The present study analyzes the concordance between arterial mapping of this sector using duplex ultrasound and intraoperative angiography.

A retrospective, single-center observational study was carried out. The study sample consisted of patients subjected to open or endovascular surgery of the femoropopliteal and distal sector with prior ultrasound arterial mapping from January 2017 to December 2022. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) of arterial mapping with duplex ultrasound versus intraoperative angiography were evaluated, the degree of concordance between the two techniques and the correlation between surgical planning and the surgery finally performed.

167 patients were analyzed. A total of 1837 segments were explored, of which 149 (8.1%) were not able to be evaluated. Regarding the global precision of ultrasound in predicting significant arterial lesions (stenosis > 50% or occlusion), sensitivity was 85.26% (95% confidence interval [95%CI]: 82.33-88.19%), specificity 88.57% (95%CI: 86.63-90.51%), PPV 80.41% (95%CI: 77.24-83.58%), and NPV 91.61% (95%CI: 89.89-93.34%). Global concordance assessed by the kappa index was 0.725 (95%CI: 0.691-759). The surgical indications based on arterial mapping coincided with the final surgery performed in 97.6% of the cases.

Arterial mapping of the femoropopliteal and distal sector with duplex ultrasound could be considered as the sole preoperative imaging technique for surgical planning.

Lower limb peripheral artery disease (PAD) is highly prevalent. Current guidelines recommend duplex ultrasound (DUS) with spectral analysis for diagnosis. This systematic review and meta-analysis assessed the diagnostic accuracy of DUS in symptomatic PAD patients. We searched electronic databases for studies comparing DUS and arteriography. Arteries were analyzed individually and grouped into segments (aorto-common femoral, femoropopliteal, below the knee, and the entire lower limb). The meta-analysis estimated sensitivity, specificity, likelihood, and diagnostic odds ratios (DOR). Fifteen studies were included, analyzing 9,067 arteries. DUS accuracy for symptomatic PAD was 0.86 (95% CI 0.81-0.90) for sensitivity and 0.95 (95% CI 0.78-0.97) for specificity. The best results were observed for the femoropopliteal segment: sensitivity 0.86 (95% CI 0.80-0.90), specificity 0.95 (95% CI 0.93-0.97). The poorest performance was observed for the below-the-knee segment: sensitivity 0.78 (95% CI 0.60-0.89), specificity 0.92 (95% CI 0.78-0.97). Most studies had high and unclear risk of bias. There is significant heterogeneity in results, with a limited number of primary studies for each arterial segment, especially for the below-the-knee segment.

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.

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.

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%.

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.

This position paper, written by members of International Union of Angiology (IUA) Youth Committee and senior experts, shows an overview of therapeutical approaches for patients with chronic limb-threatening ischemia (CLTI) and absence of 'standard' solutions for revascularization. The aim was to demonstrate the accurate management of the 'no-option' CLTI patient including the wound treatment and the rehabilitation, considering always the goal of the increase of quality of life of the patients.

The aim of this work is to compare the diagnostic accuracy of Duplex ultrasound (DUS) and CT angiography (CTA) in the study of arterial vessels, in patients with chronic peripheral arterial disease (PAD) of the lower limbs to undergo endovascular revascularization with the use of intraprocedural digital angiography (DSA).

94 patients with obstructive pathology of the arterial axes of the lower limbs were enrolled in the study. In all patients, endovascular revascularization treatment was considered the most suitable therapeutic choice. For this reason, ultrasound and CTA was performed preoperatively in all and based on the data obtained it was decided to classify the arterial tree into five segments: iliac, common femoral, superficial femoral, popliteal and infra-geniculate. According to the degree of stenosis or occlusion, the arteries were scored in no stenotic, stenotic and occluded. The comparison of the data provided by the DUS and the CTA was carried out with reference to the parameters obtained by the DSA.

The results of our experience have shown that in the iliac arterial district DUS proved to be less accurate than CT angiography when compared to DSA (Cohen's Kappa agreement of 0.91 and 1.0, respectively). Good diagnostic concordance were found in the femoro-popliteal district (Cohen's Kappa agreement 33 between 0.96 and 0.93). On the contrary, when the data of the infra-geniculate area were compared, CT angiography showed a net deficiency compared to DSA and DUS (Cohen's k: 0.75).

Due to its accuracy, high-quality DUS performed by well-trained operators may therefore represent a good alternative to CTA in patients undergoing endovascular revascularization, in order to reduce the use of contrast-enhanced radiological imaging especially when a condition of intolerance to the contrast medium and/or renal insufficiency coexists.

The aim of this study was to analyze duplex ultrasound (DUS) and intraoperative angiography concordance for diagnosis of lower limb peripheral artery disease and its value for surgical planning.

This was a prospective, observational study, including patients who underwent revascularization of the lower limbs during 2018, diagnosed by DUS only or combined with preoperative computed tomography (CT) angiography. The concordance between preoperative DUS or CT angiography and the intraoperative angiography was studied using the Cohen kappa coefficient (k). The degree of agreement between the DUS-based surgical plan and the final surgical technique was also evaluated.

