Accuracy of duplex ultrasonography in estimation of severity of peripheral vascular disease

Tomographic 3D ultrasound for grading stenosis of superficial femoral artery

INTRODUCTION

Treatment decision of lower extremity peripheral arterial disease (PAD) is governed by the severity of stenosis. Tomographic 3D ultrasound (t3DUS) is a reliable imaging technique for measuring vessel stenosis. In this study we attempted to provide a precise measurement of superficial femoral artery (SFA) stenosis using t3DUS in patients with PAD.

METHODS

t3DUS was used to measure maximum stenosis percentage in SFA from 50 patients with lower extremity PAD. The maximum stenosed segment in SFA was defined using Duplex 2DUS aliasing was noted. The peak systolic velocity (PSV) was measured at the maximum stenotic site and proximal to aliasing for calculating the velocity ratio. The association between blood flow velocity ratio and the degree of stenosis measured using Duplex 2DUS and t3DUS, respectively, was assessed using Spearman rank correlation.

RESULTS

There was a strong positive correlation between velocity ratio and degree of stenosis in SFA measured using t3DUS (correlation value (r) = 0.99, p < 0.001). The correlation between Stenosis percentage and velocity ratio in SFA are as followed: <50:<2; 50-54:2-2.4; 55-59:2.5-2.9; 60-64:3-3.4; 65-69:3.5-3.9; 70-74:4-4.4; 75-79:4.5-4.9; >80:>5.

t3DUS can be used to provide precise measurement of the severity of SFA stenosis in patients with lower extremities arterial disease. The established criteria for grading SFA stenosis in this study can be applied to the current practice alongside Duplex 2DUS as it showed a strong positive correlation with velocity ratio. Further studies investigating the sensitivity and specificity of t3DUS in the assessment of stenosis in lower limbs arteries are required.

Below-the-Knee Endovascular Revascularization: A Position Statement

Patients with chronic limb-threatening ischemia, the terminal stage of peripheral artery disease, are frequently afflicted by below-the-knee disease. Although all patients should receive guideline-directed medical therapy, restoration of inline flow is oftentimes necessary to avoid limb loss. Proper patient selection and proficiency in endovascular techniques for below-the-knee revascularization are intended to prevent major amputation and promote wound healing. This review, a consensus among an international panel of experienced operators, provides guidance on these challenges from an endovascular perspective and offers techniques to navigate this complex disease process.

Calcification detection on upper extremity arteries: a comparison of ultrasonic and X-ray methods

Background

Vascular calcification (VC) has been observed in patients with hemodialysis, whereas few studies have investigated calcification in the upper extremity vasculature. Both ultrasound and X-ray are used to investigate the calcification of arteries in patients. However, there is a lack of data on the consistency between these two methods. The aim of this study was to investigate the occurrence of VC in the radial and ulnar arteries of hemodialysis patients and investigate the detection consistency in VC between ultrasound and X-ray.

Methods

Ultrasound and X-ray examinations were performed in the radial and ulnar arteries of both the left and right upper extremities of 40 patients on hemodialysis. The calcification status of arteries was evaluated by the calcification index from ultrasound and X-ray respectively. Clinical variables of patients were collected from all the involved patients.

Results

Of the 40 patients, VC was detected in 31 patients by ultrasound, while X-ray detected VC in 22 patients. Compared to ultrasound assessment, X-ray assessment was 73.21% sensitive but only 66.35% specific with a positive predictive value of 53.95% for detecting calcifications in the radial or ulnar artery. The level of agreement between ultrasound and X-ray results was fair. In addition, our data showed that more ulnar arteries had VCs than the corresponding radial arteries.

Conclusion

Ultrasound is more sensitive in detecting the presence of calcified atherosclerotic lesions. Ultrasound and X-ray exhibited fair consistency. Ultrasound screening for upper extremity radial and ulnar arteries in hemodialysis patients may deserve attention to explore its clinical significance.

