In vitro quantification of stent-graft behaviour during chimney thoracic endovascular aortic repair.

OBJECTIVE: To quantify dynamic gutter phenomena and endograft deformations during double chimney thoracic endovascular aortic repair (ch-TEVAR) in a physiological model of the thoracic aorta subjected to pulsatile haemodynamic conditions. METHODS: Two in vitro procedures revascularizing the brachiocephalic trunk and left common carotid artery were performed representing both balloon-expandable (BE, Ankura-BeGraft) and self-expandable (SE, Ankura-Viabahn) double ch-TEVAR configurations. Retrospectively gated computed tomography (CT) was used to evaluate endograft behaviour. Device interactions were characterised according to gutter volume, gutter surface deviation, and endograft deformation (D-ratio) at end-diastolic and peak-systolic aortic pressure. RESULTS: Use of BE chimney grafts resulted in three times total gutter volume compared to SE chimney grafts. Gutter volumes were observed to vary dynamically between the end-diastolic and peak-systolic phases of the cardiac cycle, with the most substantial change associated with the BE configuration. Chimney graft deformations were dependent on device type, with SE devices exhibiting up to twice the deformation as BE devices. When adjacent, SE chimney grafts were observed to support each other, and thus tended towards a more consistently circular shape. CONCLUSION: Gutter and chimney graft behaviour were dependent on device type, and exhibited both spatial and temporal variability. This study emphasises notable differences between BE and SE double ch-TEVAR configurations which should be considered when evaluating risk of endoleak. The findings reported here also support the use of gated CT to better identify device-related complications with ch-TEVAR, and can be used in the design of next generation devices.

Successful Primary PCI in Stanford Type A Aortic Dissection Complicated by Inferior ST-Elevation Myocardial Infarction: A Case in a Facility with No Surgical Backup.

Mortality of type A aortic dissection (TAAD) complicated with coronary malperfusion syndrome is very high even when emergency surgery is performed. Several reports suggested that primary percutaneous coronary intervention (PPCI) followed by immediate corrective surgery may reduce mortality. In many countries, immediate transfer to an aortic surgery center may not be possible. We report a case of TAAD complicated by coronary malperfusion successfully treated with PPCI followed by elective corrective surgery. A 48-year-old man was referred to emergency department with acute inferior ST-elevation myocardial infarction (STEMI) and underwent PPCI. During the procedure, we realized that the cause of STEMI was TAAD. We decided to continue because the patient experienced seizures and bradycardia. Subsequently, echocardiography and computed tomography confirmed the dissection. The patient was discharged and referred to the National Cardiovascular Center where he underwent successful elective surgery. In this patient, immediate revascularization was lifesaving and served as a bridging procedure before surgical correction.

ProGlide entrapment of the occlusive balloon during repair of an iatrogenic subclavian artery injury.

The insertion of any central venous catheter (CVC) is associated with a risk of damage to neurovascular structures, pneumothorax, cardiac arrhythmias, and infection1. Unintentional arterial puncture remains rare, occurring in 6.3-9.4% of attempted internal jugular vein (IJV) catheterisation and 3.1-4.9% of attempted subclavian vein catheterisation2. We present a previously undocumented complication encountered while utilising the Perclose ProGlide device in the case of a 59-year-old male who underwent right subclavian artery closure following the accidental insertion of a 14Fr Vascath into the right subclavian artery. This was performed using two ProGlide devices and one Angio-Seal device. Following deployment of the ProGlide devices, an uninflated balloon passed into the subclavian artery as a precaution, but not used, was removed. One of the ProGlide devices became dislodged having been deployed into the balloon, threatening haemostasis.

A Deep Learning Approach to Visualize Aortic Aneurysm Morphology Without the Use of Intravenous Contrast Agents.

BACKGROUND: Intravenous contrast agents are routinely used in CT imaging to enable the visualization of intravascular pathology, such as with abdominal aortic aneurysms. However, the injection is contraindicated in patients with iodine allergy and is associated with renal complications. OBJECTIVES: In this study, we investigate if the raw data acquired from a noncontrast CT image contains sufficient information to differentiate blood and other soft tissue components. A deep learning pipeline underpinned by generative adversarial networks was developed to simulate contrast enhanced CTA images using noncontrast CTs. METHODS AND RESULTS: Two generative models (cycle- and conditional) are trained with paired noncontrast and contrast enhanced CTs from seventy-five patients (total of 11,243 pairs of images) with abdominal aortic aneurysms in a 3-fold cross-validation approach with a training/testing split of 50:25 patients. Subsequently, models were evaluated on an independent validation cohort of 200 patients (total of 29,468 pairs of images). Both deep learning generative models are able to perform this image transformation task with the Cycle-generative adversarial network (GAN) model outperforming the Conditional-GAN model as measured by aneurysm lumen segmentation accuracy (Cycle-GAN: 86.1% ± 12.2% vs Con-GAN: 85.7% ± 10.4%) and thrombus spatial morphology classification accuracy (Cycle-GAN: 93.5% vs Con-GAN: 85.7%). CONCLUSION: This pipeline implements deep learning methods to generate CTAs from noncontrast images, without the need of contrast injection, that bear strong concordance to the ground truth and enable the assessment ofimportant clinical metrics. Our pipeline is poised to disrupt clinical pathways requiring intravenous contrast.

