Comparison of duplex imaging and arteriography in the evaluation of lower limb arteries

Intravascular Ultrasound during Endovascular Intervention for Peripheral Artery Disease, by Severity, Location, Device, and Procedure

There is limited evidence for the role of intravascular ultrasound (IVUS) in patients who underwent peripheral vascular intervention (PVI). We conducted retrospective cohort study utilizing the Healthcare Cost and Utilization Project-Agency for Healthcare Research and Quality National Readmission database to delineate outcomes in IVUS-guided PVI versus non-IVUS-guided PVI. The present study utilized National Readmission database between January 1, 2016, and December 31, 2019. We identified patients who underwent endovascular intervention for peripheral artery disease using relevant International Classification of Diseases, Tenth Revision, Procedural Coding System. The cohort was divided based on the use of IVUS during the procedure. The primary outcome was major amputation at 6 months after index hospitalization. Measured confounders were matched using propensity score inverse probability of treatment weighing method. We further performed a subgroup analysis based on disease severity, location of intervention, device, and procedure. A total of 434,901 hospitalizations were included in the present analysis. PVI with IVUS compared with no IVUS had similar risk of amputation at 6 months (195 of 8,939 [2.17%] vs 10,404 of 384,003 [2.71%]), hazard ratio 0.98, CI 0.77 to 1.25. Further, there was no difference in the rates of secondary outcomes. On subgroup analysis, amputation rates were significantly lower in patients with rest pain, in iliac intervention, or patients who underwent drug-eluting stent implantation with the use of IVUS compared with no IVUS. This nationwide observational study showed that there was no difference in major amputation rates with the use of IVUS in patients who underwent PVI. However, in subgroup of patients with rest pain, iliac intervention or drug-eluting stent implantation IVUS use was associated with significantly lower major amputation rates.

Duplex Ultrasound as a reliable alternative to CT angiography for treatment planning of Peripheral Artery Disease

BACKGROUND

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).

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

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.

Ultrasound in the Modern Management of the Diabetic Foot Syndrome: A Multipurpose Versatile Toolkit

Ultrasound (US) is a noninvasive and versatile technology that in recent years found acceptance in almost all the medical specialties, with diagnostic and interventional applications. In the diabetic foot syndrome (DFS), US found specific indications mainly in the screening, quantification, and follow-up of the vascular component of the pathology, but also in the study of the deformities and structural modifications induced by neuropathy and in the diagnosis and surgical management of infections, especially those that induce anatomical changes, like abscesses and fasciitis. This review will summarize all these application of US, giving special attention to the vascular aspects, and on the predominant role that US gained in recent times to guide the indication to revascularization, on the new standardized approach to the study of the arterial tree of the limb and the foot, the so-called duplex ultrasound arterial mapping, which significantly increased the utilization of US to plan the revascularizations in this complex pathology. Outside the vascular fields, the diagnosis of neuropathy and infection and the intraoperative use of US in the surgical management of abscesses and fasciitis will be discussed, leaving the last part to the new and interesting applications of US in the management of DFU, a field that is still in evolution, offering new possibilities to the health care professionals involved in the management of these chronic wounds. The variety of applications both in diagnostic and operative fields makes US a rather versatile technology-a toolkit-that should have a special place among those at reach of the specialists of DFS care.

Ultrasound imaging of the arterial system

Ultrasound (US) and Doppler are often the first imaging to be carried out for arterial disease, and with good reason. US is noninvasive, free of radiation exposure and crucial for follow up imaging. The review that follows aims to highlight the various applications of US in imaging of the arterial system.

Peak systolic velocity ratio derived from quantitative vessel analysis for restenosis after femoropopliteal intervention: a multidisciplinary review from Endovascular Asia

With technological improvements in the endovascular armamentarium, there have been tremendous advances in catheter-based femoropopliteal artery intervention during the last decade. However, standardization of the methodology for assessing outcomes has been underappreciated, and unvalidated peak systolic velocity ratios (PSVRs) of 2.0, 2.4, and 2.5 on duplex ultrasonography have been arbitrarily but routinely used for assessing restenosis. Quantitative vessel analysis (QVA) is a widely accepted method to identify restenosis in a broad spectrum of cardiovascular interventions, and PSVR needs to be validated by QVA. This multidisciplinary review is intended to disseminate the importance of QVA and a validated PSVR based on QVA for binary restenosis in contemporary femoropopliteal intervention.

Diagnosis, classification, and treatment of femoropopliteal artery in-stent restenosis

In-stent restenosis is a pervasive challenge to the durability of stenting for the treatment of lower extremity ischemia. There is considerable controversy about the criteria for diagnosis, indications for treatment, and preferred algorithm for addressing in-stent restenosis. This evidence summary seeks to review existing information on strategies for the treatment of this difficult problem.

