showed excellent consistency with the actual measured data. Diabetes patients showed reduced lower-extremity perfusion in comparison with the control group (BPI: 106.21 ± 11.99 vs. 141.56 ± 17.38, p < 0.05; API: 12.34 ± 3.27 vs. 14.56 ± 3.12, p < 0.05). Using our model, the reductions in lower-extremity perfusion could be detected early in approximately 96.30% of diabetes patients. Patients with LEAD showed more severe reductions in lower-extremity perfusion than diabetes patients without LEAD (BPI: 47.85 ± 20.30 vs. 106.21 ± 11.99, p < 0.05; API: 7.06 ± 1.70 vs. 12.34 ± 3.27, p < 0.05). Discriminant analysis using API and BPI could successfully screen all diabetes patients with LEAD with a sensitivity of 100% and specificity of 80.77%.

CONCLUSIONS

We established a LEPA model that could successfully assess lower-extremity microvascular perfusion in diabetes patients. This model has important application value for the recognition of early-stage LEAD in patients with diabetes.

Endovascular Treatment and Outcomes for Femoropopliteal In-Stent Restenosis: Insights from the XLPAD Registry

Background

There is limited “real-world” evidence examining treatment modalities and outcomes in patients with symptomatic peripheral arterial disease undergoing endovascular treatment of femoropopliteal (FP) in-stent restenosis (ISR).

Materials and Methods

We compared outcomes in 2,895 patients from the XLPAD registry (NCT01904851) between 2006 and 2019 treated for FP ISR (n = 347) and non-ISR (n = 2,548) lesions. Primary endpoint included major adverse limb events (MALE) at 1 year, a composite of all-cause death, target limb repeat revascularization, or major amputation.

Results

ISR patients were more frequently on antiplatelet (94.5% vs 89.4%, p=0.007) and statin (68.9% vs 60.3%, p=0.003) therapies. Lesion length was similar (ISR: 145 ± 99 mm vs. non-ISR: 142 ± 99 mm, p=0.55). Fewer treated ISR lesions were chronic total occlusions (47.3% vs. 53.7%, p=0.02) and severely calcified (22.4% vs. 44.7%, p < 0.001). Atherectomy (63.5% vs. 45.0%, p < 0.001) and drug-coated balloons (DCB; 4.7% vs. 1.7%, p < 0.001) were more frequently used in ISR lesions. The distal embolization rate was higher in ISR lesions (2.4% vs. 0.9%, p=0.02). Repeat revascularization (21.5% vs. 16.7%, p=0.04; Figure) was higher and freedom from MALE at 1 year was significantly lower (87% vs. 92.5%, p < 0.001) in the ISR group.

Conclusion

Atherectomy and DCB are more frequently used to treat FP ISR lesions. Patients with FP ISR have more intraprocedural distal embolization, higher repeat revascularization procedures, and lower freedom from MALE at 1 year.

Efficacy of Cutting Balloon Angioplasty for Chronic Total Occlusion of Femoropopliteal Arteries

BACKGROUND

Chronic total occlusion (CTO) of femoropopliteal artery (FP) continues to be a lesion subset where maintaining long-term patency after endovascular treatment is challenging. We evaluated the efficacy of cutting balloon angioplasty (CBA) for de novo FP-CTOs in patients with symptomatic lower limb ischemia.

METHODS

Seventy-three limbs of 67 symptomatic patients with de novo FP-CTOs successfully recanalized using CBA alone were enrolled in this study. Primary patency was defined as the absence of recurrent symptoms and no deterioration of the ankle-brachial index (ABI) >0.10 from the immediate postinterventional value.

RESULTS

The mean age was 73.5 ± 7.3 years, and 59.7% of patients had diabetes mellitus. Most lesions were classified as Trans-Atlantic Inter-Society Consensus II type C (n = 18; 24.7%) or type D (n = 44; 60.3%), with mean lesion and occluded lengths of 24.8 ± 11.4 and 17.8 ± 11.2 cm, respectively. No procedure-related adverse events occurred, except one distal embolization. The ABI significantly increased after intervention from 0.52 ± 0.12 to 0.80 ± 0.15 (P < 0.0001), with marked improvement in clinical symptoms (Rutherford stage: 2.7 ± 1.0 to 1.1 ± 1.2, P < 0.0001). The mean follow-up period was 31.2 ± 18.0 months, and the primary patency rates at 12 and 24 months were 75.3% and 60.6%, respectively. The independent predictive factors of failed patency were baseline hemoglobin A1c (P = 0.031, hazard radio [HR] 1.51 per 1%), occluded length ≥15 cm (P = 0.036, HR 2.90), and severe dissection (P = 0.033, HR 2.85). Vessel calcification and diameter did not affect primary patency.

