Results of heparin-bonded ePTFE-covered stents for chronic occlusive superficial femoral artery disease

Systematic Review and Meta-analysis of Clinical Outcomes After Endovascular Treatment in Patients With Femoropopliteal Lesions Greater Than 150 mm

OBJECTIVE

Indications for endovascular treatment of femoropopliteal (FP) lesions have steadily increased over the past decade. Accordingly, the number of devices has also increased but the choice of the best endovascular treatment remains to be defined. The aim of this meta-analysis was to summarize all studies investigating endovascular treatment of FP lesions greater than 150 mm from 2010 to 2021.

METHODS

Articles were searched using PubMed, Scopus, and Cochrane. Included studies were randomized controlled trials (RCTs), cohort studies, and case series (prospective and retrospective) that evaluated any endovascular procedure in patients with long FP lesions classified TASC (Trans-Atlantic Inter-Society Consensus document II on management of peripheral arterial disease) C and/or D, and a mean length >150 mm, primary outcome had to be the 1-year primary patency. Overall estimate of primary patency, secondary patency, and freedom from target lesion revascularization (TLR) at 1 year depending on the different devices were investigated. The meta-analysis was conducted following the requirements of the MOOSE (Meta-analysis of Observational Studies in Epidemiology) checklist.

RESULTS

Forty-four papers comprising 4847 patients and 5282 treated limbs were included. Mean lesions length ranged from 150.5 to 330 mm. The pooled 1-year primary and secondary patencies, and freedom from TLR rates were 0.71 (95% CI: 0.67-0.74), 0.87 (95% CI: 0.83-0.91), and 0.79 (95% CI: 0.74-0.84), respectively. Primary permeability at 1 year were 0.68 (95% CI: 0.62-0.73), 0.67 (95% CI: 0.60-0.74), 0.74 (95% CI: 0.64-0.84), and 0.83 (95% CI: 0.78-0.88) for bare metal stents, covered stents (CSs), drug-eluting stents, and drug-coated balloons (DCBs), respectively. Lesions treated with DCB had the highest 1-year primary patency rate.

CONCLUSIONS

At 1-year, endovascular procedures for FP lesions greater than 150 mm obtain satisfactory results. High primary patency rates were obtained with drug-coated devices, while CSs obtained less favorable results. Randomized studies comparing different devices in the treatment of long FP lesions remain necessary to determine the most optimal approach for the management of these patients.

CLINICAL IMPACT

This paper highlights on the one hand the satisfactory results of endovascular treatment on complex femoropopliteal lesions formerly reserved for conventional surgery. On the other hand, among the available devices, paclitaxel-eluting devices seem to show superior results which should make them recommended as first-line treatment.

Is the Mid-Term Patency Rate of Small-Diameter Viabahn Stent-Grafts in Peripheral Artery Disease Related to Their Length? A Systematic Review

OBJECTIVE

Small-diameter endografts can be used for the treatment of the peripheral vascular disease, but the patency rate during the follow-up is still under debate. With this review, we aimed at analyzing the mid-term patency of small-diameter Viabahn stent-grafts and investigating the relationship between patency and the length of the graft.

METHODS

We performed a review of articles published until September 2020 and reporting use of ≤7-mm-diameter Viabahn stent-grafts in diseased peripheral arteries. Data on study type, demographic, lesion length, stent-graft diameter, length, and patency (1-year, 3-year, 5-year primary patency, primary-assisted patency, and secondary patency), follow-up, endoleak, and re-intervention rates were extracted and analyzed. A statistical test was applied to identify a correlation between stent-graft length and patency.

RESULTS

16 retrospective and 7 prospective studies reported the outcome of 1613 patients (mean age: 69.6±33.7 years). There was considerable heterogeneity in reporting standards among studies. The diameter of Viabahn stent-grafts ranged 5 to 7mm and the average length was 23.6±12.4cm. Heparin-bonded grafts were used in 46.4% of cases. Mean follow-up time was 26.4±17.6 months. The 1- and 5-year primary patency rate was 75.7% (95% CI, 73.6%-77.8%) and 46.8% (95% CI, 41.0%-52.6%), respectively. The 1- and 5-year primary-assisted patency rate was 80.9% (95% CI, 73.9%-87.8%) and 60.9% (95% CI, 46.4-75.5%), respectively. The 1- and 5-year second-assisted patency was 90.4% (95% CI, 87.4%-93.3%) and 73.7% (95% CI, 64.7%-82.8%), respectively. No correlation between the stent-graft length and patency was found.

CONCLUSIONS

Small-diameter Viabahn stent-graft implantation represents a safe treatment for patients with peripheral artery disease, and the mid-term patency rate seems not be affected by the length of the graft.

