A systematic review of duplex ultrasound, magnetic resonance angiography and computed tomography angiography for the diagnosis and assessment of symptomatic, lower limb peripheral arterial disease

Clinical physiology: the crucial role of MRI in evaluation of peripheral artery disease

Peripheral artery disease (PAD) is a common vascular disease that primarily affects the lower limbs and is defined by the constriction or blockage of peripheral arteries and may involve microvascular dysfunction and tissue injury. Patients with diabetes have more prominent disease of microcirculation and develop peripheral neuropathy, autonomic dysfunction, and medial vascular calcification. Early and accurate diagnosis of PAD and disease characterization are essential for personalized management and therapy planning. Magnetic resonance imaging (MRI) provides excellent soft tissue contrast and multiplanar imaging capabilities and is useful as a noninvasive imaging tool in the comprehensive physiological assessment of PAD. This review provides an overview of the current state of the art of MRI in the evaluation and characterization of PAD, including an analysis of the many applicable MR imaging techniques, describing the advantages and disadvantages of each approach. We also present recent developments, future clinical applications, and future MRI directions in assessing PAD. The development of new MR imaging technologies and applications in preclinical models with translation to clinical research holds considerable potential for improving the understanding of the pathophysiology of PAD and clinical applications for improving diagnostic precision, risk stratification, and treatment outcomes in patients with PAD.

Low-iodine 40-keV virtual monoenergetic CT angiography of the lower extremities

Introduction

To evaluate a reduced iodine volume protocol for lower extremity CT angiography (CTA) using dual-energy CT (DECT).

Methods

This retrospective study included consecutive patients who underwent lower extremity CTA from June to December 2022. A 10 ml 1:1 mixed test bolus was performed, followed by a 40 ml full bolus at a 2.5/s injection rate, using 400 mg/ml iodine contrast media. Conventional and 40 keV virtual monoenergetic images (VMI) were reconstructed. For both reconstructions, five main artery segments were assessed with a 3-point image quality score as well as quantitative attenuation, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) measurements with diagnostic quality thresholds (respectively >150 HU and >3).

Results

Forty patients were included in the study (mean age 68 ± 12 yo). 200 artery segments were assessed. Median qualitative image scores were 3 [IQR, 3, 3] for both reconstructions. 40 keV VMI upgraded qualitative scores for 51 (26%) of patients, including 9 (5%) from nondiagnostic to diagnostic quality. 40 keV VMI obtained attenuation and CNR diagnostic quality for respectively 100% and 100% of segments, compared with 96% and 98% for conventional images (p < 0.001). Distal artery segments showed the most differences between 40 keV VMI and conventional images.

Conclusion

A low-iodine lower extremity CTA protocol is feasible, with 40 keV virtual monoenergetic spectral reconstruction enabling maintained diagnostic image quality at the distal artery segments.

Peripheral Interventional Strategy Assessment (PISA) for Diabetic Foot Ulcer Revascularization: Preliminary Outcomes of a Multidisciplinary Pilot Study

BACKGROUND

Digital subtraction angiography (DSA) still represents the gold standard for anatomical arterial mapping and revascularization decision-making in patients with chronic limb-threatening ischemia (CLTI), although DUS (Doppler Ultrasound) remains a primary non-invasive examination tool. The Global Vascular Guidelines established the importance of preoperative arterial mapping to guarantee an adequate in-line flow to the foot. The aim of this study was to evaluate the accuracy of DUS in guiding therapeutic vascular treatments on the basis of Global Vascular Guidelines without the need of a second-level examination.

METHODS

Between January 2022 and June 2022, all consecutive patients with CLTI to be revascularized underwent clinical examination and DUS without further diagnostic examinations. Primary outcomes assessed were technical success, and 30-day mortality. Secondary outcomes were 1-year amputation free survival, and time between evaluation and revascularization.

RESULTS

Sixty-eight patients with a mean age of 73.6 ± 8.5 years underwent lower limb revascularization. Technical success was 100%, and the 30-day mortality rate was 2.9%. Mean time between evaluation and revascularization was 29 ± 17 days. One-year amputation free survival was 97.1%.

CONCLUSIONS

DUS without further diagnostic examinations can accurately assess the status of the vascular tree and foot runoff, providing enough information about target vessels to guide revascularization strategies.

Contrast-free ultrasound imaging for blood flow assessment of the lower limb in patients with peripheral arterial disease: a feasibility study

While being a relatively prevalent condition particularly among aging patients, peripheral arterial disease (PAD) of lower extremities commonly goes undetected or misdiagnosed due to its symptoms being nonspecific. Additionally, progression of PAD in the absence of timely intervention can lead to dire consequences. Therefore, development of non-invasive and affordable diagnostic approaches can be highly beneficial in detection and treatment planning for PAD patients. In this study, we present a contrast-free ultrasound-based quantitative blood flow imaging technique for PAD diagnosis. The method involves monitoring the variations of blood flow in the calf muscle in response to thigh-pressure-cuff-induced occlusion. Four quantitative metrics are introduced for analysis of these variations. These metrics include post-occlusion to baseline flow intensity variation (PBFIV), total response region (TRR), Lag0 response region (L0RR), and Lag4 (and more) response region (L4 + RR). We examine the feasibility of this method through an in vivo study consisting of 14 PAD patients with abnormal ankle-brachial index (ABI) and 8 healthy volunteers. Ultrasound data acquired from 13 legs in the patient group and 13 legs in the healthy group are analyzed. Out of the four utilized metrics, three exhibited significantly different distributions between the two groups (p-value < 0.05). More specifically, p-values of 0.0015 for PBFIV, 0.0183 for TRR, and 0.0048 for L0RR were obtained. The results of this feasibility study indicate the diagnostic potential of the proposed method for the detection of PAD.

