Three-year results of the VIBRANT trial of VIABAHN endoprosthesis versus bare nitinol stent implantation for complex superficial femoral artery occlusive disease

Peripheral Artery Disease: Evolving Role of Exercise, Medical Therapy, and Endovascular Options

The prevalence of peripheral artery disease (PAD) continues to increase worldwide. It is important to identify patients with PAD because of the increased risk of myocardial infarction, stroke, and cardiovascular death and impaired quality of life because of a profound limitation in exercise performance and the potential to develop critical limb ischemia. Despite effective therapies to lower the cardiovascular risk and prevent progression to critical limb ischemia, patients with PAD continue to be under-recognized and undertreated. The management of PAD patients should include an exercise program, guideline-based medical therapy to lower the cardiovascular risk, and, when revascularization is indicated, an "endovascular first" approach. The indications and strategic choices for endovascular revascularization will vary depending on the clinical severity of the PAD and the anatomic distribution of the disease. In this review, we discuss an evidence-based approach to the management of patients with PAD.

Techniques in Vascular and Interventional Radiology Drug Delivery Technologies in the Superficial Femoral Artery

Peripheral arterial disease (PAD) affects over 8 million people in the United States alone. Although great strides have been made in reducing the burden of cardiovascular disease the prevalence of PAD is expected to rise with the age of global population. PAD characterized by narrowing of arterial blood can be asymptomatic or cause limb threatening claudication. It has been classically treated with bypass, but these techniques have been supplanted by endovascular therapy. Plain old balloon angioplasty has been successful in helping revascularize lesions, but its effect has not been durable because of restenosis. This prompted the creation of several technologies aimed at reducing restenosis. These advances slowly improved outcomes and the durability of endovascular management. Among the main tools used in current endovascular practice are drug-delivery devices aimed at inhibiting the inflammatory and proliferative pathways that lead to restenosis. This article examines the current drug-delivery technologies used in the superficial femoral artery.

Endovascular placement of an extraluminal arterial bypass graft - in vitro feasibility study

PURPOSE

A novel approach for arterial bypass grafting using exclusively endovascular techniques was established in-vitro in a phantom model.

MATERIAL AND METHODS

The experimental setting consisted of a gel-wax phantom with two embedded parallel fluid-filled silicon tubes simulating the superficial femoral vessels. Through an 8-French sheath, a re-entry catheter (OUTBACK^®, Cordis) was placed in the simulated artery and used to puncture the vascular wall. Then a 0.014-inch guide wire was advanced into the extravascular space. With the curved needle of the re-entry catheter, the guide wire was steered on a course parallel to the vessel wall in the extravascular space for 5-10 cm. At the desired reentry site, the re-entry catheter was used to puncture the vascular wall again in order to regain access to the endovascular space. Once the tip of the guide wire had safely been placed in the vascular lumen, a self-expandable stent graft (VIABAHN^® GORE^®) was deployed to complete the extraluminal bypass.

RESULTS

Endovascular placement of an extraluminal bypass was successfully achieved in 20 attempts. The mean duration of the procedure amounted to 14:58 (minutes: seconds) (SD ± 3:56).

CONCLUSIONS

This in-vitro study suggests that endovascular placement of an extraluminal arterial bypass graft is technically feasible.

The Mid-Term Clinical Follow-Up Using Drug-Eluting Balloons on Tibial Artery "De Novo" Lesions in Patients With Critical Limb Ischemia: A Cohort Study

RATIONALE

Restenosis due to intimal hyperplasia (IH) is a major clinical issue that affects the success of lower limb endovascular surgery. After 1 year, restenosis occurs in 40% to 60% of the treated vessels. The possibility to reduce IH using local antiproliferative drugs, such as taxols, has been the rationale for the clinical applications of drug-eluting stents and drug-eluting balloons (DEBs). The purpose of this study was to evaluate the clinical and instrumental efficacy of DEBs versus simple percutaneous transluminal angioplasty (PTA) in patients affected by chronic limb ischemia (CLI) with tibial artery "de novo" lesions.

