Spontaneous bilateral superficial femoral artery pseudoaneurysms and a unilateral posterior tibial artery aneurysm in an immunocompromised patient.

Key Clinical Message: The presence of multiple pseudoaneurysms in a patient should prompt investigations for the underlying etiologies including autoimmune and immunosuppressive disease processes. Treatment options include open repair and endovascular stenting. Abstract: Pseudoaneurysms (also known as false aneurysms) are atypical dilatations or outpouchings from a vessel which are not always contained by the three layers of a normal vessel wall, namely the intima, media, and adventitia. These are distinct from a true aneurysm which has a wall comprising all three layers. The underlying etiology for both true aneurysms and pseudoaneurysm can vary. We present the rare case of bilateral superficial femoral artery pseudoaneurysms, of unknown etiology and a concurrent posterior tibial artery saccular aneurysm in a patient with Human Immunodeficiency Virus (HIV) infection and multiple comorbidities. This was managed using a combination of endovascular covered stent grafts and open surgical repair technique. The patient is doing well on follow-up a year later with no post-operative infections. A literature review of the existing reports of superficial femoral artery pseudoaneurysms and posterior tibial artery aneurysms and their management is also reported.

National UK Survey of Radiation Doses During Endovascular Aortic Interventions.

PURPOSE: Endovascular aortic repair (EAR) interventions, endovascular abdominal aortic repair (EVAR) and thoracic endovascular aortic repair (TEVAR), are associated with significant radiation exposures. We aimed to investigate the radiation doses from real-world practice and propose diagnostic reference level (DRL) for the UK. MATERIALS AND METHODS: Radiation data and essential demographics were retrospectively collected from 24 vascular and interventional radiology centres in the UK for all patients undergoing EAR-standard EVAR or complex, branched/fenestrated (BEVAR/FEVAR), and TEVAR-between 2018 and 2021. The data set was further categorised according to X-ray unit type, either fixed or mobile. The proposed national DRL is the 75th percentile of the collective medians for procedure KAP (kerma area product), cumulative air kerma (CAK), fluoroscopy KAP and CAK. RESULTS: Data from 3712 endovascular aortic procedures were collected, including 2062 cases were standard EVAR, 906 cases of BEVAR/FEVAR and 509 cases of TEVAR. The majority of endovascular procedures (3477/3712) were performed on fixed X-ray units. The proposed DRL for KAP was 162 Gy cm2, 175 Gy cm2 and 266 Gy cm2 for standard EVAR, TEVAR and BEVAR/FEVAR, respectively. CONCLUSION: The development of DRLs is pertinent to EAR procedures as the first step to optimise the radiation risks to patients and staff while maintaining the highest patient care and paving the way for steps to reduce radiation exposures.

EMBIO trial study protocol: left gastric artery embolisation for weight loss in patients living with obesity with a BMI 35-50 kg/m2.

INTRODUCTION: Left gastric artery embolisation (LGAE) is a well-established treatment for major upper gastrointestinal (GI) bleeding when control is not established via upper GI endoscopy and recently has shown promising results for weight loss in small single arm studies. LGAE could be a treatment option in between our current tier-3 and tier-4 services for obesity. EMBIO is a National Institute for Health Research funded trial, a multicentre double-blinded randomised controlled trial between Imperial College National Health Service Trust and University College London Hospital, comparing LGAE versus Placebo procedure. The key aims of the trial is to evaluate LGAE efficacy on weight loss, its mechanism of action, safety profile and obesity-related comorbidities. METHODS AND ANALYSIS: 76 participants will be recruited from the existing tier-3 database after providing informed consent. Key inclusion criteria include adults aged 18-70 with a body mass index 35-50 kg/m2 and appropriate anatomy of the left gastric artery and coeliac plexus on CT Angiogram. Key exclusion criteria included previous major abdominal and bariatric surgery, weight >150 kg, type 2 diabetes on any medications other than metformin and the use of weight modifying medications. Participants will undergo mechanistic visits 1 week prior to the intervention and 3, 6 and 12 months postintervention. Informed consent will be received from each participant and they will be randomised in a 1:1 ratio to left gastric artery embolisation and placebo treatment. Blinding strategies include the use of moderate doses of sedation, visual and auditory isolation. All participants will enter a tier-3 weight management programme postintervention. The primary analysis will estimate the difference between the groups in the mean per cent weight loss at 12 months. ETHICS AND DISSEMINATION: This trial shall be conducted in full conformity with the 1964 Declaration of Helsinki and all subsequent revisions. Local research ethics approval was granted by London-Central Research Ethics Committee, (Reference 19/LO/0509) on 11 October 2019. The Medicines and Healthcare products Regulatory Agency (MHRA) issued the Letter of No Objection on 8 April 2022 (Reference CI/2022/0008/GB). The trial's development and progress are monitored by an independent trial steering committee and data monitoring and ethics committee. The researchers plan to disseminate results at conferences, in peer- reviewed journals as well as lay media and to patient organisations. TRIAL REGISTRATION NUMBER: ISRCTN16158402.

