Efficacy of a Drug-Eluting Stent Versus Bare Metal Stents for Symptomatic Femoropopliteal Peripheral Artery Disease: Primary Results of the EMINENT Randomized Trial

BACKGROUND

A clear patency benefit of a drug-eluting stent (DES) over bare metal stents (BMSs) for treating peripheral artery disease of the femoropopliteal segment has not been definitively demonstrated. The EMINENT study (Trial Comparing Eluvia Versus Bare Metal Stent in Treatment of Superficial Femoral and/or Proximal Popliteal Artery) was designed to evaluate the patency of the Eluvia DES (Boston Scientific, Marlborough, MA), a polymer-coated paclitaxel-eluting stent, compared with BMSs for the treatment of femoropopliteal artery lesions.

METHODS

EMINENT is a prospective, randomized, controlled, multicenter European study with blinded participants and outcome assessment. Patients with symptomatic peripheral artery disease (Rutherford category 2, 3, or 4) of the native superficial femoral artery or proximal popliteal artery with stenosis ≥70%, vessel diameter of 4 to 6 mm, and total lesion length of 30 to 210 mm were randomly assigned 2:1 to treatment with DES or BMS. The primary effectiveness outcome was primary patency at 12 months, defined as independent core laboratory-assessed duplex ultrasound peak systolic velocity ratio ≤2.4 in the absence of clinically driven target lesion revascularization or surgical bypass of the target lesion. Primary sustained clinical improvement was a secondary outcome defined as a decrease in Rutherford classification of ≥1 categories compared with baseline without a repeat target lesion revascularization. Health-related quality of life and walking function were assessed.

RESULTS

A total of 775 patients were randomly assigned to treatment with DES (n=508) or commercially available BMSs (n=267). Baseline clinical, demographic, and lesion characteristics were similar between the study groups. Mean lesion length was 75.6±50.3 and 72.2±47.0 mm in the DES and BMS groups, respectively. The 12-month incidence of primary patency for DES treatment (83.2% [337 of 405]) was significantly greater than for BMS (74.3% [165 of 222]; P<0.01). Incidence of primary sustained clinical improvement was greater among patients treated with the DES than among those who received a BMS (83.0% versus 76.6%; P=0.045). The health-related quality of life dimensions of mobility and pain/discomfort improved for the majority of patients in both groups (for 66.4% and 53.6% of DES-treated and for 64.2% and 58.1% of BMS-treated patients, respectively) but did not differ significantly. At 12 months, no statistical difference was observed in all-cause mortality between patients treated with the DES or BMS (2.7% [13 of 474] versus 1.1% [3 of 263]; relative risk, 2.4 [95% CI, 0.69-8.36]; P=0.15).

CONCLUSIONS

By demonstrating superior 1-year primary patency, the results of the EMINENT randomized study support the benefit of using a polymer-based paclitaxel-eluting stent as a first-line stent-based intervention for patients with symptomatic peripheral artery disease attributable to femoropopliteal lesions.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02921230.

Direct discharge of patients with simple stable musculoskeletal injuries as an alternative to routine follow-up: a systematic review of the current literature

PURPOSE

There is growing evidence that patients with certain simple stable musculoskeletal injuries can be discharged directly from the Emergency Department (ED), without compromising patient outcome and experience. This study aims to review the literature on the effects of direct discharge (DD) of simple stable musculoskeletal injuries, regarding healthcare utilization, costs, patient outcome and experience.

METHODS

A systematic review was performed in Medline, Embase, CINAHL, Cochrane Library and Web of Science using PRISMA guidelines. Comparative and non-comparative studies on DD of simple stable musculoskeletal injuries from the ED in an adult/paediatric/mixed population were included if reporting ≥ 1 of: (1) logistic outcomes: DD rate (proportion of patients discharged directly); number of follow-up appointments; DD return rate; (2) costs; (3) patient outcomes/experiences: functional outcome; treatment satisfaction; adverse outcomes; other.

RESULTS

Twenty-six studies were included (92% conducted in the UK). Seven studies (27%) assessed functional outcome, nine (35%) treatment satisfaction, and ten (38%) adverse outcomes. A large proportion of studies defined DD eligibility criteria as injuries being minor/simple/stable, without further detail. ED DD rate was 26.7-59.5%. Mean number of follow-up appointments was 1.00-2.08 pre-DD, vs. 0.00-0.33 post-DD. Return rate was 0.0-19.4%. Costs per patient were reduced by €69-€210 (ranging from - 38.0 to - 96.6%) post-DD. Functional outcome and treatment satisfaction levels were 'equal' or 'better' (comparative studies), and 'high' (non-comparative studies), post-DD. Adverse outcomes were low and comparable.

CONCLUSIONS

This systematic review supports the idea that DD of simple stable musculoskeletal injuries from the ED provides an opportunity to reduce healthcare utilization and costs without compromising patient outcomes/experiences. To improve comparability and facilitate implementation/external validation of DD, future studies should provide detailed DD eligibility criteria, and use a standard set of outcomes. Systematic review registration number: 120779, date of first registration: 12/02/2019.

Belgian Experience with FilterWire EX in the Prevention of Embolic Events during Carotid Stenting

Purpose:

To evaluate the performance of the FilterWire EX for the capture and removal of debris and prevention of embolic events during endovascular carotid interventions.

Methods:

In the period from October 2001 to May 2002, 100 patients (60 men; mean age 72 years, range 48–90), 69 symptomatic with >50% internal carotid artery (ICA) stenosis and 31 asymptomatic with >70% stenosis were scheduled for carotid stenting with cerebral protection provided by the FilterWire EX system. Satisfactory performance of the filter was defined as effectiveness in preventing intraprocedural embolic events shown by visible debris in the filter and unchanged neurological status assessed by an independent neurologist.