METHODS

A retrospective analysis was performed and included all consecutive patients who underwent endovascular treatment for CLI in our centers between January 2011 and March 2013. Inclusion criteria were (1) "de novo" tibial artery stenosis and (2) Rutherford class >4. Lesions were further divided by TransAtlantic Inter-Societal Consensus (TASC) classification into groups A, B, C, and D.

RESULTS

Between January 2010 and March 2013, a total of 138 patients underwent simple PTA or DEB for CLI, and the groups were clinically and demographically homogenous. We decided to use DEBs in 70 cases. An improvement in the Rutherford Scale in cumulative and single TASC lesions classification was better in the DEB group (74% vs 51%; P = .024) at 24 months than in the PTA group. In the DEB group, the increase in ankle-brachial index was significantly higher than in the PTA group (P = .039).

CONCLUSIONS

Our experience in addition to the existing literature supports the use of DEB in patients with CLI Rutherford class >3.

Durable Clinical Effectiveness With Paclitaxel-Eluting Stents in the Femoropopliteal Artery: 5-Year Results of the Zilver PTX Randomized Trial

Background—

This randomized controlled trial evaluated clinical durability of Zilver PTX, a paclitaxel-coated drug-eluting stent (DES), for femoropopliteal artery lesions. Outcomes compare primary DES versus percutaneous transluminal angioplasty (PTA), overall DES (primary and provisional) versus standard care (PTA and provisional Zilver bare metal stent [BMS]), and provisional DES versus provisional BMS.

Methods and Results—

Patients with symptomatic femoropopliteal artery disease were randomly assigned to DES (n=236) or PTA (n=238). Approximately 91% had claudication; 9% had critical limb ischemia. Patients experiencing acute PTA failure underwent secondary randomization to provisional BMS (n=59) or DES (n=61). The 1-year primary end points of event-free survival and patency showed superiority of primary DES in comparison with PTA; these results were sustained through 5 years. Clinical benefit (freedom from persistent or worsening symptoms of ischemia; 79.8% versus 59.3%, P<0.01), patency (66.4% versus 43.4%, P<0.01), and freedom from reintervention (target lesion revascularization, 83.1% versus 67.6%, P<0.01) for the overall DES group were superior to standard care in nonrandomized comparisons. Similarly, clinical benefit (81.8% versus 63.8%, P=0.02), patency (72.4% versus 53.0%, P=0.03), and freedom from target lesion revascularization (84.9% versus 71.6%, P=0.06) with provisional DES were improved over provisional BMS. These results represent >40% relative risk reduction for restenosis and target lesion revascularization through 5 years for the overall DES in comparison with standard care and for provisional DES in comparison with provisional BMS.

Conclusions—

The 5-year results from this large study provide long-term information previously unavailable regarding endovascular treatment of femoropopliteal artery disease. The Zilver PTX DES provided sustained safety and clinical durability in comparison with standard endovascular treatments.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00120406.

Wire-Interwoven Nitinol Stent Outcome in the Superficial Femoral and Proximal Popliteal Arteries: Twelve-Month Results of the SUPERB Trial

BACKGROUND

Stent-based therapy in the superficial femoral and popliteal arteries in patients with peripheral artery disease is compromised by restenosis and risk of stent fracture or distortion. A novel self-expanding nitinol stent was developed that incorporates an interwoven-wire design (Supera stent, IDEV Technologies, Inc, Webster, TX) to confer greater radial strength, flexibility, and fracture resistance.

METHODS AND RESULTS

This prospective, multicenter, investigational device exemption, single-arm trial enrolled 264 patients with symptomatic peripheral artery disease undergoing percutaneous treatment of de novo or restenotic lesions of the superficial femoral or proximal popliteal (femoropopliteal) artery. Freedom from death, target lesion revascularization, or any amputation of the index limb at 30 days (+ 7 days) postprocedure was achieved in 99.2% (258/260) of patients (P < 0.001). Primary patency at 12 months (360 ± 30 days) was achieved in 78.9% (180/228) of the population (P < 0.001). Primary patency by Kaplan-Meier analysis at 12 months (360 days) was 86.3%. No stent fracture was observed by independent core laboratory analysis in the 243 stents (228 patients) evaluated at 12 months. Clinical assessment at 12 months demonstrated improvement by at least 1 Rutherford-Becker category in 88.7% of patients.

