Onyx™ Cast Fragmentation After Embolization of Endoleaks.

PURPOSE: Endoleaks are common following endovascular aneurysm repair (EVAR), and the liquid embolic material Onyx has been widely used in their treatment. We report our experience of long-term morphological changes of Onyx casts on surveillance imaging. MATERIALS AND METHODS: We identified 10 patients over 10 years who underwent Onyx embolization in our institution. Morphological changes of Onyx casts were assessed on surveillance radiographs and computed tomography (CT) scans. Relevant outcome data and sequelae were obtained via electronic patient records. RESULTS: Twelve procedures were performed on 10 cases, 9 for type 2, and 1 for a type 1a endoleak. Five cases showed evidence of Onyx fragmentation on follow-up imaging ranging from a single fracture to gross fragmentation with migration of fragments. Of these 5, 3 had achieved primary success but 2 went on to develop recurrence of endoleak. Onyx volume ranged from 4 to 46.5 ml (median 10.5 ml) per patient with larger volumes demonstrating the most marked fragmentation on follow-up. Follow-up ranged from 9 months to 8 years (median 2.25 years). CONCLUSION: To our knowledge, this is the first report of Onyx fragmentation after endoleak embolization. If long-term morphological stability of the Onyx cast is necessary to maintain aneurysm seal, then Onyx may not offer a permanent solution to some patients with post-EVAR endoleaks. Our study cannot ascertain whether the observed changes were the cause or the effect of ongoing aneurysm growth, persistent endoleak, and/or other forces acting on the solidified polymer, but it raises important questions on the use of Onyx in this setting.

Percutaneous Deep Venous Arterialization for Limb Salvage in No Option Patients with Chronic Limb-Threatening Ischemia.

An endovascular approach is often considered the first line treatment option for lower limb chronic limb-threatening ischemia (CLTI), which is defined by the presence of ischemic rest pain and severe tissue loss, such as ulcers or gangrene. Although the technical success rate of endovascular revascularization is high, in specific patients with advanced infrapopliteal disease and the absence of run-off tibial vessels, the so-called 'desert foot', the chance of successful endovascular revascularization is minimal. In order to avoid primary amputation, several treatment options are currently being investigated, including gene therapy and deep venous arterialization. This review focuses on the percutaneous deep venous arterialization technique as a promising, minimally invasive treatment option for limb salvage in CLTI patients presenting with a 'desert foot'.

CXR-Net: A Multitask Deep Learning Network for Explainable and Accurate Diagnosis of COVID-19 Pneumonia From Chest X-Ray Images.

Accurate and rapid detection of COVID-19 pneumonia is crucial for optimal patient treatment. Chest X-Ray (CXR) is the first-line imaging technique for COVID-19 pneumonia diagnosis as it is fast, cheap and easily accessible. Currently, many deep learning (DL) models have been proposed to detect COVID-19 pneumonia from CXR images. Unfortunately, these deep classifiers lack the transparency in interpreting findings, which may limit their applications in clinical practice. The existing explanation methods produce either too noisy or imprecise results, and hence are unsuitable for diagnostic purposes. In this work, we propose a novel explainable CXR deep neural Network (CXR-Net) for accurate COVID-19 pneumonia detection with an enhanced pixel-level visual explanation using CXR images. An Encoder-Decoder-Encoder architecture is proposed, in which an extra encoder is added after the encoder-decoder structure to ensure the model can be trained on category samples. The method has been evaluated on real world CXR datasets from both public and private sources, including healthy, bacterial pneumonia, viral pneumonia and COVID-19 pneumonia cases. The results demonstrate that the proposed method can achieve a satisfactory accuracy and provide fine-resolution activation maps for visual explanation in the lung disease detection. Compared to current state-of-the-art visual explanation methods, the proposed method can provide more detailed, high-resolution, visual explanation for the classification results. It can be deployed in various computing environments, including cloud, CPU and GPU environments. It has a great potential to be used in clinical practice for COVID-19 pneumonia diagnosis.

CurveletTransform-Based Texture Analysis of Carotid B-mode Ultrasound Images in Asymptomatic Men With Moderate and Severe Stenoses: A Preliminary Clinical Study.