The Current Use of Drug-Eluting Balloons and Stents in Peripheral Arterial Disease: An Online Survey by the Cardiovascular and Interventional Radiological Society of Europe (CIRSE).

PURPOSE: To assess the current use of drug-eluting devices for peripheral arterial disease (PAD) among interventional radiologists following the controversy caused by the 2018 meta-analysis suggesting an increased mortality risk for paclitaxel-eluting devices. METHODS: An anonymous survey was sent to 7035 CIRSE members via email; only complete responses were included and statistically analysed. RESULTS: Three hundred and seven members (4.4%) completed the survey. Among these, 95.8% indicated that they personally perform peripheral vascular procedures. Thirty-eight percentage of respondents did not see any change of practice since 2018, while 47% reported that the use of drug-eluting devices decreased; for 13%, the use stopped altogether, while it increased in 3% of responses. 45.6% of respondents also felt the impact of the controversy in terms of pricing, availability or directives from hospital administration. A large majority of respondents (83.7%) who perform peripheral vascular procedures consider the use of these devices as safe, 12.9% were undecided and 3.4% did not consider them as safe. Among the respondents who do not perform endovascular procedures, 77% considered these devices as safe and 23% were undecided. CONCLUSION: Although the 2018 meta-analysis had a disruptive impact on the use of drug-eluting devices in PAD, with the increasing body of evidence available, a majority of respondents continue to believe in the safety of these devices for use in femoropopliteal disease.

Interventional radiology training in the UK: a view from within-a national survey.

OBJECTIVE: Interventional radiology (IR) training in the UK has evolved since recognition as a subspecialty in 2010 and introduction of a new curriculum in 2021. The changing landscape, increasing workload and COVID-19 have affected training. The purpose of this study was to review trainees' perspectives on training and develop strategies to further improve training. METHODS: Online survey approved by the British Society of Interventional Radiology Council distributed to British Society of Interventional Radiology Trainee members between 9 March 22 and 25 March 2022. The survey was open to all UK based ST4-6 IR trainees and fellows. Descriptive and thematic analysis was undertaken. RESULTS: 43 responses were received from 17/19 UK training regions. Females represented 10% (4/41) and 5% (2/43) less than full time (LTFT) trainees. 82% (31/38) felt their curriculum was suitable for their training and 28/38 (74%) were satisfied with IR training. Vascular IR, Interventional Oncology, paediatrics and stroke thrombectomy were identified as areas of training desiring improvement. 45% (18/40) stated exposure to IR led clinics and 17.5% (7/40) to IR led ward rounds. Only 6/38 (15.7%) received structured IR teaching at least once a month. Approximately, a third of respondents (13/38) stated training opportunities were significantly compromised secondary to COVID-19. CONCLUSION: This survey shows overall good satisfaction with IR training. However, improved training opportunities in vascular IR, interventional oncology, paediatric IR and stroke thrombectomy are required. In addition, access to clinics, ward rounds and protected time for research is needed to improve training quality. ADVANCES IN KNOWLEDGE: New national UK IR training survey.

Computational modeling of low-density lipoprotein accumulation at the carotid artery bifurcation after stenting.