Fifty-one patients were included, with mean age of 71.8 ± 11.96 years (46-94); 23 had chronic kidney disease (45%). In 17 patients (34%), preoperative CT angiography was also performed. DUS showed a sensitivity of 100% (95% confidence interval (CI) [83.3-100%]), 80% (95% CI [50.21-100%,]), and 100% (95% CI [96.43-100%]) at the iliac, femoral, and popliteal sector, respectively, and a specificity of 93.55% (95% CI [83.29-100%]), 95.45% (95% CI [84.48-100%]), and 90.48% (95% CI [75.54-100%]) at the iliac, femoral, and popliteal sector, respectively. The positive predictive value for DUS was 60% (95% CI [7.06-100%]), 88.9% (95% CI [62.8-100%]), and 87.5% (95% CI [68.17-100%]) for the iliac, femoral, and popliteal sectors, respectively, whereas the negative predictive value was 100% (95% CI [98.28-100%]), 91.3% (95% CI [77.61-100%]), and 100% (95% CI, [97.37-100%]). The concordance between DUS and intraoperative angiography showed a k index of 0.587 (P = 0.000) in the iliac sector, 0.799 in the femoral sector (P = 0.000), and 0.699 in the popliteal sector (P = 0.000). The concordance between CT angiography/intraoperative angiography had a k index of 0.71 in the iliac sector (P = 0.0093), 0.566 in the femoral sector (P = 0.006), and 0.5 in the popliteal sector (P = 0.028). DUS-based surgical plan was accurate in 86% of cases (n = 44).

Our experience suggests that DUS arterial mapping of the femoral and popliteal areas is better than CT angiography and can be considered as a unique preoperative imaging test during the surgical planning in patients undergoing a lower limb revascularization procedure.

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).

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.

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).

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.

Physiologic assessment of lower limb peripheral artery occlusive disease is based on indirect physiologic measurement of ankle-brachial systolic pressure index (ABI) and recording ultrasound tibial artery waveforms. Duplex ultrasound testing affords direct tibial artery imaging and assessment of pulsed-Doppler tibial artery waveforms, which is more accurate then measurement of ABI for peripheral artery occlusive disease severity assessment. Tibial artery peak systolic velocity (PSV) is of particular value in the evaluation of patients with incompressible tibial arteries producing a falsely elevated ABI. Calculation of the ankle-profunda index (average tibial artery PSV/proximal profunda femoris artery PSV) also correlates with ABI reduction and can be used as an additional measure of peripheral artery occlusive disease. Tibial artery PSVs can be used to supplement ABI as an objective outcome measure after peripheral arterial interventions, and this aspect of duplex scanning warrants further clinical research.

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.

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.

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.

The aim of this study was to evaluate duplex ultrasound arterial mapping (DUAM) as the sole imaging modality when planning for bypass surgery (BS) and endovascular revascularization (EvR) in patients with critical limb ischemia for TransAtlantic Inter-Society Consensus (TASC) II C/D infrainguinal lesions.

This was a retrospective review evaluating the accuracy of DUAM as the sole imaging tool in determining patient suitability for BS vs EvR. Primary outcomes were the sensitivity and specificity of DUAM compared with intraoperative digital subtraction angiography. Secondary outcomes were procedural, hemodynamic, and clinical outcomes, amputation-free survival, and freedom from major adverse clinical events.

From 2002 to 2012, a total of 4783 patients with peripheral arterial disease were referred, of whom 622 critical limb ischemia patients underwent revascularization for TASC C and D lesions (EvR: n = 423; BS: n = 199). Seventy-four percent of EvR and 82% of BS were performed for TASC D (P = .218). The DUAM showed sensitivity of 97% and specificity of 98% in identifying lesions requiring intervention. Of the 520 procedures performed with DUAM alone, there was no difference regarding the number of procedures performed for occlusive or de novo lesions (EvR: 65% and 71%; BS: 87% and 78%; P = .056). Immediate clinical improvement to the Rutherford category ≤3 was 96% for EvR and 97% for BS (P = .78). Hemodynamic success was 79% for EvR and 77% for BS (P = .72). Six-year freedom from binary restenosis was 71.6% for EvR and 67.4% for BS (P = .724). Six-year freedom from target lesion revascularization was 81.1% for EvR and 70.3% for BS (P = .3571). Six-year sustained clinical improvement was 79.5% for EvR and 66.7% for BS (P = .294). Six-year amputation-free survival was 77.2% for EvR and 74.6% for BS (P = .837). There was a significant difference in risk of major adverse clinical events between EvR and BS (51% vs 70%; P = .034). Only 16.4% of patients required magnetic resonance angiography, which tended to overestimate lesions with 84% agreement with intraoperative findings. Six-year binary restenosis was 71% for DUAM procedures compared with 55% for magnetic resonance angiography procedures (P = .001), which was solely based on the prospective modality.

The DUAM epitomizes a minimally invasive, economically proficient modality for road mapping procedural outcome in BS and EvR. It allows for high patient turnover with procedural and clinical success without compromising hemodynamic outcome. The DUAM is superior to other available modalities as the sole preoperative imaging tool in a successful limb salvage program.

Lower extremity peripheral arterial disease (PAD) affects approximately 10% of the American population, with 30% to 40% of these patients presenting with claudication symptoms. The prevalence of PAD increases with age and the number of vascular risk factors. More importantly, it is a marker of atherosclerotic disease burden, and is associated with increased mortality from cardiovascular and cerebrovascular causes. There have been recent advances in noninvasive imaging, endovascular approaches for revascularization, and aggressive risk factor management for prevention of cardiac and cerebrovascular complications in PAD. There is now a trend toward aggressive risk factor modification and endovascular revascularization for most patients, with surgical interventions reserved for certain situations only. In the present article, a systematic review is presented, focusing on the key aspects of the disease epidemiology, presentation, natural history, diagnosis and available management options.