CONCLUSIONS

CBA is a feasible option for endovascular treatment of FP-CTOs. Diabetic status, occlusion length, and severe dissection after CBA are independent negative predictors of long-term patency.

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.

Cryoplasty for the Treatment of Femoropopliteal Arterial Disease: Extended Follow-up Results

Purpose:

To report the findings from a multicenter study of patients treated with cryoplasty who were then followed for an average of >2 years post-treatment.

Methods:

Extended clinical follow-up was obtained for 70 patients (45 men; mean age 70.5±8.8 years) who originally received cryoplasty therapy to treat symptoms of intermittent claudication as part of a multicenter investigational device exemption (IDE) study. For all subjects, cryoplasty was used to treat stenoses or occlusions ≤10 cm in the femoropopliteal arteries. The original IDE study protocol enrolled 102 patients with a primary endpoint of target lesion patency at 9 months post-treatment. This collection of additional longer term follow-up data was initiated 2.5 years after the onset of study enrollment.

Results:

Extended clinical follow-up ranged from 11 to 41 months (mean 31). The clinical patency rate (freedom from target lesion revascularization) calculated by the Kaplan-Meier method was 83.2% after the original follow-up period of 300 days. After >3 years (1253 days), the clinical patency rate was well maintained at 75.0%.

Conclusions:

Long-term data indicate that cryoplasty is a durable therapy, with relatively low long-term restenosis rates compared to other endovascular treatment approaches.

Indications and Results with Cryoplasty in the Treatment of Infrainguinal Arterial Occlusive Disease

Percutaneous transluminal angioplasty of the superficial femoral and popliteal arteries has been an accepted therapy for short focal stenosis. Elastic recoil and flow-limiting dissection have limited the durability of angioplasty, especially in long lesions and total occlusions. Cryoplasty couples cold therapy with angioplasty to induce mechanical and biologic effects to reduce elastic recoil and potentially to reduce restenosis. The mechanical and biologic mechanisms of this therapy are discussed. The results of cryoplasty for femoropopliteal lesions from a single-center series and a multicenter registry are reviewed. Cryoplasty appears to improve patency over conventional angioplasty and to reduce the need for bailout stenting in femoropopliteal stenoses and occlusions < 10 cm in length. Cryoplasty appears to be promising to treat critical limb ischemia in patients with tibial disease.

Endovascular intervention for peripheral artery disease

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

Paclitaxel-eluting stents for the treatment of femoropopliteal arterial stenoses: focus on the Zilver PTX drug-eluting peripheral stent

Restenosis is one of the major limitations of the percutaneous treatment of peripheral artery disease, leading to the need for repeat interventions, limb loss and increased cost of therapy. The current standard of percutaneous treatment of stenotic lesions in the femoropopliteal arterial segment includes balloon angioplasty and bare-metal stenting. Recently, research in the field adapting the coronary arterial bed treatment model led to the inclusion of antimitotic drugs in the form of drug-eluting stents to combat neointimal proliferation and reduce the burden of restenosis. Randomized trial and registry data emerged indicating improved long-term outcomes with drug-eluting stents in peripheral arteries, lending the way to more widespread adaptation of this modality in the management of patients with peripheral artery disease.

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.

Successful angioplasty for radial artery chronic total occlusion in a patient with digital gangrene

Critical hand ischemia caused by chronic occlusive arterial disease is an uncommon condition. Diabetes mellitus and chronic renal insufficiency are the concomitant conditions in most of these patients. A 59-year-old woman with diabetic nephropathy being treated with hemodialysis was referred to the Cardiology Department for a non-healing necrotic lesion in the distal part of the fourth finger. We performed balloon angioplasty for diffuse and severe calcified total occlusion of the radial artery using long and high pressure resistant balloons. After successful angioplasty the symptoms were relieved immediately and the finger was almost healed within 2 months of follow-up.

Subintimal recanalization of occluded stents: the substent technique

PURPOSE

Application of metal stents is complicated by neointimal hyperplasia leading to vessel restenosis and reocclusion. Treatment options in cases presenting with complete occlusion of the stented segment and recurrent critical limb ischemia (CLI) are limited. We present the option of the subintimal/substent technique in dealing with occluded stents.

METHODS

The study included patients presenting with recurrent CLI due to impaired blood flow as a result of complete occlusion of previously inserted metal stents and unsuccessful intraluminal crossing of the lesion via either the antegrade or retrograde approach. In these cases, crossing the occlusion through the subintimal/substent plane was attempted. Primary end points included technical success, safety of the procedure, clinical improvement, and limb salvage, while secondary end points were patient survival, primary patency, and vessel restenosis rates at 1-year follow-up. Study end points were calculated by Kaplan-Meier survival analysis.