Development and Validation of Machine Learning Models to Classify Artery Stenosis for Automated Generating Ultrasound Report

Duplex ultrasonography (DUS) is a safe, non-invasive, and affordable primary screening tool to identify the vascular risk factors of stroke. The overall process of DUS examination involves a series of complex processes, such as identifying blood vessels, capturing the images of blood vessels, measuring the velocity of blood flow, and then physicians, according to the above information, determining the severity of artery stenosis for generating final ultrasound reports. Generation of transcranial doppler (TCD) and extracranial carotid doppler (ECCD) ultrasound reports involves a lot of manual review processes, which is time-consuming and makes it easy to make errors. Accurate classification of the severity of artery stenosis can provide an early opportunity for decision-making regarding the treatment of artery stenosis. Therefore, machine learning models were developed and validated for classifying artery stenosis severity based on hemodynamic features. This study collected data from all available cases and controlled at one academic teaching hospital in Taiwan between 1 June 2020, and 30 June 2020, from a university teaching hospital and reviewed all patients' medical records. Supervised machine learning models were developed to classify the severity of artery stenosis. The receiver operating characteristic curve, accuracy, sensitivity, specificity, and positive and negative predictive value were used for model performance evaluation. The performance of the random forest model was better compared to the logistic regression model. For ECCD reports, the accuracy of the random forest model to predict stenosis in various sites was between 0.85 and 1. For TCD reports, the overall accuracy of the random forest model to predict stenosis in various sites was between 0.67 and 0.86. The findings of our study suggest that a machine learning-based model accurately classifies artery stenosis, which indicates that the model has enormous potential to facilitate screening for artery stenosis.

Comparison Between Below Knee Contrast Enhanced Tomographic 3D Ultrasound and CT, MR or Catheter Angiography for Peripheral Artery Imaging

OBJECTIVE

Clear imaging of below knee and foot arteries is essential to plan distal reconstructions. Contrast enhanced tomographic 3D ultrasound (CEtUS) is novel and entirely safe with no exposure to ionising radiation or nephrotoxic contrast. In the present study, inter- and intra-observer agreement of CEtUS was calculated, and compared with below knee angiography.

METHODS

In the same week as computed tomography, magnetic resonance or catheter angiography, CEtUS was performed using intravenous 1.2 mL bolus injections of Sonovue with a maximum of 5 mL administered per patient. CEtUS was reported by a vascular scientist blinded to the angiograms reported by a consultant radiologist. Images were compared using a modified Society of Vascular Surgery (SVS) runoff score.

RESULTS

Of the 181 patients recruited with peripheral arterial disease, 20 were excluded from analysis as they withdrew consent, could not be cannulated, or their images were non-diagnostic. In the remaining 161 patients, there were 175 comparative patient images split into two groups: 81 had calf imaging and 94 had pedal imaging representing 405 and 198 imaged arteries, respectively. Weighted quadratic kappa/ICC values for intra- and inter-observer agreement were excellent (κ/ICC = 0.83 to 0.95) and had narrow confidence intervals in both groups. When comparing angiography and CEtUS, weighted quadratic κ/ICC agreement was moderate with acceptable confidence intervals in both groups (Calf κ/ICC = 0.54; Pedal κ/ICC = 0.53). Agreement decreased from popliteal to pedal vessels as diameter decreased. Agreement between CEtUS and digital subtraction angiography was best, and computed tomography angiography the weakest.

CONCLUSION

CEtUS is a novel imaging modality with strong observer agreement that achieves clear peripheral and foot images without ionising radiation exposure or nephrotoxic X-ray contrast media. CEtUS enhances visualisation of runoff vessels, which may play a role in planning of limb salvage or targeted assessment.

Diagnosis and Management of Peripheral Artery Diseases

Распространенность заболеваний периферических артерий (ЗПА) во всем мире достигает порядка 200 миллионов человек. Самым частым клиническим проявлением ЗПА является перемежающая хромота, возникающая вследствие недостаточного кровоснабжения пораженной конечности. В настоящем обзоре литературы обобщены и систематизированы последние достижения в области диагностики и лечения пациентов с перемежающей хромотой. Тщательный сбор анамнеза и физикальное обследование являются первоочередными мероприятиями для установления предварительного диагноза и направлены на дифференциацию сосудистых и нейрогенных причин перемежающей хромоты. Лодыжечно-плечевой индекс относится к наиболее часто используемым методам скрининга и диагностики ЗПА. Основу лечения составляют четыре взаимодополняющих подхода: немедикаментозное и лекарственное лечение для купирования симптомов хронической ишемии, фармакотерапия для вторичной профилактики сердечно-сосудистых осложнений, открытая или эндоваскулярная реваскуляризация для увеличения дистанции безболевой ходьбы. Недавнее исследование COMPASS продемонстрировало преимущества комбинированного применения 2,5 мг ривароксабана дважды в день и аспирина в части снижения уровня неблагоприятных сердечно-сосудистых событий, при этом отмечался более высокий риск геморрагических осложнений. На сегодняшний день цилостазол является единственным препаратом, обладающим доказанной терапевтической эффективностью в отношении перемежающей хромоты. Программы лечебной физкультуры под наблюдением врача либо в домашних условиях способствуют улучшению коллатерального кровообращения и увеличивают дистанцию ходьбы без боли. Назначение высоких доз статинов и антитромбоцитарных препаратов абсолютно обосновано всем пациентам с ЗПА. Ингибиторы ангиотензин-превращающего фермента обеспечивают дополнительное снижение кардиоваскулярных рисков, в особенности у пациентов с сахарным диабетом и артериальной гипертензией.