CLINICAL IMPACT

The use of small diameter stent-grafts for peripheral vascular disease is an established technique but the patency rate is still under debate. With this review we have investigated the relationship between the mid-term patency and the diameter of the stent-grafts. Afterv having analysed data from 23 published studies including 1613 patients we can conclude that the treatment of the peripheral artery disease with small diameter stent-grafts is safe and the mid-term patency rate seems not be affected by the lenght of the grafts.

Design of an Ultralow Molecular Weight Heparin That Resists Heparanase Biodegradation

Heparanase, an endo-β-d-glucuronidase produced by a variety of cells and tissues, cleaves the glycosidic linkage between glucuronic acid (GlcA) and a 3-O- or 6-O-sulfated glucosamine, typified by the disaccharide -[GlcA-GlcNS3S6S]-, which is found within the antithrombin-binding domain of heparan sulfate or heparin. As such, all current forms of heparin are susceptible to degradation by heparanase with neutralization of anticoagulant properties. Here, we have designed a heparanase-resistant, ultralow molecular weight heparin as the structural analogue of fondaparinux that does not contain an internal GlcA residue but otherwise displays potent anticoagulant activity. This heparin oligosaccharide was synthesized following a chemoenzymatic scheme and displays nanomolar anti-FXa activity yet is resistant to heparanase digestion. Inhibition of thrombus formation was further demonstrated after subcutaneous administration of this compound in a murine model of venous thrombosis. Thrombus inhibition was comparable to that observed for enoxaparin with a similar effect on bleeding time.

Individual patient data meta-analysis of patients treated with a heparin-bonded Viabahn in the femoropopliteal artery for chronic limb-threatening ischemia

Objectives

The aim of the study was to analyze available data on patients treated for chronic limb‐threatening ischemia (CLTI) with the heparin‐bonded Viabahn endoprosthesis.

Background

The patency of self‐expanding covered stents in patients with complex femoropopliteal lesions is encouraging. However, data were mostly derived in patients with intermittent claudication. Patients with CLTI often have more advanced disease and worse outcome.

Methods

After the abstract screening, full‐text papers were checked. Authors were approached to consider joining the consortium. Data were sent anonymously, databases were merged and an individual patient data meta‐analysis was performed. Kaplan–Meier curves were used to calculate the freedom from amputations, the amputation‐free survival, and patency rates.

Results

Seven studies were enrolled, representing 161 limbs that were treated for CLTI. Median lesion length was 28.0 cm (interquartile range 25.0–33.0 cm) and 82.7% were chronic total occlusions. The technical success rate was 98.1% and the 30‐day mortality 1.9%. Through 2‐year follow‐up, the freedom‐from‐major‐amputations was 99.3%, with an amputation‐free survival of 78.8%. The freedom‐from‐loss‐of primary, primary‐assisted, and secondary patency was 70.4%, 71.8%, and 88.2%, respectively, at 1‐year and 59.5%, 62.7%, and 86.1% at 2‐year follow‐up, respectively. The reintervention‐free survival was 62.2% at a 2‐year follow‐up.

Conclusions

Treatment of femoropopliteal disease in CLTI patients with the use of the heparin‐bonded Viabahn is safe and effective with favorable clinical outcomes and low amputation rates. Reinterventions are needed in a subset of the population to maintain endoprosthesis patency. Close follow‐up using duplex is recommended to detect potential edge stenosis, allowing treatment before device occlusion.

Endovascular Intervention for the Treatment of Trans-Atlantic Inter-Society Consensus (TASC) D Femoropopliteal Lesions: A Systematic Review and Meta-Analysis

PURPOSE

Advancements in the endovascular treatment of femoropopliteal atherosclerotic lesions have led to treatment of more complex lesions, particularly long lesions. The aim of this study was to determine the meta-analytic primary patency and need for re-intervention among patients treated for very long lesions (>200 mm) at the femoropopliteal segment and to identify potential risk factors for loss of patency.

METHODS

This study was performed according to the PRISMA guidelines. A random effects model meta-analysis was conducted, and the I-square was used to assess heterogeneity.

RESULTS

Fifty-one studies comprised of 3029 patients were included. The mean lesion length was 269 mm. The primary patency rate at 30 days, 6 m, 1-, 2- and 5-years of follow-up was 98%, 76%, 62%, 55%, and 39% respectively. The incidence of TLR was 16% at one year and 32% at two years. The secondary patency rate at 1, 2, 3 and 5 years was 85%, 71%, 64%, and 64% respectively. Heparin bonded ePTFE covered stents (69%) and paclitaxel eluting stents (73%) demonstrated higher 1-year primary patency rates than self-expanding nitinol stents (55%) or uncoated percutaneous transluminal angioplasty (PTA) with provisional stenting (54%). Lesions treated with a heparin bonded ePTFE covered stent had statistically significant higher odds of remaining patent at 1-year of follow-up (OR: 2.74; 95%CI: 1.63-4.61; p < 0.001) than lesions treated with BMS or PTA. Patients with long femoropopliteal lesions causing critical limb ischemia (CLI) developed restenosis or occlusion more often than patients treated for claudication (HR: 1.63; 95%CI: 1.06-2.49; p = 0.026) during an average follow-up of 26 months.