Restenosis typically occurs in regions of low and oscillating wall shear stress, which also favor the accumulation of atherogenic macromolecules such as low-density lipoprotein (LDL). This study aims to evaluate LDL transport and accumulation at the carotid artery bifurcation following carotid artery stenting (CAS) by means of computational simulation. The computational model consists of coupled blood flow and LDL transport, with the latter being modeled as a dilute substance dissolved in the blood and transported by the flow through a convection-diffusion transport equation. The endothelial layer was assumed to be permeable to LDL, and the hydraulic conductivity of LDL was shear-dependent. Anatomically realistic geometric models of the carotid bifurcation were built based on pre- and post-stent computed tomography (CT) scans. The influence of stent design was investigated by virtually deploying two different types of stents (open- and closed-cell stents) into the same carotid bifurcation model. Predicted LDL concentrations were compared between the post-stent carotid models and the relatively normal contralateral model reconstructed from patient-specific CT images. Our results show elevated LDL concentration in the distal section of the stent in all post-stent models, where LDL concentration is 20 times higher than that in the contralateral carotid. Compared with the open-cell stents, the closed-cell stents have larger areas exposed to high LDL concentration, suggesting an increased risk of stent restenosis. This computational approach is readily applicable to multiple patient studies and, once fully validated against follow-up data, it can help elucidate the role of stent strut design in the development of in-stent restenosis after CAS.

Well-being and Burnout Amongst Interventional Radiologists in the United Kingdom.

PURPOSE: To assess the prevalence of burnout amongst Interventional Radiologists (IRs) in the United Kingdom and identify demographic and practice-related stressors that may adversely affect well-being. MATERIALS AND METHODS: A survey of 36 questions was divided into two sections. Section A consisted of 14 questions that assessed demographics and work characteristics; Section B assessed burnout, utilizing the 22-item Maslach burnout inventory. Four additional open-ended questions were included to allow participants to voice opinions on the biggest contributors to workplace burnout and plans that could be implemented to alleviate this. The questionnaire was distributed to the British Society of interventional (BSIR) members. The study was conducted between August and September 2022. RESULTS: Moderate to severe scores in emotional exhaustion (EE) were recorded in 65% of participants (moderate 26%; severe 39%) of participants r. Moderate to severe depersonalization (DP) scores were recorded in 46% of participants (moderate 23%; severe 23%). Low-moderate levels of personal accomplishment (PA) scores were recorded in 77% of respondents (low 50%; moderate 27%). Weekly hours and out-of-hour IR cover were statistically significant in predicting emotional exhaustion. Age, sex (male), time available for teaching, and weekly hours were statistically significant in predicting the depersonalisation score. Age was a predictive factor for personal accomplishment. The most recurring themes in open response to major contributors of burnout were shortage of IR clinicians and supporting staff as well as the increasing IR workload. CONCLUSIONS: This survey has demonstrated high prevalence of burnout amongst Interventional Radiologists in UK. Urgent measures are required to tackle the workforce shortage, recognition of IR workload and control IR resources.

Umbrella review and meta-analysis of reconstructed individual patient data of mortality following conventional endovascular and open surgical repair of infrarenal abdominal aortic aneurysm.

OBJECTIVES: This umbrella review aims to quality assess published meta-analyses, conduct a de-novo meta-analysis of the available randomized control trials (RCTs), and test the hypothesis that there is a long-term difference in mortality between OSR and EVAR. METHODS: A systematic search was conducted in MEDLINE and EMBASE's bibliographic databases (June 2022). Data were extracted using standardized extraction forms. The methodological quality of publications was assessed using the ROBIS tool. Data were analyzed with 'one-stage' and 'two-stage' approaches. RESULTS: According to two-stage analysis, EVAR has significantly favorable mortality for up to four years (increasing evidence). Subsequently, until the longest available time period, there is no difference between EVAR and OSR; all the results are statistically non-significant.In one stage analysis, the Cox model demonstrated a non-significant (weak evidence) hazard ratio of 1.03 (95% confidence interval [CI]: 0.94-1.12) in favor of OSR. The best-fitting parametric model (generalized gamma), leads to an hazard ratio of 0.97 (95% CI: 0.93-1.01) in favor of EVAR, with the results approaching significance (weak evidence). CONCLUSION: The results of this umbrella systematic review and meta-analysis failed to demonstrate any difference in long-term mortality following planned EVAR, compared with OSR of infrarenal AAA.

Carbon dioxide flushing versus saline flushing of thoracic aortic stents (INTERCEPTevar): protocol for a multicentre pilot randomised controlled trial.