The prevalence of peripheral artery disease (PAD) worldwide reaches about 200 million people. The most frequent clinical manifestation of PAD is intermittent claudication, which occurs due to insufficient blood supply to the affected limb. This literature review summarizes and systematizes recent advances in the diagnosis and treatment of patients with intermittent claudication.Thorough case history collection and physical examination are the primary measures for making a preliminary diagnosis, which is aimed at differentiating the vascular and neurogenic causes of intermittent claudication. The ankle-shoulder index is one of the most commonly used methods for screening and diagnosing PAD. The basis of treatment consists of four complementary approaches: non-pharmacological and pharmacological treatment for the relief of symptoms of chronic ischemia, pharmacotherapy for the secondary prevention of cardiovascular complications, open or endovascular revascularization to increase the distance of pain-free walking. A recent COMPASS study demonstrated the benefits of combining 2.5 mg of rivaroxaban twice daily with aspirin in reducing adverse cardiovascular events, however there was a higher risk of hemorrhagic complications. Today, cilostazol is the only drug with proven therapeutic effectiveness against intermittent claudication. Physical therapy programs under the supervision of a doctor or at home help to improve collateral blood circulation and increase the walking distance without pain. The administration of high doses of statins and antiplatelet drugs is absolutely justified in all patients with PAD. Angiotensin converting enzyme inhibitors provide an additional reduction in cardiovascular risks, especially in patients with diabetes and hypertension.

How To Assess a Claudication and When To Intervene

PURPOSE OF THE REVIEW

Peripheral artery disease (PAD) affects close to 200 million people worldwide. Claudication is the most common presenting symptom for patients with PAD. This review summarizes the current diagnostic and treatment options for patients with claudication. Comprehensive history and physical examination in order to differentiate between claudication secondary to vascular disease vs. neurogenic causes is paramount for initial diagnosis. Ankle-brachial index is the most commonly used test for screening and diagnostic purposes. Treatment consists of four different approaches, which are best utilized in combination: non-pharmacological treatment for claudication improvement, pharmacological treatment for claudication improvement, pharmacological treatment for secondary risk reduction, and interventional treatment for claudication improvement.

RECENT FINDINGS

Cilostazol is the only Food and Drug Administration (FDA)-approved agent for symptomatic treatment of claudication. Supervised exercise programs provide the maximum benefit for claudication improvement, but home-based exercise programs are an alternative. High-intensity statins and an antiplatelet agent should be prescribed to all patients with PAD. Angiotensin-converting-enzyme inhibitors can provide additional risk reduction, especially in patients with diabetes or hypertension. Rivaroxaban of low dosage (2.5 mg twice daily) in combination with aspirin further decreases cardiovascular risk, but this reduction comes at the cost of higher bleeding risk. Peripheral artery disease (PAD) is a form of atherosclerotic disease that affects hundreds of millions of people worldwide-one of its most common manifestations is intermittent claudication (IC), which results from insufficient blood flow to meet the metabolic demands of an affected extremity. This paper reviews the current literature regarding the workup, diagnosis, diagnostic modalities, treatment options, and management of intermittent claudication.

Vascular Tests for Dermatologists

Dermatologists encounter patients with a variety of lower extremity ulcers including those related to venous insufficiency and peripheral arterial disease. Vascular studies, including ankle brachial pressure index, toe pressure, toe brachial index, Doppler arterial waveform, Duplex ultrasonography, and angiography, play an essential role in the prevention, diagnosis, and management of vascular diseases. In fact, dermatologists are often the first medical providers to see patients with complex vascular conditions. Knowledge of the appropriate indications, interpretations, limitations, and advantages of the various vascular studies is critical to the successful and swift management of each patient presenting with a lower extremity ulcer. This study reviews the most commonly ordered arterial and venous studies and discusses the appropriate indications and interpretation of these studies.