Comparison of Various Modalities Utilized for Preoperative Planning in Microsurgical Reconstructive Surgery

BACKGROUND

 The benefits of preoperative perforator imaging for microsurgical reconstruction have been well established in the literature.

METHODS

 An extensive literature review was performed to determine the most commonly used modalities, and their applicability, advantages and disadvantages.

RESULTS

 The review demonstrated varioius findings including decreases in operative time and cost with the use of CT angiography to identification of perforators for inclusion in flap design with hand-held Doppler ultrasound. Modalities like MR angiography offer alternatives for patients with contrast allergies or renal dysfunction while maintaining a high level of clarity and fidelity. Although the use of conventional angiography has decreased due to the availability of less invasive alternatives, it continues to serve a role in the preoperative evaluation of patients for lower extremity reconstruction. Duplex ultrasonography has been of great interest recently as an inexpensive, risk free, and extraordinarily accurate diagnostic tool. Emerging technologies such as indocyanine green fluorescence angiography and dynamic infrared thermography provide real-time information about tissue vascularity and perfusion without requiring radiation exposure.

CONCLUSION

 This article presents an in-depth review of the various imaging modalities available to reconstructive surgeons and includes hand held Doppler ultrasound, CT angiography, MR angiography, conventional angiography, duplex ultrasonography, Indocyanine Green Fluorescence Angiography and Dynamic Infrared Thermography.

Association between heart rate-corrected QT interval and severe peripheral arterial disease in patients with type 2 diabetes and foot ulcers

BACKGROUND

A prolonged heart rate-corrected QT interval (QTc) has been associated with peripheral artery disease (PAD) in the general population. However, no study to date has identified a link between prolonged QTc and the severity of PAD in patients with diabetes mellitus and foot ulcers (DFUs). This study aimed to investigate this relationship.

METHODS

This multicenter study enrolled 281 patients with DFUs. The severity of PAD was classified into no severe PAD group (without stenosis or occlusion) and severe PAD group (with stenosis or occlusion) based on duplex ultrasonography. The association of prolonged QTc with severe PAD was evaluated in a multivariable mixed-effect logistic regression model, with the hospital as a random effect. Directed acyclic graphs were used to drive the selection of variables to fit the regression model.

RESULTS

Patients with severe PAD had longer QTc than those without. Based on the multivariable mixed-effect logistic regression model, a prolonged QTc was positively associated with severe PAD (odds ratio (OR) = 2.61; 95% CI: 1.07-6.35) and severe DFUs (Wagner grade score ≥ 3) (OR = 2.87; 95% CI: 1.42-5.81).

CONCLUSIONS

A prolonged QTc was associated with severe PAD in patients with DFUs. Further research is required to ascertain whether the association is causal.

High Apolipoprotein E Levels Predict Adverse Limb Events in Patients with Peripheral Artery Disease Due to Peripheral Artery Disease Undergoing Endovascular Treatment and On-Statin Treatment

Little is known about the association between limb prognosis in peripheral artery disease and apolipoprotein E (apoE). We evaluated the long-term impact of apoE on adverse limb events in patients with intermittent claudication receiving statin treatment.A total of 218 consecutive patients (mean age, 73 ± 8 years; 81% men) with intermittent claudication who underwent their first intervention between 2009 and 2020 were included in this study. All patients had achieved LDL-C < 100 mg/dL on statin treatment and were divided into two groups based on the apoE value (≥ 4.7 or < 4.7 mg/dL). We evaluated the incidence of major adverse limb events (MALEs), including vessel revascularization and limb ischemia development.A total of 39 and 179 patients were allocated to the higher and lower apoE groups, respectively. Compared to the lower apoE group, the higher apoE group had a significantly higher total cholesterol level, triglyceride level, and non-high-density lipoprotein cholesterol level. During the median follow-up period of 3.6 years, 30 patients (13.8%) developed MALEs. Kaplan-Meier analysis revealed that the cumulative incidence of MALEs in the higher apoE group was significantly higher than that in the lower apoE group (44.0% versus 21.6%, log-rank test, P = 0.002). During multivariable Cox hazard analysis, higher apoE level (≥ 4.7 mg/dL) (hazard ratio, 2.61; 95% confidence interval, 1.18-5.70, P = 0.019) was the only strong independent predictor of MALEs.ApoE levels could be a strong predictor and residual risk for long-term limb prognosis in patients with intermittent claudication and achieving LDL-C < 100 mg/dL with statin treatment.