INTRODUCTION: Thoracic endovascular aortic repair (TEVAR) carries a 3%-6.1% stroke risk, including risk of 'silent' cerebral infarction (SCI). Stent-grafts are manufactured in room air and retain air. Instructions for use recommend saline flushing to 'de-air' the system prior to insertion, but substantial amounts of air are released when deploying them, potentially leading to downstream neuronal injury and SCI. Carbon dioxide (CO2) is more dense and more soluble in blood than air, without risk of bubble formation, so could be used in addition to saline to de-air stents. This pilot trial aims to assess the feasibility of a full-scale randomised controlled trial (RCT) investigating the neuroprotective benefit against SCI with the use of CO2-flushed aortic stent-grafts. METHODS AND ANALYSIS: This is a multicentre pilot RCT, which is taking place in vascular centres in the UK, USA and New Zealand. Patients identified for TEVAR will be enrolled after informed written consent. 120 participants will be randomised (1:1) to TEVAR-CO2 or TEVAR-saline, stratified according to TEVAR landing zone. Participants will undergo preoperative neurocognitive tests and quality of life assessments, which will be repeated at 6 weeks, or first outpatient appointment, and 6 months. Inpatient neurological testing will be performed within 48 hours of return to level 1 care for clinical stroke or delirium. Diffusion-weighted MRI will be undertaken within 72 hours postoperatively (1-7 days) and at 6 months to look for evidence and persistence of SCI. Feasibility will be assessed via measures of recruitment and retention, informing the design of a full-scale trial. ETHICS AND DISSEMINATION: The study coordination centre has obtained approval from the London Fulham Research Ethics Committee (19/LO/0836) and Southern Health and Disability Ethics Committee (NZ) and UK's Health Regulator Authority (HRA). The study has received ethical approval for recruitment in the UK (Fulham REC, 19/LO/0836), New Zealand (21/STH/192) and the USA (IRB 019-264, Ref 378630). Consent for entering into the study will be taken using standardised consent forms by the local study team, led by a local PI. The results of the trial will be submitted for publication in an open access journal. TRIAL REGISTRATION NUMBER: NCT03886675.

Current State of Robotics in Interventional Radiology.

As a relatively new specialty with a minimally invasive nature, the field of interventional radiology is rapidly growing. Although the application of robotic systems in this field shows great promise, such as with increased precision, accuracy, and safety, as well as reduced radiation dose and potential for teleoperated procedures, the progression of these technologies has been slow. This is partly due to the complex equipment with complicated setup procedures, the disruption to theatre flow, the high costs, as well as some device limitations, such as lack of haptic feedback. To further assess these robotic technologies, more evidence of their performance and cost-effectiveness is needed before their widespread adoption within the field. In this review, we summarise the current progress of robotic systems that have been investigated for use in vascular and non-vascular interventions.

Evaluating the Haemodynamic Performance of Endografts for Complex Aortic Arch Repair.

Thoracic endovascular aortic repair (TEVAR) of aortic aneurysms and dissections involving the arch has evolved over the last two decades. Compared to conventional surgical methods, endovascular repair offers a less invasive treatment option with lower risk and faster recovery. Endografts used in TEVAR vary in design depending on the procedure and application. Novel endografts (e.g., branched stent-graft) were developed to ensure perfusion of blood to the supra-aortic vessels, but their haemodynamic performance and long-term durability have not been adequately studied. This review focuses on the use of computational modelling to study haemodynamics in commercially available endografts designed for complex aortic arch repair. First, we summarise the currently adopted workflow for computational fluid dynamics (CFD) modelling, including geometry reconstruction, boundary conditions, flow models, and haemodynamic metrics of interest. This is followed by a review of recently (2010-present) published CFD studies on complex aortic arch repair, using both idealized and patient-specific models. Finally, we introduce some of the promising techniques that can be potentially applied to predict post-operative outcomes.

Endovascular Stenting in Superior Vena Cava Syndrome: A Systematic Review and Meta-analysis.