CONCLUSIONS

The SUPERB Trial, an investigational device exemption study using an interwoven nitinol wire stent in the femoropopliteal artery, achieved the efficacy and safety performance goals predesignated by the Food and Drug Administration. On the basis of the high primary patency rate, absence of stent fracture, and significant improvements in functional and quality-of-life measures, the Supera stent provides safe and effective treatment of femoropopliteal lesions in symptomatic patients with peripheral artery disease.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00933270.

[Stent-assisted recanalization of femoropopliteal arterial occlusive disease. Influence of stent design on patency rates]

BACKGROUND

Despite enormous technical progress the results of endovascular treatment of the femoropopliteal vasculature are unsatisfactory and its role is still controversially discussed. In the past decade numerous new stent designs have come onto the market but it is unclear whether they have benefits with respect to patency rates.

OBJECTIVES

Comparison of published data on patency rates and target lesion revascularization rates after use of different stent designs in the femoropopliteal vasculature.

MATERIAL AND METHODS

Analysis of 25 published studies and registries from 2006 to 2015 for classical open-cell stents, interwoven stents and partially or fully covered stents.

RESULTS AND CONCLUSION

The published data are heterogeneous and comparative studies for different stent designs are completely missing. Over the past decade the patency rates after femoropopliteal stenting could be improved. According to available data stenting of short lesions < 5 cm does not show any benefit compared to isolated balloon angioplasty. Primary stenting is now recommended for intermediate and longer lesions > 6.4 cm. Due to the heterogeneity of published data a clear benefit for a specific stent design is not obvious; however, data for interwoven stents are promising and show a tendency towards improved patency, at least for certain lesions. Randomized controlled comparative trials are needed to confirm this result.

Comparison between superficial femoral artery stenting and bypass surgery in severe lower-limb ischaemia: a retrospective study

BACKGROUND

Symptomatic femoro-popliteal disease is treated by bypass surgery or angioplasty with or without stenting. The aim of this study was to compare the results of stenting and bypass surgery with regard to limb salvage in patients with severe leg ischaemia.

METHODS

A total of 213 patients with femoro-popliteal disease presenting with severe claudication or critical limb ischaemia between January 2009 and December 2013 were evaluated; 118 patients (139 limbs) had stents placed and 95 patients (104 limbs) had bypass surgery. Most (60%) presented with critical limb ischaemia (rest pain 40%, tissue necrosis 20%), and the remainder with severe claudication. The treatment groups had matching risk factors.

RESULTS

The average age was 66 years and 73% were male. Tissue necrosis was found in 26% of the stent group and 12% of the bypass group (p = 0.009). In the stent group 26% had adjunctive procedures, compared to 16% in the bypass group (p = 0.138). During the one-year follow up, there were 30 stent occlusions (22%) and 18 graft occlusions (17%) (p = 0.42). There were 14 major amputations (10%) in the stent group, and 13 (13%) in the bypass group (p = 0.68). Limb salvage rate was 90% in the stent group, and 88% in the bypass group (p = 0.68). There were no peri-operative deaths in the stent group, but one in the bypass group (1%). One-year mortality rate was equal (8%) in both groups (p = 1.00).

CONCLUSION

One-year outcome was comparable in both groups with regard to mortality, stent or graft patency and limb salvage rates.

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

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

Treating on the edge

Treatment of stent graft edge restenosis can be successfully treated but optimal treatment has not been identified. The practice of continued duplex surveillance for stent grafts appears to be important. Randomized trials comparing drug technology and to properly sized stent graft extension will be needed.