Results:

The placement and retrieval of the FilterWire EX was technically successful in 93 of 100 patients. Five delivery failures were due to severe ICA angulation; one stenosis was underestimated on preprocedural imaging, and one case was aborted following a major stroke during sheath manipulation before filter introduction. In 56.9% of the protected cases, the filter contained debris. One neurological event occurred 6 hours after the procedure: a transient ischemic attack from which the patient recovered fully after 2 hours. No other procedure-related events were recorded within 30 days of the procedure. The procedural success among the 93 patients stented under FilterWire EX protection was 98% (92% by intention to treat).

Conclusions:

The FilterWire EX appears to be an effective tool in the prevention of embolic events and in preserving neurological status during endovascular treatment of carotid artery stenosis.

Right-sided Cockett's syndrome

Background Cockett and Thomas described and named Cockett's syndrome in 1965, commonly referred to as iliac vein compression syndrome (IVCS). It is often found as underlying cause in iliofemoral deep venous thrombosis (DVT). They described the syndrome mostly seen on the left side and predominantly in women during the second to the fourth decade of life. In this article, we present a patient with a Cockett's syndrome on the right side. Case presentation Our patient is a 52-year old female with edema of the right leg since 4 months. She had no signs of a DVT and did not benefit from a 3-month compression therapy. She was diagnosed using a CT-scan. Endovascular treatment was performed with a venous stent in the right common iliac vein (CIV). No postoperative complications were seen. After a 6-month follow-up, patient was free of pain and had no residual edema of the right leg. Conclusions Our patient presented with a non-complicated right-sided Cockett's syndrome. She was successfully treated with balloon dilatation and additional stenting of the right common iliac vein. Because of the clinical improvement of the patient together with the excellent long-term results and good patency results of the stenting, guidelines nowadays advise more and more venous stenting to prevent DVT and to relieve symptoms in case of vein compression syndromes.

High sensitivity 10Gb/s Si photonic receiver based on a low-voltage waveguide-coupled Ge avalanche photodetector

We demonstrate low-voltage germanium waveguide avalanche photodetectors (APDs) with a gain × bandwidth product above 100GHz. A photonic receiver based on such a Ge APD, including a 0.13μm SiGe BiCMOS low-noise trans-impedance amplifier and a limiting amplifier, is realized. A 5.8dB sensitivity improvement is demonstrated at -5.9V bias at an avalanche gain of 6 through bit error ratio measurements. The absolute sensitivity in avalanche mode is -23.4dBm and -24.4dBm at a bit error ratio of 1 × 10(-12) and 1 × 10(-9) respectively.

Which is currently the best strategy for treatment of SFA in-stent restenosis?

Stents have been created to prevent vessel recoil after percutaneous transluminal angioplasty (PTA). Despite the evolution in stent design, intimal hyperplasia and stent fractures and the resulting in-stent restenosis (ISR) still occur. Different strategies to treat ISR have been described with variable results in patency rates in the short and the long-term. PTA only in the treatment of ISR showed high procedural success, but the mid and long-term patency rates were very disappointing. Atherectomy devices have showed same insufficient results. If stent fracture is the cause of the ISR, the fracture has to be overstent. The best two options are covered stents and drug eluting stents (DES). Drug eluting devices like DES and drug eluting balloons (DEBs) showed promising results, with patency rates up to over 90% after one year. DEBs have the advantage of leaving nothing behind. Combined treatment of ISR with atherectomy and DEB has a similar good result. Endovascular brachytherapy showed high patency rates after one year but this technique is limited due to the time-consuming nature of the procedure, complex radiation safety measurements, and staffing requirements. Overall drug-eluting devices are emerging as the best treatment of SFA ISR with patency rates over 90% after 2 years.

Clinical and epidemiological assessment concerning hybrid revascularization techniques in the treatment of multilevel arterial occlusive disease

Aim of the study was to report a novel hybrid technique for multilevel arterial lesions of the lower extremities and to evaluate the clinical outcomes. In patients with multilevel arterial disease, the combined (hybrid) treatment, consisting of endovascular intervention and classical surgical intervention on the same vascular axis seems to be the most indicated treatment in order to obtain an adequate inflow and outflow.

MATERIAL AND METHODS

We have performed a non-randomized study during a 44-month period (January 2010 - September 2013) in a number of 94 patients treated by hybrid revascularization techniques. All the patients included in the study have been post-surgically surveyed at well established intervals (1, 3, 6, 9, 12, 24 and 36 months) by: clinical examination, laboratory tests, Duplex ultrasound, and, as needed, CT or MR Angiography.

RESULTS

The 6 months primary patency in each studied group (corresponding to the years of 2010, 2011 and 2012) was 58.69%, 68.42%, and 62.06%, respectively; the 12 months primary patency was 45.65%, 57.89%, and 34.48%, respectively. Clinical improvement has been noticed in 83 patients (88.29%). There have been registered 19 amputations (20.21% of the cases): 11 majors (thigh and below the knee), representing 11.7% of the total number of cases and 8 minors (toe or transmetatarsal), representing 8.51% of the total number of cases. The amputation-free survival period ranged between 7 days and 24 months, with an average of 7.66 months.

CONCLUSIONS

The hybrid techniques are a feasible option for the multilevel arterial disease, with favorable patency and limb salvage rates.

Popliteal artery aneurysm: when open, when endo?

The purpose of this article was to obtain a more clear view in the management of popliteal artery aneurysms (PAAs). When do we need to treat it and how is it best treated? After going through multiple review articles and case reports concerning this matter, we came to the following conclusions. Repair of a PAA is indicated when it reaches a postero-anterior diameter of 3 cm (at higher risk for thrombosis) or becomes symptomatic (mild claudication or severe ischemic symptoms). Whether the repair is then performed in an endovascular (Endovascular repair) or open way (Open repair), depends on the personal experience and clinical evaluation of the surgeon.