RESULTS

Between July 2006 and October 2011, a total of 14 patients (mean age 69.14 ± 12.59 years, 12 men) were treated with the substent technique and included in the analysis. Technical success rate was 85.71% (12 of 14), with a total lesion length of 193.57 ± 90.78 mm. The mean occluded stented segment length was 90.21 ± 44.34 mm. In 10 (83.33%) of 12 cases, a new stent had to be placed by the side of the old occluded one, while the remaining two cases (16.67%) were treated only with balloon angioplasty. No serious adverse events were noted during the immediate postprocedural period. All successfully treated patients improved clinically. Estimated limb salvage was 90.9%, and patient survival rate was 90.0% at 1 year's follow-up. Primary patency was 45.50% and vessel restenosis 77.30%.

CONCLUSION

Subintimal recanalization of occluded metal stents through the substent plane is a valuable alternative treatment option, especially in patients with recurrent CLI with few alternatives.

Current state of diagnosis and management of critical limb ischemia

Critical limb ischemia represents the most severe form of peripheral arterial disease and carries with it severe morbidity and mortality risks. Because of comorbidity risks, early diagnosis and aggressive medical management make up an important part of the treatment paradigm for these individuals. However, in addition to managing these comorbid conditions, the physician caring for these individuals must be able to provide revascularization options that will improve arterial flow to the threatened extremity and assure healing of complicated wounds. Both open surgical and endovascular therapies have proven beneficial in restoring flow to severely ischemic limbs in these patients. Additionally, combinations of the above therapeutic methods have offered more available options for these patients. This article reviews care of patients with critical limb ischemia with critical assessment of options for medical and revascularization options.

Inhibition of neointimal hyperplasia after stent placement with rhenium 188-filled balloon dilation in a canine iliac artery model

PURPOSE

To evaluate the efficacy of beta-irradiation therapy with rhenium 188 ((188)Re) mercaptoacetyltriglycine (MAG3)-filled balloon dilation to prevent neointimal hyperplasia after stent placement in a canine iliac artery model.

MATERIALS AND METHODS

A total of 15 stents were implanted into the iliac arteries of eight dogs (one or two stents in each dog). Rhenium 188 MAG3-filled balloon dilation was performed immediately after placement of 10 bare stents-20 Gy in group II (n = 5) and 40 Gy in group III (n = 5)-and conventional balloon dilation was performed immediately after placement of the remaining five bare stents (group I). A follow-up angiogram was obtained 8 weeks after the procedure, and percentage of luminal stenosis was calculated for the proximal and distal ends of each stent. Neointimal thickening (expressed as the neointimal area divided by the sum of neointimal area and media area) was assessed for microscopic examination.

RESULTS

All eight dogs survived until they were euthanized 8 weeks after the procedures. The mean luminal stenosis measurements at 8-week follow-up angiography in groups I, II, and III were 26.63%, -0.44%, and 10.53%, respectively. The mean neointimal thickening measurements in groups I, II, and III were 0.77, 0.21, and 0.34, respectively. The mean percentage of luminal stenosis and neointimal thickening differed significantly among the three groups (P < .05).

CONCLUSIONS

beta-Irradiation with (188)Re-MAG3-filled balloon dilation has the potential to reduce neointimal hyperplasia secondary to stent placement in a canine iliac artery model. A dose of 20 Gy may be preferable versus a dose of 40 Gy to reduce neointimal hyperplasia.

Role of superficial femoral artery stents in the management of arterial occlusive disease: review of current evidence

The objectives of this study were to compare the 1-year patency of superficial femoral artery (SFA) stent placement with percutaneous transluminal angioplasty (PTA) alone and to attempt to define the role of stents in arterial occlusive disease. Literature searches of the Embase, Medline, and Cochrane databases identified relevant articles, which were split into two subgroups: those containing case-controlled matches for stenting and PTA and those considering only stent placement. The review conformed to the QUORUM statement. One-year patency rates were 219 of 383 (57%) in the stented group and 319 of 607 (53%) in the PTA group for matched cases (odds ratio 1.206 [95% CI 0.932-1.559; p = .115]). The patency of stents deployed secondarily was 554 of 909 (61%). The combined 1-year patency of primary and secondary SFA stents for matched and unmatched case series was 816 of 1,282 (64%). One-year patency rates following stent placement or PTA alone in well-matched patient groups demonstrated no significant difference. This would suggest that the routine use of primary SFA stenting should be undertaken only in selected cases and should mainly be used in "bailout" situations or for complex lesions where surgery is precluded. However, the studies used displayed a high degree of heterogeneity, and some used stent technology that is now considered obsolete. Ongoing randomized controlled trials will provide a more definitive answer to this important problem.