CONCLUSION

Primary stenting of femoropopliteal TASC D lesions using drug eluting stents or covered stents results in sustained patency over time. PTA or uncoated nitinol stents demonstrated lower patency rates. However, additional comparative studies are needed to determine the efficacy of newer technologies for the treatment of complex femoropopliteal lesions and provide evidence for the most optimal treatment approach.

Laser Atherectomy for the Treatment of Peripheral Arterial Disease

BACKGROUND

The aim of the study was to investigate the clinical results of laser atherectomy in the treatment of peripheral arterial disease.

METHODS

Retrospective analysis of consecutive patients underwent laser atherectomy at a single institution during a 7-year period by vascular surgeons and interventional cardiologists in a tertiary university-affiliated hospital. Clinical data were retrieved from patient charts and hospital electronic medical records along with the associated arteriograms.

RESULTS

A total of 461 lesions in 343 limbs were treated in 300 patients with a mean age of 70 years. The indication was critical limb ischemia (CLI) with rest pain or tissue loss in 227 (66%) of interventions and claudication in 116 (34%). All procedures included an associated balloon angioplasty, while stenting was performed in 33%. Technical success was achieved in 99% with only 2 (<1%) cases with an acute procedure-related complication requiring surgical intervention. At a mean follow-up of 28 months (range, 1-87 months; median 24 months), 156 patients (45%) became asymptomatic or achieved significant clinical improvement (resolution of tissue loss or rest pain), 60 (17%) remained with CLI, 30 (9%) had a major proximal amputation, and 18 (5%) had a minor amputation. Freedom from major amputation was 90% at 5 years by life-table analysis. Univariate statistical analysis demonstrated the risk of a major amputation to be associated with diabetes, hemodialysis, and tissue loss (P < 0.05 to P < 0.005), while multivariate logistic regression analysis indicated diabetes to be overwhelmingly important (RR: 4.84; 95% confidence interval [CI]: 1.1-21.3; P < 0.05). In a similar manner, multivariate analysis indicated dialysis (RR: 2.46; 95% CI: 1.01-5.98; P < 0.05) and CLI (RR: 2.27; 95% CI: 1.42-3.65; P < 0.01) were associated with higher likelihood for lack of clinical improvement. There was no difference in major amputation rates between surgeons and interventional cardiologists (RR: 1.5; 95% CI: 0.7-2.1; P < 0.1) although it was 3 times more likely for the patients treated by surgeons to suffer from CLI (odds ratio: 3.2; 95% CI: 1.9-5.4; P < 0.0001).

CONCLUSIONS

Laser atherectomy is a safe and useful adjunct in limb salvage. Diabetics have much higher probability of requiring a proximal amputation, while those on dialysis and with CLI are least likely to gain clinical benefit.

Five-Year Outcome of Self-Expanding Covered Stents for Superficial Femoral Artery Occlusive Disease and an Analysis of Factors Predicting Failure

Purpose: To investigate the 5-year outcome of patients treated with self-expanding covered stents for superficial femoral artery (SFA) occlusive disease and identify parameters that could predict loss of primary patency. Methods: In a dual-center study, 315 consecutive patients (mean age 69.0±10.1 years; 232 men) treated for SFA occlusive disease in 334 limbs with Viabahn self-expanding covered stents between 2001 and 2014 were retrospectively analyzed. Mean lesion length was 11.7±8.8 cm, and half of the lesions were classified as TASC II C/D. Five-year patency rates were calculated, and Cox regression analyses were performed to assess potential factors affecting patency. Results: All-cause mortality at 5 years was 14.1%. Primary patency rates at 1, 3, and 5 years were 72.2%, 51.8%, and 47.6%, respectively, with secondary patency rates of 86.2%, 78.7%, and 77.5%. Parameters predicting loss of primary patency in a univariate analysis were covered stent diameter (p=0.001), the number of covered stents per lesion (p=0.015), and TASC II D classification (p=0.007). Covered stent diameter was the only parameter predicting loss of primary patency in the multivariate regression analysis (p=0.001), with 7-mm covered stents having superior performance. Conclusion: Five-year patency rates of self-expanding covered stents inserted for SFA occlusive disease are within an acceptable range. Covered stent diameter is the most relevant factor in predicting loss of primary patency, and thus, an adequate diameter of the distal landing site seems to be among the most important factors in the decision-making process. In smaller vessels, one should not use covered stents but venous conduits, as oversizing may be detrimental.