New devices for a better endovascular approach

The endovascular approach has known a great evolution in terms of vessel patency and treatment possibilities. Longer and more complex lesions with a difficult anatomy can be addressed by a range of endovascular tools. However, to maintain the patency of the treated lesion is the true challenge. In order to fulfill these long-term expectations, newer devices have been developed. The drug-coated balloon combines local drug uptake with no residual material after treatment. To maintain patency and prevent recoil of the arterial wall, the drug-eluting stent has been created to offer stent support with an antiproliferative drug. The main drawbacks of the drug-coated balloon and the drug-eluting stent are being addressed by the drug-eluting absorbable scaffold. The initial scaffolding support in combination with the drug release during a prolonged period, poses the same advantages while the scaffold is being metabolized over time. This continuing evolution in endovascular tools paves the way to an endovascular treatment for the majority of peripheral artery diseases.

Spontaneous rupture of an aneurysm of the right subclavian artery as a first presentation of Ehlers Danlos syndrome in a 15-year old boy

We report a case of a spontaneous rupture of a right subclavian aneurysm in a 15 year-old patient. This ruptured aneurysm was successfully treated in an endovascular manner by placing a covered stent-graft in the right subclavian artery via right brachial access. Subsequent work-up by skin biopsy and fibroblast culture and by DNA-screening revealed the diagnosis of Ehlers Danlos type IV. Meanwhile, the patient developed twice a spontaneous pneumothorax, treated with thoracoscopic pleurodesis. This article provides a clear overview of the clinical and genetic characteristics of a case of Ehlers Danlos type IV and illustrates the importance of avoiding surgery in patients with connective tissue disease because of the high risk of perioperative complications.

Drug-eluting technologies in femoral artery lesions

The treatment of femoropopliteal lesions has known an important evolution in the last years. An important limitation of current endovascular therapy remains the occurrence of restenosis. In order to minimize restenosis rates, drug eluting technologies are evolving. The use of drug-eluting stents (DES) in coronary arteries shows beneficial results, leading to investigation of DES in femoropopliteal arteries. In this article, we give an overview of current available data on treatment with drug eluting technologies in the superficial femoral artery (SFA). This paper summarizes also the current available data of the use of drug-coated balloons (DCB) in the femoropopliteal tract. Currently, no data are available on the use of DCB in long lesions. A drug eluting bioresorbable scaffold seems to be very promising in coronary arteries. The transfer to the peripheral area is nowadays ongoing. Which technique and device for which lesion and patient requires further investigation to build up a real evidence based SFA treatment strategy.

BRAVISSIMO: 12-month results from a large scale prospective trial

The BRAVISSIMO study is a prospective, non-randomized, multi-center, multi-national, monitored trial, conducted at 12 hospitals in Belgium and 11 hospitals in Italy. This manuscript reports the findings up to the 12-month follow-up time point for both the TASC A&B cohort and the TASC C&D cohort. The primary endpoint of the study is primary patency at 12 months, defined as a target lesion without a hemodynamically significant stenosis on Duplex ultrasound (>50%, systolic velocity ratio no greater than 2.0) and without target lesion revascularization (TLR) within 12 months. Between July 2009 and September 2010, 190 patients with TASC A or TASC B aortoiliac lesions and 135 patients with TASC C or TASC D aortoiliac lesions were included. The demographic data were comparable for the TASC A/B cohort and the TASC C/D cohort. The number of claudicants was significantly higher in the TASC A/B cohort, The TASC C/D cohort contains more CLI patients. The primary patency rate for the total patient population was 93.1%. The primary patency rates at 12 months for the TASC A, B, C and D lesions were 94.0%, 96.5%, 91.3% and 90.2% respectively. No statistical significant difference was shown when comparing these groups. Our findings confirm that endovascular therapy, and more specifically primary stenting, is the preferred treatment for patients with TASC A, B, C and D aortoiliac lesions. We notice similar endovascular results compared to surgery, however without the invasive character of surgery.

Refining stent technologies for femoral interventions

Stents were created as a mechanical scaffold to prevent vessel recoil and luminal renarrowing after percutaneous transluminal angioplasty (PTA). In femoropopliteal arteries, indication for stent implantation remains a topic much debated on, especially in long lesion configurations. Ever since the first stents were introduced on the market, in-stent restenosis (ISR) has been an important issue. The evolution in stent design has known a major progression in the last decades from the first generation of stents, plagued with high fracture rates and low primary patency rates, to the design of newer stents to tackle these outcomes. More flexible and longer stents decreased the high fracture rates and drug-eluting stents offered a solution to the restenosis rates by local drug application. The difficult recrossibility of the lesion because of the presence of a permanent vascular scaffold is an obstacle that the drug-coated balloon (DCB) overcomes. Future perspectives in the treatment of femoropopliteal lesions are found in the bioresorbable stent implantation. The bioresorbable stent combines the advantages of a drug-eluting scaffolding stent without the remainder of a foreign object in the long-term. Further investigations in this area will eventually evolve in the creation of a superior endovascular treatment modality with high long-term patency rates and minimal detriments.

Dysphagia lusoria. Indications and surgical approaches for non-aneurysmatic aberrant right subclavian artery

Non-aneurysmatic aberrant right subclavian artery is a rare cause of dysphagia. We report a case of a 65-year-old female patient having a symptomatic lusorian artery. We reviewed literature as for indications and operative techniques for type I lusorian arteries. Different types of surgical approaches have been reported but there is no consensus to date. We performed a minimally invasive sternotomy with right cervicotomy. This surgical approach maximized our visibility resulting in a safe dissection, resection and reinsertion of the aberrant right subclavian artery. Postoperative morbidity was low.

In lower extremity PTAs intraluminal is better than subintimal

With subintimal recanalization, a channel is deliberately created by dissecting the vessel wall in order to replace the native occluded lumen. This is opposed to intraluminal recanalization, where passage of an arterial obstructive lesion is performed by central luminal navigation. Both intraluminal and subintimal treatment has its proponents and adversaries. The appreciation of an investigator for a certain technique is commonly related to the training received and the personal experience. Yet, the intraluminal technique uses the clinically preferred route for adjunctive treatment, such as balloon angioplasty or stent deployment. A wide variety of devices designed to obtain intraluminal lesion passage is available and is currently being used in vascular centers worldwide. With intraluminal techniques, success rates of up to 95% have been reported.