Endovascular Treatment of Innominate Artery Occlusion With Simultaneous Vertebral and Carotid Artery Distal Protection

OBJECTIVE

Atherosclerotic stenosis or obstruction of the innominate artery is rare. Traditional surgical management is a technically demanding intervention with acceptable, but not negligible, rates of morbidity and mortality. Endovascular approaches to supraaortic lesions have been successful and are now the preferred treatment for stenoses of the brachiocephalic vessels. The use of cerebral protection devices in subclavian and innominate interventions is less established.

CLINICAL PRESENTATION

A 58-year-old woman had Takayasu giant cell arteritis with a history of a left middle cerebral artery stroke 3 weeks after undergoing placement of a left common carotid artery (CCA) stent and right innominate artery stent in 1998. She recently presented with worsening dizziness, ataxia, and right arm numbness and was referred to the endovascular neurosurgery service for management.

INTERVENTION

Initial angiography revealed left CCA stenosis and right innominate occlusion. The patient initially underwent left CCA angioplasty, planned as a staged procedure. This was followed by recanalization of the right innominate artery through an approach using both femoral arteries and the right brachial artery. This 3-site technique allowed simultaneous distal protection of both the right cervical vertebral and carotid arteries.

CONCLUSION

Reopening a chronically occluded innominate artery risks an embolic shower through both the right vertebral and carotid arteries. Using multiple sites of arterial access, distal protection devices can be deployed in both the cervical vertebral and carotid arteries to reduce the risk of stroke.

Endovascular treatment of peripheral vascular disease

Peripheral arterial disease (PAD) affects about 27 million people in North America and Europe, accounting for up to 413,000 hospitalizations per year with 88,000 hospitalizations involving the lower extremities and 28,000 involving embolectomy or thrombectomy of lower limb arteries. Many patients are asymptomatic and, among symptomatic patients, atypical symptoms are more common than classic claudication. Peripheral arterial disease also correlates strongly with risk of major cardiovascular events, and patients with PAD have a high prevalence of coexistent coronary and cerebrovascular disease. Because the prevalence of PAD increases progressively with age, PAD is a growing clinical problem due to the increasingly aged population in the United States and other developed countries. Until recently, vascular surgical procedures were the only alternative to medical therapy in such patients. Today, endovascular practice, percutaneous transluminal angioplasty with or without stenting, is used far more frequently for all types of lower extremity occlusive lesions, reflecting the continuing advances in imaging techniques, angioplasty equipment, and endovascular expertise. The role of endovascular intervention in the treatment of limb-threatening ischemia is also expanding, and its promise of limb salvage and symptom relief with reduced morbidity and mortality makes percutaneous transluminal angioplasty/stenting an attractive alternative to surgery and, as most endovascular interventions are performed on an outpatient basis, hospital costs are cut considerably. In this monograph we discuss current endovascular intervention for treatment of occlusive PAD, aneurysmal arterial disease, and venous occlusive disease.

Below knee angioplasty in elderly patients: predictors of major adverse clinical outcomes

AIM

To determine predictors of clinical outcome following percutaneous transluminal angioplasty (PTA) in elderly patients with below knee atherosclerotic lesions causing intermittent claudication (IC) or critical limb ischaemia (CLI).

MATERIALS AND METHODS

Over 7.5 years, 76 patients (CLI 72%, n = 55) underwent below knee PTA. The composite end-point of interest was major adverse clinical outcome (MACO) of the treated limb at follow-up which was defined as clinical failure, need for subsequent endovascular or surgical revascularization or amputation. Actuarial freedom from MACO was assessed using Kaplan-Meier curves and multivariable Cox proportional hazards regression.

RESULTS

IC was improved in 95% at mean 3.4 years (range 0.5-108 months). Successful limb salvage and ulcer healing were seen in 73% with CLI. Most failures were in the CLI group (27% CLI vs. 5% IC), with an amputation rate of 16% for CLI vs. 5% for IC and persistent ulceration in 24% of CLI. Significant independent predictors of MACO were ulceration (hazard ratio 4.02, 95% CI = 1.55-10.38) and family history of atherosclerosis (hazard ratio 2.53, 95% CI = 1.1-5.92).

CONCLUSION

Primary below knee PTA is a feasible therapeutic option in this elderly population. Limb ulceration and family history of atherosclerosis may be independent predictors of adverse outcome.

Restenosis after lower extremity interventions: current status and future directions

The incidence of restenosis after percutaneous peripheral interventions (PPI) varies considerably depending upon the vascular bed but appears to be highest in the femoropopliteal and tibioperoneal arteries. The restenosis process in the periphery does not appear to stop at the 6-month mark, as seen with bare metal stents in the coronary arteries, but continues for a longer time, possibly years, after the intervention. This review evaluates the incidence of restenosis following lower extremity arterial interventions and potential drugs or devices that could alter this process, including nonpharmacological (stents, cryoplasty, Cutting Balloon angioplasty, atherectomy, brachytherapy, and photodynamic therapy) and pharmacological (systemic and direct drug delivery) approaches. A global strategy to achieve optimal outcome with PPI is offered: (1) obtain excellent acute angiographic results with less dissection and recoil, (2) protect the distal tibial vascular bed, and (3) reduce smooth muscle cell proliferation with pharmacological intervention.