Non-invasive vascular studies can provide crucial information on the presence, location, and severity of critical limb ischaemia (CLI), as well as the initial assessment or treatment planning. Ankle-brachial index with Doppler ultrasound, despite limitations in diabetic and end-stage renal failure patients, is the first-line evaluation of CLI. In this group of patients, toe-brachial index measurement may better establish the diagnosis. Other non-invasive measurements, such as segmental limb pressure, continuous-wave Doppler analysis and pulse volume recording, are of limited accuracy. Transcutaneous oxygen pressure (TcPO(2)) measurement may be of value when rest pain and ulcerations of the foot are present. Duplex ultrasound is the most important non-invasive tool in CLI patients combining haemodynamic evaluation with imaging modality. Computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are the next imaging studies in the algorithm for CLI. Both CTA and MRA have been proven effective in aiding the decision-making of clinicians and accurate planning of intervention. The data acquired with CTA and MRA can be manipulated in a multiplanar and 3D fashion and can offer exquisite detail. CTA results are generally equivalent to MRA, and both compare favourably with contrast angiography. The individual use of different imaging modalities depends on local availability, experience, and costs. Contrast angiography represents the gold standard, provides detailed information about arterial anatomy, and is recommended when revascularisation is needed.

The International Working Group on the Diabetic Foot (IWDGF) has produced in 2011 a guideline on the diagnosis and treatment of peripheral arterial disease in patients with diabetes and a foot ulcer. This document, together with a systematic review that provided the background information on management, was produced by a multidisciplinary working group of experts in the field and was endorsed by the IWDGF. This progress report is based on these two documents and earlier consensus texts of the IWDGF on the diagnosis and management of diabetic foot ulcers. Its aim is to give the clinician clear guidance on when and how to diagnose peripheral arterial disease in patients with diabetes and a foot ulcer and when and which treatment modalities should be considered, taking both risks and benefits into account.

Peripheral arterial disease (PAD) is very frequent in diabetics, and it increases with age. Foot examination contributes poorly to diagnosis of PAD. The ankle-brachial index (ABI) measurement is considered the most accurate noninvasive diagnostic method when evaluating PAD: ABI evaluation is recommended in all diabetics aged >50 years. Many diabetic patients with PAD have a concomitant sensitive neuropathy: as a consequence, perception of ischemic pain is remarkably reduced or completely blocked. The result is that the prevalence of claudication in the diabetic population with PAD is lower than the prevalence of critical limb ischemia (CLI) in this population. CLI is a major risk factor for lower extremity amputation without revascularization. Ankle and toe pressures and oxygen tension at the foot are the noninvasive diagnostic parameters of CLI though the medial artery calcification inhibits accurate determination of the ankle and toe pressures, especially when a forefoot ulcer is present. In diabetics, the anatomical localization is mainly distal; arterial wall calcification is frequently observed and occlusion occurs more frequently than stenosis. Such anatomical features, along with the difficulties in the diagnostic approach, account for the fundamental role of CLI as the main prognostic indicator for major amputation. PAD is an expression of systemic atherosclerotic disease. Prognosis of patients with PAD is related to the presence and extent of underlying coronary artery disease (CAD) but also to the severity of PAD: in particular, patients in whom revascularization is not feasible have the highest mortality rate.

Quantitative information on time-resolved blood velocity along the femoral/popliteal artery can provide clinical information on peripheral arterial disease and complement MR angiography as not all stenoses are hemodynamically significant. The key disadvantages of the most widely used approach to time-resolve pulsatile blood flow by cardiac-gated velocity-encoded gradient-echo imaging are gating errors and long acquisition time. Here, we demonstrate a rapid nontriggered method that quantifies absolute velocity on the basis of phase difference between successive velocity-encoded projections after selectively removing the background static tissue signal via a reference image. The tissue signal from the reference image's center k-space line is isolated by masking out the vessels in the image domain. The performance of the technique, in terms of reproducibility and agreement with results obtained with conventional phase contrast-MRI was evaluated at 3 T field strength with a variable-flow rate phantom and in vivo of the triphasic velocity waveforms at several segments along the femoral and popliteal arteries. Additionally, time-resolved flow velocity was quantified in five healthy subjects and compared against gated phase contrast-MRI results. To illustrate clinical feasibility, the proposed method was shown to be able to identify hemodynamic abnormalities and impaired reactivity in a diseased femoral artery. For both phantom and in vivo studies, velocity measurements were within 1.5 cm/s, and the coefficient of variation was less than 5% in an in vivo reproducibility study. In five healthy subjects, the average differences in mean peak velocities and their temporal locations were within 1 cm/s and 10 ms compared to gated phase contrast-MRI. In conclusion, the proposed method provides temporally resolved arterial velocity with a temporal resolution of 20 ms with minimal post processing.

To assess the reliability and applicability of duplex ultrasound scanning (DUS) of lower limb arteries, compared with digital subtraction angiography (DSA), in patients with peripheral arterial disease (PAD).

A prospective, blinded, comparative study.

