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The long-term survival of patients on hemodialysis (HD) is dependent on adequate HD which depends on quality and degree of functionality of vascular access. The aim of our study is to detect the role of color Doppler ultrasonography in evaluation of arteriovenous fistula (AVF). Between January 2017 and October 2017, 60 patients had complicated AVF at Qena General Hospital & Qena University Hospital as primary and tertiary centers respectively with the same age group between 18 and 50 years old, had no diabetes mellitus were evaluated using color duplex-Doppler ultrasound (CDUS) after AVF maturation for detection of complications and comparison between primary and tertiary centers of its incidence. The overall results revealed that 11 patients from 30 patients that had been referred to tertiary centers have complicated AVF (36.7%), and 19 patients had no shunt complication (63.3%). Twenty-two patients from 30 patients that had been referred to primary HD centers had complicated shunts. Thrombosis at tertiary centers represents 13.3%, stenosis 3.3% (1 patient), aneurysmal formation had 6.6% for (2 patients), hematoma 6.6%(2 patients), infection 3.3% (1 patient), venous hypertension 3.3% (1 patient), thrombosis and hematoma at primary centers 16.6% (5 patients for each), aneurysmal formation and infection 13.3% for each, and stenosis 10%. CDUS is a readily-available, non-invasive, risk-free, bed-side technique that allows precise anatomic knowledge, qualitative, and quantitative data of the upper limb vascular system which greatly help in preoperative planning of AVF creation, assessment of prime time for puncture (maturation), early detection of complications, and choice of appropriate therapeutic procedure for their treatment.

In the past few decades, imaging has been developed to a high level of sophistication. Improvements from one-dimension (1D) to 2D images, and from 2D images to 3D models, have revolutionized the field of imaging. This not only helps in diagnosing various critical and fatal diseases in the early stages but also contributes to making informed clinical decisions on the follow-up treatment profile. Carotid artery stenosis (CAS) may potentially cause debilitating stroke, and its accurate early detection is therefore important. In this paper, the technical development of various CAS diagnosis imaging modalities and its impact on the clinical efficacy is thoroughly reviewed. These imaging modalities include duplex ultrasound (DUS), computed tomography angiography (CTA) and magnetic resonance angiography (MRA). For each of the imaging modalities considered, imaging methodology (principle), critical imaging parameters, and the extent of imaging the vulnerable plaque are discussed. DUS is usually the initial recommended CAS diagnostic examination. However, for the therapeutic intervention, either MRA or CTA is recommended for confirmation, and for added information on intracranial cerebral circulation and aortic arch condition for procedural planning. Over the past few decades, the focus of CAS diagnosis has also shifted from pure stenosis quantification to plaque characterization. This has led to further advancement in the existing imaging tools and development of other potential imaging tools like Optical coherence tomography (OCT), photoacoustic tomography (PAT), and infrared (IR) thermography.

This review presents an update on the diagnosis and management of acute limb ischemia (ALI), a severe condition associated with high mortality and amputation rates. A comprehensive spectrum of ALI etiology is presented, with highlights on embolism and in situ thrombosis. The steps for emergency diagnosis are described, emphasizing the role of clinical data and imaging, mainly duplex ultrasound, CT angiography and digital substraction angiography. The different therapeutic techniques are presented, ranging from pharmacological (thrombolysis) to interventional (thromboaspiration, mechanical thrombectomy, and stent implantation) techniques to established surgical revascularization (Fogarty thrombembolectomy, by-pass, endarterectomy, patch angioplasty or combinations) and minor or major amputation of necessity. Postprocedural management, reperfusion injury, compartment syndrome and long-term treatment are also updated.

The first accounts of measuring cerebral blood flow (CBF) in humans were made by Angelo Mosso in ~1880, who recorded brain pulsations in patients with skull defects. In 1890, Charles Roy and Charles Sherrington determined in animals that brain pulsations—assessed via a similar method used by Mosso—were altered during a variety of stimuli including sensory nerve stimulation, asphyxia, and pharmacological interventions. Between 1880 and 1944, measurements for CBF were typically relied on skull abnormalities in humans. Thereafter, Kety and Schmidt introduced a new methodological approach in 1945 that involved nitrous oxide dilution combined with serial arterial and jugular venous blood sampling. Less than a decade later (1950’s), several research groups employed the Kety-Schmidt technique to assess the effects of exercise on global CBF and metabolism; these studies demonstrated an uncoupling of CBF and metabolism during exercise, which was contrary to early hypotheses. However, there were several limitations to this technique related to low temporal resolution and the inability to measure regional CBF. These limitations were overcome in the 1960’s when transcranial Doppler ultrasound (TCD) was developed as a method to measure beat-by-beat cerebral blood velocity. Between 1990 and 2010, TCD further progressed our understanding of CBF regulation and allowed for insight into other mechanistic factors, independent of local metabolism, involved in regulating CBF during exercise. Recently, it was discovered that TCD may not be accurate under several physiological conditions. Other measures of indexing CBF such as Duplex ultrasound and magnetic resonance imaging, although not without some limitations, may be more applicable for future investigations.