The curvelet transform, which represents images in terms of their geometric and textural characteristics, was investigated toward revealing differences between moderate (50%-69%, n = 11) and severe (70%-100%, n = 14) stenosis asymptomatic plaque from B-mode ultrasound. Texture features were estimated in original and curvelet transformed images of atheromatous plaque (PL), the adjacent arterial wall (intima-media [IM]) and the plaque shoulder (SH) (i.e., the boundary between plaque and wall), separately at end systole and end diastole. Seventeen features derived from the original images were significantly different between the two groups (4 for IM, 3 for PL and 10 for SH; 9 for end diastole and 8 for end systole); 19 of 234 features (2 for IM and 17 for SH; 8 for end systole and 11 for end diastole) derived from curvelet transformed images were significantly higher in the patients with severe stenosis, indicating higher magnitude, variation and randomness of image gray levels. In these patients, lower body height and higher serum creatinine concentration were observed. Our findings suggest that (a) moderate and severe plaque have similar curvelet-based texture properties, and (b) IM and SH provide useful information about arterial wall pathophysiology, complementary to PL itself. The curvelet transform is promising for identifying novel indices of cardiovascular risk and warrants further investigation in larger cohorts.

Early and eighteen month clinical outcomes of first UK case of percutaneous deep vein arterialisation (pDVA) to treat "no option" chronic limb-threatening ischemia using the LimFlow system.

BACKGROUND: Chronic limb-threatening ischaemia (CLTI) in cases where there are no further standard treatment options for limb salvage represents the most advanced stage of peripheral arterial disease. For these "no-option" CLTI patients, an experimental treatment of foot vein arterialisation (FVA) was first described in 1912, however, it was never widely adopted as outcomes varied significantly most likely due to the complexity of the surgical intervention and lack of standardisation. In recent years there have been significant developments in performing FVA fully percutaneously and standardising the procedure with the introduction of specific indications for patient selection, a dedicated set of devices and structured follow up. This case represents the first UK use of the dedicated LimFlow System as a standardised procedure to perform percutaneous deep vein arterialisation (pDVA) in a "no option" CLTI patient according to the latest treatment recommendations in the literature, with outcomes out to 18 months post-procedure. CASE PRESENTATION: We present the case of a 78 year old male diabetic patient with a history of contralateral below knee amputation who presented with ischaemic rest pain and dry gangrene involving his left heel and first and second toes. Following review by the lower limb multi-disciplinary team at our institution, the patient was deemed to have no surgical or endovascular treatment options, apart from major amputation, as there was no suitable target for either angioplasty or bypass. He was therefore referred as a candidate for percutaneous deep vein arterialisation (pDVA) with the LimFlow System (LimFlow SA, France). After screening of the patient according to the indications for use, the pDVA procedure was successfully performed resulting in complete resolution of ischaemic rest pain immediately following the procedure, and adequate revascularisation of the foot. Following the index procedure, the subject went on to have minor amputation of the first, second and third toes 2 months post initial procedure with further secondary angioplasty procedures to optimise the flow throughout the arterialised circuit up to 4 months after the initial procedure. He underwent elective completion transmetatarsal amputation at 13 months post index procedure. The surgical wounds post minor amputation and the heel wound showed continued healing, especially after secondary optimisation of the pDVA outflow, with tissue epithelialisation by 6 months and complete healing by 18 months after the index procedure. CONCLUSIONS: This case report demonstrates the clinical outcomes of a technically-successful standardised pDVA procedure with the LimFlow system including both limb salvage and wound healing at 18 months. It also highlights the importance of close clinical and radiological surveillance post-index procedure and the requirement for re-interventions to optimise wound healing.

Combined rheolytic thrombectomy and stent placement in SVC and brachiocephalic vein thrombosis due to metastatic lymphadenopathy.

The current management of neoplastic obstruction, SVC, and brachiocephalic vein thrombosis, especially of SVC, is based on the combined use of interventional (endovascular thrombolysis or thrombectomy, stent placement) and noninterventional (radiation, chemotherapy) means of treatment. We present the case of a forty-year-old woman with SVC and left brachiocephalic vein thrombosis secondary to lymph node metastasis of non-small-cell lung cancer. A combination of rheolytic thrombectomy (Angiojet device) and stent placement was performed for both venous sites with complete technical success. We discuss the principles of percutaneous rheolytic thrombectomy, its effectiveness, and potential complications.