A total of 169 patients were examined by DUS and DSA. Intermittent claudication (IC) was present in 42 (25%) patients and critical limb ischaemia (CLI) in 127 (75%) patients. To allow segment-to-segment comparison, the arterial tree was divided into 15 segments. In total, 2535 segments were examined using kappa (κ) statistics to test the agreement.

The agreement between DUS and DSA was very good (κ>0.8) or good (0.8 ≥ κ>0.6) in most segments, but moderate (0.6 ≥ κ>0.4) in the tibio-peroneal trunk and the peroneal artery. Agreement between the two techniques was significantly better in the supragenicular (κ=0.75 (95% confidence interval (CI): 0.70-0.80)) than in the infragenicular segments (κ=0.63 (0.59-0.67)) (p<0.001). Similarly, the technical success rate was significantly higher in the supragenicular segments (DUS: 100%; DSA: 99%) than in the infragenicular segments (both 93%) (p<0.001). DUS was the best technique for imaging of the distal crural arteries (92% vs. 97%; p<0.001) and DSA was the best technique for imaging of the proximal crural arteries (95% vs. 91%; p<0.01). Neither the agreement nor the technical success rate was influenced by the severity of PAD, that is, IC versus CLI.

The agreement between DUS and DSA was generally good, irrespective of the severity of ischaemia. DUS performed better in the supragenicular arteries than in the infragenicular arteries. However, DUS compared favourably with DSA in both tibial vessels, particularly in the distal part, which makes DUS a useful non-invasive alternative to DSA.

Duplex ultrasound arterial mapping (DUAM) allows precise evaluation of peripheral vascular disease (PVD). However, magnetic resonance angiography (MRA) and digital-subtraction angiography (DSA) are the diagnostic tools used most frequently prior to intervention. Our aim was to compare clinical pragmatism, hemodynamic outcomes, and cost-effectiveness when using DUAM alone compared to DSA or MRA as preoperative assessment tools for endovascular revascularization (EvR) in critical lower limb ischemia (CLI). From 2002 through 2005, 465 patients were referred with PVD. Of these, 199 had CLI and 137 required EvR. Preoperative diagnostic evaluation included DUAM (n = 41), DSA (n = 50), or MRA (n = 46). EvR was aortoiliac in 27% of cases and infrainguinal in 73%. Patients were assessed at day 1, 6 weeks, 3 months, and 6 months. Composite end points were relief of rest pain, ulcer/gangrene healing, and increase in perfusion pressure, as measured by ankle-brachial index (ABI) and digital pressures. Patency by DUAM, limb salvage, morbidity, mortality, length of stay, and cost-effectiveness were compared between groups using nonparametric t-test, analysis of variance, and Kaplan-Meier analysis. The three groups were comparable in terms of age, sex, comorbidity, and Society for Vascular Surgery/International Society of Cardiovascular Surgery clinical classification. Six-month mean improvement in ABI in the DUAM group was comparable to that in the DSA group (P = 0.25) and significantly better than that in the MRA group (P < 0.05). Six-month patency rates for the DUAM group were comparable to those in the DSA group (P = 0.68, relative risk [RR] = 0.74, 95% confidence interval [CI] 0.18-2.99) and superior to that in the MRA group (P = 0.022, RR = 0.255, 95% CI 0.09-0.71). Length of hospital stay was lower in the DUAM group compared with the DSA group (P < 0.0001) and the MRA group (P = 0.0003). The cost of DUAM is lower than that of both DSA and MRA. DUAM accurately identified the total number of target lesions for revascularization; however, MRA overestimated it. Our results indicate that DUAM is outstanding when compared with other available modalities as a preoperative imaging tool in a successful EvR program. DUAM is a minimally invasive preoperative evaluation for EvR and offers precise consecutive data with patency and limb salvage rates comparable to EvR based on DSA and superior to MRA. We believe that our feasibility study has established DUAM as an economically proficient primary modality for investigating patients with CLI that significantly shortens length of hospital stay.

Each year 1-2% of patients with peripheral arterial occlusive disease (pAOD) develop critical limb ischemia (CLI), characterized by rest pain and peripheral ulcer or gangrene. This aggravation of the disease is accompanied by an increase of the 1-year mortality rate up to 25% and a similarly increased frequency of major amputation. We can choose between conservative, endovascular, and surgical procedures for an adequate therapy of the underlying vascular stenoses or occlusions. Yet, clear therapeutic recommendations only exist for suprapopliteal lesions. However, in a number of cases, especially in diabetics, target lesions have an infrapopliteal location. Since endovascular procedures have undergone significant improvement in the last few years, the following review discusses methods for infrapopliteal revascularization taking into consideration the newest publications on this topic.

In patients being considered for a microsurgical fibular transfer, thorough examination of the vascular supply to the lower leg is indisputably necessary. The aim of this study was to evaluate the validity of color-coded duplex sonography (CCDS) in the assessment of the arteries of the lower leg.

In 13 patients needing bony reconstruction of the jaw 22 legs were examined using CCDS. The three arteries of the lower leg were visualized and traced from the ankle to the popliteal fossa. At every arterial segment Doppler sonographic examination was also performed. All 13 patients underwent digital subtraction arteriography (DSA) of the lower extremities, additionally.