24-carat gold, 14-carat gold, or platinum standards in the treatment of critical limb ischemia: bypass surgery or endovascular intervention?

Critical limb ischemia (CLI) remains a poorly understood, rarely reported, and inconsistently treated major global healthcare epidemic. The incidence in the US is estimated at 1% of the population aged 50 years and older and at approximately double that rate in the over-70 age group. These frequencies are expected to increase significantly with the aging population and the expected increase in diabetes. Within 1 year of being diagnosed with CLI, 40% to 50% of the now 20 million US diabetics will experience an amputation, and 20% to 25% will die. The estimate for treating CLI in the US alone is $10 to $20 billion per year, but just a 25% reduction in amputations could save $2.9 to $3.0 billion annually. Infrainguinal bypass surgery (IBS) utilizing autogenous saphenous vein has been considered the "24-carat gold standard" treatment for CLI, but over the last decade, endovascular therapy has emerged to seriously challenge IBS, which has created considerable controversy. Despite an overall lack of "hard" level I data, many interventionists are questioning the role of IBS as a first-line CLI therapy or are at least now considering IBS a "tainted" gold standard ("14-carat"). This review will examine the available evidence, but there should be no doubt regarding the huge global clinical and economic impact of CLI and amputations.

Primary cryoplasty therapy provides durable support for limb salvage in critical limb ischemia patients with infrapopliteal lesions: 12-month follow-up results from the BTK Chill Trial

PURPOSE

To report the 12-month follow-up data from the prospective 16-center Below-the-Knee (BTK) Chill Trial, which examined the use of primary cryoplasty for BTK occlusive disease in patients with critical limb ischemia (CLI).

METHODS

The trial included 108 patients (77 men; mean age 73 +/- 11 years, range 41-101) with CLI (Rutherford categories 4-6) involving 111 limbs with 115 target infrapopliteal lesions. Angiographic inclusion criteria were reference vessel diameter > or = 2.5 mm and < or = 5.0 mm and target lesion stenosis > or = 50%. The primary study endpoints were acute technical success (the ability to achieve < or = 50% residual stenosis and continuous inline flow to the foot) and absence of major amputation of the target limb at 6 months. Secondary endpoints were serious adverse events specifically related to use of primary cryoplasty and absence of major amputation of the target limb at 1, 3, and 12 months.

RESULTS

Acute technical success was achieved in 108 (97.3%) of treated limbs, with only 1 clinically significant dissection (> or = type C) and 2 residual stenoses >50%; stent placement was required following cryoplasty in only 3 (2.7%) procedures. At 6 months and 1 year, major amputation was avoided in 93.4% (85/91) and 85.2% (69/81) of patients, respectively. Through 1 year, 21% (17/81) of patients underwent target limb revascularization. Rates of major amputation and death at 1 year were 0% for limbs of patients with initial Rutherford category 4; 11.4% and 0%, respectively, for initial category 5; and 40.0% and 31.8% for initial category 6. One-year rates of major amputation and death were 20.4% and 8.8%, respectively, for diabetics, versus 4.0% and 10.7% for non-diabetics. At 1 year, major amputation occurred in 16.7% (2/12) of limbs that were expected to be amputated at the time of treatment.

CONCLUSION

Cryoplasty therapy is a safe and effective method of treating infrapopliteal disease, providing excellent results and a high rate of limb salvage in patients with CLI. Study outcomes through 1 year support the use of cryoplasty as a primary treatment option for patients with CLI secondary to BTK occlusive disease.

Endovascular procedures for below the knee arteries in diabetics

Patients with below the knee (BTK) lesions may present either with intermittent claudication (IC) or with critical limb ischemia (CLI). Generally, these patients with a high incidence of diabetes have a high rate of myocardial infarction and mortality. So, even if, the surgery is potentially a very good technique with excellent results when the best conduit as a vein graft is used, the ratio benefice/risk seems too low for the IC patients. On another hand for the CLI patients a lot of reasons contraindicate or are unfair to the surgical option: lack of conduit, bad or unclear run-off or distal outflow site, bad local cutaneous conditions. Endovascular option by specialists with experience of coronary devices should be the treatment of choice. We review the different techniques and their recent upgrades in order to improve the percutaneous endovascular treatment of BTK lesions.

