The use of chimney technique in endovascular repair of abdominal aortic aneurysms (ChEVAR) has had a secondary role. Although it was first developed in an emergent/urgent setting, the publication of various important studies has helped overcome scepticism towards this technique in elective procedures. This paper reviews current evidence about ChEVAR, focusing on clinical results, technical notes and comparisons with other techniques. The new ChEVAR findings show favourable mid- and long-term clinical outcomes, even in elective patients. These results, comparable to those related to fenestrated endografts, have been achieved through standardisation in planning and materials. An adequate endograft oversizing associated to the right aortic neck length is fundamental to avoid ChEVAR-related complications, such as type 1a endoleaks. These data indicate that ChEVAR, compared to other complex endovascular treatments, has comparable outcomes along with features that could make it an essential option in every clinical setting.
Current guidelines dictate emergency repair for an acute complicated type B aortic dissection (TBAD). Surgical approaches for the treatment of acute complicated TBAD can be divided into open and endovascular. The endovascular approach is further divided into central aortic repair and alternative endovascular techniques. Central repair includes endoluminal aortic stent graft repair, such as thoracic endovascular aortic aneurysm repair and provisional extension to induce complete attachment, extended provisional extension to induce complete attachment and stent-assisted balloon-induced intimal disruption and re-lamination in aortic dissection repair techniques. Alternative endovascular techniques include reno-visceral stenting, endovascular aortic membrane fenestration and targeted false lumen thrombosis. This review discusses and compares the various endovascular approaches to repair of acute complicated TBAD, focusing on central versus alternative endovascular techniques. We also discuss indications for technique selection, focusing on the acute management of complicated TBAD.
Venous stenting was introduced in the 1990s and has continued to evolve to become the first-line therapy for symptomatic iliofemoral venous outflow pathology. There are several dedicated venous stents available in addition to Boston Scientific’s Wallstent and Cook’s Z-Stent. Numerous studies from tertiary referral centres, as well as industry-sponsored trials, have demonstrated the safety and efficacy of these endovascular devices for non-thrombotic iliac vein (NIVL) and post-thrombotic syndrome (PTS) lesions. Patients presenting with acute deep venous thrombosis (aDVT) may also undergo stenting following thrombus removal. The standard of care for NIVL, PTS and aDVT patients has become venography and intravascular ultrasound, and if an underlying iliofemoral stenosis is identified, a stent is placed. There is a concern that inflammation may affect the results of stenting in the aDVT population. Although endovascular stenting for acute venous diseases appears promising and safe, there is a paucity of data on efficacy in aDVT patients. There are only two industry-sponsored trials and a few publications and presentations at academic society meetings to examine. This review assesses the available results for endovascular stenting for aDVT and PTS patients, but not for NIVL.
Atherosclerotic disease significantly impacts patients with type 2 diabetes, who often present with recalcitrant peripheral ulcers. The angiosome model of the foot presents an opportunity to perform direct angiosome-targeted endovascular interventions to maximise both wound healing and limb salvage. A systematic review was performed, with 17 studies included in the final review. Below-the-knee endovascular interventions present significant technical challenges, with technical success depending on the length of lesion being treated and the number of angiosomes that require treatment. Wound healing was significantly improved with direct angiosome-targeted angioplasty, as was limb salvage, with a significant increase in survival without major amputation. Indirect angioplasty, where the intervention is applied to collateral vessels to the angiosomes, yielded similar results to direct angiosome-targeted angioplasty. Applying the angiosome model of the foot in direct angiosome-targeted angioplasty improves outcomes for patients with recalcitrant diabetic foot ulcers in terms of primary wound healing, mean time for complete wound healing and major amputation-free survival.
Below-the-knee (BTK) peripheral arterial disease (PAD) is a significant source of cardiovascular morbidity and mortality. Patients with chronic limb-threatening ischaemia in BTK PAD represent one of the highest-risk cohorts of PAD patients, with little progress having been made regarding long-term patency and mortality over the past four decades. Although conventional balloon angioplasty has long been the standard of care, several novel scaffolds have been introduced over the past decade with promising 1-year patency rates and freedom from clinically driven target limb revascularisation, which may herald a new age of endovascular intervention for BTK PAD. In this review, we present a critical appraisal of the literature surrounding novel scaffolds and drug-eluting technology in the treatment of BTK PAD.
2][3][4][5] To better understand the mechanism of thrombus formation at this specific anatomical level, subclavian DVT has been categorised as primary and secondary.
Endovascular treatment has become an accepted method in the treatment of aortoiliac occlusive disease. Bare metal stents have been used in the treatment of aortoiliac disease since the early 1990s. More recently, the use of covered stent grafts in the aortoiliac segment has shown clinical benefit in terms of patency, freedom from reintervention and quality of life. The VBX FLEX study evaluated the safety and efficacy of the Gore VBX stent graft for use in the aortoiliac segment. The early and mid-term data on the Gore VBX stent graft have shown it to be a safe device for use in the treatment of aortoiliac occlusive disease. This review examines the use of stents in aortoiliac occlusive disease with specific focus on the VBX FLEX Study.
