Functional and clinical outcomes of nitinol stenting with and without abciximab for complex superficial femoral artery disease: A randomized trial

Full Drug-Eluting Stent Jacket: Two-Year Results of a Single-Center Experience With Zilver PTX Stenting for Long Lesions in the Femoropopliteal Arteries

Purpose: To evaluate the 1- and 2-year patency and reintervention rates with the Zilver PTX drug-eluting stent (DES) in long complex femoropopliteal disease. Methods: A retrospective review was conducted of 89 consecutive patients (mean age 68.7±9.8 years; 86 men) with femoropopliteal occlusive disease (Rutherford category 2–6) treated with the Zilver PTX between December 2012 and December 2013. Mean lesion length for the entire cohort was 24.2±11.3 cm (median 24.0, range 4–48). The patient population was dichotomized into a short lesion (≤20 cm) group (n=41; mean lesion length 13.3±5.6 cm) and the full DES jacket (>20 cm) group (n=48; mean lesion length 33.0±6.5 cm). Primary endpoints were duplex-derived restenosis (peak systolic velocity ratio >2.5), clinically driven reintervention, and major amputation. Results: The incidence of restenosis was lower in the short lesion group at 1 year (19% vs 40% for the longer lesions, p=0.050) and 2 years (39% vs 54%, respectively; p=0.331). The short lesion group had significantly lower rates of reintervention at both 1 year (2% vs 21% in long lesions, p=0.009) and 2 years (12% vs 33%, p=0.019). Conclusion: Treatment of femoropopliteal lesions >20 cm with the Zilver PTX appears to be a clinically effective therapy for patients with symptomatic peripheral artery disease. However, there is an increase in restenosis and a need for reintervention that continues to progress up to 2 years.

Impact of Glycoprotein IIb/IIIa Inhibitors Use on Outcomes After Lower Extremity Endovascular Interventions From Nationwide Inpatient Sample (2006-2011)

OBJECTIVE

The aim of our study was to study the impact of glycoprotein IIb/IIIa inhibitors (GPI) on in-hospital outcomes.

BACKGROUND

There is paucity of data regarding the impact of GPI on the outcomes following peripheral endovascular interventions.

METHODS

The study cohort was derived from Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS) database between the years 2006 and 2011. Peripheral endovascular interventions and GPI utilization were identified using appropriate ICD-9 Diagnostic and procedural codes. Two-level hierarchical multivariate mixed models were created. The study outcomes were: primary (in-hospital mortality and amputation studied separately) and secondary (composite of in-hospital mortality and postprocedural complications). Hospitalization costs were also assessed.

RESULTS

GPI utilization (OR, 95% CI, P-value) was independently predictive of lower amputation rates (0.36, 0.27-0.49, <0.001). There was no significant difference in terms of in-hospital mortality (0.59, 0.31-1.14, P 0.117), although GPI use predicted worse secondary outcomes (1.23, 1.03-1.47, 0.023). Following propensity matching, the amputation rate was lower (3.2% vs. 8%, P < 0.001), while hospitalization costs were higher in the cohort that received GPI ($21,091 ± 404 vs. 19,407 ± 133, P < 0.001).

CONCLUSIONS

Multivariate analysis revealed GPI use in peripheral endovascular interventions to be suggestive of an increase in composite end-point of in-hospital mortality and postprocedural complications, no impact on in-hospital mortality alone, significantly lower rate of amputation, and increase in hospitalization costs. © 2016 Wiley Periodicals, Inc.

Antithrombotic Strategies in Endovascular Interventions: Current Status and Future Directions

Despite increasing numbers of endovascular interventions to treat arterial and venous disease, scant level 1 evidence is available regarding the role of antithrombotic and antiplatelet therapy in patients undergoing these procedures. The current practice in this regard is heterogeneous and has mainly been driven by data from coronary artery disease and percutaneous coronary intervention. This article discusses the role of antithrombotic and antiplatelet agents for endovascular intervention.