B-Flow Imaging in Lower Limb Peripheral Arterial Disease and Bypass Graft Ultrasonography

Doppler ultrasonography plays a key role in the diagnosis of peripheral arterial disease, but is often limited by pitfalls that may be overcome by B-flow imaging. Thus far, there is little information on B-flow imaging for the assessment of peripheral arterial disease and bypass grafts in lower limbs. This article describes the authors' early experience with B-flow in the lower extremities. Sixty patients were included among a large cohort of patients routinely referred to the vascular laboratory for peripheral arterial disease and bypass graft assessments. Two experienced vascular sonographers performed all scans, comparing color Doppler ultrasonography with B-flow imaging. All scans were performed using a combination of the 9 L linear and C2-9 curvilinear transducers with the LOGIQ E9 system (GE Healthcare, Waukesha, WI, USA). Our experience indicates that this relatively unexplored technology has the potential to significantly improve peripheral blood flow evaluation. Nevertheless, B-flow imaging is not exempt from limitations and should be considered complementary to color Doppler ultrasonography.

Review: The clinical evaluation of lower limb perfusion in diabetic foot disease

Athorough clinical assessment and evaluation of foot perfusion is essential in managing diabetic foot disease. The treatment of macrovascular disease is key to reducing the high amputation rates seen in diabetic patients, particularly as small vessel dysfunction may make diabetic individuals more vulnerable to the effects of macrovascular, atherosclerotic disease. The clinical assessment remains paramount in the management of diabetic foot disease. The confounding effects of peripheral neuropathy on the symptoms and signs of lower limb arterial insufficiency can make assessment difficult. This article provides a resume of the clinical manifestation of lower limb ischaemia and neuropathy and the importance of accurate evaluation of the diabetic foot.

Review: The laboratory evaluation of lower limb perfusion in diabetes mellitus. A clinical review

on-invasive laboratory tests are commonly employed in the assessment of lower limb perfusion. The accuracy of non-invasive assessments in diabetes remains a concern. We evaluated the more commonly used methods with particular reference to diabetic foot disease. A literature review and clinical evaluation of tests for macrovascular disease, including hand held Doppler, blood pressure measurement and indices, Doppler waveform analysis, colour duplex imaging and plethysmography was performed. Tests reflecting tissue perfusion, including infrared detectors, transcutaneous oxygen tension, laser Doppler, capillaroscopy and skin temperature were also reviewed. Non-invasive laboratory tests reduce the requirement for invasive investigations and their inherent risks. More traditional non-invasive methods are being replaced by evolving techniques employing ultrasound technology. Arterial calcification and peripheral neuropathy associated with diabetes can potentially reduce the reliability of these methods. Distal limb and tissue perfusion assessments are more likely to reflect local vascularity. Tissue perfusion indicators are generally slow and vulnerable to environmental influences, thus limiting their clinical use. Nevertheless, non-invasive tests are an important adjunct to the clinical evaluation of diabetic foot disease. However, diabetes potentially reduces their reliability and the results require careful interpretation. Distal perfusion tests have potential advantages over macrovascular assessments. The influence of diabetes on non-invasive tests needs further evaluation.

Duplex Sonography versus Angiography for Assessment of Femoropopliteal Arterial Disease in a “Real-World” Setting

Purpose:

To evaluate the agreement of duplex ultrasound (DUS) versus digital subtraction angiography (DSA) for assessment of femoropopliteal arterial disease in a real-world clinical setting.

Methods:

Consecutive patients with peripheral artery disease who were scheduled for a percutaneous intervention were included in this retrospective study. During an 18-month period, 491 patients (276 men; median age 73 years, interquartile range 64–81) were enrolled. A peak systolic velocity ratio (PSVR) >2.4 was the optimal cutoff for detecting a >50% stenosis by DSA. Findings of preprocedural DUS in the proximal, middle, and distal ipsilateral superficial femoral artery and in the popliteal segment were analyzed for agreement with preprocedural femoropopliteal DSA using kappa statistics. Only the target limb in each patient was analyzed, for a total of 1964 vascular segments.

Results:

Agreement for the degree of stenosis in 10% increments was only moderate (weighted kappa 0.67, 95% CI 0.65 to 0.69). Using the PSVR >2.4 cutoff, agreement between DUS and DSA for a >50% stenosis was good (kappa 0.79, 95% CI 0.77 to 0.81). Sensitivity, specificity, positive predictive value, and negative predictive value for correctly detecting a >50% stenosis by DUS were 0.81 (0.78 to 0.84), 0.93 (0.91 to 0.94), 0.84 (0.81 to 0.87), and 0.91 (0.87 to 0.95), respectively. Comparable findings were observed within different patient subgroups.

Conclusion:

Agreement between DUS and DSA in the femoropopliteal segment is only moderate with respect to the absolute degree of stenosis. However, detection of a >50% stenosis can be done with acceptable precision in routine clinical practice using PSVR >2.4 as a threshold.

Color Doppler Sonographic and Cadaveric Study of the Arterial Vascularity of the Lateral Upper Arm Flap

OBJECTIVES

To determine the importance of adequate preoperative assessment with color Doppler sonography to assist in the successful transfer of lateral upper arm flaps by studying the lateral upper arm flap with color Doppler sonography and analyzing the anatomic features of the radial collateral artery.