Subclavian artery revascularization: an outcome analysis based on mode of therapy and presenting symptoms

Therapy for atherosclerotic occlusive subclavian arterial disease is undergoing a paradigm shift from open to endoluminal therapy. The aim of this study was to review the changing patterns of presentation and clinical outcomes based on presenting symptoms of subclavian artery revascularization. We performed a retrospective analysis of consecutive patients treated for symptomatic atherosclerotic occlusive subclavian arterial disease from 1992 through 2006. Mean follow-up was 4 years. One hundred fourteen patients with a mean age of 63 years (range 33-89, 61% female) underwent 137 procedures. Of these, 89% had hypertension, 32% were diabetic, 69% had hyperlipidemia, and 13% had chronic renal insufficiency. Sixty-seven primary stent attempts (five technical failures) and 70 open (64 carotid-subclavian bypasses, six subclavian-carotid transpositions) were performed. No deaths occurred within the 30-day perioperative period. Fifty-seven percent of the patients presented with symptoms of arm ischemia: exertional pain (84%), rest pain (12%), and ulceration (4%). The assisted primary patency was 81 +/- 7% and 80 +/- 10% at 5 and 10 years, respectively. Symptoms resolved in all patients, and none required major or minor amputations. Freedom from recurrent arm symptoms was 71 +/- 8% and 71 +/- 10% at 5 and 10 years, respectively. Twenty-five percent of the patients presented with a cardiac indication: preparation for a left internal mammary artery (IMA) bypass in 61% and recurrent cardiac ischemia in the remainder. The assisted primary patency was 97 +/- 6% at 5 years. No IMAs were abandoned in this group, and the freedom from recurrent cardiac symptoms related to IMA distribution was 79 +/- 10% at 5 years. Eighteen percent of patients presented with posterior circulation symptoms secondary to vertebrobasilar disease. The assisted primary patency was 100 +/- 0% and 100 +/- 0% at 5 and 10 years, respectively. Freedom from recurrent vertebrobasilar symptoms was 95 +/- 6% and 95 +/- 10% at 5 and 10 years, respectively. Subclavian artery revascularization is safe and effective, but long-term outcomes are determined by the presenting symptomatology.

Cryoplasty therapy for limb salvage in patients with critical limb ischemia

PURPOSE

To report the 6-month outcomes from a prospective multicenter study investigating the use of cryoplasty (cold balloon angioplasty) to treat below-knee occlusive disease in patients with critical limb ischemia (CLI).

METHODS

Between August 2004 and October 2005, 108 patients (77 men; mean age 73+/-12 years, range 41-101) with CLI involving 111 limbs were enrolled in a prospective multicenter trial (Below-the-Knee Chill Study), which was conducted at 16 institutions. The primary study endpoints were acute technical success, defined as the ability to achieve < or =50% residual stenosis and continuous inline flow to the foot, and absence of major (above or below-knee) amputation of the target limb 180 days post procedure.

RESULTS

Acute technical success was achieved in 108 (97.3%) of the 111 limbs treated, with only 1 (0.9%) clinically significant dissection (> or =type C) and 2 residual stenoses >50%. During the 180-day follow-up, 15 (13.9%) of the initial 108 patients either withdrew or were lost to follow-up. Five (4.6%) deaths occurred, leaving 88 (81.5%) patients with 91 (82.0%) treated limbs available for 180-day assessment. The rate of freedom from major amputation at 180 days was 93.4%. Amputation-free survival was 89.3% at 180 days (5 deaths, 6 major amputations). Stratifying data by diabetics (n=71) versus non-diabetics (n=34), the 180-day death and amputation rates were 4.9% and 10.0%, respectively, for diabetics versus 6.7% and 0.0%, respectively, for non-diabetics.

CONCLUSION

Cryoplasty therapy is a safe and effective method of treating infrapopliteal disease, providing excellent acute outcomes and a high rate of limb salvage in patients with CLI. Study outcomes support the use of cryoplasty therapy as a primary treatment option for patients with CLI secondary to below- knee disease.

Endovascular treatment of vertebral artery-origin and innominate/subclavian disease: indications and technique

Approximately 20% to 40% of patients who have cerebral vascular disease have a vertebral artery-origin stenosis. Atherosclerotic lesions of vertebral arety origin are a potential cause of posterior circulation ischemia, which can be disabling or deadly. Endovascular treatment of vertebral artery-origin and innominate/subclavian artery stenosis has changed in the last 15 years. Surgery usually is successful technically; however, it is also associated with high rates of procedural and periprocedural complications. New techniques and technologies that can be used in the treatment of such lesions are being developed. In this article, the authors discuss the indications, technical aspects, and long-term results of angioplasty and stenting of these vessels.