Lower extremity CT angiography in peripheral arterial disease: from the established approach to evolving technical developments

With the advent of multidetector computed tomography (CT), CT angiography (CTA) has gained widespread popularity for noninvasive imaging of the arterial vasculature. Peripheral extremity CTA can nowadays be performed rapidly with high spatial resolution and a decreased amount of both intravenous contrast and radiation exposure. In patients with peripheral artery disease (PAD), this technique can be used to delineate the bilateral lower extremity arterial tree and to determine the amount of atherosclerotic disease while differentiating between acute and chronic changes. This article provides an overview of several imaging techniques for PAD, specifically discusses the use of peripheral extremity CTA in patients with PAD, clinical indications, established technical considerations and novel technical developments, and the effect of postprocessing imaging techniques and structured reporting.

Duplex ultrasound versus CT angiography for the treatment planning of lower-limb arterial disease

PURPOSE

This study aimed to assess the diagnostic accuracy of duplex sonography (DUS) compared with that of computed tomography angiography (CTA) in detecting occlusion and stenosis in peripheral arterial disease (PAD) in candidate patients for endovascular revascularization with intraprocedural digital subtraction angiography (DSA).

METHODS

The study involved 94 patients suffering from PAD who were candidates for endovascular procedures requiring DSA. They were all submitted preoperatively to DUS and CTA. Based on image analysis, five segments of the arterial tree were assessed: iliac, common femoral, superficial femoral, popliteal, and infrageniculate. According to the stenosis or occlusion degree, the arteries were rated as nonstenotic, stenotic, and occluded.

RESULTS

The agreement between DUS and CTA findings using DSA as a reference modality was expressed as a Cohen's kappa (κ) statistic agreement. Our results show that DUS has been less accurate than CTA in evaluating iliac arterial diseases (Cohen's κ agreement of 0.91 and 1.0, respectively) when measured against DSA. We found good diagnostic concordance between DUS and DSA in detecting hemodynamic stenosis and occlusion of the femoro-popliteal axis (Cohen's κ agreement between 0.96 and 0.93). Below the knee, CTA showed even less concordance with DSA (Cohen's κ 0.75).

CONCLUSIONS

Because of its accuracy, high-quality DUS performed by well-trained operators may therefore represent a good alternative to CTA in patients undergoing endovascular revascularization to minimize the use of contrast-enhanced radiological imaging. Nevertheless, preoperative CTA imaging is required in cases of nondiagnostic DUS or when a more complete overview of the vascular tree is needed for complex invasive interventions.

Lower extremity artery disease in patients with type 2 diabetes

Among all peripheral arterial diseases, lower extremity arterial disease is a serious condition in subjects with type 2 diabetes mellitus, associated with important disability, cardiovascular risk, and socio-economic burden. Patients with both conditions generally display poorer prognosis of affected limbs compared with non-diabetic subjects, leading to increased rates of adverse limb events including amputations. Nonetheless, awareness on lower extremity arterial disease remains somehow suboptimal in the diabetic population, partly related to an atypical clinical presentation in several cases. A regular and appropriate screening for lower extremity arterial disease in patients suffering from type 2 diabetes mellitus is therefore recommended. Affected subjects should receive optimal medical treatment including careful management of the different cardiovascular risk factors through a healthy lifestyle, a regular and structured physical activity, the administration of lipid-lowering, antidiabetic drugs, and (when indicated) antihypertensive and antithrombotic drugs. This review aims to outline current evidence about lower extremity arterial disease in patients with type 2 diabetes mellitus, in order to elucidate its epidemiology, pathophysiology, screening and diagnosis, and management options.

Association of severity of coronary artery disease by SYNTAX score (SS) and lower extremity arterial disease by duplex ultrasound (DUS) study-an Indian perspective

Background

Coronary artery disease (CAD) and lower extremity artery disease (LEAD) often coexist. Ankle brachial index (ABI) has been shown to be an independent predictor of CAD. Studies have reported correlation of CAD and LEAD on the basis of ABI and also invasive angiography. But rigorous searching did not reveal any similar research where severity of LEAD was assessed by duplex ultrasound (DUS).

In this study, we assessed the association of severity and localisation of LEAD by DUS with SYNTAX score (SS).

Results

A total of 637 subjects above 45 years of age with coronary angiographic confirmation of CAD were studied in this single centre cross-sectional, descriptive and analytical research. High SS was significantly more common in subjects with LEAD (p = 0.04). In the femoro-popliteal segment, total occlusion of arteries was found in significantly more proportion of subjects with high SS. A progressive increase in mean SS was noted across the grades of arterial disease in the femoro-popliteal segment (p = 0.007). 85.2% of the LEAD was in the femoro-popliteal segment, while below-knee arterial disease was present in 98.5% of subjects with LEAD. Hypertension, smoking, history of CVE and presentation with ACS independently increased the risk of LEAD.

Conclusion

High prevalence of asymptomatic LEAD and association of high SS with LEAD as a whole as well as femoro-popliteal involvement suggests the need for a point of care DUS study (POCUS) since treatment varies with location and extent of disease which cannot be fathomed by ABI alone. Being the largest study on association of CAD and LEAD from Indian subcontinent till date and also the first study to use non-invasive tool as DUS for LEAD assessment while studying its association with CAD makes this a landmark experience.

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.