INTRODUCTION: Posterior circulation ischemia syndrome is a common feature of the poor blood flow to the posterior cerebral regions which is generally caused by atherosclerotic involvement of vertebral arteries (VA). However, the risk factors for VA atherosclerosis remain largely unknown. Lipoprotein (a) (Lp(a)), a modified low-density lipoprotein, has been implicated as a risk factor for coronary and peripheral artery disease. Our aim was to investigate the possible association of Lp(a) with low vertebral artery flow, a marker representing VA atherosclerosis. METHODS: An institutional registry database was used for the present study. A complete dataset, including Doppler ultrasound imaging of the carotid and VA was available in 135 of 718 cases, and these cases were included in the analysis. RESULTS: 29 (21.1%) patients had Lp(a)>30 mg/dL, and total VA flow in these patients was significantly less than in patients with Lp(a)<30 mg/dL (243.0 mL/min [212.0–276.0] vs. 256.0 mL/min [230.0–307.0], p=0.03). Lp(a) had a significant correlation with VA flow (r=−0.24, p=0.004), and this association remained significant after adjustment for other lipid parameters (β=−0.244, p=0.004) and demographic variables (β=−0.225, p=0.007). Furthermore, the correlation between Lp(a) and VA flow was stronger in 11 patients with evidence of carotid atherosclerosis on DUS (r=−0.74, p<0.001). DISCUSSION AND CONCLUSION: Lp(a) concentration is inversely related with VA flow.

PurposeDiagnosing carotid near-occlusion (CNO) with colour duplex ultrasound (CDU) is challenging. We hypothesised that CNO is associated with a reduced distal internal carotid artery (ICA) velocity and aimed to assess if distal velocity is able to diagnose CNO accurately. If not, we aimed to develop CDU rule-out and rule-in criteria to diagnose CNO.MethodsThis is a prospective cross-sectional study in consecutive participants with suspected ≥ 50% carotid stenosis on CT angiography (CTA). CDU velocities in the common carotid artery, the stenosis and distal to the stenosis were examined. CTAs were assessed for CNO, serving as a reference test. If no CDU parameter was both sensitive and specific for CNO, rule-out (98% sensitive) and rule-in (99% specific) criteria were created.ResultsOf the 315 included participants with ≥ 50% stenosis, 190 (60%) were conventional ≥ 50% stenosis and 125 (40%) CNO. No CDU parameter was both sensitive and specific for CNO. The best exclusion criteria were stenosis end diastolic velocity (EDV) ≤ 63 cm/s and/or distal peak systolic velocity (PSV) > 23 cm/s, seen in 115 (38%) participants. The best rule-in criteria were stenosis EDV ≥ 280 cm/s and/or distal PSV ≤ 23 cm/s, seen in 35 (12%) participants. Of the remaining participants, 143 (47%) were uncertain (74 CNOs) and 9 (3%) were misdiagnosed as carotid occlusion (all CNOs).ConclusionsCDU alone cannot diagnose CNO but can rule in or rule out CNO in half of participants with ≥ 50% stenosis. These criteria are intended for inclusion in an algorithm, sorting cases needing further exams, such as CTA and/or phase-contrast magnetic resonance angiography.

BackgroundFollowing catheter ablation, vascular access management involves potential complications and prolonged recovery. Recently, suture-mediated closure (SMC) devices were approved for venous access procedures. The objective of this study is to evaluate the safety of a commercially available SMC for multiple access site venous closure by duplex ultrasound (DUS) in asymptomatic subjects with non-visible complications.MethodsThirty-six subjects (63 ± 10.7 years old, 12 female) were enrolled. Following catheter ablation for atrial fibrillation, all subjects had SMC of every venous access site. Subjects underwent DUS of femoral veins and arteries. DUS was performed at discharge, and again at 30 days. Subjects were evaluated for clinically apparent vascular complications.ResultsMean procedure duration was 138.6 min, and the time to hemostasis was 3.1 min/access site and 9.5 min/subject. Median time to ambulation was 193.5 min, and median time to discharge was 5.95 h, with discharge as early as 2.4 h. A median of 2 sheaths/vein and a median of 2 SMC devices/vein were used. There were no major complications and a 16.7% (6/36) minor complication rate at discharge. All complications resolved at 30 days. The complication rate was not higher in patients with 2 SMC per access site as compared to the patients who just received 1 SMC per access site.ConclusionsThis study demonstrates the safety of multi-access closure using SMC, following catheter ablation procedures, for closure of sites that use sheath sizes from ≤ 8F to ≥ 15F and for those that use 2 or more SMCs per access site.

