Offroad re-entry catheter system for subintimal recanalization of chronic total occlusions in femoropopliteal arteries: primary safety and effectiveness results of the re-route trial.

AIM: Aim of the study was to provide additional clinical data regarding the safety and technical success of the OffRoad Re-Entry Catheter System (Boston Scientific, Natick, MA, USA) for subintimal recanalization of chronic total occlusions (CTO) in the femoropopliteal arteries. METHODS: A total of 92 patients (mean age 70.3±10.6 years; 70% male) were enrolled in this prospective, single-arm, post-market study conducted at 12 European centers. Patients were required to have claudication or critical limb ischemia and a CTO lesion in a native femoropopliteal artery. The primary safety endpoint was the composite rate of device-related major adverse events (MAEs; i.e., death, perforation requiring intervention, clinically significant peripheral embolism, and major amputation of the treated lower limb) at 30 days. Effectiveness was based on device technical success, defined as placement of a guidewire in the true lumen distal to a CTO. RESULTS: Ninety patients were evaluable for the primary safety endpoint. The 30-day device-related MAE rate was 3.3% (3/90), with an upper confidence bound of 6.5%, which was lower than the prespecified performance goal of 15%. All 3 events were clinically significant peripheral emboli. Technical success was 84.8% (78/92) with a lower confidence bound of 78.6%, which exceeded the prespecified performance goal of 76%. A decrease of ≥1 Rutherford category was observed in 75% (65/87) of patients at the 30 day visit. CONCLUSION: The Re-ROUTE trial results demonstrate acceptable performance of the OffRoad system in terms of safety and technical success for the recanalization of femoropopliteal CTOs.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.