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

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

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

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

Endovascular intervention for peripheral artery disease

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

Supera self-expanding stents for endovascular treatment of femoropopliteal disease: a review of the clinical evidence

Femoropopliteal lesions account for a significant proportion of endovascular interventions for peripheral artery disease in patients with disabling claudication or chronic limb ischemia. The femoropopliteal artery crosses two joint structures (hip and knee joints) and courses through the muscular adductor canal in the thigh, which places the artery at increased biomechanical stress. There is a critical need for stent platforms with a reduced risk of stent fracture while maintaining patency during long-term follow-up. The Supera peripheral stent system has a braided nickel–titanium alloy stent designed to withstand the unique stressors along the course of the femoropopliteal artery. This design may be associated with improved patency in association with reduced stent fracture rates on short- and medium-term follow-up. Further studies, including randomized controlled studies, comparing the Supera interwoven nickel–titanium alloy stent system with other stent platforms and angioplasty alone are needed.

A single stent strategy in patients with lifestyle limiting claudication: 3-year results from the Durability II trial

OBJECTIVES

To evaluate longer-term safety and efficacy of a single self-expanding stent up to 20 cm in length in patients with atherosclerotic disease of the superficial femoral (SFA) and proximal popliteal arteries.

BACKGROUND

Angioplasty and stenting are options for revascularization of symptomatic peripheral artery disease. While angioplasty alone is effective in short lesions, outcomes in longer lesions (i.e., mean 8.7 cm) show suboptimal patency rates of 33% at one year.

METHODS

Two hundred eighty-seven patients (mean age 68 years, 66% male) were treated with the EverFlex™ Self-Expanding Peripheral Stent System. Patients were followed through 3 years with yearly core lab adjudicated duplex ultrasonography for patency, radiographic assessment of stent fractures, and resting ankle brachial indices.

RESULTS

Overall freedom from loss of primary patency at 3 years was 60.0%. Patency was significantly higher for lesions ≤8 cm compared with lesions >8 cm (71.0 vs. 50.5%, P < 0.0001). There was no significant difference in patency between single-stent and multistent recipients (60.4 vs. 52.4%, P = 0.343). The three-year freedom from clinically driven target lesion revascularization was 70.0%. At 3 years, the overall stent fracture rate was 0.9%.

CONCLUSIONS

DURABILITY II is the first investigational device exemption trial to report 3-year duplex Doppler defined stent patency and CD-TLR outcomes in long SFA and proximal popliteal lesions and demonstrated acceptable stent patency and freedom from CD-TLR with a low fracture rate. These data suggest that use of a single long stent provides reasonable long-term outcomes when intervention is required for symptomatic SFA and proximal popliteal arterial disease.

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

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

Stenting of femoropopliteal lesions using interwoven nitinol stents

OBJECTIVE

The Supera stent (Abbott Laboratories, Abbott Park, Ill) has a unique biomimetic design allowing axial and longitudinal flexibility and fracture resistance. The aim of this retrospective study was to assess the midterm patency of Supera stents used to treat patients with superficial femoral and popliteal arterial disease by a single practice.

METHODS

From April 2010 to December 2011, 53 patients and 59 limbs with symptomatic femoropopliteal lesions underwent angioplasty and stenting with the Supera stent. Five patients had no follow-up and were excluded. Demographics of the patients, radiographic images, morphologic features of the lesions, procedural reports, reinterventions, and follow-up clinical visit notes were reviewed. Primary patency was defined as clinical resolution of symptoms with no secondary interventions. Primary and secondary patency rates at 12, 24, and 36 months were estimated by Kaplan-Meier analysis.