Hybrid Revascularization Using Silverhawk Atherectomy and Infrapopliteal Bypass for Limb Salvage

Patients with limb-threatening ischemia and a paucity of ipsilateral greater saphenous vein for conduit represent a challenge for lower extremity revascularization. We present four patients with limited autogenous conduit who underwent hybrid revascularization using the Silverhawk atherectomy device and infrapopliteal artery bypass for limb-threatening ischemia. All patients experienced complete wound healing in early follow-up. Hybrid revascularization appears safe, produces excellent short-term outcomes, and may be appropriate for patients with limited autogenous vein who require lower extremity revascularization.

A novel approach using atherectomy for chronic total occlusion of the brachial artery: a case report

Chronic upper limb ischemia is uncommon, and is most often secondary to subclavian artery stenosis. Percutaneous intervention for subclavian stenosis usually includes balloon angioplasty and stent implantation. Brachial artery stenosis is even more scarce and accounts for approximately 12% of symptomatic upper extremity ischemia. Because it is rare, the optimal treatment strategy for brachial artery stenosis remains uncertain. We describe a case of chronic brachial artery ischemia due to atherosclerotic disease treated with the SilverHawk plaque excision system and review the available data regarding its use.

Nitinol Stent Implantation Versus Percutaneous Transluminal Angioplasty in Superficial Femoral Artery Lesions up to 10 cm in Length

BACKGROUND

Endoluminal treatment of superficial femoral artery lesions is a matter of controversy. The present study was designed to investigate the impact of nitinol stenting of superficial femoral artery lesions with a maximum length of 10 cm on restenosis and clinical outcomes at 1 year.

METHODS AND RESULTS

Two hundred forty-four patients (168 men; 66+/-9 years) with a single superficial femoral artery lesion and chronic limb ischemia were randomized to implantation of a single Bard Luminexx 3 stent (123 patients) or stand-alone percutaneous transluminal angioplasty (PTA) (121 patients). Mean lesion length was 45 mm. Technical success (residual stenosis <50% for PTA, <30% for stenting) was achieved in 96 patients assigned to PTA (79%) and 117 patients assigned to stenting (95%); 13 PTA group patients (11%) "crossed over" to stenting. At 1 year, the primary end point of ultrasound-assessed binary restenosis was reached in 39 of 101 PTA group patients (38.6%) and 32 of 101 stent group patients (31.7%; absolute treatment difference, -6.9%; 95% CI, -19.7% to 6.2%; P=0.377). Target lesion revascularization rates at 1 year were 18.3% and 14.9%, respectively (absolute treatment difference, -3.3%; 95% CI, -13.0% to 6.4%; P=0.595). No statistically significant difference between treatment groups was observed at 12 months in the improvement by at least 1 Rutherford category of peripheral arterial disease.

CONCLUSIONS

In the present study of patients with short superficial femoral artery lesions, the hypothesized absolute difference of 20% in binary restenosis at 1 year between the implantation of a single Luminexx nitinol stent and stand-alone PTA could not be demonstrated. A smaller difference requiring a larger trial might have been missed.

Stenting for chronic total occlusion of the proximal subclavian artery

SUMMARY

We report the results of 26 patients who underwent stent deployment for chronic total occlusion of proximal subclavian artery. From January 1998 to October 2005, 26 patients (18 male; mean age, 62.7 years, range 22 to 83 years), 28 lesions, underwent 29 procedures of stenting for chronic total occlusion of the proximal subclavian artery.Twenty-three patients had symptoms of claudication in their arm, no patients had subclavian steal syndrome.A brachial approach was used in 21 procedures, a femoral approach was used in five procedures, and combined femoral-brachial approach was required in three procedures. Primary stent deployment was success in 24 lesions (85.7%), and secondary procedure was success in one patient, totally 25 lesions (89.3%) were successfully treated by stenting. Procedure related complication occurred in four cases, including stent migration without symptoms in two procedures, hemianopsia on next day in a case, and TIA on unclear reason in one case. Permanent morbidity rate is 3.4% in procedure. Target lesion re-treatment required in three lesions, caused by subacute thrombosis, in-stent-restenosis, and dissection of the vessel by stent edge. The cases of subacute thrombosis and in-stent-restenosis were treated by re-PTA, and the case of dissection was treated by additional stenting. Secondary patency was 100%. We conclude that stenting for chronic total occlusion of subclavian arteries appears feasible and safe.

[Chronic critical ischemia of the lower leg: pretherapeutic imaging and methods for revascularization]

Each year 1-2% of patients with peripheral arterial occlusive disease (pAOD) develop critical limb ischemia (CLI), characterized by rest pain and peripheral ulcer or gangrene. This aggravation of the disease is accompanied by an increase of the 1-year mortality rate up to 25% and a similarly increased frequency of major amputation. We can choose between conservative, endovascular, and surgical procedures for an adequate therapy of the underlying vascular stenoses or occlusions. Yet, clear therapeutic recommendations only exist for suprapopliteal lesions. However, in a number of cases, especially in diabetics, target lesions have an infrapopliteal location. Since endovascular procedures have undergone significant improvement in the last few years, the following review discusses methods for infrapopliteal revascularization taking into consideration the newest publications on this topic.