BRAVISSIMO study: 12-month results from the TASC A/B subgroup

AIM

The BRAVISSIMO study is a prospective, non-randomized, multicenter, multinational, monitored trial, conducted at 12 hospitals in Belgium and 11 hospitals in Italy. This manuscript reports on the BRAVISSIMO TASC A&B iliac lesion cohort, based on data collected up to the 13-month time point. The primary endpoint of the study is primary patency at 12 months, defined as a target lesion without a hemodynamically significant stenosis on duplex ultrasound (>50%, systolic velocity ratio no greater than 2.0) and without Target Lesion Revascularization (TLR) within 12 months.

METHODS

Between July 2009 and February 2010, a total of 190 patients who presented with TASC A or TASC B aorto-iliac lesions were included, of which 140 patients were enrolled in Belgium and 50 in Italy.

RESULTS

The demographic data were comparable for the TASC A and TASC B patients groups. The number of occlusions, the average degree of stenosis, the average lesion length was significantly higher in the group of TASC B lesions, which is congruent with the TASC lesions definitions. Similarly, there were significantly more unilateral lesions in the TASC A group, compared to the TASC B group. The 12-month primary patency rate was 94.0% for TASC A lesions and 96.5% for TASC B lesions, which is not statistically significant. The 12-month primary patency rate was 92.9% in lesions treated with the Omnilink Elite stent, 97.1% in lesions treated with the Absolute Pro stent groups, and 100% in lesions treated with both stents.

CONCLUSION

Our findings confirm that endovascular therapy, and more specifically primary stenting, is the preferred treatment for patients with TASC A/B aortoiliac lesions. Currently, we are collecting the 12-month data for the TASC C/D subgroup in the BRAVISSIMO study. Upon release of the results from this subgroup, we will be able to compare the results from both arms of this large-scale international study.

Endovascular procedures and new insights in diabetic limb salvage

Critical limb ischemia (CLI) is affecting an increasing number of patients, mainly due to an ageing population and the growing number of diabetics. Clinically, CLI is characterized by rest pain, non-healing foot wounds and gangrene, due to insufficient arterial blood supply. Limb preservation should be the goal in patients with diabetic foot due to tibial occlusive disease. As surgery is associated with considerable morbidity and mortality rates, endovascular therapy can offer a valuable alternative. Small-diameter below-the-knee arteries that were previously unamenable to surgical methods, can now be reached and treated. Currently, many endovascular techniques are available, from regular PTA and bare metal stents to drug-coated balloons and drug-eluting stents. In our opinion the results of endovascular therapy for below-the-knee vessels will be further improved by the continuous technical evolution and new material developments. In the light of the current evolution towards minimally invasive techniques, an increasing number of experienced centers will be able to treat the vast majority of all below-the-knee arterial pathology by endovascular means.

Drug-eluting stents below the knee

The fear that early thrombosis and late luminal loss due to intimal hyperplasia formation potentially leads to insufficient long-term patency rates can explain the reluctance on implanting stents in small diameter below-the-knee (BTK) arteries. Drug-eluting stent (DES) technology was developed to prevent early thrombosis and late luminal loss to potentially improve long-term patency rates. Currently, the first level 1 evidence from prospective, randomized, controlled DESTINY and ACHILLES studies indicate that the implantation of DES in short lesion lenghts in the infrapopliteal vasculature leads to favorable outcomes with high primary patency rates. This makes that primary DES placement can be recommended as treatment strategy in short BTK-lesions.

Prevention and treatment of in-stent restenosis

In-stent restenosis has always been an important issue, since the launch of the first stents on the market. The occurrence of in-stent restenosis (ISR) is due to two main reasons. First, the presence of stent fractures significantly influences restenosis rates. Second, the continuous interaction between the permanently implanted artificial material and the vessel tissue, leads to physical irritation, long-term endothelial dysfunction, or chronic inflammatory reactions. In the Literature only very limited data on ISR treatment in the peripheral arteries are available. There are no peer-reviewed publications or studies with in-depth follow-up on this specific indication. The underlying reason for this probably being that currently available treatments do not yield satisfactory results. However, the continuing search for better solutions and the technological evolution lead to the introduction of the Viabahn with PROPATEN coating, DES and DCB, which may result in the first promising treatment options for ISR.

The role of carotid artery stenting for recent cerebral ischemia

Patients with cerebral ischemia as a result of acute cervical internal carotid artery occlusion are generally considered to have a poor prognosis. Despite maximal medical treatment, a better treatment for patients with acute ischemic stroke who present with serious neurologic symptoms on admission or continue to deteriorate neurologically due to a total occlusion, a dissection or a high-grade stenosis of the internal carotid artery is required. An effective intervention to improve their neurologic symptoms and clinical outcome has not yet been established and represents a challenging and complex problem. Treatment of acute symptomatic occlusion of the cervical internal carotid artery includes intravenous administration of thrombolytic agent, carotid endarterectomy and an interventional approach (intra-arterial administration of thrombolytic agent, transluminal angioplasty with or without stenting). The endovascular interventional approach is becoming a part of the stroke therapy armamentarium for intracranial occlusion. It may also now be considered in select patients with acute internal carotid artery occlusion. Stenting and angioplasty for acute internal carotid artery occlusion appears to be feasible, safe and may be associated with early neurological improvement. The encouraging preliminary results await confirmation from prospective, randomized studies.