Severe Type of Minocycline-Induced Hyperpigmentation Mimicking Peripheral Arterial Occlusive Disease in a Bullous Pemphigoid Patient

Minocycline is a tetracycline group antibiotic that is known to cause significant antibacterial and anti-inflammatory effects. Minocycline has been widely used to treat systemic infection, acne, dermatitis, and rosacea. However, various dose-related side effects of hyperpigmentation in whole body tissues have been reported. Three main types of minocycline-induced hyperpigmentation have been identified. In rare severe hyperpigmentation cases, drug-induced hyperpigmentation can mimic local cellulitis or peripheral arterial occlusive disease (PAOD). These processes require different therapeutic strategies. Therefore, early diagnosis is extremely important for physicians to determine the etiology of the hyperpigmentation, and subsequently discontinue the minocycline if indicated. We describe a rare case presenting a severe form of type III minocycline-induced hyperpigmentation mimicking peripheral arterial occlusive disease in a bullous pemphigoid patient.

Peripheral artery disease: the new frontiers of imaging techniques to evaluate the evolution of regenerative medicine

Introduction: Stem cells (ESC, iPSC, MSC) are known to have intrinsic regenerative properties. In the last decades numerous findings have favored the development of innovative therapeutic protocols based on the use of stem cells (Regenerative Medicine/Cell Therapy) for the treatment of numerous diseases including PAD, with promising results in preclinical studies. So far, several clinical studies have shown a general improvement of the patient's clinical outcome, however they possess many critical issues caused by the non-randomized design of the limited number of patients examined, the type cells to be used, their dosage, the short duration of treatment and also their delivery strategy. Areas covered: In this context, the use of the most advanced molecular imaging techniques will allow the visualization of very important physio-pathological processes otherwise invisible with conventional techniques, such as angiogenesis, also providing important structural and functional data. Expert opinion: The new frontier of cell therapy applied to PAD, potentially able to stop or even the process that causes the disease, with particular emphasis on the clinical aspects that different types of cells involve and on the use of more innovative molecular imaging techniques now available.

Guiding peripheral arterial disease management with magnetic resonance imaging

Abstract. Peripheral arterial disease (PAD) management is exceptionally challenging. Despite advances in diagnostic and therapeutic technologies, long-term vessel patency and limb salvage rates are limited. Patients with PAD frequently require extensive workup with noninvasive tests and imaging to delineate their disease and help guide appropriate management. Ultrasound and computed tomography are commonly ordered in the workup of PAD. Magnetic resonance imaging (MRI), on the other hand, is less often acknowledged as a useful tool in this disease. Nevertheless, MRI is an important test that can effectively characterize atherosclerotic plaque, assess vessel patency in highly calcified disease, and measure lower extremity perfusion.

Variation in duplex peak systolic velocity measurement in a multi-site vascular service

Objective:

Duplex US (DUS) is increasingly utilised as a first-line investigation for the assessment of carotid disease. For clinical decision-making, DUS assessment must be accurate and reproducible to ensure reliability. We aimed to investigate the variability in peak systolic velocity (PSV) measurement in a multi-site vascular network.

Methods:

DUS measurements of PSV were taken from continuous and pulsatile flow, generated by a high fidelity phantom, by 12 experienced vascular scientists across four hospitals. Participants were blinded to the actual PSV value (50 cm/s).

Results:

We observed an average error of 13.2% (± 8.3) and 11.6% (± 7.5) in PSV measurements taken from pulsatile and continuous waveforms, respectively. Measurements of PSV using the pulsatile waveform demonstrated statistically significant variation across all hospitals; ((hospital/mean) A 43.9 cm/s, B 61.7 cm/s, C 57.4 cm/s, D 47.7 cm/s, p=0.001). Further analysis demonstrated statistically significant variation in 4 instrumentation-related factors when measuring from a pulsatile waveform (Doppler angle, angle of insonation, velocity range, scale range).

Conclusion:

We observed a significant level of error and variation in PSV measurements across four sites within our vascular network. Variation in instrumentation-related factors may be accountable for this. In light of the centralisation of vascular services, it is increasingly important to unify and implement scanning protocols in order to reduce error and inter-site variability.