The current status of interventional radiology in the undergraduate medical curriculum and the way forward.

Interventional radiology (IR) is underrepresented in undergraduate medical school curricula. Despite the introduction of a suggested undergraduate curriculum for IR by the British Society of Interventional Radiology (BSIR), current evidence suggests there is inadequate knowledge and awareness of IR amongst medical students. As a result of this, there is a lack of visibility of the subspeciality amongst medical students and junior doctors contributing to the shortage of IR trainees resulting in an IR workforce crisis in the UK. The uptake of the proposed undergraduate IR curriculum remains unclear, highlighting the need for a thorough audit and improvement of IR teaching in undergraduate medical education. In this commentary, we discuss the importance of including IR in the undergraduate curriculum, the evidence surrounding undergraduate IR education, the reasons for the potential lack of interest in IR from medical students and future steps to ensure optimal IR exposure in undergraduate medical school curricula.

Leadership in Interventional Radiology - Fostering a Culture of Excellence.

This invited article reviews the current status of Interventional Radiology (IR), in terms of its status as a speciality, and outlines the conditions needed for IR to function optimally within healthcare settings. Guidance is offered in terms of developing an IR department, ensuring high-quality practice, dealing with administrative and political challenges, dealing with industry and creating a legacy.

CIRSE Standards of Practice on Varicocele Embolisation.

BACKGROUND: Percutaneous embolisation is an effective, minimally invasive means of treating a variety of benign and malignant lesions and has been successfully used to treat varicoceles since the late 1970s, with refined and expanded techniques and tools currently offering excellent outcomes for varicocele embolisation. PURPOSE: This document will presume that the indication for treatment is clear and approved by the multidisciplinary team (MDT) and will define the standards required for the performance of each modality, as well as their advantages and limitations. CIRSE Standards of Practice documents are not intended to impose a standard of clinical patient care, but recommend a reasonable approach to, and best practices for, the performance of percutaneous varicocele embolisation. METHODS: The writing group was established by the CIRSE Standards of Practice Committee and consisted of five clinicians with internationally recognised expertise in embolisation of male varicoceles. The writing group reviewed the existing literature on varicocele embolisation, performing a pragmatic evidence search using PubMed to search for publications in English and relating to human subjects published from 2006 to 2021. The final recommendations were formulated through consensus. CONCLUSION: Embolisation has an established role in the successful management of male varicoceles. This Standards of Practice document provides up-to-date recommendations for the safe performance of varicocele embolisation.

Catheter-directed therapies for the treatment of high risk (massive) and intermediate risk (submassive) acute pulmonary embolism.