PURPOSE: Endovascular stenting has been used to manage superior vena cava syndrome for several decades and has become standard firstline practice. This study aims to investigate the outcomes of endovascular stenting in the management of superior vena cava syndrome (SVCS). METHODS: MEDLINE, EMBASE and PUBMED online databases were searched, with studies involving more than ten adult patients included. Studies identified spanned 27 years, from 1993 to 2020. Meta-analyses were performed based on Clopper-Pearson estimation. RESULTS: Fifty-four studies were identified, for a total of 2249 patients, of which 2015 had malignant SVCS and 222 benign SVCS. Pooled technical success and clinical success rates were 96.8% (95% CI 96.0-97.5%) and 92.8% (95% CI 91.7-93.8%). Technical success and clinical success rates for studies investigating benign SVCS alone were identical at 88.8% (95% CI 83.0-93.1%). Pooled patency remained above 90% for the first year. Average complication and re-intervention rates were 5.78% (SD = 9.3182) and 9.11% (SD = 11.190). CONCLUSIONS: This review confirms the effectiveness of endovascular stenting in managing SVCS. Further directions of research may include specific outcomes of endovascular stenting in benign SVCS, and the impact of procedural characteristics, such as the use of anticoagulation and type of stent used, on outcomes. LEVEL OF EVIDENCE: Level III, systematic review of retrospective cohort studies.

Haemodynamic Analysis of Branched Endografts for Complex Aortic Arch Repair.

This study aims to investigate the haemodynamic response induced by implantation of a double-branched endograft used in thoracic endovascular aortic repair (TEVAR) of the aortic arch. Anatomically realistic models were reconstructed from CT images obtained from patients who underwent TEVAR using the RelayPlus double-branched endograft implanted in the aortic arch. Two cases (Patient 1, Patient 2) were included here, both patients presented with type A aortic dissection before TEVAR. To examine the influence of inner tunnel branch diameters on localised flow patterns, three tunnel branch diameters were tested using the geometric model reconstructed for Patient 1. Pulsatile blood flow through the models was simulated by numerically solving the Navier-Stokes equations along with a transitional flow model. The physiological boundary conditions were imposed at the model inlet and outlets, while the wall was assumed to be rigid. Our simulation results showed that the double-branched endograft allowed for the sufficient perfusion of blood to the supra-aortic branches and restored flow patterns expected in normal aortas. The diameter of tunnel branches in the device plays a crucial role in the development of flow downstream of the branches and thus must be selected carefully based on the overall geometry of the vessel. Given the importance of wall shear stress in vascular remodelling and thrombus formation, longitudinal studies should be performed in the future in order to elucidate the role of tunnel branch diameters in long-term patency of the supra-aortic branches following TEVAR with the double-branched endograft.

Use and effectiveness of Pioneer re-entry device for subintimal true lumen re-entry: single-centre data and a review of the literature.

INTRODUCTION: During subintimal angioplasty (SIA), it is not always possible to re-enter the vessel lumen due to a variety of factors. Recanalization using hydrophilic wires and catheters alone, apart from its potential technical failure, is also limited by minimal control over the re-entry point. This is frequently well beyond the point of occlusion, thus often compromising important collaterals. In order to bypass the obstruction and attain controlled re-entry into the lumen of the diseased vessel, a re-entry device (RED) may be required. This paper assesses our centre's experience with the safety and efficacy of the Pioneer re-entry system and systematically reviews the pertinent literature. METHOD: A single centre retrospective study of subintimal angioplasty involving the use of the Pioneer Plus intravascular guided reentry catheter was performed. Patient demographics including age, gender, risk factors, comorbidities clinical indication and complications were recorded. Lesion characteristics, including location and severity of calcification were also assessed. A systematic literature review of all reported studies where the Pioneer RED was used for iliac and lower limb revascularization was conducted by 2 of the authors using the PubMed (MEDLINE) and EMBASE databases. RESULTS: The study comprised 30 cases. Technical success was 97%. A small, quickly resolved extravasation was the only device related complication. These results are in line with the systematic review which identified 16 studies using the Pioneer RED, reporting a technical success rate of 87.4-100% (median = 100%) and complication rate of 0-25.8% (median = 0%). However, due to heterogeneity in definitions of technical success, data was not pooled.

Clinical experience with a shape memory polymer peripheral vascular embolisation plug: a case series.