RESULTS

A total of 48 patients (42 men, six women; 54 limbs; mean age, 64.3 years [range, 51-87]) received Supera stents and had at least one follow-up visit as part of their treatment for femoropopliteal disease. Primary indications for intervention included claudication, rest pain, and tissue loss, at rates of 54% (29 of 54), 26% (14 of 54), and 20% (11 of 54), respectively; 22% of lesions were TransAtlantic Inter-Society Consensus type A or B and 78% were type C or D. Mean lesion length was 24.0 cm (range, 3-51). Mean follow-up was 27.5 months (range, 1-45). The ankle-brachial index increased from 0.58 ± 0.20 preoperatively to 0.77 ± 0.18 postoperatively (P = .00004). Primary, primary assisted, and secondary patency rates at latest follow-up were 79.6%, 88.9%, and 92.3%, respectively. Cumulative primary patency rates by Kaplan-Meier analysis at 12, 24, and 36 months were 85.6%, 83.1%, and 76.7%, respectively. Secondary patency rates by Kaplan-Meier estimates at 12, 24, and 36 months were 93.8%, 93.8%, and 89.3%, respectively. No stent fractures were found at the time of any reinterventions. Long lesions >30 cm (n = 18) showed equivalent patency to lesions of 1 to 15 cm (n = 18) and lesions 15 to 30 cm in length (n = 18).

CONCLUSIONS

Our midterm results show that Supera stents are durable in treating femoropopliteal lesions, with notably high patency rates in patients with long lesion lengths.

Covered stents for endovascular repair of iatrogenic injuries of iliac and femoral arteries

BACKGROUND

The growing number of complex endovascular procedures is expected to increase the risk of iatrogenic injuries of peripheral arteries. A strategy of percutaneous transluminal angioplasty (PTA) with covered stent (CS) may represent a valuable alternative to open surgery. However, systematic evaluations of CS in this setting represent a scientific gap. In the present study, we investigate the procedural and clinical outcomes associated with PTA and CS implantation to repair iatrogenic injuries of peripheral arteries.

METHODS

All patients undergoing PTA with CS for endovascular repair of iatrogenic injuries of peripheral arteries between August 2010 and July 2013 at our Institution were retrospectively analyzed. The primary endpoint was the technical success. Secondary endpoints were in-hospital mortality and cumulative death, target lesion revascularization (TLR), amputation and major stroke at 12-month follow-up.

RESULTS

During the period of observation, a total of 30 patients underwent PTA with either self-expandable (43.3%) or balloon-expandable CS (56.7%) for iatrogenic injuries of peripheral arteries. Injuries consisted of perforation/rupture (76.7%), arteriovenous fistula (16.7%) and pseudoaneurysm (6.7%) of iliac-femoral arteries. Technical success was achieved in all cases. Median follow-up was 409days [210-907]. The incidence of in-hospital mortality was 10.0%. At 12-month follow-up, the incidence of death, TLR, amputation and major stroke was 20.0%, 17.0%, 3.3% and 6.7%, respectively.

CONCLUSION

The use of covered stents for endovascular repair of iatrogenic injuries of peripheral arteries shows a high technical success and may be alternative to surgery. Further studies with larger populations are needed to confirm these preliminary findings.

Stent Placement vs. Balloon Angioplasty for Popliteal Artery Treatment

Purpose: To investigate the 2-year technical and clinical results of primary nitinol stent placement in comparison with percutaneous transluminal angioplasty (PTA) in the treatment of de novo lesions of the popliteal artery. Methods: The ETAP study (Endovascular Treatment of Atherosclerotic Popliteal Artery Lesions: balloon angioplasty vs. primary stenting; www.ClinicalTrials.gov identifier NCT00712309) is a prospective, randomized trial that enrolled 246 patients (158 men; mean age 72 years) who were randomly assigned to receive a nitinol stent (n=119) or PTA (n=127) for lesions averaging 42.3 mm in length. The results of the primary study endpoint were published. Secondary outcome measures and endpoints included primary patency (freedom from duplex-detected target lesion restenosis), target lesion revascularization (TLR), secondary patency, changes in ankle-brachial index and Rutherford class, and event-free survival (freedom from target limb amputation, TLR, myocardial infarction, and death). Results: In total, 183 patients (89 stent and 94 PTA) were available for the 2-year analysis. The primary patency rate was significantly higher in the stent group (64.2%) than in the PTA group (31.3%, p=0.0001). TLR rates were 22.4% and 59.5%, respectively (p=0.0001). When provisional stent placement in the PTA arm was not considered as TLR and loss in patency, the differences prevailed between the study groups but were not significant (64.2% vs. 56.1% for primary patency, respectively; p=0.44). A significant improvement in ABI and Rutherford category was observed at 2 years in both groups. Conclusion: In treatment of obstructive popliteal artery lesions, provisional stenting reveals equivalent patency in comparison to primary stenting. However, the 2-year results of this trial suggest the possibility of a shift toward higher patency rates in favor of primary stenting.