BACKGROUND: Acute pulmonary embolism (APE) is a major cause of acute morbidity and mortality. APE results in long-term morbidity in up to 50% of survivors, known as post-pulmonary embolism (post-PE) syndrome.  APE can be classified according to the short-term (30-day) risk of mortality, based on a variety of clinical, imaging and laboratory findings. Most mortality and morbidity is concentrated in high-risk (massive) and intermediate-risk (submassive) APE. The first-line treatment for APE is systemic anticoagulation.  High-risk (massive) APE accounts for less than 10% of APE cases and is a life-threatening medical emergency, requiring immediate reperfusion treatment to prevent death. Systemic thrombolysis is the recommended treatment for high-risk (massive) APE. However, only a minority of the people affected receive systemic thrombolysis, due to comorbidities or the 10% risk of major haemorrhagic side effects. Of those who do receive systemic thrombolysis, 8% do not respond in a timely manner. Surgical pulmonary embolectomy is an alternative reperfusion treatment, but is not widely available.  Intermediate-risk (submassive) APE represents 45% to 65% of APE cases, with a short-term mortality rate of around 3%. Systemic thrombolysis is not recommended for this group, as major haemorrhagic complications outweigh the benefit. However, the people at higher risk within this group have a short-term mortality of around 12%, suggesting that anticoagulation alone is not an adequate treatment. Identification and more aggressive treatment of people at intermediate to high risk, who have a more favourable risk profile for reperfusion treatments, could reduce short-term mortality and potentially reduce post-PE syndrome. Catheter-directed treatments (catheter-directed thrombolysis and catheter embolectomy) are minimally invasive reperfusion treatments for high- and intermediate-risk APE. Catheter-directed treatments can be used either as the primary treatment or as salvage treatment after failure of systemic thrombolysis. Catheter-directed thrombolysis administers 10% to 20% of the systemic thrombolysis dose directly into the thrombus in the lungs, potentially reducing the risks of haemorrhagic side effects. Catheter embolectomy mechanically removes the thrombus without the need for thrombolysis, and may be useful for people with contraindications for thrombolysis.  Currently, the benefits of catheter-based APE treatments compared with existing medical and surgical treatment are unclear despite increasing adoption of catheter treatments by PE response teams. This review examines the evidence for the use of catheter-directed treatments in high- and intermediate-risk APE. This evidence could help guide the optimal treatment strategy for people affected by this common and life-threatening condition. OBJECTIVES: To assess the effects of catheter-directed therapies versus alternative treatments for high-risk (massive) and intermediate-risk (submassive) APE. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search was 15 March 2022. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of catheter-directed therapies for the treatment of high-risk (massive) and intermediate-risk (submassive) APE. We excluded catheter-directed treatments for non-PE. We applied no restrictions on participant age or on the date, language or publication status of RCTs. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. The main outcomes were all-cause mortality, treatment-associated major and minor haemorrhage rates based on two established clinical definitions, recurrent APE requiring retreatment or change to a different APE treatment, length of hospital stay, and quality of life. We used GRADE to assess certainty of evidence for each outcome. MAIN RESULTS: We identified one RCT (59 participants) of (ultrasound-augmented) catheter-directed thrombolysis for intermediate-risk (submassive) APE. We found no trials of any catheter-directed treatments (thrombectomy or thrombolysis) in people with high-risk (massive) APE or of catheter-based embolectomy in people with intermediate-risk (submassive) APE. The included trial compared ultrasound-augmented catheter-directed thrombolysis with alteplase and systemic heparinisation versus systemic heparinisation alone. In the treatment group, each participant received an infusion of alteplase 10 mg or 20 mg over 15 hours. We identified a high risk of selection and performance bias, low risk of detection and reporting bias, and unclear risk of attrition and other bias. Certainty of evidence was very low because of risk of bias and imprecision.  By 90 days, there was no clear difference in all-cause mortality between the treatment group and control group. A single death occurred in the control group at 20 days after randomisation, but it was unrelated to the treatment or to APE (odds ratio (OR) 0.31, 95% confidence interval (CI) 0.01 to 7.96; 59 participants). By 90 days, there were no episodes of treatment-associated major haemorrhage in either the treatment or control group. There was no clear difference in treatment-associated minor haemorrhage between the treatment and control group by 90 days (OR 3.11, 95% CI 0.30 to 31.79; 59 participants). By 90 days, there were no episodes of recurrent APE requiring retreatment or change to a different APE treatment in the treatment or control group. There was no clear difference in the length of mean total hospital stay between the treatment and control groups. Mean stay was 8.9 (standard deviation (SD) 3.4) days in the treatment group versus 8.6 (SD 3.9) days in the control group (mean difference 0.30, 95% CI -1.57 to 2.17; 59 participants). The included trial did not investigate quality of life measures.  AUTHORS' CONCLUSIONS: There is a lack of evidence to support widespread adoption of catheter-based interventional therapies for APE. We identified one small trial showing no clear differences between ultrasound-augmented catheter-directed thrombolysis with alteplase plus systemic heparinisation versus systemic heparinisation alone in all-cause mortality, major and minor haemorrhage rates, recurrent APE and length of hospital stay. Quality of life was not assessed.  Multiple small retrospective case series, prospective patient registries and single-arm studies suggest potential benefits of catheter-based treatments, but they provide insufficient evidence to recommend this approach over other evidence-based treatments. Researchers should consider clinically relevant primary outcomes (e.g. mortality and exercise tolerance), rather than surrogate markers (e.g. right ventricular to left ventricular (RV:LV) ratio or thrombus burden), which have limited clinical utility. Trials must include a control group to determine if the effects are specific to the treatment.

A Deep Learning Pipeline to Automate High-Resolution Arterial Segmentation With or Without Intravenous Contrast.