Imaging in Chronic Wound Diagnostics

Significance: Chronic wounds affect millions of patients worldwide, placing a huge burden on health care resources. Although significant progress has been made in the development of wound treatments, very few advances have been made in wound diagnosis. Recent Advances: Standard imaging methods like computed tomography, single-photon emission computed tomography, magnetic resonance imaging, terahertz imaging, and ultrasound imaging have been widely employed in wound diagnostics. A number of noninvasive optical imaging modalities like optical coherence tomography, near-infrared spectroscopy, laser Doppler imaging, spatial frequency domain imaging, digital camera imaging, and thermal and fluorescence imaging have emerged over the years. Critical Issues: While standard diagnostic wound imaging modalities provide valuable information, they cannot account for dynamic changes in the wound environment. In addition, they lack the capability to predict the healing outcome. Thus, there remains a pressing need for more efficient methods that can not only indicate the current state of the wound but also help determine whether the wound is on track to heal normally. Future Directions: Many imaging probes have been fabricated and shown to provide real-time assessment of tissue microenvironment and inflammatory responses in vivo. These probes have been demonstrated to noninvasively detect various changes in the wound environment, which include tissue pH, reactive oxygen species, fibrin deposition, matrix metalloproteinase production, and macrophage accumulation. This review summarizes the creation of these probes and their potential implications in wound monitoring.

Changing National Medicare Utilization of Catheter, Computed Tomography, and Magnetic Resonance Extremity Angiography: A Specialty-focused 16-Year Analysis

To assess changing utilization of extremity angiography from 2001 to 2016, focusing on modalities and provider specialties. Medicare PSPS Master Files from 2001-2016 and POSPUF from 2016 were used to determine overall and specialty utilization of diagnostic catheter angiography (DCA), CT angiography (CTA), and MR angiography (MRA). From 2001 to 2016, extremity angiography increased from 1107 to 1590 extremities imaged per 100,000 beneficiaries, with rapid expansion of CTA (22 in 2001 to 619 in 2009; plateau of 645 in 2016), but declines in DCA (1039 to 914) and MRA (45 to 30). Over time, extremity angiography shifted from 94% DCA, 4% MRA, and 2% CTA to 58% DCA, 41% CTA, and 2% MRA. For radiologists, extremity angiography increased slightly (741 to 767) with increases in CTA (20 to 595) and large decreases in DCA (681 to 145), with MRA remaining low (40 to 27). Extremity angiography increased for cardiologists (197 to 349) and vascular surgeons (87 to 351), both overwhelmingly performing DCA. Radiologists' share of all extremity angiography shifted from 67% to 48%, with interventionalists (47%), generalists (43%), and abdominal radiologists (7.4%) providing most radiologist services in 2016. Throughout, radiologists were the dominant providers of CTA (89% to 92%) and MRA (89% to 90%). Extremity angiography utilization in Medicare beneficiaries increased nearly 50% from 2001 to 2016, largely related to CTA performed by radiologists. Of radiologists, interventionalists and generalists together render most services. Cardiologists and surgeons assumed a large share of DCA previously performed by radiologists.

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.

Clinical significance of mirror lesions in lower extremity arterial disease

OBJECTIVE

The aim of this study was to investigate the clinical relevance of bilateral peripheral arterial disease (PAD) patterns.

BACKGROUND

No prior study has evaluated the clinical significance of symmetrical lesion patterns, particularly the coexistence of same-level significant plaques in both lower extremities ("mirror lesions").

METHODS

We conducted a single-facility, primary data analysis involving 225 patients with symptomatic PAD.

RESULTS

Eighty-two percent of the patients had bilateral lesions: 14.2% had femoropopliteal, 38.7% had infrapopliteal, and 27.1% had both femoropopliteal and infrapopliteal lesions. The lesions were found in the exact same arteries bilaterally in 24.9% of the patients, while 26.7% had a local mirror pattern limited to the femoropopliteal (13.7%) or infrapopliteal (12.9%) arteries. Having a lesion in an artery was a risk factor for occlusive disease of the corresponding artery on the other side. Patients presenting with critical limb ischemia (CLI) had a history of resting pain (17%), ulceration/gangrene (13%), or prior amputation (26%) of the contralateral limb. Patients with significant bilateral disease had unilateral false-negative ABI results in 11.6% of the cases. The arterial Doppler study results were unilaterally false-negative in 19.6% and bilaterally false-negative in 2.8% of the patients.

CONCLUSIONS

Patients with known peripheral arterial disease need to have both limbs fully evaluated and monitored, even in cases with negative screening results. Mirror angiographic imaging is common and often accompanied by symptoms of claudication. Unilateral ischemia is a strong risk factor for contralateral disease. Patients with CLI are at high risk for occlusive lesions of the nonindex limb.

The role of amputative and non-amputative foot deformities severity in the risk for diabetic ulceration classification systems building: a cross-sectional and case-control pilot investigation

Introduction

Foot deformities and amputations are parameters that have been studied as risk factors for diabetic foot ulceration (DFU). However, inclusion of "foot deformities" and "amputations" in a single, broad variable and with reference to the severity of these deformities, may better characterize subjects who are prone to develop DFU.

Methods

The objective of the study was the examination of amputative and non-amputative foot deformities severity as risk factor for DFU in relation with the other established risk factors. A cross-sectional and case-control study was conducted from October 2005 to November 2016. One hundred and thirty-four subjects with type 1 and 2 diabetes, with and without active foot ulcers, participated. A structured quantitative interview guide was used. Univariate logistic regression analysis for the literature's established risk factors was performed, as well as for two versions of the "amputative and non-amputative foot deformities severity" variable. Subsequently, multivariate logistic regression analysis (MLRA) for three models and receiver operating characteristic (ROC) curve analysis were carried out.