BACKGROUND: Shape memory polymers are materials that are manufactured in a certain shape, can be stored in a temporary deformed shape, and then return to - or remember - their original shape upon exposure to external stimuli such as temperature and moisture. This property lends itself to application in endovascular medical devices. Peripheral vasculature embolisation devices incorporating this novel technology have become commercially available and this case series, where the data were collected as part of a post market registry, outlines initial clinical experience with these novel devices. RESULTS: Eight cases are described in this series. The disease state/conditions for which embolisation was indicated were right common iliac artery aneurysms (n = 3), a type II endoleak into the thoracic aorta following thoracic endovascular aneurysm repair (n = 1), a left inferior gluteal artery aneurysm (n = 1), left internal iliac artery aneurysms (n = 2), and a case of splenomegaly, where splenectomy was planned after the embolisation procedure (n = 1). Target arteries were 5-10 mm in diameter. In each case, at least one IMPEDE Embolization Plug (IMP-Device) of an appropriate diameter was used. All procedures were technically successful and target vessel thrombosis was achieved in all cases. Follow-up imaging available during the 45-90-day data collection timeframe showed sustained vessel occlusion. This case series includes examples of situations commonly encountered when embolising the peripheral vasculature, namely, the use of one or multiple devices in a single vessel and in combination with the use of other embolic devices (e.g., microcoils, gelatin sponge, and PVA particles) in the same case. There were no adverse events related to the specific use of the device. CONCLUSIONS: This small series illustrates the safety and efficacy of this novel sponge-based embolic device for the embolisation of small and medium sized arteries and further experience will demonstrate the utility of the shape memory polymer devices.

Robot-Assisted Carotid Artery Stenting: A Safety and Feasibility Study.

PURPOSE: Endovascular robotics is an emerging technology within the developing field of medical robotics. This was a prospective evaluation to assess safety and feasibility of robotic-assisted carotid artery stenting. MATERIALS AND METHODS: Consecutive cases of carotid artery stenting cases performed over period of 24 months, from May 2015 to October 2016, using the Magellan Robotic System (Hansen, Mountain View, CA) were included. All cases utilised the robotic system to navigate the arch, obtain a stable position in the common carotid artery, followed by manual manipulation of Embolic Protection Devices and self-expandable stents through the robotic catheter. Patients demographics, clinical indications, anatomical features, technical and clinical success, complication rate and hospital stay were prospectively recorded. RESULTS: Thirteen patients, 10 males (78.5%), with an average age of 68.7 years were treated. Mean follow up time was 30 months. Ten patients (91%) were symptomatic at presentation. Anatomical indications for endovascular stent insertion were previous open surgery to the neck ± radiotherapy (87.5%) and hostile anatomy for open surgery (12.5%). Technical success was 100% and the robotic system demonstrates enhanced stability during arch and lesion crossing. There were no neurological complications post-operatively. Average hospital stay was 3 days (range 2-6 days) and a change in serum creatinine of -7.8 µmol/L. There was no documented case of in stent restenosis, new or worsening neurology during follow-up. CONCLUSION: These results illustrate safety and feasibility of robotic endovascular revascularisation for carotid disease and demonstrates potential to enhance peri-procedural safety through improved control and stability.

Endovascular repair of ascending aortic diseases with custom-made endografts.

OBJECTIVES: The aim of this article is to report the mid-term results of ascending thoracic endovascular aortic repair using a custom-made device (CMD). METHODS: This was a retrospective study performed at tertiary centres. Nine patients considered unfit for open surgery received elective total endovascular repair of the ascending aorta with a Relay® (Terumo Aortic, Sunrise; FL, USA) CMD: pseudoaneurysn (n = 5), localized dissection (n =3) and contained rupture (n = 1). RESULTS: Primary clinical success was achieved in all patients with no major complications and no early conversion to open surgery. All patients were discharged home and independent: median length of stay was 7 days (interquartile range, 6-18). No patient was lost to follow-up at a median 26 months (interquartile range, 12-36). Three patients died 2, 6 and 24 months after intervention; 1 was aorta related (late aorto-atrial fistula due to infection that required open surgery). At the last follow-up available, no endoleaks, migrations, fractures or ruptures were observed in the remaining 6 patients. CONCLUSIONS: Ascending thoracic endovascular aortic repair with Terumo Aortic CMDs was technically feasible, effective and safe in very selected lesions. CMDs showed good ascending aorta conformability with different configurations and diameters, and satisfactory mid-term durability as shown by both structural integrity and aortic lesion exclusion.