We were able to visualize and to assess all but one of the arteries using CCDS. In 13 extremities of 9 patients CCDS exhibited a normal vascular supply to the lower leg provided by three regular arteries. DSA confirmed this and the patients underwent fibular transfer. In the other 4 patients a regular vascular situation could not be shown by CCDS because of nonvisualization of arterial segments or pathological findings. Two of these patients received alternative bony transplants. In the remaining two patients angiography exhibited one leg to have a normal three vessel supply, respectively. Fibular transplants could be raised from this leg. In all patients CCDS was able to localize between 3 and 7 perforators branching off the peroneal artery. Their position determined the placement of the skin paddle to be raised with the bone. Further advantages of CCDS were the universal applicability to all patients and the possibility of performing it at our own department. The time required for the examination and the necessity of having adequate technical equipment were the disadvantages.

In patients being considered for a microsurgical fibular transplantation, we recommend CCDS of the lower leg as a screening tool for the vascular supply of the lower leg. DSA and MRA are predominantly advocated for those patients, in whom CCDS reveals pathological or uncertain findings.

The standard preoperative duplex arteriography (DA) from the aorta to the pedal vessels is time consuming and may be unnecessary in patients presenting with calf claudication alone. The feasibility of a shortened protocol was evaluated. Of 286 femoral-popliteal reconstruction based on DA during the last 4A years, 79 (28%) were primary operations for calf claudication. Eliminating the aortoiliac portion of the test except for the distal external iliac artery and limiting the scanning of the infrapopliteal vessels to one or two arteries in the leg would significantly shorten the exam. To confirm the adequacy of the inflow tract, we relied on the common femoral artery Doppler waveform analysis and the intraoperative graft pressure upon completion of the bypass. Of the 79 primary femoral-popliteal bypasses, 53 (67%) had triphasic common femoral artery waveform and the remaining 26 had monophasic or biphasic waveforms. Three (6%) of the 53 femoral-popliteal bypasses in the former group had significant pressure gradients measured intraoperatively and were treated with iliac angioplasties and stents for unsuspected stenoses in 2 cases and a covered stent for a common iliac aneurysm in 1 case. Three, two, and one infrapopliteal vessel runoff was observed in 24 (45%), 16 (30%), and 9 (17%) extremities, respectively. Four patients (8%) had significant stenoses (>50%) or occlusion of all three infrapopliteal arteries. Eighty-one percent of the patients would have completed the short protocol had we scanned the peroneal artery initially. An additional 8% would have required scanning of a second vessel (anterior tibial) and only 11%, scanning of all three infrapopliteal vessels. The time interval for completion of short-protocol DA was significantly less than the time for the standard DA (16.2 A+/- 5.2A min vs. 35.1 A+/- 10.6 min) ( p < 0.01). We believe that the proposed short DA protocol combined with intraoperative graft pressure measurements can be used in 94% of the patients who have a patent popliteal artery (>/= 7 cm). It is a totally noninvasive approach that is particularly suitable for vascular technologists and surgeons who wish to start utilizing DA instead of contrast arteriography prior to infrainguinal reconstructions. However, the short protocol does not avert the need for completion arteriography of the inflow arteries and readiness to perform endovascular procedures to correct lesions not suspected by common femoral artery waveform analysis.

The limitations and complications associated with contrast angiography (CA) prior to lower extremity revascularization have led to an increased interest in duplex arteriography (DA) as a potential replacement. We report our experience with DA in patients with diabetes and/or chronic renal insufficiency (CRI) that would particularly benefit from a noninvasive approach to preoperative evaluation of the arterial tree. From January 1998 to November 2000, DA was performed in 145 patients with diabetes mellitus and/or CRI prior to 180 arterial reconstructions. One hundred twenty-one procedures were performed on 91 patients with diabetes alone, 41 on 33 patients with diabetes and CRI, and 18 on 15 patients with CRI alone. Patient ages ranged from 36 to 98 years (mean 72 +/- 12 years). Indications for surgery were severe claudication in 33 (18%), rest pain in 37 (21%), nonhealing ischemic ulcers in 52 (29%), and limb gangrene in 58 (32%). Optimal inflow and outflow anastomotic sites were selected according to a diagram based on DA that included arterial tree imaging from mid-aorta to the pedal vessels. Preoperative contrast arteriography was performed in 16 cases (9%) because of extremely poor runoff based on DA and limited visualization of outflow vessels. The distal anastomosis was to the popliteal artery in 89 cases (49%) and to the tibial and pedal arteries in 91 (51%). Intraoperative findings confirmed the preoperative DA results with the exception of one (0.6%) where the distal anastomosis was placed proximal to a significant stenosis requiring an extension graft. The use of DA presents a safe and reliable option to prebypass CA for many patients with diabetes or CRI. The ease of use and favorable patient outcomes achieved by this imaging modality may rival the use of CA for these patients.