Results

From the MLRA, only PAD (peripheral arterial disease) was significant (OR 3.56, 95% CI 1.17-10.82, P=0.025 and OR 3.33, 95% CI 1.02-10.08, P=0.033). Concerning the ROC curve analysis of the models, the one with the three categories amputative and non-amputative foot deformities severity variable, had the greatest area under the ROC curve (0.763, P<0.001).

Conclusion

A united variable for lower extremity amputations and other foot deformities with reference to their severity, could be more helpful to the clinicians in identifying patients with diabetes at risk for foot ulceration.

Global Vascular Guidelines on the Management of Chronic Limb-Threatening Ischemia

GUIDELINE SUMMARY

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

Global vascular guidelines on the management of chronic limb-threatening ischemia

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

Inflammation and Peripheral Arterial Disease

Peripheral arterial disease (PAD) is an atherosclerotic disease closely associated with high morbidity and mortality in cardiac events. Inflammation is crucial in atherosclerosis both at triggering and in progression. Numerous inflammatory biomarkers (cytokines, matrix metalloproteinases (MMPs), selectin, intracellular adhesion molecule (ICAM), vascular cell adhesion molecule (VCAM) C-reactive protein (CRP), fibrinogen) have been measured in atherosclerotic diseases including PAD. This paper summarizes the data on the inflammatory biomarkers for PAD pathophysiology and highlights the most useful markers in monitoring PAD outcomes.

Systematic Review of Economic Models Used to Compare Techniques for Detecting Peripheral Arterial Disease

BACKGROUND AND OBJECTIVE

Peripheral arterial disease (PAD) is a common condition, in which atherosclerotic narrowing in the arteries restricts blood supply to the leg muscles. In order to support future model-based economic evaluations comparing methods of diagnosis in this area, a systematic review of economic modelling studies was conducted.

METHODS

A systematic literature review was performed in June 2017 to identify model-based economic evaluations of diagnostic tests to detect PAD, with six individual databases searched. The review was conducted in accordance with the methods outlined in the Centre for Reviews and Dissemination's guidance for undertaking reviews in healthcare, and appropriate inclusion criteria were applied. Relevant data were extracted, and studies were quality assessed.

RESULTS

Seven studies were included in the final review, all of which were published between 1995 and 2014. There was wide variation in the types of diagnostic test compared. The majority of the studies (six of seven) referenced the sources used to develop their model, and all studies stated and justified the structural assumptions. Reporting of the data within the included studies could have been improved. Only one identified study focused on the cost-effectiveness of a test typically used in primary care.

CONCLUSIONS

This review brings together all applied modelling methods for tests used in the diagnosis of PAD, which could be used to support future model-based economic evaluations in this field. The limited modelling work available on tests typically used for the detection of PAD in primary care, in particular, highlights the importance of future work in this area.

Current concepts for the evaluation and management of diabetic foot ulcers

The lifetime risk for diabetic patients to develop a diabetic foot ulcer (DFU) is 25%. In these patients, the risk of amputation is increased and the outcome deteriorates.More than 50% of non-traumatic lower-extremity amputations are related to DFU infections and 85% of all lower-extremity amputations in patients with diabetes are preceded by an ulcer; up to 70% of diabetic patients with a DFU-related amputation die within five years of their amputation.Optimal management of patients with DFUs must include clinical awareness, adequate blood glucose control, periodic foot inspection, custom therapeutic footwear, off-loading in high-risk patients, local wound care, diagnosis and control of osteomyelitis and ischaemia. Cite this article: EFORT Open Rev 2018;3:513-525. DOI: 10.1302/2058-5241.3.180010.

Diagnostic modalities in peripheral artery disease

Peripheral artery disease (PAD) affects approximately one in five persons older than 70 years of age and it is often present in patients with concomitant vascular disease in different body territories (e.g. coronary artery disease). Diagnosis at an early stage is important in order to achieve improvement in patient's symptoms and prognosis. Remarkable improvements in the field of noninvasive and invasive imaging techniques have led to an advanced level the management of patients with PAD. Throughout this review article, the clinically available diagnostic modalities in PAD are presented. Strong and weaker points are stressed out in a manner that elucidates that no perfect diagnostic method exists. Based on the patient's individual profile, as well as on certain aspects of the disease (e.g. morphology of carotid plaque lesions) the attending physician will ultimately decide which diagnostic path will lead to a prompt and correct diagnosis of PAD with the minimum amount of exams and risk for the patient.

Upper extremity non-contrast magnetic resonance venography (MRV) compared to contrast enhanced MRV and ultrasound

PURPOSE

To assess feasibility, image quality and measured venous caliber of non-contrast MRV (NC-MRV) of central and upper extremity veins, compared to contrast-enhanced MRV (CE-MRV) and ultrasound (US) in healthy volunteers.

MATERIALS AND METHODS

10 subjects underwent NC-MRV and CE-MRV at 1.5 T, with comparison to US. Two radiologists evaluated MRI for image quality (IQ) and venous caliber.