Review of Currently Available GP IIb/IIIa Inhibitors and Their Role in Peripheral Vascular Interventions

The glycoprotein IIb/IIIa (GP IIb/IIIa) antagonists are the most recent additions to the antiplatelet agents available to the interventional radiologist. The currently available GP IIb/IIIa antagonists are abciximab, eptifibatide, and tirofiban. These medications have demonstrated excellent safety and efficacy in the setting of coronary arterial interventions. The fundamental benefit of the GP IIb/IIIa antagonists lies in their unique mechanism of action: the ability to prevent platelet aggregation, thrombus formation, and distal thromboembolism while preserving initial platelet binding to damaged vascular surfaces. A paucity of data exists regarding the role of GP IIb/IIIa inhibitors in peripheral vascular interventions. The GP IIb/IIIa antagonists would theoretically provide excellent antiplatelet therapy in patients undergoing any of a variety of endovascular interventions during which thrombosis or thromboembolism may endanger distal perfusion in patients with peripheral vascular disease. The goal of this summary is to review the indications for use, pharmacology, and evidence for efficacy of the GP IIb/IIIa antagonists in hopes of translating these data for application in the peripheral arterial circulation. Further research is necessary to determine how these agents may be safely used in combination with other anticoagulants or with stents, efficacy compared with standard regimens, success at preventing distal thromboembolism, and cost effectiveness.

Antiplatelet and anticoagulant drugs for prevention of restenosis/reocclusion following peripheral endovascular treatment

BACKGROUND

Peripheral arterial disease (PAD) is frequently treated by balloon angioplasty. Restenosis/reocclusion of the dilated segments occurs often, depending on length of occlusion, lower leg outflow, stage of disease and presence of cardiovascular risk factors. To prevent reocclusion, patients are treated with antithrombotic agents. This is an update of a review first published in 2005.

OBJECTIVES

To determine whether any antithrombotic drug is more effective in preventing restenosis or reocclusion after peripheral endovascular treatment, compared to another antithrombotic drug, no treatment, placebo or other vasoactive drugs.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched 14 February 2012) and CENTRAL (2012, Issue 1).

SELECTION CRITERIA

We selected randomised controlled trials (RCTs). Participants were patients with symptomatic PAD treated by endovascular revascularisation of the pelvic or femoropopliteal arteries. Interventions were anticoagulant, antiplatelet or other vasoactive drug therapy compared with no treatment, placebo or any other vasoactive drug. Clinical endpoints were reocclusion, restenosis, amputation, death, myocardial infarction, stroke, major bleeding and other side effects, such as minor bleeding, puncture site bleeding, gastrointestinal side effects and haematoma.

DATA COLLECTION AND ANALYSIS

We independently extracted and assessed details of the number of randomised patients, treatment, study design, patient characteristics and risk of bias. Analysis was based on intention-to-treat data. To examine the effects of outcomes such as reocclusion, restenosis, amputation and major bleeding, we computed odds ratios (OR) with 95% confidence intervals (CI) using a fixed-effect model.

MAIN RESULTS

Twenty-two trials with a total of 3529 patients are included (14 in the original review and a further eight in this update). For the majority of comparisons, only one trial was available so results were rarely combined in meta-analyses. Individual trials were generally small and risk of bias was often unclear due to limitations in reporting. Three trials reported on drug versus placebo/control; results were consistently available for a maximum follow-up of only six months. At six months post intervention, a statistically significant reduction in reocclusion was found for high-dose acetylsalicylic acid (ASA) combined with dipyridamole (DIP) (OR 0.40, 95% CI 0.19 to 0.84), but not for low-dose ASA combined with DIP (OR 0.69, 95% CI 0.44 to 1.10; P = 0.12) nor in major amputations for lipo-ecraprost (OR 0.89, 95% CI 0.44 to 1.80). The remaining trials compared different drugs; results were more consistently available for a longer period of 12 months. At 12 months post intervention, no statistically significant difference in reocclusion/restenosis was detected for any of the following comparisons: high-dose ASA versus low-dose ASA (OR 0.98, 95% CI 0.64 to 1.48; P = 0.91), ASA/DIP versus vitamin K antagonists (VKA) (OR 0.65, 95% CI 0.40 to 1.06; P = 0.08), clopidogrel and aspirin versus low molecular weight heparin (LMWH) plus warfarin (OR 0.31, 95% CI 0.06 to 1.68; P = 0.18), suloctidil versus VKA: reocclusion (OR 0.59, 95% CI 0.20 to 1.76; P = 0.34), restenosis (OR 1.87, 95% CI 0.66 to 5.31; P = 0.24) and ticlopidine versus VKA (OR 0.71, 95% CI 0.37 to 1.36; P = 0.30). Treatment with cilostazol resulted in statistically significantly fewer reocclusions than ticlopidine (OR 0.32, 95% CI 0.13 to 0.76; P = 0.01). Compared with aspirin alone, LMWH plus aspirin significantly decreased occlusion/restenosis (by up to 85%) in patients with critical limb ischaemia (OR 0.15, 95% CI 0.06 to 0.42; P = 0.0003) but not in patients with intermittent claudication (OR 1.73, 95% CI 0.97 to 3.08; P = 0.06) and batroxobin plus aspirin reduced restenosis in diabetic patients (OR 0.28, 95% CI 0.13 to 0.60). Data on bleeding and other potential gastrointestinal side effects were not consistently reported, although there was some evidence that high-dose ASA increased gastrointestinal side effects compared with low-dose ASA, that clopidogrel and aspirin resulted in fewer major bleeding episodes compared with LMWH plus warfarin, and that abciximab resulted in more severe bleeding episodes.