•The higher risk of developing a venous thromboembolism in meningioma is debatable•Low-molecular-weight heparin administration aims to lower venous thromboembolism•However, low-molecular-weight is associated with a risk of postoperative hemorrhage•Early mobilization is a valid strategy in preventing venous thromboembolism Historically, the development of venous thromboembolism (VTE) including deep venous thrombosis (DVT) and pulmonary thromboembolism (PE) was cited as a higher post-operative risk for patients harboring meningiomas. However, recent literature has suggested that there may be no elevated risk for VTE among these patients. The authors perform both a retrospective review of their own cases as well as a systematic review of the literature in order to determine the frequency of the VTE and rate of post-operative hemorrhage in this patient population. Patients undergoing surgery for intracranial and spinal meningioma from 2012 to 2019 were retrospectively reviewed for patient demographics, clinical characteristics, and post-operative complications. Logistic regression was used to determine risk factors for the development of VTE. Additionally, a PubMed search was performed to identify patients addressing this topic. Our retrospective review included 189 patients who underwent 197 operations. The rate of VTE for patients receiving LMWH was 3.55 % vs. 4.06 % for those not receiving LMWH. There were no observed hemorrhages after initiation of LMWH. Multivariate analysis found tumor volume, history of DVT, and length of hospital stay as independent risk factors for VTE. In the systematic review, 11 papers describing 28,954 patients were included. The risk of developing a VTE with or without LMWH was 2.71 % versus 4.07 %, respectively. The hemorrhage risk was 2.23 % on LMWH versus 4.20 % not on LMWH. In several heterogeneous series of all types of neurosurgical procedures, the reported rate of VTE was 11.1 %. In our review of the literature, the VTE rate of 2.71 % was similar to our cohort's rate of 3.55 %, for patients administered LMWH postoperatively. Higher rates of VTE with meningiomas may not be the case as once thought. Regular use of LMWH appears to be a safe, but it also did not necessarily lower the rates of VTE in our cohort. The use of routine lower-extremity duplex ultrasound, mechanical prophylaxis, and early mobilization, may have contributed to these lower rates of VTEs in patients with meningiomas.

Vascular Malformations belong to the spectrum of orphan diseases and can involve all segments of the vascular tree: arteries, capillaries, and veins, and similarly the lymphatic vasculature. The classification according to the International Society for the Study of Vascular Anomalies (ISSVA) is of major importance to guide proper treatment. Imaging plays a crucial role to classify vascular malformations according to their dominant vessel type, anatomical extension, and flow pattern. Several imaging concepts including color-coded Duplex ultrasound/contrast-enhanced ultrasound (CDUS/CEUS), 4D computed tomography angiography (CTA), magnetic resonance imaging (MRI) including dynamic contrast-enhanced MR-angiography (DCE-MRA), and conventional arterial and venous angiography are established in the current clinical routine. Besides the very heterogenous phenotypes of vascular malformations, molecular and genetic profiling has recently offered an advanced understanding of the pathogenesis and progression of these lesions. As distinct molecular subtypes may be suitable for targeted therapies, capturing certain patterns by means of molecular imaging could enhance non-invasive diagnostics of vascular malformations. This review provides an overview of subtype-specific imaging and established imaging modalities, as well as future perspectives of novel functional and molecular imaging approaches. We highlight recent pioneering imaging studies including thermography, positron emission tomography (PET), and multispectral optoacoustic tomography (MSOT), which have successfully targeted specific biomarkers of vascular malformations.

Superficial venous thrombosis (SVT) is a fairly common disorder, characterized by the formation of thrombi inside superficial veins, with or without an associated inflammatory reaction. Its evolution is frequently self-limited. However, serious complications may change this clinical course with extension to deep vein thrombosis (DVT) and pulmonary embolism (PE). SVT shares similar risk factors with DVT and is frequently associated with the presence of varicose veins. However, the occurrence of non-varicose veins could conceal risk factors such as malignancies, thrombophilia, or Buerger’s disease. While the clinical diagnosis is generally straightforward, additional diagnostic evaluations are often necessary. Duplex ultrasound (DUS) is an invaluable tool that provides the location of SVT, the proximity to the sapheno–femoral junction, and the clot length, all of which influence the decision for optimal management. The treatment of SVT should be symptomatic, pathogenic (limiting the extension of thrombosis), and prognostic (to prevent complications). There are several guidelines that provide recommendations, and despite the need for more consensus and for further studies, the treatment of SVT should be mainly medical, including anticoagulation in specific clinical situations and symptom relief, with invasive treatment in a minority of cases. Initiation, intensity, and length of anticoagulant treatment should be based on the eventual risk of progression to DVT or PE, which can be high, intermediate, or low, based on the location of SVT and the clot length. Our review summarizes the evaluation and proper management of SVT and highlights the importance of a shared decision within the heart team regarding this condition in order to prevent further complications.