Endovascular management of acute limb ischemia

Acute limb ischemia (ALI) refers to a rapid worsening of limb perfusion resulting in rest pain, ischemic ulcers or gangrene. With an estimated incidence of 140 million/year, ALI is serious limb-threatening and life-threatening medical emergency demanding prompt action. Three prospective, randomized clinical trials provide data on trombolytic therapy versus surgical intervention in patients with acute lower extremity ischemia. Although they did not give us the final answer, satisfactory results are reported for percutaneous thrombolysis compared with surgery. Moreover, they suggest an important advantage of thrombolysis in acute bypass graft occlusions. Therefore, we believe thrombolytic therapy should be a part of the vascular surgeon's armamentarium to safely and successfully treat ALI patients.

Variants of the BMP15 gene in a cohort of patients with premature ovarian failure

BACKGROUND

Bone morphogenetic protein 15 (BMP15) is an oocyte-derived growth factor acting as a major player in follicle differentiation in mammals. Mutations in the BMP15 gene, some of which lead to defective secretion of bioactive dimers, have been associated with premature ovarian failure (POF) in humans.

METHODS

Fifty patients diagnosed with POF with a normal karyotype were included in the study. After DNA extraction and amplification by PCR, the entire coding sequence and intron-exon junctions of BMP15 gene were analysed in the cohort of POF patients and in a control group of 214 patients.

RESULTS

Nine variants of the BMP15 gene including six missense substitutions and one insertion of three nucleotides were identified in the POF group. Three of them were previously described as single nucleotide polymorphisms and were also found in the control group. Two variants (H81R and G199R) have not been previously described and were not identified among controls but were not predicted to be deleterious. One variant (A180T) was identified among two POF cases, and also in two controls. One variant (F194S), predicted as potentially deleterious, was identified for the first time in a POF patient but also identified in one control. One variant (L148P), potentially deleterious, previously reported in POF patients, was identified for the first time among controls. The variant 788insTCT, previously identified among POF patients, probably has a low biological impact as it was also found in control patients and is a common polymorphism in sub-Saharan African populations.

CONCLUSIONS

Various missense variants of the BMP15 gene were identified among patients with POF. For most variants, the impact of the amino-acid substitution on the protein structure and function was predicted to be low. The two variants predicted as potentially deleterious were also identified among controls and could be considered as rare polymorphisms. Although some of these variants could contribute to the development of POF in a complex manner, the demonstration of their role in the pathogenesis of POF requires additional functional studies.

Are drug-eluting stents the future of SFA treatment?

Drug-eluting stent (DES) technology was developed to prevent early thrombosis and late luminal loss to potentially improve long-term patency rates. Although favorable DES results have recently become available with the Zilver PTX and STRIDES studies, the high price of DES is a major drawback for this technology to become the golden standard for peripheral endovascular therapy in de novo femoro-popliteal (FP) lesions. Nevertheless, DES has the potential to make the difference and to establish itself as an important treatment option in patients presenting with TASC C&D FP lesions who are at high-risk for surgery and for the treatment of in-stent restenosis, where until now, no valuable treatment option has proven to be beneficial.

Are bio-absorbable stents the future of SFA treatment?

Several limitations inherent to the implantation of a metallic device, such as the occurrence of in-stent re-stenosis, in an arterial lumen intuitively explain the interest for developing bio-absorbable stents. Two main types of bio-absorbable stents currently exist: polymer stents and metallic stents. To date, no studies with bio-absorbable stents have been conducted in the superficial femoral artery (SFA). Because of their strut thickness and lack of radial force, polymer stents are no good candidates for endovascular use. Absorbable metal stents (AMS) do have the potential to perform well for artery treatment, although current evidence from in-human coronary and infrapopliteal studies yield unsatisfactory results. Drastic technological improvements are mandatory before AMS can be considered for every day practice. Yet, it is our belief that further development of other metal and non-metal bio-absorbable stents, with or without drug-coating, may lead to the creation of the ultimate SFA stent.

Treatment of a left common iliac aneurysm with endovascular Powerlink stentgraft in a patient with an occlusion of a left common iliac stent

Isolated iliac aneurysms are uncommon and account for only 2% of all abdominal aneurysms. Typically, patients presenting with this pathology are operated on surgically. In our patient, however, surgery could have been an option but the patient had undergone a laparotomy more than 50 years earlier because of a gun-shot wound, so we preferred an endovascular repair. Furthermore, regular endovascular repair with a straight tube stentgraft was impossible due to the absence of a proximal neck. Consequently, we opted for placing a bifurcated stentgraft to exclude the iliac aneurysm.

Other endovascular methods of treating the diabetic foot

Critical limb ischemia (CLI) is an endstage manifestation of peripheral artery disease (PAD) and typically describes patients with ischemic rest pain (Rutherford Category 4), or patients with ischemic skin lesions, either ulcers or gangrene (Rutherford Category 5-6). CLI due to infrapopliteal lesions is often not a good indication for infrageniculate bypass surgery placement, due to the presence of prohibitive comorbidities, inadequate conduit, and lack of suitable distal targets for revascularization. Therefore, CLI patients due to blockage of below-the-knee arteries are in benefit of the endovascular approach. Infrapopliteal PTA became feasible with the introduction of low-profile peripheral balloon systems and the use of coronary balloons. Stent implantation, however, is generally reserved for cases with a suboptimal outcome after PTA (i.e. >50% residual stenosis, flow-limiting dissection). Because of the fear that early thrombosis and late luminal loss due to intimal hyperplasia formation will potentially lead to insufficient long-term patency rates, efforts to extend the range of endovascular approaches to CLI are presently focused on. Cryoplasty, scoring balloon angioplasty, excimer laser therapy and atherectomy using different types of atherectomy devices have been introduced. The current article provides an overview of the endovascular treatment strategies for infrapopliteal lesions in patients with CLI.