AUTHORS' CONCLUSIONS

There is limited evidence suggesting that restenosis/reocclusion at six months following peripheral endovascular treatment is reduced by use of antiplatelet drugs compared with placebo/control, but associated information on bleeding and gastrointestinal side effects is lacking. There is also some evidence of variation in effect according to different drugs with cilostazol reducing reocclusion/restenosis at 12 months compared with ticlopidine and both LMWH and batroxobin combined with aspirin appearing beneficial compared with aspirin alone. However, available trials are generally small and of variable quality and side effects of drugs are not consistently addressed. Further good quality, large-scale RCTs, stratified by severity of disease, are required.

Ultrasound-guided percutaneous delivery of tissue-engineered endothelial cells to the adventitia of stented arteries controls the response to vascular injury in a porcine model

OBJECTIVE

High restenosis rates are a limitation of peripheral vascular interventions. Previous studies have shown that surgical implantation of a tissue-engineered endothelium onto the adventitia surface of injured vessels regulates vascular repair. In the present study, we developed a particulate formulation of tissue-engineered endothelium and a method to deliver the formulation perivascular to injured blood vessels using a percutaneous, minimally invasive technique.

METHODS

Stainless steel stents were implanted in 18 balloon-injured femoral arteries of nine domestic swine, followed by ultrasound-guided percutaneous perivascular injection of gelatin particles containing cultured allogeneic porcine aortic endothelial cells (PAE). Controls received injections of empty particles (matrix) or no perivascular injection (sham) after stent deployment. Animals were sacrificed after 90 days.

RESULTS

Angiographic analysis revealed a significantly greater lumen diameter in the stented segments of arteries treated with PAE/matrix (4.72 ± 0.12 mm) compared with matrix (4.01 ± 0.20 mm) or sham (4.03 ± 0.16 mm) controls (P < .05). Similarly, histologic analysis revealed that PAE/matrix-treated arteries had the greatest lumen area (20.4 ± 0.7 mm(2); P < .05) compared with controls (16.1 ± 0.9 mm(2) and 17.1 ± 1.0 mm(2) for sham and matrix controls, respectively) and the smallest intimal area (3.3 ± 0.4 mm(2); P < .05) compared with controls (6.2 ± 0.5 mm(2) and 4.4 ± 0.5 mm(2) for sham and matrix controls, respectively). Overall, PAE-treated arteries had a 33% to 50% decrease in percent occlusion (P < .05) compared with controls. Histopathological analysis revealed fewer leukocytes present in the intima in the PAE/matrix group compared with control groups, suggesting that the biological effects were in part due to inhibition of the inflammatory phase of the vascular response to injury.

CONCLUSIONS

Minimally invasive, perivascular delivery of PAE/matrix to stented arteries was performed safely using ultrasound-guided percutaneous injections and significantly decreased stenosis. Application at the time of or subsequent to peripheral interventions may decrease clinical restenosis rates.

Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial: Analysis of amputation free and overall survival by treatment received

BACKGROUND

An intention-to-treat analysis of randomized Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial data showed that initial randomization to a bypass surgery (BSX)-first strategy was associated with improvements in subsequent overall survival (OS) and amputation-free survival (AFS) of about 7 and 6 months, respectively. We describe the nature and timing of first, crossover, and reinterventions and examine AFS and OS by first treatment received. We also compare vein with prosthetic BSX and transluminal with subintimal balloon angioplasty (BAP) and examine outcomes from BSX after failed BAP.

METHODS

We randomly assigned 452 patients with SLI due to infrainguinal disease in 27 United Kingdom hospitals to a BSX first (n = 228) or a BAP first (n = 224) revascularization strategy. All patients have been monitored for 3 years and more than half for >5 years. We prospectively collected data on every procedure, major amputation, and death.