Computation of blood flow through collateral circulation of the superficial femoral artery

OBJECTIVE

Obliteration of collaterals during (endo)vascular treatment of peripheral arterial occlusive disease is considered detrimental. We use a model to calculate maximum collateral bed flow of the superficial femoral artery in order to provide insight in their hemodynamic relevance.

METHOD

A computational model was developed using digital subtraction angiographies in combination with Poiseuille's equation and Ohm's law. Lesions were divided into short and long (<15 cm and ≥15 cm, respectively) and into stenosis and occlusions. Data are presented in relation to the calculated maximum healthy superficial femoral artery flow.

RESULTS

Stenotic lesions are longer than occlusive lesions (P < 0.05) and occlusions had more and larger collaterals (P < 0.05). In all four study groups the collateral flow significantly increased the total flow (P < 0.05). The maximum collateral system flow in the stenosis and occlusion groups was 5.1% and 20.8% of healthy superficial femoral artery flow, respectively (P < 0.05), and there were no significant differences between short and long lesions (11.2% and 6.7% of healthy superficial femoral artery flow, respectively).

CONCLUSION

The maximum collateral system flow of the superficial femoral artery is only a fraction, with a maximum of one fifth, of healthy superficial femoral artery flow. Effects of collateral vessel occlusion during (endo)vascular treatment may therefore be without detrimental consequences.

Superiority of Stent-Grafts for In-Stent Restenosis in the Superficial Femoral Artery

Purpose: To evaluate the short- and midterm outcomes of the Viabahn endoprosthesis with Propaten Bioactive Surface vs. standard balloon angioplasty for treatment of in-stent restenosis in the superficial femoral artery. Methods: Between June 2010 and February 2012, 83 patients with superficial femoral artery in-stent and Rutherford category 2 to 5 ischemia were enrolled at 7 sites participating in this prospective randomized controlled study (RELINE; ClinicalTrials.gov; identifier NCT01108861). The patients were randomized to treatment with either the heparin-bonded Viabahn endoprosthesis (n=39: 29 men; mean age 67.7±9.8 years) or a standard angioplasty balloon (n=44: 32 men; mean age 69.0±9.7 years). The primary effectiveness outcome was primary patency at 12 months, defined as no restenosis/occlusion within the target lesion based on duplex ultrasound and no target lesion revascularization. The primary safety endpoint was the incidence of serious device-related adverse events within 30 days of the procedure. Results: All patients randomized to receive dilation or the Viabahn stent-graft were treated according to their assignment. The technical success was 100% for the Viabahn group and 81.8% for the angioplasty group (p=0.002) owing to 9 patients requiring a bailout procedure after unsuccessful angioplasty. The 12-month primary patency rates were 74.8% for the Viabahn group and 28.0% for the angioplasty group (p<0.001). Excluding the 9 angioplasty patients who received bailout stenting, the primary patency for optimal balloon angioplasty was 37.0% (p<0.001). Three patients experienced device-related adverse events within 30 days: occlusion of the target lesion (Viabahn group), peripheral embolization (angioplasty group), and reocclusion of the target lesion (angioplasty group). Conclusion: In this study, the treatment of femoropopliteal in-stent restenosis with a Viabahn endoprosthesis showed significantly better results than treatment with a standard balloon at 1 year.

Endoluminal occlusion devices: technology update

Endoluminal occlusion has been performed since the early beginning of interventional radiology. Over recent decades, major technological advances have improved the techniques used and different devices have been developed for changing conditions. Most of these occlusion devices have been implemented in the vascular territory. Early embolization materials included glass particles, hot contrast, paraffin, fibrin, and tissue fragments such as muscle fibers and blood clots; today, occlusion materials include metallic devices, particles, and liquid materials, which can be indicated for proximal or distal occlusion, high-flow and low-flow situations, and in large-caliber and small-caliber vessels, based on need. Technological progress has led to a decreased size of delivery catheters, and an increase in safety due to release systems that permit the withdrawing and replacement of embolization material. Furthermore, bioactive embolization materials have been developed to increase the efficacy of embolization or the biological effect of medication. Finally, materials have been modified for changing indications. Intravascular stents were initially developed to keep an artery open; however, by adding a covering membrane, these stents can be used to occlude the wall of a vessel or other endoluminal structures. This article gives an overview of the devices most utilized for occlusion of endoluminal structures, as well as their major purpose in the endovascular territory.

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.

Immobilization of actively thromboresistant assemblies on sterile blood-contacting surfaces

Rapid one-step modification of thrombomodulin with alkylamine derivatives such as azide, biotin, and PEG is achieved using an evolved sortase (eSrtA) mutant. The feasibility of a point-of-care scheme is demonstrated herein to site-specifically immobilize azido-thrombomodulin on sterilized commercial ePTFE vascular grafts, which exhibit superior thromboresistance compared with commercial heparin-coated grafts in a primate model of acute graft thrombosis.