Importance of exchange of vascular trainees among centers.

Training in surgery has for a long time been based on the classical model of master-apprentice, leading to the creation of "schools" comparable to the famous painter schools of Rubens, Rembrandt and many others during the Middle Ages. Although it may offer some advantages, this model is no longer suitable today. Modern vascular surgery covers several fields, including not only open vascular and endovascular treatment, but also non-invasive diagnosis and medical treatment of vascular diseases in different parts of the human body. However, the goal of training remains the formation of a "holistic vascular surgeon", with knowledge of and experience in all these areas. As most training centers are more focused on and have more expertise in one or some of these areas, an ideal training curriculum would consist of a rotation between different centers with different points of attention and possibly even rotations in other specialties, such as interventional radiology, vascular medicine or ultrasonography. Such an exchange cannot only be beneficial for the trainee but contact with trainees with a different background can also offer an added value to the training center. Thanks to new ways of communication and transportation, exchange of trainees, even in different countries, has become much easier. Nevertheless, a problem often arises concerning the requirements for training as, despite the many efforts already undertaken, it still differs significantly between different countries. The development of a core-curriculum and mutual recognition of training centers is urgently needed and further steps in the harmonization of training programs and requirements need to be stimulated.

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.

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.

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.

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 use of the cryoplasty technique in the treatment of infrapopliteal lesions for Critical Limb Ischemia patients in a routine hospital setting: one-year outcome of the Cryoplasty CLIMB Registry.

AIM: It was the objective of the Cryoplasty CLIMB to evaluate the effectiveness of the PolarCath device in a standard clinical practice in the treatment of infrapopliteal lesions in critical limb ischemia patients. METHODS: Between May 2007 and July 2008, 100 patients (72 years, 67%male) with CLI were enrolled in the trial for the treatment of 100 infrapopliteal stenoses or occlusions. The mean lesion length and diameter stenosis were 54.9+/-55.8 mm and 91.3+/-8.3%. Primary endpoint was defined as 12-month primary patency based on duplex. Secondary endopoints were immediate success and 12-month limb salvage and survival rate. RESULTS: Multiple cryoplasty cycles were performed in 56 cases (2.1 inflations per patient) and in 4 the use of a different size balloon was required. The immediate technical success rate was 95.0% and the stent rate was 17.0%. The 12 month primary patency, limb salvage and survival rates were 55.9+/-7.4%, 93.8+/-2.5% and 81.8+/-3.9%, respectively. Stratification for lesion length did not show significant outcome differences for lesions < or =50.0 mm and those >50.0 mm neither for primary patency (P=0.94), nor for limb salvage (P=0.32). CONCLUSION: The cryoplasty technique is effective for the treatment of infrapopliteal lesions in CLI patients. The results seem to be within the range of those of conventional PTA. Especially for shorter lesion (<50.0 mm), the wide-spread use of cryoplasty is not recommended. For lesions with a minimal length of 50.0 mm, the results are encouraging.

Impact of stent design on the outcome of intervention for carotid bifurcation stenosis.

Over the past several years, there has been continued significant interest in refinement of patient selection, devices, procedures and protocols in an effort to optimize the outcome of percutaneous intervention for carotid bifurcation stenosis, including: ongoing National Institutes of Health and manufacturer trials and registries; the further refinement of existing devices and emergence of new platforms to attain distal embolic protection; ongoing study of what really constitutes a high-risk carotid surgery or stenting patient; and attention to device characteristics and patient-device matching. Within the latter area, considerable interest has focused on stent characteristics that have the potential to impact short and long-term outcome when compared with other stent design strategies when studied in large series. The stent in carotid artery intervention occupies a unique role in that after the embolic protection system has been removed, it is the main line of defense (in concert with aggressive dual antiplatelet therapy) from embolic and thromboembolic complications that may arise from the newly remodeled plaque after post-stent angioplasty. In this review, we aim to update the current status of efforts to relate stent design strategy to outcome in intervention for extracranial carotid artery disease with a focus primarily on the function of "free cell area" (typically lower with closed-cell stents and higher with open-cell stents) in analyses of outcome in carotid artery stenting. Also, the potential role of closed-cell vs. open-cell stent selection in other reports related to carotid artery stenting outcome or complications is reviewed. Rigorous studies have examined the issue of free cell area and arrived at disparate conclusions. Randomized data on the impact of free cell area and cell design strategy on carotid intervention are presently lacking. However, we believe sufficient data and rationale exist 1) to warrant ongoing study of the impact of stent design on outcome in carotid intervention; and 2) to make consideration of closed-cell (low free cell area) stent use a reasonable approach to device selection--when patient factors, lesion characteristics, or device availability make doing so possible.

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.

Carotid endovascular interventions: patient selection, devices, techniques and tips.

The optimal treatment of patients with asymptomatic or symptomatic carotid artery disease (CAD) has been a long-lasting debate. The choice between carotid endarterectomy (CEA), carotid artery stenting (CAS) and/or optimal medical therapy to treat patients with CAD, depends on their risk profile. Recent data from EVA-3S, SPACE randomized trials failed to demonstrate non-inferiority for CAS over CEA. However, other publications suggest that with growing experience and the development of dedicated CAS technology, CAS can be performed safely and efficiently. The success of carotid stenting does not solely depend on the operator's skills and experience, but also on the adequate selection of carotid stents and cerebral protection devices. Currently, CAS practitioners are confronted with a large number of dedicated CAS devices (stents and embolic protection devices). This wide array of products makes individual treatment strategies difficult to generalise as no single device possesses all of the optimal features to treat all types of carotid plaques and patients. This article reviews the principles of patient selection and device selection in contemporary CAS practice.

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.

What practical factors guide the choice of stent and protection device during carotid angioplasty?

The importance of angioplasty and stenting in the treatment of carotid artery disease cannot be underestimated. Successful carotid stenting does not only depend of the operator's skills and experience, but also an adequate selection of cerebral protection devices and carotid stents can help avoiding neurological complications. A broad spectrum of carotid devices is currently on the market and since all have their assets and downsides, it is virtually impossible to acclaim one specific device as being the best. The individual characteristics of each specific protection system or stent may make it an attractive choice in one circumstance, but render it a less desirable option in others situations. The applicability depends primarily on the arterial anatomy and the specific details of the lesion being treated. But certainly, personal preferences and familiarity with a specific device may legitimately influence the decision to choose one over another.

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.

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.

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.

Review of stents for the carotid artery.

The individual characteristics of a stent may make it an attractive choice in some circumstances, but render it a less desirable option in others. The applicability depends primarily on the arterial anatomy and the specific details of the lesion being treated. A careful assessment by the interventionalist is required to select the proper type of stent that is of appropriate size. Certainly, personal preferences and familiarity with a specific device may legitimately influence the decision to choose one stent over another. Finally, stent design can play a role in the selection procedure. Although carotid stents are often functionally equivalent in the clinical setting and have been used successfully to treat a wide variety of lesions, a basic knowledge of stent geometry can contribute to make up your mind in certain carotid cases.

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.

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.