RESULTS

Patients randomized to BAP were more likely to have their assigned treatment first (94% vs 85%, P = .01, chi(2)test). BAP had a higher immediate technical failure rate of 20% vs 2.6% (P = .01, chi(2)test). By 12 weeks after randomization 9 BAP (4%) vs 23 BSX (10%) patients had not undergone revascularization; 3 BAP (1.3%) vs 13 BSX (5.8%) had undergone the opposite treatment first; and 35 BAP (15.6%) and 2 (0.9%) BSX had received the assigned treatment and then undergone the opposite treatment. BSX distal anastomoses were divided approximately equally between the above and below knee popliteal and crural arteries; most originated from the common femoral artery. About 25% of the grafts were prosthetic and >90% of vein BSX used ipsilateral great saphenous vein. Most (80%) BAP patients underwent treatment of the SFA alone (38%) or combined with the popliteal artery (42%) and crural arteries (20%). Outcome of vein BSX was better for AFS (P = 0.003) but not OS (P = 0.38, log-rank tests) than prosthetic BSX. There were no differences in outcome between approximately equal numbers of transluminal and subintimal BAP. AFS (P = 0.006) but not OS (P = 0.06, log rank test) survival was significantly worse after BSX after failed BAP than after BSX as a first revascularization attempt.

CONCLUSIONS

BAP was associated with a significantly higher early failure rate than BSX. Most BAP patients ultimately required surgery. BSX outcomes after failed BAP are significantly worse than for BSX performed as a first revascularization attempt. BSX with vein offers the best long term AFS and OS and, overall, BAP appears superior to prosthetic BSX.

Primary nitinol stenting for femoropopliteal disease

The 1- to 2-year primary patency rates associated with self-expanding nitinol stents for the treatment of symptomatic femoropopliteal disease are superior to those for percutaneous transluminal angioplasty (PTA) and the first-generation stainless steel balloon-expandable stents. The advantages of nitinol stents include improved radial strength and flexibility, the ability to recover from being crushed, reduced foreshortening, and (importantly) deployability without balloon dilation of the stent edge (which may decrease the incidence of the edge stenosis, or "candy-wrap" effect, often observed with balloon-expandable stents). The technical success rate associated with primary deployment of nitinol stents is very high, and acute to 6-month patency results are predictably excellent. Prior to the introduction of nitinol stents, the original guidelines (2000) of the multidisciplinary TransAtlantic Inter-Society Consensus (TASC I) recommended only an adjunctive role for femoropopliteal stents following suboptimal PTA. The abbreviated 2007 TASC II report essentially extended this recommendation to nitinol stents. Here, current trials of nitinol stenting in the femoropopliteal segment are discussed, with emphasis on the advantages of primary (and often direct) deployment in selected circumstances dependent on factors including lesion length, lesion location, indication for treatment (critical limb ischemia or claudication, in-stent restenosis, stent-graft restenosis), and the relative appropriateness of other modalities (e.g., covered stents). Technical considerations in primary nitinol stenting are briefly reviewed. Open questions regarding the factors involved in nitinol stent fracture and the possible association of fracture and restenosis are examined in the context of current clinical trials. A new generation of femoropopliteal nitinol stents combining superior durability and flexibility is expected soon. Development and implementation of uniform reporting and surveillance standards is important for optimizing current and future research.

Medical and endovascular management of critical limb ischemia

Critical limb ischemia (CLI) is the term used to designate the condition in which peripheral artery disease has resulted in resting leg or foot pain or in a breakdown of the skin of the leg or foot, causing ulcers or tissue loss. If not revascularized, CLI patients are at risk for limb loss and for potentially fatal complications from the progression of gangrene and the development of sepsis. The management of CLI requires a multidisciplinary team of experts in different areas of vascular disease, from atherosclerotic risk factor management to imaging, from intervention to wound care and physical therapy. In the past decade, the most significant change in the treatment of CLI has been the increasing tendency to shift from bypass surgery to less invasive endovascular procedures as first-choice revascularization techniques, with bypass surgery then reserved as backup if appropriate. The goals of intervention for CLI include the restoration of pulsatile, inline flow to the foot to assist wound healing, the relief of rest pain, the avoidance of major amputation, preservation of mobility, and improvement of patient function and quality of life. The evaluating physician should be fully aware of all revascularization options in order to select the most appropriate intervention or combination of interventions, while taking into consideration the goals of therapy, risk-benefit ratios, patient comorbidities, and life expectancy. We discuss the incidence, risk factors, and prognosis of CLI and the clinical presentation, diagnosis, available imaging modalities, and medical management (including pain and ulcer care, pharmaceutical options, and molecular therapies targeting angiogenesis). The endovascular approaches that we review include percutaneous transluminal angioplasty (with or without adjunctive stenting); subintimal angioplasty; primary femoropopliteal and infrapopliteal deployment of bare nitinol, covered, drug-eluting, or bioabsorbable stents; cryoplasty; excimer laser-assisted angioplasty; excisional atherectomy; and cutting balloon angioplasty.