The objective of this study was to compare magnetic resonance angiography (MRA), contrast arteriography (CA), and duplex arteriography (DA) for defining anatomic features relevant to performing lower extremity revascularizations. From March 1, 2001 to August 1, 2001, 33 consecutive inpatients with chronic lower extremity ischemia underwent CA, MRA, and DA before undergoing lower extremity revascularization procedures. The reports of these tests were compared prospectively and the differences in the aortoiliac segment, femoral-popliteal, and infrapopliteal segments were noted. The vessels were classified as mild disease (<50%), moderate disease (50-70%), severe disease (71-99%), and occluded. These studies and treatment plans based on these data were compared. During this time period, 11 patients were not able to undergo MRA and therefore were excluded from the study. Thirty-three patients were included in this study. These patients underwent 35 procedures, as 2 patients underwent bilateral procedures. The mean age of the 33 patients was 76+/-10 years (SD). Indications for the procedures included gangrene (20), ischemic ulcer (8), rest pain (4), and severe claudication (1). Patients' medical history included diabetes mellitus (25), hypertension (20), and end-stage renal disease (5). No differences were noted between intraoperative findings and CA in this series. Two of the three differences between DA and CA were felt to be clinically significant whereas 9 of the 12 differences between MRA and CA were felt to be clinically significant. On the basis of these data in this series, MRA does not yet seem to be able to obtain adequate data on infrapopliteal segments, at least not for this highly selected population. When severe tibial calcification or very low flow states are identified, CA may be necessary for patients undergoing DA.

Diabetic foot ulcers are frequently complicated by the presence of arterial occlusive disease (PAD). It is often difficult to assess the severity of ischemia by history and physical examination alone; a combination of different types of noninvasive laboratory testing may be necessary. Pulse-volume recordings and segmental pressures should be routinely obtained. If questions persist, an anatomic study is warranted. Duplex ultrasonography can provide accurate information with little risk to the patient and so should be readily obtained.

The aim of this prospective study conducted at a tertiary referral center was to evaluate the efficacy of high-frequency duplex scanning in the preoperative evaluation of potential pedal target vessels. Material and methods The study population consisted of thirty-three consecutive diabetics suffering critical limb ischemia, with indications of infra-popliteal occlusive disease. Duplex ultrasound was performed by an angiologist unaware of any prior imaging procedures. The pedal vessels were divided into four segments. The inner diameter-, the grade of calcification (on a scale from 1-to-3), the maximal systolic velocity, and the resistance index ([V.max syst-V min syst]/V max syst), were assessed by using a 13-MHz probe, and the pedal target vessel best suited for surgery was identified. Results of duplex scanning were compared to (1) the results of selective digital subtraction angiography (DSA) and contrast-enhanced magnetic resonance angiography (CE-MRA) studies interpreted by two radiologists, (2) the site of distal anastomosis predicted by a vascular surgeon according to DSA and CE-MRA studies, (3) the definitive site of distal anastomosis, and (4) early postoperative results (patency at three months).

Duplex scanning depicted significantly more pedal vascular segments than selective DSA- (P =.004, McNemar test). Agreement in predicting the site of distal anastomosis expressed as kappa value as follows: duplex versus DSA/CE-MRA, kappa 0.71;-DSA/CE-MRA versus definitive anastomosis, kappa 0.67; -and duplex versus definitive anastomosis kappa 0.82. Two patients were excluded from surgery as all three imaging modalities failed to demonstrate a pedal target vessel. Two patients had exploratory dissection of a pedal vessel (according to CE-MRA findings) that turned out to be occluded (as predicted by duplex scanning). In one patient the operation had to be terminated due to lack of autologous bypass material. In 31 patients who underwent pedal artery bypass, the resistance index could not be correlated to the run-off as assessed by intra-operative angiography.

High-frequency duplex focusing on the vacular-morphology is a worthwhile diagnostic tool to evaluate-potential pedal target vessels and extremely helpful when contrast-related methods (selective DSA, CE-MRA) do not sufficiently depict the pedal vasculature.

To determine the association between pre- and postintervention serum C-reactive protein (CRP) levels and 6-month restenosis after endovascular treatment of atherosclerotic lesions in arteries below the knee.

Eighty-nine patients with peripheral arterial disease underwent primary successful percutaneous transluminal angioplasty (PTA) of the distal popliteal, anterior tibial, posterior tibial, and fibular arteries. Six-month patency was evaluated with the ankle brachial index (ABI) and color-coded duplex ultrasonography (US). The association between restenosis and preintervention and 48-hour postintervention CRP levels was assessed with multiple logistic regression analysis.

ABI improved from a preintervention median of 0.54 to a postintervention median of 0.75 (P <.001). The primary technical success rate was 94% (100 of 106). In 50 patients, a suboptimal technical result was achieved with 30%-40% residual stenosis at the dilated segment. The median ABI at 6 months was 0.65, and it was inversely correlated with preintervention (r = -0.27, P =.009) and 48-hour postintervention (r = -0.40, P <.001) CRP levels. With duplex US at 6 months, restenosis (> or =50%) occurred in 36 patients. Patients with a preintervention CRP level of 0.23-0.92 mg/dL (2.3-9.2 mg/L) had a 3.7-fold increased adjusted risk for restenosis (P =.05); patients with a preintervention CRP level greater than 0.92 mg/dL (9.2 mg/L) had a 4.7-fold increased adjusted risk (P =.03). Postintervention CRP values greater than 2.42 mg/dL (24.2 mg/L) were associated with a 10.7-fold adjusted risk for restenosis (P =.002). Suboptimal PTA result was the only other parameter associated with an increased risk for restenosis (odds ratio, 3.7; P =.03).

Pre- and postintervention CRP levels were associated with restenosis after PTA of the distal popliteal and tibioperoneal arteries, which indicates that inflammation plays a crucial role in the pathophysiology of this process.