External Beam Irradiation and Restenosis Following Femoral Stenting: Long-Term Results of a Prospective Randomized Study

PURPOSE

To assess the long-term outcome of external beam irradiation (EBI) for the prevention of restenosis due to neointimal hyperplasia, following percutaneous transluminal angioplasty (PTA) and stenting of the superficial femoral artery.

METHODS

Sixty consecutive patients with peripheral arterial disease, who were treated with "bail-out" stent implantation in the superficial femoral artery due to suboptimal PTA, were included in this study. Patients were randomly allocated into two groups, receiving either external beam irradiation (6 MV photons, total dose 24 Gy in a hypofractionated schedule) plus antiplatelet therapy (EBI group) or antiplatelet therapy alone (control group).

RESULTS

No procedure-related complications occurred, and all patients of the EBI group received the full dose of 24 Gy. During the long-term follow-up, an overall statistically significant difference was demonstrated in favor of the EBI group patients, regarding both the in-stent (log-rank test, p = 0.0072) and the in-segment binary restenosis (log-rank test, p = 0.0103). The primary patency rates were also significantly better in the EBI group at specific time-points, such as in the first (74.2% vs 46.5%, p = 0.019), second (62.5% vs 33.8%, p = 0.020), and third (54.6% vs 29.0%, p = 0.039) year, respectively. Moreover, the overall clinically driven reintervention rate was significantly lower among patients of the irradiated group (log-rank test, p = 0.038).

CONCLUSION

Our long-term follow-up analysis revealed that EBI following femoral artery PTA and stenting significantly reduces restenosis and reintervention rates, while improving primary patency.

Lost in publication: Half of all renal practice evidence is published in non-renal journals

Physicians often scan a select number of journals to keep up to date with practice evidence for patients with kidney conditions. This raises the question of where relevant studies are published. We performed a bibliometric analysis using 195 renal systematic reviews. Each review used a comprehensive method to identify all primary studies for a focused clinical question relevant to patient care. We compiled all the primary studies included in these reviews, and considered where each study was published. Of the 2779 studies, 1351 (49%) were published in the top 20 journals. Predictably, this list included Transplantation Proceedings (5.9% of studies), Kidney International (5.3%), American Journal of Kidney Diseases (4.7%), Nephrology Dialysis Transplantation (4.3%), Transplantation (4.2%), and Journal of the American Society of Nephrology (2.4%). Ten non-renal journals were also on this list, including New England Journal of Medicine (2.4%), Lancet (2.3%), and Diabetes Care (2.2%). The remaining 1428 (51%) studies were published across other 446 journals. When the disciplines of all journals were considered, 59 were classified as renal or transplant journals (42% of articles). Other specialties included general and internal medicine (16%), endocrinology (diabetes) and metabolism (6.5%), surgery (6.2%), cardiovascular diseases (6.1%), pediatrics (4.3%), and radiology (3.3%). About half of all renal practice evidence is published in non-renal journals. Browsing the top journals is important. However, relevant studies are also scattered across a large range of journals that may not be routinely scanned by busy physicians, and keeping up with this literature requires other continuing education strategies.

Thrombolysis for Acute Lower Limb Ischaemia—A Prospective, Randomised, Multicentre Study Comparing Two Strategies

OBJECTIVES

To test if initial high-dose, pulse-spray thrombolysis improves the early and late outcome of lower limb ischaemia as compared with low-dose infusion alone.

DESIGN

Prospective randomised multicentre study.

MATERIAL AND METHODS

Patients with acute and sub-acute (<30 days) lower limb ischaemia were randomised following angiography. Group 1 (n=58) received pulse-spray infusion of recombinant plasminogen activator (rt-PA, 15 mg/h) for 2h followed by low-dose infusion if needed. Group 2 (n=63) were only treated with low-dose infusion (0.5mg/h) of rt-PA for 48 h. Underlying lesions were corrected if required.

RESULTS

The study was stopped prematurely. Complications were equally frequent in both groups. More than 75% lysis was accomplished in 78 versus 67% of the patients (p=0.21). Primary endpoints (re-occlusion, incomplete lysis, life-threatening complication, amputation, or death) were reached in 24 versus 32% of the patients (p=0.35). Neither vascular patency nor clinical parameters differed during the first year, but re-interventions tended to be more frequent (p=0.040 at 1 month; p=0.090 at 1 year) and of a greater magnitude (p=0.028) in group 2.

CONCLUSIONS

There was no obvious advantage with initial high-dose thrombolysis, which may be a type-2 error. A reduction of major re-interventions was recorded.