Society for Vascular Surgery practice guidelines for atherosclerotic occlusive disease of the lower extremities: management of asymptomatic disease and claudication

Peripheral arterial disease (PAD) continues to grow in global prevalence and consumes an increasing amount of resources in the United States health care system. Overall rates of intervention for PAD have been rising steadily in recent years. Changing demographics, evolution of technologies, and an expanding database of outcomes studies are primary forces influencing clinical decision making in PAD. The management of PAD is multidisciplinary, involving primary care physicians and vascular specialists with varying expertise in diagnostic and treatment modalities. PAD represents a broad spectrum of disease from asymptomatic through severe limb ischemia. The Society for Vascular Surgery Lower Extremity Practice Guidelines committee reviewed the evidence supporting clinical care in the treatment of asymptomatic PAD and intermittent claudication (IC). The committee made specific practice recommendations using the GRADE (Grades of Recommendation Assessment, Development and Evaluation) system. There are limited Level I data available for many of the critical questions in the field, demonstrating the urgent need for comparative effectiveness research in PAD. Emphasis is placed on risk factor modification, medical therapies, and broader use of exercise programs to improve cardiovascular health and functional performance. Screening for PAD appears of unproven benefit at present. Revascularization for IC is an appropriate therapy for selected patients with disabling symptoms, after a careful risk-benefit analysis. Treatment should be individualized based on comorbid conditions, degree of functional impairment, and anatomic factors. Invasive treatments for IC should provide predictable functional improvements with reasonable durability. A minimum threshold of a >50% likelihood of sustained efficacy for at least 2 years is suggested as a benchmark. Anatomic patency (freedom from restenosis) is considered a prerequisite for sustained efficacy of revascularization in IC. Endovascular approaches are favored for most candidates with aortoiliac disease and for selected patients with femoropopliteal disease in whom anatomic durability is expected to meet this minimum threshold. Conversely, caution is warranted in the use of interventions for IC in anatomic settings where durability is limited (extensive calcification, small-caliber arteries, diffuse infrainguinal disease, poor runoff). Surgical bypass may be a preferred strategy in good-risk patients with these disease patterns or in those with prior endovascular failures. Common femoral artery disease should be treated surgically, and saphenous vein is the preferred conduit for infrainguinal bypass grafting. Patients who undergo invasive treatments for IC should be monitored regularly in a surveillance program to record subjective improvements, assess risk factors, optimize compliance with cardioprotective medications, and monitor hemodynamic and patency status.

S.M.A.R.T. self-expanding nitinol stent for the treatment of atherosclerotic lesions in the superficial femoral artery (STROLL): 1-year outcomes

PURPOSE

To assess safety and efficacy of the S.M.A.R.T. Vascular Stent System (Cordis Corp, Fremont, California) in obstructive superficial femoral artery (SFA) disease.

MATERIALS AND METHODS

The single-arm, multicenter STROLL study (S.M.A.R.T. Nitinol Self-Expanding Stent in the Treatment of Obstructive Superficial Femoral Artery Disease) included 250 patients (250 lesions in SFA or proximal popliteal artery). The efficacy endpoint was primary patency defined by freedom from binary restenosis (peak systolic velocity ratio > 2.5) as derived by duplex ultrasound plus clinically driven target lesion revascularization (TLR) at 12 months.