The risks of undiagnosed peripheral arterial disease (PAD) include progressive reduction in quality of life, potential limb loss, and unrecognized comorbid atherosclerotic (concomitant coronary and cerebrovascular) disease. Although a thorough historical review of symptoms and a comprehensive physical examination may lead the clinician to an appropriate index of suspicion, accurate diagnostic testing is crucial. Accredited vascular diagnostic laboratories provide a risk-free description of the presence, severity, and location of PAD. This article describes the basic noninvasive diagnostic tests, criteria for diagnosis, advantages and disadvantages of each diagnostic modality, and a strategy for PAD therapy.

to evaluate if ultrasound contrast-agent infusion could improve duplex-ultrasound imaging of peripheral arterial disease (PAD) and increase the agreement with digital subtraction arteriography (DSA).

prospective and consecutive study.

of 60 consecutive PAD patients, 15 were found to have an inconclusive duplex-ultrasound scan of the trifurcation and were included in the study. All 15 patients (53% male) were scheduled for DSA, all being candidates for vascular surgery due to claudication (n = 3, 20%), rest pain (n = 5, 33%) and tissue loss (n = 7, 47%).

on the day before DSA, a duplex-ultrasound scan of the trifurcation was performed. If the duplex-ultrasound scan was found inconclusive, it was repeated during continuous ultrasound contrast-agent infusion. DSA was performed unaware of the duplex-ultrasound results and served as the gold standard.

after contrast-agent administration, the number of inconclusively diagnosed segments was significantly reduced by 26 (70%), from 37 to 11(p < 0.001). In 19 segments (73%) contrast-agent infusion changed the diagnosis in accordance with the DSA (p < 0.05). Values of sensitivity and positive predictive value were improved from 0.20 (0.04-0.62) to 0.47 (0.26-0.69) and 0.50 (0.10-0.91) to 0.80 (0.49-0.93), respectively. Specificity and negative predictive value were unchanged. Agreement between duplex-ultrasound and DSA were improved from poor (kappa = 0.18 (95% CI: 0-0.82)) to moderate (kappa = 0.45 (0.17-0.74)) (p = 0.44).

ultrasound contrast-agents improve the diagnostic ability of duplex-ultrasound when scanning difficult arterial segments in patients suffering from PAD.

The prevalence of peripheral arterial disease (PAD) continues to increase, with recent data suggesting that almost 30% of patients in at-risk populations have PAD. Interest in the management of PAD has increased, partly secondary to the technologic advancement of devices and procedures capable of treating a wide array of vascular disorders via endoluminal techniques. A thorough clinical evaluation and accurate noninvasive testing remain the cornerstones of successful patient management and will promote improved outcomes through better patient selection. The utility of physiologic tests for determination of the presence and severity of PAD and more sophisticated imaging studies will allow the cardiovascular specialist to make appropriate decisions about management options. The currently accepted methods for determining the presence of PAD include a historic review of patient symptoms and atherosclerotic risk factors, physical examination, and the appropriate use of noninvasive modalities and X-ray digital subtraction angiography.

Approximately 10% of people age >55 years have asymptomatic peripheral atherosclerotic disease (PAD), 5% have intermittent claudication (IC, the cardinal symptom), and 1% critical leg ischemia (rest pain or gangrene). In patients with IC, worsening occurs in approximately 16%, bypass surgery is required in approximately 7%, and amputation in approximately 4%. Disease progresses more frequently in diabetics and in tobacco smokers. Patients with PAD suffer increased cardiovascular morbidity related mainly to coronary artery disease with a mortality rate of approximately 30% after 5 years. Compared to patients without PAD, the relative risk of coronary death is approximately 6.6, overall cardiovascular mortality 5.9, and all-cause mortality 3.1. Pain at rest or ischemic gangrene indicates severe, often multilevel arterial occlusive disease and calls for aggressive management, which usually includes angiography and revascularization by percutaneous angioplasty or surgery. Critical limb ischemia results in some 150,000 amputations annually in the U.S., with perioperative mortality rates of 5-10% for below-knee and up to 50% for above-knee amputation because of comorbidities. Physical findings include trophic signs of ischemia, vascular bruits and peripheral pulse deficits. Ischemic ulcers usually involve the tips of the toes or the heel of the foot, and are typically painful on elevation and most bothersome at night. Ancillary diagnostic modalities begin with the ankle/arm systolic pressure index (ABI); a value <0.90 indicates PAD with significant prognostic implications. More precise assessment in the noninvasive vascular laboratory may involve a combination of segmental limb pressure measurements and pulse volume waveform recording, which is over 90% accurate for predicting the level and extent of PAD. Exercise testing enhances the value of these observations. Magnetic resonance imaging methods are emerging to characterize the arterial wall and atherosclerotic lesions. The diagnosis of PAD does not generally require invasive techniques, and most patients with IC do not need contrast angiography. Angiography is indicated for mapping of the extent and location of arterial pathology prior to revascularization.

to evaluate preoperative duplex as the sole investigation prior to lower limb reconstruction. Design retrospective analysis.

between January 1995 and December 1999, 157 of 329 surgical interventions for chronic infrainguinal arterial or aneurysmal disease were performed without preoperative angiography.

in patients undergoing femoral artery endarterectomy, the extent of the stenosis and the status of the distal deep femoral artery were correctly diagnosed with duplex scanning in all but one patient. Duplex scan findings in patients undergoing infrainguinal bypass procedures were in agreement with the findings obtained from on-table angiography in regard to the selection of optimal outflow anastomotic sites in 123 (98%). Duplex scanning correctly evaluated the status of runoff in 113 (90%). There were no significant differences in 30-day occlusion rate and patency at 12 months between reconstructions performed with and without preoperative angiography.

in patients with conclusive duplex scan findings there is no need to perform angiography prior to lower limb reconstruction.