Patients with post-thrombotic syndrome (PTS) and iliac vein obstruction have lower extremity symptoms, activity limitation and impairment of health-related quality of life. Preliminary studies suggest that iliac vein stent placement, which eliminates venous outflow obstruction, may reduce the clinical severity of PTS. However, stent placement is associated with patient risk, inconvenience and cost. Therefore, the Chronic Venous Thrombosis – Relief with Adjunctive Catheter-directed Therapy (C-TRACT) trial was launched to rigorously assess the risk–benefit ratio of stent placement for the treatment of moderate or severe PTS. In the trial, patients in both treatment groups receive a high quality of multi-modality PTS care that includes medical, compressive, and ulcer therapies. Due to the COVID-19 pandemic, the trial protocol and practices were modified to enhance the study feasibility while preserving its ability to answer its primary question. This review summarises the current status of the trial and the potential impact of the pandemic-related adaptations to future venous clinical practice and research.
Renal injuries are the most common urinary tract injury secondary to external abdominal trauma. They are caused by blunt, penetrating and iatrogenic mechanisms. Despite the high number of blunt renal injuries, little evidence is available to guide management, especially with the evolution of embolisation as a minimally invasive treatment. Consequently, clinical practice is driven by results of observational studies and anecdote. We have reviewed the current trends in practice when using renal artery embolisation in the management of blunt renal injuries. Three key principles are highlighted. First, high-grade blunt renal injuries can be successfully managed with embolisation. Second, embolisation should be considered when there is radiological evidence of active contrast extravasation, pseudoaneurysm or arteriovenous fistula. Third, embolisation can be used to manage blunt renal injuries in haemodynamically unstable patients. Beyond this, evidence regarding optimal technique, CT indications, clinical status, comorbidities and complications are inconclusive. We discuss the implications for clinical practice and how these findings should define the agenda for future clinical research.
Non-thrombotic iliac vein lesions (NIVLs) refer to iliac vein lumen stenosis, usually secondary to extrinsic compression, without associated thrombosis. Clinical presentation varies; patients may be asymptomatic, have symptoms of lower extremity venous hypertension, or in women, may be associated with chronic pelvic pain. Given the significant variability in symptomatology, thorough history and physical examination are mandatory in excluding other causes of symptoms. Non-invasive imaging, such as venous duplex/insufficiency ultrasound examinations, and axial imaging aid in the diagnosis of a NIVL in the appropriate clinical context. Catheter venography and intravascular ultrasound remain the primary modalities for definitive diagnosis, treatment planning, and ultimately placement of self-expanding venous stents to resolve the causative iliofemoral venous obstruction. In appropriately selected patients, stent placement can lead to marked improvements in symptoms, heal stasis ulceration when present, and improve disease-specific and overall quality of life. Stents placed in patients with NIVL demonstrate high long-term primary patency. In this article, the authors discuss clinical presentation, diagnostic workup, endovascular interventions and outcomes of NIVL treatment.
Historically, anticoagulation has been the primary treatment for acute lower extremity deep venous thrombosis (DVT) with or without thrombolysis. Despite large amounts of clinical research data supporting an ‘open vein hypothesis’, which favours early thrombus removal, clinicians have been hesitant to take this option due to a historically high risk of major bleeding and a few notable studies that failed to show any meaningful benefit. The ATTRACT trial failed to show the benefit of using pharmacomechanical catheter-directed thrombolysis (PCDT) for iliofemoral and femoropopliteal DVT but did result in more bleeding. However, the CaVent study before it revealed a significant reduction in post-thrombotic syndrome (PTS) for patients with iliofemoral and femoral DVT after long-term follow-up past 24 months that grew over time. Since these trials, there have been significant advancements in magnetic resonance and CT venography, intravascular ultrasound (IVUS), venous stenting and thrombectomy catheters meaning there is little to no need for adjunct thrombolytics. Results from ongoing research such as CLEAR-DVT reflect the advances in modern technology.
Chronic venous disease (CVD) of the lower extremities is a complex process encompassing abnormalities related to venous drainage secondary to thrombotic and non-thrombotic pathologies. CVD can have an untold economic impact due to lost productivity and the costs of treating its sequela and underlying aetiologies. Building a comprehensive venous service for the treatment of CVD requires a multifaceted approach with longitudinal care, similar to those that have been developed for peripheral arterial disease and oncology.
Extension of an iliofemoral thrombosis into the inferior vena cava (IVC), or from the IVC descending into the iliofemoral segments, can confer significant morbidity and mortality. Interventional management of acute deep vein thrombosis (DVT) has been controversial, but there is little doubt that certain subpopulations benefit, such as those with symptomatic IVC thrombosis. When considering an intervention, caval involvement introduces technical difficulties due to its larger diameter, high thrombus burden, bilateral limb clot extension and need for dual access. The frequent coexistence of an IVC filter increases the complexity even more. This review summarises the current indications and treatment modalities available for the management of acute DVT involving the vena cava.