RESULTS

Mean age of patients was 67.7 years ± 10.3; 47.2% of patients had diabetes; distribution of Rutherford/Becker classes 2, 3, and 4 was 45.8%, 51.4%, and 2.8%. Mean lesion length and reference vessel diameter were 77.3 mm ± 35.3 and 4.9 mm ± 0.7, respectively (23.6% cases with total occlusions). The 30-day freedom from major adverse events (death, index limb amputation, clinically driven TLR) was 100%. The 1-year primary patency was 81.7% by Kaplan-Meier estimate. The presence of diabetes or total occlusion had no effect on primary patency. Ankle-brachial index was 0.4-0.8 in 84.6% of patients at baseline and improved to > 0.8 in 81.0% of patients at 12 months. The proportion of patients in Rutherford/Becker class 3-4 was reduced from 54.2% at baseline to 8.0% at 12 months. Four patients (2.0%) experienced single-stent strut fracture (type I) at 1 year, without associated loss of stent patency.

CONCLUSIONS

The S.M.A.R.T. Vascular Stent System proved to be safe and effective for endovascular treatment of obstructive SFA and proximal popliteal artery disease, based on 1-year vessel patency and associated hemodynamic and clinical improvements.

A successful experimental model for intimal hyperplasia prevention using a resveratrol-delivering balloon

OBJECTIVE

Restenosis due to intimal hyperplasia is a major clinical problem that compromises the success of angioplasty and endovascular surgery. Resveratrol (RSV) has demonstrated a beneficial effect on restenosis from angioplasty. Unfortunately, the physicochemical characteristics of RSV reduce the practicality of its immediate clinical application. This work proposes an experimental model aiming to setup an intravessel, elutable, RSV-containing compound.

METHODS

A 140 μg/mL RSV sterile injectable solution with a suitable viscosity for intravascular administration by drug-delivery catheter (RSV-c) was prepared. This solution was locally administered in the common iliac artery of adult male New Zealand White rabbits using a dedicated device (Genie; Acrostak, Geneva, Switzerland) after the induction of intimal hyperplasia by traumatic angioplasty. The RSV concentrations in the wall artery were determined, and the thickness of the harvested iliac arteries was measured over a 1-month period.

RESULTS

The Genie catheter was applied in rabbit vessels, and the local delivery resulted in an effective reduction in restenosis after plain angioplasty. Notably, RSV-c forced into the artery wall by balloon expansion might accumulate in the interstitial areas or within cells, avoiding the washout of solutions. Magnification micrographs showed intimal proliferation was significantly inhibited when RSV-c was applied. Moreover, no adverse events were documented in in vitro or in vivo studies.

CONCLUSIONS

RSV can be advantageously administered in the arterial walls by a drug-delivery catheter to reduce the risk of restenosis.

Optimal management of infrainguinal arterial occlusive disease

Peripheral arterial occlusive disease is becoming a major health problem in Western societies as the population continues to age. In addition to risk of limb loss, the complexity of the disease is magnified by its intimate association with medical comorbidity, especially cardiovascular and cerebrovascular disease. Risk factor modification and antiplatelet therapy are essential to improve long-term survival. Surgical intervention is indicated for intermittent claudication when a patient’s quality of life remains unacceptable after a trial of conservative therapy. Open reconstruction and endovascular revascularization are cornerstone for limb salvage in patients with critical limb ischemia. Recent advances in catheter-based technology have made endovascular intervention the preferred treatment approach for infrainguinal disease in many cases. Nevertheless, lower extremity bypass remains an important treatment strategy, especially for reasonable risk patients with a suitable bypass conduit. In this review, we present a summary of current knowledge about peripheral arterial disease followed by a review of current, evidence-based medical and surgical therapy for infrainguinal arterial occlusive disease.