BACKGROUND: Existing methods to reconstruct vascular structures from a computerized tomography (CT) angiogram rely on contrast injection to enhance the radio-density within the vessel lumen. However, pathological changes in the vasculature may be present that prevent accurate reconstruction. In aortic aneurysmal disease, a thrombus adherent to the aortic wall within the expanding aneurysmal sac is present in >90% of cases. These deformations prevent the automatic extraction of vital clinical information by existing image reconstruction methods. AIM: In this study, a deep learning architecture consisting of a modified U-Net with attention-gating was implemented to establish a high-throughput and automated segmentation pipeline of pathological blood vessels in CT images acquired with or without the use of a contrast agent. METHODS AND RESULTS: Seventy-Five patients with paired noncontrast and contrast-enhanced CT images were randomly selected from an ongoing study (Ethics Ref 13/SC/0250), manually annotated and used for model training and evaluation. Data augmentation was implemented to diversify the training data set in a ratio of 10:1. The performance of our Attention-based U-Net in extracting both the inner (blood flow) lumen and the wall structure of the aortic aneurysm from CT angiograms was compared against a generic 3-D U-Net and displayed superior results. Implementation of this network within the aortic segmentation pipeline for both contrast and noncontrast CT images has allowed for accurate and efficient extraction of the morphological and pathological features of the entire aortic volume. CONCLUSIONS: This extraction method can be used to standardize aneurysmal disease management and sets the foundation for complex geometric and morphological analysis. Furthermore, this pipeline can be extended to other vascular pathologies.

Clinical Performance Status and Technical Factors Affecting Outcomes from Percutaneous Transhepatic Biliary Interventions; A Multicentre, Prospective, Observational Cohort Study.

PURPOSE: The purpose of this study was to evaluate the predictive value of a 'Modified Karnofsky Scoring System' on outcomes and provide real-world data regarding the UK practice of biliary interventions. MATERIALS AND METHODS: A prospective multi-centred cohort study was performed. The pre-procedure modified Karnofsky score, the incidence of sepsis, complications, biochemical improvement and mortality were recorded out to 30 days post procedure. RESULTS: A total of 292 patients (248 with malignant lesions) were suitable for inclusion in the study. The overall 7 and 30 day mortality was 3.1% and 16.1%, respectively. The 30 day sepsis rate was 10.3%. In the modified Karnofsky 'high risk' group the 7 day mortality was 9.7% versus 0% for the 'low risk' group (p = 0.002), whereas the 30 day mortality was 28.8% versus 13.3% (p = 0.003). The incidence of sepsis at 30 days was 19% in the high risk group versus 3.3% at the low risk group (p = 0.001) CONCLUSION: Percutaneous biliary interventions in the UK are safe and effective. Scoring systems such as the Karnofsky or the modified Karnofsky score hold promise in allowing us to identify high risk groups that will need more careful consideration and enhanced patient informed consent but further research with larger studies is warranted in order to identify their true impact on patient selection and outcomes post biliary interventions.

CIRSE Standards of Practice on Below-the-Knee Revascularisation.

The CIRSE Standards of Practice Committee established a writing group that was tasked with producing up-to-date recommendations for performing below-the-knee revascularisation, taking into account data on novel techniques, devices, and long-term outcomes that have emerged over the last decade. CIRSE Standards of Practice documents are not clinical practice guidelines or systematic reviews of the literature. This document is not intended to impose a standard of clinical patient care but recommends a reasonable approach to and best practices for performing below-the-knee revascularisation.

Catheter-Directed Hemorrhoidal Dearterialization Technique for the Management of Hemorrhoids: A Meta-Analysis of the Clinical Evidence.

PURPOSE: To assess the efficacy and safety of a catheter-directed hemorrhoidal dearterialization technique for the management of hemorrhoidal bleeding. MATERIALS AND METHODS: A systematic review and meta-analysis of pubmed, cochrane, and scopus databases was conducted according to the preferred reporting items for systematic reviews and meta-Analysis (PRISMA) guidelines. Clinical studies reporting on catheter-directed hemorrhoidal dearterialization for rectal bleeding were analyzed. RESULTS: Fourteen studies (n = 362) were identified. The mean maximum follow-up duration was 12.1 months (SD, 7.31; range, 1-28; median, 12), and the mean length of hospital stay was 1.5 days (SD, 1.1; range, 0-2.5). The mean technical success was 97.8% (SD, 3.5), and the mean clinical success was 78.9% (SD, 10.5). A statistically significant reduction in the french bleeding score before and after embolization was noted (P = .004). In subgroup analysis, when the coils-only group was compared with the coils and particles group, the average rebleeding rate was 21.5% (n = 111; SD, 18.2; range, 0%-44%) versus 10.05% (N = 108; SD, 4.8; range, 5%-15.7%), respectively (P < .0001). No bowel ischemia/necrosis or anorectal complications were reported. CONCLUSIONS: The current preliminary clinical evidence suggests that catheter-directed hemorrhoidal dearterialization is an effective and safe procedure for the treatment of hemorrhoidal bleeding. The standardization of the technique and the generation of higher level evidence will be required to compare this minimally invasive procedure with more invasive surgical options for patients with grades I-III hemorrhoids and chronic bleeding.