A new smart polymer technology developed by Shape Memory Medical is available to endovascular specialists. The shape memory polymer is incorporated into vascular plugs and coils. Dr Ross Milner, a vascular surgeon at University of Chicago Medicine, gives his perspective on the properties of the shape memory polymer and how smart polymer devices may be used in vascular surgery.
Carotid interventions, carotid endarterectomy and carotid artery stenting (CAS) have proven to be effective treatments for the prevention of ischaemic stroke in recently symptomatic patients. Most studies were conducted before the development of strict statin guidance and the systematic use of antiplatelet drugs. The advances in medical treatments have raised questions regarding the benefit of carotid endarterectomy or CAS, especially for high-grade asymptomatic internal carotid artery stenosis. Reviewing the literature indicates that carotid artery stenosis of any degree is a relatively weak predictor of ipsilateral stroke, in the absence of recent symptoms referable to the carotid disease. This risk does not appear reduced by revascularisation by CAS if added to modern day best medical therapy. On-going trials are key to understanding if current techniques can provide an additional benefit.
The anterior accessory saphenous vein (AASV) is a common source of primary and recurrent lower extremity varicose veins. Reflux in the AASV can occur independently or simultaneously with great saphenous vein (GSV) reflux. A number of published reports describe recommendations and treatment of symptomatic refluxing AASVs, but descriptions of combined treatment are sparse. Treatment options for ablation of the AASV include both thermal and non-thermal techniques, and results are equivalent to ablation of the great and small saphenous veins. Although not commonly performed, concomitant ablation of the AASV and the GSV is effective and safe, and can be accomplished with minimal additional time. Concomitant treatment is an appropriate option that should be discussed with the patient.
The role of paclitaxel in the treatment of femoropopliteal peripheral arterial disease is currently ambiguous. A summary-level meta-analysis of randomised trials published in 2018 demonstrated that paclitaxel-coated devices were associated with an increased all-cause mortality in those who underwent treatment at 2 years and 5 years. Further evaluation has been undertaken to establish whether there is a specific dose response, mechanism or reproducible signal. At this time, there has been no confirmation of dose response, as was initially asserted by the summary-level meta-analysis. No mechanism of harm has been identified. Although an association with increased mortality has been confirmed by patient-level meta-analysis, the strength of the signal has been inconsistent. The information suggests there is only an association between paclitaxel-coated devices and increased all-cause mortality, not causation. The authors encourage additional studies designed to follow long-term results after treatment with paclitaxel-coated devices, using real patient data, before a conclusion can be made.
Giant visceral aneurysms (or pseudoaneurysms) are aneurysmal lesions of the splanchnic vessels that are larger than 5 cm in diameter. As with other visceral aneurysms, treatment may be either surgical or endovascular. Both treatments face challenges given the anatomical complexity of such lesions. However, in the era of novel tools and techniques that have been developed in this field, an increasing number of giant visceral aneurysms can now be treated using endovascular approaches. The purpose of this article is to offer an overview of the most current techniques and trends in the endovascular treatment of giant visceral artery aneurysms.
Drug-coated balloons (DCBs) have become an established therapy for the treatment of above-the-knee peripheral artery disease. The paclitaxel DCB has shown clinical benefit in terms of patency and freedom from re-intervention in multiple randomised trials. However, a recent meta-analysis has suggested an association between mortality and the use of paclitaxel-coated devices. Sirolimus is another potential choice of anti-proliferative agent for use in DCBs because of its wider therapeutic index and lower risk for dose-dependent toxicity. More recently, encapsulating sirolimus in micro-reservoirs or polymers has facilitated the development of effective sirolimus DCBs, some of which are available in Europe and Asia. In this review, the authors focus on paclitaxel and sirolimus DCB technologies from the standpoint of drug characteristics and clinical trials.
Transradial access (TRA) via the left radial artery is an alternative to traditional transfemoral access for catheter-based procedures that is becoming increasingly more relevant in all types of arterial vascular interventions. First investigated in the realm of cardiology, TRA has been proven to provide many benefits (such as lower complication rates, lower cost, and improved patient comfort during and after the procedure) when compared with traditional femoral access while maintaining efficacy. This article provides an in-depth summary of the technical aspects of radial access while incorporating more recent data to explain patient preference for TRA, and the ways that TRA can improve peri-procedure workflow and compensation. It also describes potential complications, such as radial artery spasm, difficult anatomic variants and radial artery occlusion, and then gives techniques for mitigating and treating these complications. The article explains why TRA has become an important option for vascular and interventional radiology physicians, and why it is likely that this will continue to grow in relevance.