RESULTS AND CONCLUSIONS

NC-MRV is feasible, with inferior IQ but comparable venous caliber measurements CE-MRV (mean 7.9±4.58 mm vs. 7.83±4.62, p=0.13). Slightly larger upper limb caliber measurements were derived for NC-MRV and CE-MRV compared to US (NC-MRV 5.2±1.8 mm, CE-MRV 4.9±1.6 mm, US 4.5±1.8 mm, both p<0.001).

Improved centerline tree detection of diseased peripheral arteries with a cascading algorithm for vascular segmentation

Vascular segmentation plays an important role in the assessment of peripheral arterial disease. The segmentation is very challenging especially for arteries with severe stenosis or complete occlusion. We present a cascading algorithm for vascular centerline tree detection specializing in detecting centerlines in diseased peripheral arteries. It takes a three-dimensional computed tomography angiography (CTA) volume and returns a vascular centerline tree, which can be used for accelerating and facilitating the vascular segmentation. The algorithm consists of four levels, two of which detect healthy arteries of varying sizes and two that specialize in different types of vascular pathology: severe calcification and occlusion. We perform four main steps at each level: appropriate parameters for each level are selected automatically, a set of centrally located voxels is detected, these voxels are connected together based on the connection criteria, and the resulting centerline tree is corrected from spurious branches. The proposed method was tested on 25 CTA scans of the lower limbs, achieving an average overlap rate of 89% and an average detection rate of 82%. The average execution time using four CPU cores was 70 s, and the technique was successful also in detecting very distal artery branches, e.g., in the foot.

A Robotic Ultrasound Scanner for Automatic Vessel Tracking and Three-Dimensional Reconstruction of B-Mode Images

Locating and evaluating the length and severity of a stenosis is very important for planning adequate treatment of peripheral arterial disease (PAD). Conventional ultrasound (US) examination cannot provide maps of entire lower limb arteries in 3-D. We propose a prototype 3D-US robotic system with B-mode images, which is nonionizing, noninvasive, and is able to track and reconstruct a continuous segment of the lower limb arterial tree between the groin and the knee. From an initialized cross-sectional view of the vessel, automatic tracking was conducted followed by 3D-US reconstructions evaluated using Hausdorff distance, cross-sectional area, and stenosis severity in comparison with 3-D reconstructions with computed tomography angiography (CTA). A mean Hausdorff distance of 0.97 ± 0.46 mm was found in vitro for 3D-US compared with 3D-CTA vessel representations. To evaluate the stenosis severity in vitro, 3D-US reconstructions gave errors of 3%-6% when compared with designed dimensions of the phantom, which are comparable to 3D-CTA reconstructions, with 4%-13% errors. The in vivo system's feasibility to reconstruct a normal femoral artery segment of a volunteer was also investigated. These results encourage further ergonomic developments to increase the robot's capacity to represent lower limb vessels in the clinical context.

Korean Guidelines for Interventional Recanalization of Lower Extremity Arteries

Peripheral arterial occlusive disease caused by atherosclerosis can present with intermittent claudication or critical limb ischemia. Proper diagnosis and management is warranted to improve symptoms and salvage limbs. With the introduction of new techniques and dedicated materials, endovascular recanalization is widely performed for the treatment of peripheral arterial occlusive disease because it is less invasive than surgery. However, there are various opinions regarding the appropriate indications and procedure methods for interventional recanalization according to operator and institution in Korea. Therefore, we intend to provide evidence based guidelines for interventional recanalization by multidisciplinary consensus. These guidelines are the result of a close collaboration between physicians from many different areas of expertise including interventional radiology, interventional cardiology, and vascular surgery. The goal of these guidelines is to ensure better treatment, to serve as a guide to the clinician, and consequently, to contribute to public health care.

Lower limb complications of diabetes mellitus: a comprehensive review with clinicopathological insights from a dedicated high-risk diabetic foot multidisciplinary team

Diabetic complications in the lower extremity are associated with significant morbidity and mortality, and impact heavily upon the public health system. Early and accurate recognition of these abnormalities is crucial, enabling the early initiation of treatments and thus avoiding or minimizing deformity, dysfunction and amputation. Following careful clinical assessment, radiological imaging is central to the diagnostic and follow-up process. We aim to provide a comprehensive review of diabetic lower limb complications designed to assist radiologists and to contribute to better outcomes for these patients.

Hemodynamic monitor for rapid, cost-effective assessment of peripheral vascular function

Peripheral vascular diseases affect hundreds of millions of people worldwide and are often symptomless and undiagnosed. Early diagnosis is crucial for effective treatment and reducing personal and economic costs, particularly where early treatment is geared towards preventing lower extremity amputation. New diagnostic tools are needed to enable this earlier intervention. We have developed a new low-cost, easy to use, non-invasive hemodynamic monitor, HeMo, to address this large and growing problem. Using a novel combination of impedance tomography and electrical volumetric measurements we can calculate real-time changes in peripheral blood volume. We believe that this work will lead to the availability of a fast, easy to use and cost-effective vascular assessment tool, dramatically shortening the time to diagnosis and subsequently intervention, dramatically improving the prognosis of affected patients.

Vascular imaging: the evolving role of the multidisciplinary team meeting in peripheral vascular disease

This article reviews the importance of preinterventional cross-sectional imaging in the evaluation of peripheral arterial disease, as well as discussing the pros and cons of each imaging modality. The importance of a multidisciplinary team approach is emphasized.