This study reviews our experience with duplex ultrasound arterial mapping (DUAM) for preoperative evaluation in 466 patients (262 men) who underwent 485 lower extremity revascularization procedures from January 1, 1998 to May 30, 2001. Preoperative imaging consisted of DUAM alone in 449 procedures and DUAM and contrast angiography (CA) in 36. An attempt to image from the distal aorta to the pedal arteries was made in all the patients. The selection of optimal inflow and outflow bypasses anastomotic sites was based on a schematic drawing following DUAM examination. Inflow disease was also assessed by intraoperative pressure gradient (IPG) between the distal anastomosis and radial arteries, and completion arteriography of the runoff vessels was obtained, which was correlated with the preoperative findings. Indications for surgery were severe claudication in 91 (19%) limbs, tissue loss in 197 (40%), rest pain in 113 (23%), acute ischemia in 46 (10%), popliteal aneurysm in 18 (4%), superficial femoral artery aneurysm in 1, abdominal aortic aneurysm with claudication in 1, and failing graft in 18 (4%). Age ranged from 30 to 97 years (mean 72 +/- 12 (SD) years) and risk factors such as diabetes, hypertension, use of tobacco, coronary artery disease, and end-stage renal disease were present in 45%, 45%, 44%, 44%, and 13% of the patients, respectively. One hundred twenty-one (25%) limbs had at least 1 previous ipsilateral revascularization. The mean DUAM time was 66 +/- 20 (SD) min (30-150 min). Additional preoperative imaging was deemed necessary in 36 cases due to extensive ulcers, edema, severe arterial wall calcification, and very poor runoff. The distal anastomosis was to the popliteal artery in 173 cases and to the tibial and pedal arteries in 255. Inflow procedures to the femoral arteries, embolectomy, thrombectomy, balloon angioplasty, and patch angioplasty accounted for the remaining 57 cases. Overall, 6-, 12-, and -24- month secondary patency rates were 86%, 80%, and 66%, respectively. This early experience shows that high-quality arterial ultrasonography performed by a highly skilled vascular technologist may represent an alternative to conventional arteriography for patients in need of lower extremity revascularization. Because of limitations inherent to the technique and very poor runoff observed on ultrasonographic examination, additional preoperative imaging procedure's are needed for certain patients.

Until April 1997 we routinely performed intra-arterial digital subtraction angiography (iaDSA) in all patients with severe lower leg ischemia requiring intervention. After a comparative study of duplex scanning (DS), pulsegenerated runoff, and iaDSA of the lower leg arteries, we postulated that management could be based on DS/pulse-generated runoff in 59% of patients. We prospectively evaluated the safety of such a noninvasive workup strategy.

All consecutive patients referred with severe lower leg ischemia between April 1997 and September 1998 were eligible. Management was based on DS with iaDSA being performed only on indication. Complications within 30 days and 12- and 24-month patency, survival, and limb salvage rates were recorded and compared with historical controls.

A total of 125 limbs in 114 patients were evaluated (74% rest pain or tissue loss). In 97 (78%) of 125 limbs, management was based on DS. It comprised conservative treatment (n = 33, 0% after iaDSA), percutaneous transluminal angioplasty (n = 25, 16% iaDSA), femoropopliteal bypass graft (n = 29, 17% iaDSA), femorotibial bypass graft (n = 29, 62% iaDSA), and other surgical procedures (n = 8, 4% iaDSA). Overall, the mortality within 30 days was 4% (5/114), and 2-year survival was 83%. Two-year primary and secondary patency and limb salvage rates were 75%, 93%, and 93% after a femoropopliteal bypass operation, respectively. One-year primary and secondary patency and limb salvage rates were 35%, 73%, and 74%, respectively, after a femorocrural bypass operation. There were no differences in patient characteristics, indication for specific treatment, and immediate and intermediate term outcome between the study and reference population.

In a vascular unit with wide expertise in DS of the lower leg arteries, management of patients with severe lower leg ischemia can be based on DS in most patients without negative effects on clinical outcome within 30 days and at 2-years' follow-up.

Recently, contrast arteriography has been challenged as the diagnostic test of choice for lower extremity arterial disease because of its associated morbidity and questionable accuracy in identifying suitable distal outflow arteries. The purpose of this report was to analyze our experience to determine if these concerns were justified. We reviewed 500 consecutive contrast arteriograms performed at our hospital for aortoiliac and lower extremity arterial disease between November 1994 and November 1998. Arteriograms performed in conjunction with therapeutic procedures such as balloon angioplasty, stent placement, and thrombolysis were excluded, leaving 244 diagnostic cases for analysis. Forty-six percent (112) of patients had diabetes mellitus, 14% (34) had an elevated baseline serum creatinine (> or =1.5 mg/dL), and an additional 7% (17) were dialysis dependent. Radiologists limited contrast volume by imaging only the symptomatic extremity when appropriate and using digital subtraction techniques as indicated. Our results showed that diagnostic contrast arteriography is associated with an acceptably low morbidity, has an accuracy that is unlikely to be surpassed by other modalities, and remains the diagnostic test of choice for lower extremity arterial disease.