Update management below knee intervention

The application of percutaneous techniques for the treatment of peripheral arterial occlusive disease (PAOD) has gained widespread interest over the last decade. Together with the development of new endovascular tools and with an increasing operator experience, the minimal invasive percutaneous therapy became first line therapy at many institutions. Patients with critical limb ischemia (CLI) due to infrapopliteal lesions are often no good candidates infra-geniculate bypass surgery (IBS), as they often present with prohibitive comorbidities, inadequate conduit, and lack of suitable distal targets for revascularization. Therefore, CLI patients due to blockage of below-the-knee (BTK) arteries are in benefit of the endovascular approach: it offers the advantages of local anesthesia, potentially reduced costs (even anticipating the need for reintervention in many patients), shorter hospital stays The current article provides an overview of the diagnosis and endovascular treatment strategies for infrapopliteal lesions in patients with CLI and gives recommendations for future infrapopliteal device technology advancements.

Current status of infrapopliteal artery stenting in patients with critical limb ischemia

Due to the fear that early thrombosis and late luminal loss resulting from intimal hyperplasia might impede sustained patency of small-caliber arteries, such as those of the infrapopliteal bed, stent implantation in below-knee vessels remains controversial and is generally reserved for cases with a suboptimal outcome after percutaneous transluminal angioplasty (i.e. > 50% residual stenosis, flow-limiting dissection). Although evidence starts to build, favoring the use of stenting in the tibial area, results of well-conducted randomized controlled trials have to be awaited to change this strategy. Because of diameter similarities with coronary arteries, the first stents applied in the infrapopliteal vessels were all coronary devices. Once the feasibility of the stenting approach with these coronary products was shown, device manufacturers started to develop a dedicated infrapopliteal product range. To date, a broad spectrum of stent types has been used and investigated for the given indication. This article overviews the available literature and results of different balloon-expandable (bare metal, passive coated, drug eluting), self-expanding and absorbable stent types available for below-the-knee application and gives recommendations for future device technology advancements.

Present and future of endovascular SFA treatment: stents, stent-grafts, drug coated balloons and drug coated stents

The current evolution towards treating more complex femoropopliteal lesions as seen in the renewed TASC II recommendations clearly reflects the continuous evolutions in femoropopliteal stent design. Recent stent design improvements focus on decreasing stent fractures rates which can negatively impact patency rates. By rearranging strut alignment towards helical connecting bridges or full helical stent designs, stent designers have successfully improved the fracture resistance of their stents. The superior fracture resistance of the latest stent generation in combination with the production of long nitinol stents of up to 20 cm in length allow that more difficult and complex lesions can be treated endovascularly. The continuous perfection of nitinol stent platforms followed by the transfer of coronary technologies (e.g. active coatings) towards peripheral devices might broaden the indications for the minimal invasive strategy towards TransAtlantic Inter-Society Consensus (TASC) II C&D lesions.

Nitinol stenting for treatment of ''below-the-knee'' critical limb ischemia: 1-year angiographic outcome after Xpert stent implantation

AIM

We investigated the efficacy of Xpert (Abbott Vascular Devices) nitinol stents for the treatment of infrapopliteal lesions in patients with critical limb ischemia (CLI).

METHODS

Between May and October 2005, 47 CLI patients (35 men, mean age 73 years) received 67 Xpert stents for the treatment of 58 infrapopliteal lesions in 51 limbs; 43 patients (84.3%) were classified in Rutherford Category 4 and 8 (15.7%) in Category 5. Clinical examination and quantitative vascular analysis (QVA) were performed before and after the intervention and at 12-months follow-up. The primary endpoint was defined as 1-year angiographic binary restenosis rate (>50% stenosis on QVA); the secondary endpoints were 1-year primary patency and limb salvage rate.

RESULTS

QVA after 1 year showed a binary restenosis rate of 20.45%. Kaplan-Meier analysis revealed 1-year primary patency and limb salvage rates of 76.3% and 95.9%, respectively. The limb salvage rate was significantly better in patients with proximal below-the-knee (BTK) than in those with mid-section or distal lesions (100% vs 81.8%; P=0.0071).

CONCLUSION

Our results suggest that treatment with nitinol Xpert stents in CLI patients is effective and yields satisfactory angiographic and clinical outcome.

Endovascular therapy as the primary approach for limb salvage in patients with critical limb ischemia: experience with 443 infrapopliteal procedures

Endovascular strategies for the treatment of critical infrageniculate peripheral arterial occlusive disease exist and are becoming the primary methodology for such lesions at many centers. Although technically feasible for experienced operators, the evidence to support this strategy for below the knee (BTK) interventions is still evolving. We studied the 6-month and 1-year outcomes of percutaneous transluminal angioplasty (PTA) alone, PTA with stenting, and excimer laser recanalization for BTK lesions in patients with critical limb ischemia. Between September 2002 and June 2005, 443 patients (355 Rutherford category 4, 82 category 5, 6 category 6) underwent intervention for 681 BTK lesions. Follow-up was performed at 6-month intervals after index intervention: limb salvage data were recorded and duplex ultrasonography was performed to measure the patency of treated areas. The primary patency and limb salvage rates of the entire population were 85.2% and 97.0% and 74.2% and 96.6% at 6 months and 1 year, respectively. Stratified for the treatment strategy (PTA alone in 79, PTA with stenting in 300 patients, and excimer laser in 64), 1-year primary patency rates were 68.6%, 75.5%, and 75.4%, whereas the limb salvage rates were 96.7%, 98.6%, and 87.9% for each modality, respectively. Endovascular intervention will become the primary treatment for BTK lesions in patients with critical limb ischemia, with 1-year primary patency and limb salvage rates that compare favorably with published surgical data. Prospective, randomized, multicenter trials will be needed to further establish the role of endovascular intervention in this challenging patient group.

Are there predictive risk factors for complications after carotid artery stenting?

AIM

The aim of this study was to identify predictive risk factors for complications during and after carotid artery stenting (CAS).