Mapping of autogenous saphenous veins as an imaging adjunct to peripheral MR angiography in patients with peripheral arterial occlusive disease and peripheral bypass grafting: prospective comparison with ultrasound and intraoperative findings

BACKGROUND

Mapping of the great saphenous vein is very important for planning of peripheral and coronary bypass surgery. This study investigated mapping of the great saphenous vein as an adjunct to peripheral MR angiography using a blood pool contrast agent in patients who were referred for evaluation of peripheral arterial occlusive disease and bypass surgery.

METHODS

38 patients with peripheral arterial occlusive disease (21 men; mean age: 71 years, range, 44-88 years) underwent peripheral MR angiography using the blood pool contrast agent Gadofosveset trisodium. Apart from primary arterial assessment images were evaluated in order to determine great saphenous vein diameters at three levels: below the saphenofemoral junction, mid thigh and 10 cm above the knee joint (usability: diameter range: >3 and <10 mm at one level and >3.5 and <10 mm at a neighboring level). Duplex ultrasound was performed by an independent examiner providing diameter measurements at the same levels. Additionally, vessel usability was determined intraoperatively by the vascular surgeon during subsequent bypass surgery.

RESULTS

Mean venous diameters for MR angiography/duplex ultrasound were 5.4±2.6/5.5±2.8 mm (level 1), 4.7±2.7/4.6±2.9 mm (level 2) and 4.4±2.2/4.5±2.3 mm (level 3), respectively, without significant differences between the modalities (P = 0.207/0.806/0.518). Subsequent surgery was performed in 27/38 patients. A suitable saphenous vein was diagnosed in 25 and non-usability was diagnosed in 2 of the 27 patients based on MR angiography/duplex ultrasound, respectively. Usability was confirmed by intraoperative assessment in all of the 24 patients that received a venous bypass graft in subsequent bypass surgery. In 1 case, in which the great saphenous vein was assessed as useable by both MR angiography and duplex ultrasound, it was not used during subsequent bypass surgery due to the patients clinical condition and comorbidities.

CONCLUSION

Simultaneous mapping of the great saphenous vein as an imaging adjunct to peripheral MR angiography with a blood pool contrast agent is an alternative to additive duplex ultrasound in patients undergoing subsequent peripheral bypass grafting.

Systematic reviews and meta-analyses for more profitable strategies in peripheral artery disease

In the peripheral arteries, a thrombus superimposed on atherosclerosis contributes to the progression of peripheral artery disease (PAD), producing intermittent claudication (IC), ischemic necrosis, and, potentially, loss of the limb. PAD with IC is often undiagnosed and, in turn, undertreated. The low percentage of diagnosis (∼30%) in this setting of PAD is of particular concern because of the potential worsening of PAD (amputation) and the high risk of adverse vascular outcomes (vascular death, coronary artery disease, stroke). A Medline literature search of the highest-quality systematic reviews and meta-analyses of randomized controlled trials documents that, due to risk of bias, imprecision, and indirectness, the overall quality of the evidence concerning diagnostic tools and antithrombotic interventions in PAD is generally low. Areas of research emerge from the information collected. Appropriate treatments for PAD patients will only derive from ad-hoc studies. Innovative imaging techniques are needed to identify PAD subjects at the highest vascular risk. Whether IC unresponsive to physical exercise and smoking cessation identifies those with a heritable predisposition to more severe vascular events deserves to be addressed. Devising ways to improve prevention of vascular events in patients with PAD implies a co-ordinated approach in vascular medicine.

Peripheral artery disease and non-coronary atherosclerosis in Hispanics: another paradox?

Hispanic Americans (HA) are a significant and increasing segment of the population who must be considered in future health planning. HA, compared to European Americans (EA), have a lower prevalence of coronary artery disease, but higher burden of cardiovascular disease risk factors. It remains unclear if this observation termed the 'Hispanic Paradox' also exists for vascular beds outside the heart. We present a review of the literature which suggests that this paradox may also exist for arteries in the extremities and neck.

Variations of the popliteal artery branching with multidetector CT angiography

OBJECTIVE

To date the anatomy of the popliteal artery variations using multidetector-row computed tomography angiography (MD CTA) was not assessed. The objective of this study is to establish 3D CT anatomy of the popliteal artery variations.

MATERIALS AND METHODS

A total of 126 lower limbs that underwent CTA using 64-detector MDCT were retrospectively reviewed. The anatomical variations of the distal popliteal artery branching were assessed.

RESULTS

Ninety-seven lower limbs (83.6%) had the usual branching pattern (type 1 A) with tibialis anterior artery (TA) arising first followed by the tibial-peroneal trunk, which then gives rise to the tibialis posterior artery (TP) and peroneal artery. Variations in popliteal branching pattern were seen in 19 (16.4%) limbs. The commonest variation was first branch of the TP in 5 (4.4%) of the limbs (type 1 C) or high origin with anterior course of popliteus muscle of the TA in 5 (4.4%) limbs (type 2 A II).

CONCLUSION

Many variations exist in the running patterns of the branching pattern of the popliteal artery. Knowledge of the branching pattern of the popliteal artery will be beneficial to radiologist for the evaluation of CT angiograms and interventional vascular procedures, and to vascular surgeons for various surgical approaches. MD CTA provides noninvasive means of assessing distal popliteal artery variations.