Atherectomy for infrainguinal peripheral artery disease

Compared to conventional percutaneous transluminal angioplasty (PTA) and stent implantation for arterial occlusive diseases, atherectomy offers the theoretical advantages of eliminating stretch injury on arterial walls and reducing the, rate of restenosis. Historically, however, neither rotational nor directional atherectomy, whether used alone or with adjunctive PTA, has shown any significant long-term benefit over PTA alone in the coronary or peripheral arteries. However, the SilverHawk Plaque Excision System has produced positive results in single-center prospective registries of patients with femoropopliteal and infrainguinal lesions, with reduced adjunctive PTA, minimal adjunctive stenting, and competitive 6-month and 12-month patency rates. In the observational nonrandomized TALON (Treating Peripherals with SilverHawk: Outcomes Collection) registry, freedom from target lesion revascularization was 80% for 87 patients at 12 months. Questions remaining for further research with this device include more accurate determination of an event rate for distal embolization, the appropriate use of distal protection, the value of and appropriate circumstances for adjunctive angioplasty, and definitive patency and clinical outcomes. Other atherectomy devices are discussed.

Atualização sobre endopróteses vasculares (stents): dos estudos experimentais à prática clínica

Atualmente, o tratamento das doenças vasculares periféricas é uma das áreas da medicina de maior expansão. O número de intervenções vasculares aumenta e os resultados das novas técnicas endovasculares estão muito próximos aos das tradicionais cirurgias vasculares. Embora a angioplastia ofereça bons resultados em curto prazo, o implante de stents procura melhorar o sucesso do procedimento e estender o seu uso a um número maior de pacientes com doença vascular periférica. Entretanto, a sua utilização ainda é controversa. O implante de stents no sistema aorto-ilíaco tem bons resultados; porém, a sua indicação para as lesões femoro-poplíteas ainda é discutida. Além disso, o rápido desenvolvimento de stents e sua escolha para uso no sistema vascular periférico têm sido uma difícil tarefa para o cirurgião endovascular. Muitos fatores influenciam a escolha do stent, e um amplo conhecimento desse material é essencial. Tal escolha depende da avaliação pré-operatória, da localização e das características da lesão e também do uso do stent primário ou seletivo. Nesse trabalho, são realizadas revisão do histórico do desenvolvimento dos stents, desde os estudos experimentais até os ensaios clínicos e também discussão sobre a sua aplicação no tratamento das doenças vasculares periféricas.

Long-term follow-up of Symphony nitinol stents in iliac arteriosclerosis obliterans

The purpose of this study was to evaluate the long-term results of iliac artery stent placement with use of the symphony stent for the treatment of patients with intermittent claudication. In a prospective study, 31 cases of iliac occlusive arterial disease were treated in 26 patients. Stenoses (n = 27) were treated after failed angioplasty, and occlusions (n = 4) were treated with primary stent placement. Clinical history, clinical stage and the ankle brachial-index (ABI) examination measurement were assessed. The patients were followed up with clinical examination, ABI examination measurement and intravenous angiography. The follow-up period ranged between 9.5 months and 7.5 years (median = 5.9 yr). Data were analyzed using the univariate analysis (Kaplan-Meier method). The mean+/-SD ABI pre-, post-procedure and in the last control was 0.70+/-0.17, 0.97+/-0.15, and 0.96+/-0.20, respectively. Primary patency rates (%) +/- SE were 83+/-7 after 3 years, 75+/-8 after five years, and 67+/-9 after seven years, and secondary patency rates were 93+/-5 after three years, 86+/-7 after five years, and 86+/-7 after seven years. During the first 24 hours, one patient presented occlusion of the treated segment. During follow-up, 9 (29%) patients were admitted to our hospital because of worsening of the symptoms. In this study, the symphony stent has been proven to be a good device to treat lesions in the iliac region but more experience is needed to optimize endovascular treatment in this area. In our experience the treatment of iliac artery occlusive disease with symphony stents can be considered a good option with acceptable patency rates and low morbidity and mortality.