METHODS

A multivariate analysis was performed on the databases of 4 European high-volume centers regarding risk factor distribution between patients presenting with or without neurological complications 30 days after CAS. The cumulative 30-day neurological complication rate (death, major stroke, minor stroke and transient ischemic attack) was 2.8% in the total examined cohort of 3 179 consecutive CAS procedures. The following risk factors were taken into consideration for statistical analysis: age, symptomatic, male gender, nicotine abuse, hypertension, hypercholesterolemia, polyvascular disease, diabetes, restenosis after carotid endarterectomy (CEA)/CAS, calcified internal carotid artery.

RESULTS

Symptomatic (P=0.02) or hypercholesterolemic (P=0.02) patients are at significantly increased risk for neurological events 30 days after CAS. Asymptomatic women and men without hypercholesterolemia have the lowest risk on any 30-day neurological complications after CAS.

CONCLUSIONS

CAS is a safe technique in experienced hands. Preprocedural neurological complaints and hypercholesterolemia can be defined as predisposing factors for 30-day neurological complications after CAS.

Does Free Cell Area Influence the Outcome in Carotid Artery Stenting?

OBJECTIVES

To identify if carotid stent design, especially free cell area, impacts on the 30-day rates for stroke, death and TIA after carotid artery stenting (CAS).

MATERIAL AND METHODS

A CAS database of 3179 consecutive CAS patients was retrospectively assessed. The distribution of neurological complications were analysed for association with the different stent types and designs. Events where subdivided into procedural and postprocedural events.

RESULTS

The overall combined rate of TIA, stroke and death was 2.8% at 30 days (late events 1.9%). The post-procedural event rate analyzed for differences stents varied from 1.2% using BSCI Carotid Wallstent to 5.9% using Medtronic Exponent. The late event rates varied from 1.2% to 3.4% for free cell areas <2.5mm(2) and >7.5mm(2) respectively (p<0.05). Post-procedural event rate was 1.3% for closed cells and 3.4% for open cells. All these differences were highly pronounced among symptomatic patients (p<0.0001).

CONCLUSIONS

After carotid stenting, complication rates vary according to stent type, free cell area and cell design. In the symptomatic population (and also in the total population), post-procedural complication rates are highest for the open cell types and increase with larger free cell area.

Flemish experience using the Advanta V12 stent-graft for the treatment of iliac artery occlusive disease

AIM

The aim of this study was to evaluate the technical feasibility and safety of implanting a polytetrafluoroethylene (PTFE) covered balloon expandable stent to treat iliac artery stenoses and occlusions. Additionally, the primary patency and clinical and hemodynamic efficacy at 1 year were analysed.

METHODS

This nonrandomized, prospective study involved patients with claudication and iliac artery occlusive disease at 2 participating centres. Patients with suitable lesions determined by clinical examination, ankle-brachial indices (ABIs), colour-flow duplex ultrasound (CFDU), magnetic resonance angiogram (MRA) and confirmed with biplanar digital subtraction angiography (DSA) were treated with PTFE-covered stainless steel stents. Procedural and 30-day periprocedural complications were recorded prospectively. According to in-hospital standards, follow-up with clinical ischemia category determination, ABI and CFDU was performed at 1, 6 and 12 months to determine treatment efficacy and primary limb patency.

RESULTS

In total, 91 limbs were treated in 65 patients (51 male; mean age 65 years). Stent-graft deployment was successful in 91 (100%) limbs. There were no limbs with residual stenosis >30%. There were no procedural or 30-day complications. The clinical ischemia category distribution improved significantly at 1, 6 and 12 months. The mean ABI rose significantly from 0.59 before treatment to 0.98, 0.98 and 0.99 at 1, 6 and 12 months after the procedure. Primary limb patency at 1-year was 91.1%

CONCLUSIONS

Implantation of Advanta V12 PTFE-covered stent for iliac occlusive disease shows to be safe and feasible with excellent clinical results at 1 year in the investigated patient cohort.

Do device characteristics impact outcome in carotid artery stenting?

OBJECTIVES

The study was conducted to identify patient and procedural parameters that negatively impact the 30-day rates for stroke, death and transient ischemic attack (TIA) after carotid artery stenting (CAS) and that might be modified or further studied in future efforts to improve CAS.

METHODS

This was a retrospective investigation of a dual-center CAS database of 701 consecutive CAS patients (414 men; mean age, 72.4 +/- 8.4). A subset of patient-related, lesion-related, or procedure-related variables (age >or=80, left sided lesion, symptomatic, nicotine abuse, hypertension, diabetes mellitus, other peripheral vascular disease, hypercholesterolemia, embolic protection devices usage, predilation, ulcerated lesion, echolucent plaque, restenosis after surgery) were analyzed for association with occurrence of stroke, death, or TIA <or=30 days after CAS. The odds ratio (OR) and 95% confidence interval (CI) and P value were calculated for each variable to predict adverse outcome.

RESULTS

The overall combined rate of stroke, death, and TIA within this database was 3.7% at 30 days. In the total population of 701 patients, only the OR of 2.7 for hypercholesterolemia (95% CI, 1.0 to 7.3; P = .041) was found to be significant. Subgroup analysis of the 304 symptomatic patients (43%) showed that open-cell stent designs and concentric EPD designs yielded an OR of 4.1 (95% CI, 1.4 to 12, P = .0136) and 3.3 (95% CI, 1.016 to 10, P = .0525), respectively, for 30-day stroke/death/TIA within this database. Analysis of open-cell stent designs and concentric EPD designs in patients with echolucent lesions yielded an OR of 3.1 (95% CI,1.2 to 8.2, P = .0343) and 3.7 (95% CI, 1.3 to 10, P = .0174), respectively, for 30-day stroke/death/TIA.

CONCLUSIONS

We conclude that increased analysis of device design variables may be necessary. Particularly in symptomatic patients or with echolucent lesions, closed-cell design and eccentric filters seem superior. Prospective investigation comparing open-cell vs closed-cell stents and eccentric vs concentric filter devices may be warranted.