CT angiography after 20 years: a transformation in cardiovascular disease characterization continues to advance

Through a marriage of spiral computed tomography (CT) and graphical volumetric image processing, CT angiography was born 20 years ago. Fueled by a series of technical innovations in CT and image processing, over the next 5-15 years, CT angiography toppled conventional angiography, the undisputed diagnostic reference standard for vascular disease for the prior 70 years, as the preferred modality for the diagnosis and characterization of most cardiovascular abnormalities. This review recounts the evolution of CT angiography from its development and early challenges to a maturing modality that has provided unique insights into cardiovascular disease characterization and management. Selected clinical challenges, which include acute aortic syndromes, peripheral vascular disease, aortic stent-graft and transcatheter aortic valve assessment, and coronary artery disease, are presented as contrasting examples of how CT angiography is changing our approach to cardiovascular disease diagnosis and management. Finally, the recently introduced capabilities for multispectral imaging, tissue perfusion imaging, and radiation dose reduction through iterative reconstruction are explored with consideration toward the continued refinement and advancement of CT angiography.

Screening for peripheral arterial disease

BACKGROUND

In the general population, up to 10% of people younger than 70 years and 15% to 20% of people older than 70 years have peripheral arterial disease (PAD). Symptomatic and asymptomatic PAD has an estimated prevalence of 13% in the over 50 years age group. However, asymptomatic PAD can account for up to 75% of PAD patients and only 10% of PAD patients have typical intermittent claudication. People with PAD are at an increased risk of death, heart and cerebrovascular disease and are recommended to receive treatment to manage their cardiac risk. They suffer from significant functional limitations in their daily activities and the most severely affected are at risk of limb loss. Many people with PAD do not have any symptoms. Only some people have discomfort or pain in the lower legs when walking, so PAD often goes undetected. Given the high incidence of asymptomatic and undiagnosed PAD, it is important to determine the effectiveness of a screening intervention in preventing cardiovascular adverse outcomes, both fatal and non-fatal.

OBJECTIVES

To determine the effectiveness of screening for PAD in asymptomatic and undiagnosed individuals in terms of reduction of all-cause mortality, cardiovascular events (for example myocardial infarction and stroke), morbidity from PAD (intermittent claudication, amputation, reduced walking distance) and improvement in quality of life.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched November 2013) and CENTRAL (2013, Issue 10).

SELECTION CRITERIA

All published and unpublished randomised controlled trials (RCTs) of screening for PAD were sought without language restriction.

DATA COLLECTION AND ANALYSIS

Studies identified for potential inclusion in the review were independently assessed by both review authors. We planned to conduct data collection and analysis in accordance with the Cochrane Handbook for Systematic Review of Interventions.

MAIN RESULTS

No RCTs were identified that met the inclusion criteria.

AUTHORS' CONCLUSIONS

Unfortunately, no randomised controlled trial data are available regarding screening for PAD. Therefore, we are unable to determine the effects of screening for PAD in order to guide decision making by healthcare providers and planners. High quality randomised controlled trials evaluating the effectiveness of screening for PAD in asymptomatic and undiagnosed individuals in terms of reduction of all-cause mortality, cardiovascular events (for example myocardial infarction and stroke), morbidity from PAD (intermittent claudication, amputation, reduced walking distance) and improvement in quality of life are needed.

Patterns of disease distribution of lower extremity peripheral arterial disease

Peripheral arterial disease (PAD) is a common manifestation of atherosclerosis that is associated with an increased risk of mortality and cardiovascular (CV) events. Peripheral arterial disease involves the arteries distal to the aortic bifurcation in a nonuniform manner. Studies have shown that symptoms and prognosis of patients with PAD vary according to the location and size of the affected artery. Several modalities have been used to identify the location of PAD, including noninvasive evaluations and invasive procedures. Peripheral arterial disease has a risk factor profile similar to that associated with coronary artery disease (ie, age, gender, diabetes, smoking, hypertension, and hyperlipidemia). Many studies have shown that the distribution, extent, and progression of PAD are influenced by CV risk factors but the findings are not consistent. Management strategies for PAD are different for proximal and distal PAD. The objective of this review is to discuss the patterns of diseases distribution in patients with PAD.

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

Duplex ultrasonography (DUS) is a safe, noninvasive method for imaging vasculature when compared with conventional angiography. Our goal is to assess the accuracy of DUS compared with angiography of the lower extremities. We reviewed a total of 373 lesions in 278 patients from July 2005 through June 2010. Patients underwent DUS followed by angiography within 30 days. Peak systolic velocities (PSV) were stratified into one of four categories and compared with the angiographic findings. Seventy-five chronic total occlusions were found. Of the remaining 298 lesions, a significant relationship was found between PSV and degree of angiographic stenosis (p < 0.001). DUS was found to demonstrate a sensitivity of 79.7%, specificity of 79.2%, positive predictive value of 88.2%, and negative predictive value of 66.7% for lesions ≥ 70%. The 66.7% of the false-negative lesions with the lowest velocities were below the knee joint. DUS of the lower extremities is accurate in determining the degree of stenosis ranging from mild-to-severe disease. Some limitation may exist in estimating the degree of stenosis below the knee.