Performance goals and endpoint assessments for clinical trials of femoropopliteal bare nitinol stents in patients with symptomatic peripheral arterial disease

OBJECTIVE

This analysis proposes safety and performance goals for prospective single-arm trials of bare nitinol stents to treat patients with debilitating claudication associated with femoropopliteal (FP) atherosclerotic lesions.

BACKGROUND

To date there have been no analyses of clinical trials data to set efficacy and safety benchmarks for new bare nitinol stents in the treatment of claudication from FP disease. Industry has been reluctant to sponsor studies of nitinol stents due to logistical barriers.

METHODS

VIVA Physician's, Inc. (VPI) analyzed subject-level data from the PTA control arm of three randomized FDA device trials conducted by industry. Subjects with Rutherford category 2-4 claudication and FP lesion lengths 4-15 cm with 12 month duplex ultrasound (DUS) assessment were identified. These data were combined with the results of a survey of the medical literature (1990-2006) for similar subjects.

RESULTS

Analysis of the industry derived control arm PTA data identified 116 patients (mean lesion length 8.7 cm) with a 12 month DUS defined FP patency of 28%. A similar cohort of 191 patients was identified from the medical literature in which the 12-month vessel patency equaled 37%; from these combined patient cohorts, expected vessel patency for PTA was estimated to equal 33%.

CONCLUSION

Based on the PTA performance efficacy rate of 33% derived from industry clinical trial data and the medical literature, and the requirement that the bare nitinol stent 12-month efficacy performance goal be set to equal twice this rate, the patency efficacy goal equals 66%. Additional information is provided on safety and other reporting standards and stent integrity evaluation for bare metal stents.

Standardized evaluation and reporting of stent fractures in clinical trials of noncoronary devices

OBJECTIVES

Define the prospective surveillance and reporting parameters for assessment of metallic stents used in clinical trials of superficial femoral artery atherosclerosis.

BACKGROUND

While advances in medical therapies to improve atherosclerotic risk factor profiles in patients with peripheral arterial disease have focused on prevention of disease progression, the development of endovascular devices is altering the therapeutic algorithm for patients with peripheral arterial disease. Stents have emerged as one of the advances that may promote durable patency, particularly in the infrainguinal arteries.

METHODS

The Zilver-PTX is a prospective multicenter randomized trial of bare metal versus drug-eluting nitinol stents for superficial femoral artery peripheral arterial disease. A predefined surveillance program is mandated in this trial. During the genesis of this program, it became clear that no single standard has existed to identify, classify, and report fractures of metallic stents placed in peripheral arteries.

RESULTS

This report defines the key components of prospective stent fracture surveillance, including location of radiographic images obtained, types of radiographic equipment, methods of limb, and image intensifier positioning, intervals required for imaging, grading schemes for reporting, and methods of analyzing the images.

CONCLUSIONS

As the proliferation of minimally invasive revascularization strategies continues, the stability of metallic endoprostheses is increasingly critical. Uniform surveillance of these devices for fracture and disarticulation is important in order to compare the relative merits of various stent-based devices in clinical trials.

Stenting in the Femoropopliteal Arterial Segment

In the femoropopliteal arterial segment, balloon angioplasty is a recommended treatment strategy for short lesions. Over the past few years, several reports have emerged on the potential role of self-expanding stents for treating longer, more complex disease segments where the patency following balloon angioplasty is notoriously dismal. This paper will attempt to review the emerging role of nitinol stents for treating patients with chronic lower limb ischemia, secondary to severe femoropopliteal arterial disease.

The Use of Femoropopliteal Stent-Grafts for Critical Limb Ischemia

Peripheral vascular disease of the femoropopliteal segment is one of the most common anatomic locations leading to patient symptoms. Traditional open surgical bypass has started to be supplanted by a surge in lower risk endovascular procedures. Though midterm results of endovascular therapy have been acceptable, longer term results, especially in long diffuse disease, appear to be less durable than their surgical alternatives. Recently the Viabahn, a percutaneously placed PTFE stent-graft, has been approved for use in the femoropopliteal artery. Though the majority of the data for this stent-graft has been derived from patients with complex (>10 cm length) lesions, most of the patients have been claudicants. The population with critical limb ischemia is at particularly high risk for cardiovascular mortality and may benefit from this less invasive approach. However, stent-graft utilization is more complex and many variables must be evaluated before and during the procedure to allow for optimal procedural outcomes.