Results with heparin bonded polytetrafluoroethylene grafts for femorodistal bypasses

AIM

Expanded polytetrafluoroethylene (ePTFE) grafts are commonly used for femoropopliteal (FP) and femorocrural (FC) bypass grafting. Especially in below-knee (BK) reconstructions, patency is often inferior to the outcome in patients eligible for venous bypass grafting. This study assesses whether the Carmeda BioActive Surface (CBAS), which employs covalent end-point linkage to retain heparin on the device surface, as it is used on the Propaten vascular graft successfully, can prolong patency.

METHODS

From June 2002 to December 2005, 138 patients (97 men and 41 women; mean age: 73 years) received the CBAS-ePTFE graft for 153 infrainguinal bypass procedures. Seventy-five above-knee (AK) and 78 BK (including 37 FC) procedures were performed. Follow-up evaluations consisted of clinical examinations, ultrasonographic studies, and distal pulse assessments. Patency and limb salvage rates were assessed by using life-table analyses.

RESULTS

The overall primary and secondary 2-year patency rates were 73.6% and 86%, respectively. Two-year primary patency rates according to bypass type were 76.2%, 72.6%, and 68.9% for AK FP, BK FP, and FC bypasses, respectively; the corresponding secondary patency rates were 87.5%, 87.8%, and 79.4%. The 2-year limb salvage rate in patients with critical limb ischemia (n=68) was 89.9%.

CONCLUSION

Our findings show that CBAS-ePTFE bypass grafts appear to give prolonged patency rates and indicate that the use of this graft may represent a viable alternative for BK bypasses, which have traditionally yielded less than desirable outcomes. A prospective randomized trial is required to provide more definitive information about the graft's patency and limb salvage performance.

Will absorbable metal stent technology change our practice?

Peripheral stents aim to support revascularization procedures of intravascular stenoses by mechanically preventing vessel recoil and counteracting pathophysiologic processes of luminal re-narrowing triggered by procedural injury of the vessel wall. Despite improvements in stenting techniques and concomitant medication, repeated intervention due to target lesion re-stenosis is necessary on a significant percentage of patients. The permanent presence of an artificial implant plays a prominent role in the discussion of mechanisms causing in-stent restenosis. Permanent metallic implants pose the risk of a continuous interaction between non-absorbable stent and surrounding tissue, leading to physical irritation, long-term endothelial dysfunction, or chronic inflammatory reactions. In addition, there is a risk of stent fracture due to external mechanical forces. To overcome these shortcomings, technology of stenting has moved towards the development of temporary implants composed of biocompatible materials which mechanically support the vessel during the period of high risk for recoil and then completely degrade in the long-term perspective. This removes a potential trigger for late restenosis.

Balloon-expandable, radially reinforced ePTFE relining of the superficial femoral artery after remote endarterectomy

AIM

The aim of this paper was to evaluate the mid-term results of remote endarterectomy and balloon-expandable, radially reinforced ePTFE endograft uplining of the superficial femoral artery (SFA) for long occlusions.

METHODS

One hundred and two limbs in 92 patients were included in this prospective, multicenter study. Indications were disabling claudication (n=74), restpain (n=10) and tissue loss (n=16) due to an SFA occlusion of at least 10 cm in length. Remote endarterectomy of the SFA using a modified ringcutter in an over-the-wire technique, was followed by implantation of a balloon-expandable Enduring endovascular graft. Control visits were performed at 1, 3 and 6 months postprocedure and every half year from then on. Follow-up protocol included physical examination, Doppler ankle-brachial index measurement and, in case of doubt, duplex examination.

RESULTS

A technical success rate of 98% was achieved. Mean follow-up was 36 months. Four patients were lost to follow-up and 17 patients died of nondevice-related causes. The primary, primary assisted and secondary patency rates were 68%, 73% and 97.5% at 1 year and 50%, 60%, and 89% at 3 years, respectively.

CONCLUSION

Although technical success rate is high and early patency rates are good, mid-term results are inferior to those of conventional femoro-popliteal synthetic bypass grafts. In order to become competitive to conventional bypass surgery, further technical refinements will be necessary, especially to overcome the problem of stenoses at the distal transition zone.

Percutaneous transluminal angioplasty for treatment of ''below-the-knee'' critical limb ischemia: early outcomes following the use of sirolimus-eluting stents

AIM

We investigated the safety and efficacy of sirolimus-eluting stents in the treatment of patients with severe below-the-knee' critical limb ischemia.

METHODS

Between October 2004 and January 2005 we performed 20 percutaneous transluminal angioplasty procedures on 18 patients (7 female, 11 male, mean age 72.8 years), implanting 24 sirolimus-eluting stents. At pre-procedure, 12 patients (66.7%) presented with a Rutherford Category 4, 4 (22.2%) with Category 5 and 2 (11.1%) with Category 6. The majority of patients (72.2%, n=13) were non-smokers and 77.8% (n=14) presented with hypercholesterolemia. Calcification was present in 52.2% (n=12) of lesions. Pre-dilation was performed in half the patients. The majority of lesions (95.7%, n=22) were treated with a single sirolimus-eluting stent. Two patients underwent 2 procedures, each one receiving 2 sirolimus-eluting stents. Clinical examination and quantitative vascular analysis were performed in all patients at discharge and at 6-month follow-up.

RESULTS

Percutaneous transluminal angioplasty was successfully performed on all 18 patients. The mean stent length and stent diameter were 30.29 mm and 3.23 mm, respectively. Mean follow-up was 256 days (170-368 days). At the 6-month follow-up, the minimum lumen diameter as measured by Quantitative Vessel Analysis was 2.39 mm with an attendant LLS of 0.38 mm. The overall 6-month survival and limb salvage rate were 94.4% and 94%, respectively.

CONCLUSIONS

Our results suggest that treatment with sirolimus-eluting stents can be considered as an effective and safe treatment of patients with critical ischemia.