Contemporary Management of Femoral Popliteal Revascularization

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

Defining risks and predicting adverse events after lower extremity bypass for critical limb ischemia

Successful treatment of patients with critical limb ischemia (CLI), hinges on the adequacy of revascularization. However, CLI is associated with a severe burden of systemic atherosclerosis, and patients often suffer from multiple cardiovascular comorbidities. Therefore, CLI patients in general represent a cohort at increased risk for procedural complications and adverse events. Although endovascular therapy represents a minimally invasive alternative to open surgical bypass, the durability of surgical reconstruction is superior, and it remains the "gold standard" approach to revascularization in CLI. Therefore, selection of the optimal treatment modality for individual patients requires careful consideration of the procedural risks and likelihood of adverse events associated with surgery. Individualized decision-making with regard to revascularization strategy requires a comprehensive understanding of the likelihood of adverse outcomes after major surgery. Here we review the risks of surgical bypass in patients with CLI, with particular emphasis on the identification of preoperative variables that predict poor outcome.

SCAI expert consensus statement for femoral-popliteal arterial intervention appropriate use

Successful endovascular intervention for femoral-popliteal (FP) arterial disease provides relief of claudication and offers limb-salvage in cases of critical limb ischemia. Technologies and operator technique have evolved to the point where we may now provide effective endovascular therapy for a spectrum of lesions, patients, and clinical scenarios. Endovascular treatment of this segment offers a significant alternative to surgical revascularization, and may confer improved safety for a wide range of patients, not solely those deemed high surgical risk. Although endovascular therapy of the FP segment has historically been hampered by high rates of restenosis, emerging technologies including drug-eluting stents, drug-coated balloons, and perhaps bio-absorbable stent platforms, provide future hope for more durable patency in complex disease. By combining lessons learned from clinical trials, international trends in clinical practice, and insights regarding emerging technologies, we may appropriately tailor our application of endovascular therapy to provide optimal care to our patients. This document was developed to guide physicians in the clinical decision-making related to the contemporary application of endovascular intervention among patients with FP arterial disease.

Critical evaluation of stents in the peripheral arterial disease of the superficial femoral artery - focus on the paclitaxel eluting stent

The endovascular management of obstructive disease of the superficial femoral artery (SFA) is challenging due to unique anatomical and biomechanical forces. Obstructive lesions of the SFA make up the largest proportion of lesions leading to symptomatic peripheral arterial disease. Accordingly, endovascular treatment of SFA disease is becoming increasingly common and, in many cases, is the preferred initial therapy. The use of self-expanding nitinol stents have proven superior to percutaneous transluminal balloon angioplasty in the treatment of intermediate length SFA stenosis. However, achieving durable results, as well as attaining adequate therapy for long occlusions typically seen in clinical practice, remains problematic. Newer technologies, such as paclitaxel eluting stents, seem promising in improving outcomes.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

SUPERA interwoven nitinol Stent Outcomes in Above-Knee IntErventions (SAKE) study

PURPOSE

To report experience with the novel interwoven-wire self-expanding nitinol SUPERA stent (IDEV Technologies, Inc/Abbott Laboratories, Inc, Webster, Texas) for the treatment of severely diseased superficial femoral and popliteal arteries.

MATERIALS AND METHODS

Consecutive patients with severely diseased superficial femoral and popliteal arteries who received SUPERA stents (n = 80 patients [98 limbs]; mean age, 70.8 y; 80% male) were retrospectively identified. Patients were followed for an average of 14.3 months after intervention.

RESULTS

Total occlusions were present in 39% of the lesions, 21% had tissue loss, and 61% demonstrated calcification on fluoroscopy. Patients were prescribed dual antiplatelet therapy (aspirin and clopidogrel) for at least 30 days unless contraindicated, followed by aspirin alone indefinitely. The mean (± SD) lesion length was 143 mm (± 98). Based on need for clinical intervention, primary patency was 96.9% at 6 months and 85.8% at 12 months (Kaplan-Meier estimates). Assisted primary patency and secondary patency rates at 12 months were 96.8% and 100%, respectively. Ankle-brachial index increased from 0.60 at baseline to 0.83 at last follow-up (P < .001). No stent fractures were found by fluoroscopy inspection in 19 limbs (16 patients) that required reintervention.

CONCLUSIONS

Based on experience with multiple operators at a single clinical center, the interwoven nitinol stent design provides a viable option for high-grade obstructive disease in the femoropopliteal artery.