METHODS

A clinical case-control study was performed. The radial collateral artery was studied with color Doppler sonography in 15 healthy volunteers. The origins, courses, variations, and locations of the perforators of the radial collateral artery were recorded. The results and data from the color Doppler sonographic investigation were compared with an anatomic study that was performed on 22 adult cadaveric upper limb specimens.

RESULTS

The volunteer group (14 of 15 volunteers) and the cadaveric group (19 of 22 upper arm specimens) clearly showed that the branch pattern of the arterial supply was as follows: brachial artery → deep brachial artery → radial collateral artery → posterior radial collateral artery → myocutaneous perforator. Variations in the origin of the radial collateral artery were identified in 1 volunteer bilaterally and in 3 upper arm specimens. The diameters of the artery and vein measured at the distal insertion of the deltoid and the origin of the deep brachial artery were not significantly different between the volunteer and cadaver groups (P > .05). Due to the difference in measuring methods, the length of the vascular pedicles was significantly different between the groups (P < .05).

CONCLUSIONS

Color Doppler sonography can facilitate the preoperative assessment of the origin, course, variations, and locations of the radial collateral artery and therefore may increase the success rate of lateral upper arm flap transfer.

Duplex Ultrasound Assessment of Native Stenoses in the Superficial Femoral and Popliteal Arteries

Purpose: To evaluate duplex ultrasonography (DUS) in the assessment of femoropopliteal stenoses comparing a single native stenosis (SNS) to multisegmental native stenoses (MNS). Methods: Among the 1284 patients treated for atherosclerotic occlusive disease involving the femoropopliteal segment between November 2002 and November 2012, 139 patients (97 men; mean age 68±8 years) with 142 SNS or 143 MNS in 79 and 60 patients, respectively, were eligible for this retrospective analysis. The peak systolic velocity ratios with proximal (PSVRprox) and distal (PSVRdist) reference for the 285 lesions were compared with their respective angiographic stenosis grade as measured by 2 independent readers using quantitative vascular analysis to ensure objectivity. Receiver operating characteristic curve analysis was used to evaluate sensitivity, specificity, and the optimal thresholds of PSV and PSVR for detection of stenoses by grade (>50%, >70%, or >80% diameter stenosis). The area under the curve (AUC) values of dependent and independent receiver operating characteristic curves were compared. Results: For SNS, correlation of PSVRprox to diameter stenosis (R=0.88) was higher (p<0.001) than the correlation for MNS (R=0.78). In the SNS group, the AUC for detecting a >50% (0.99±0.01), >70% (0.98±0.01), and >80% (0.96±0.01) stenosis with PSVRprox was significantly higher than in the MNS group [AUC50% 0.93±0.02 (p=0.01), AUC70% 0.92±0.02 (p=0.02), and AUC80% 0.87±0.03 (p=0.003)]. The optimal thresholds for detecting >50%, >70%, and >80% stenoses for SNS using PSVRprox were 2.6, 3.3, and 3.9, respectively. For MNS, the optimal thresholds of PSVRprox were 2.6, 3.4, and 3.9, respectively, with respective sensitivities of 87%, 81%, and 75%; respective specificities of 93%, 90%, and 82%; negative predictive values of 45%, 64%, and 74%; and positive predictive values of 99%, 95%, and 83%. Conclusion: DUS is an optimal tool for quantification of SNS. However, a multisegment setting has a significant negative impact on the quantification of femoropopliteal artery stenosis.

Duplex criteria for in-stent restenosis in the superficial femoral artery

OBJECTIVES

To elucidate the optimal cutoff and accuracy of duplex ultrasonography (DUS) parameters for in-stent restenosis (ISR) after nitinol stenting in the superficial femoral artery (SFA).

BACKGROUND

Few data are available regarding the performance of DUS for binary ISR based on quantitative vessel analysis (QVA) in the era of SFA nitinol stenting.

METHODS

This retrospective study included 74 in-stent stenoses of SFA who underwent DUS before follow-up angiography. DUS parameters, such as peak systolic velocity (PSV) and the peak systolic velocity ratio (PSVR), were compared with percent diameter stenosis (%DS) from a QVA basis.

RESULTS

There was a statistically significant correlation (P < 0.001) between "%DS and PSV" and "%DS and PSVR," and the correlation with %DS proved to be stronger in PSVR (R = 0.720) than in PSV (R = 0.672). The best performing parameter for ISR (50% or greater stenosis) was revealed PSVR, as the areas under the receiver operator characteristics curves using PSVR and PSV were 0.908 and 0.832, respectively. A PSVR cut off value of 2.85 yielded the best predictive value with sensitivity of 88%, specificity of 84%, and accuracy of 86%. The positive predictive value was 85% and the negative predictive value was 88%.

CONCLUSIONS

A PSVR of 2.85 is the optimal threshold for ISR after nitinol stenting in the SFA. Further large prospective studies are required for the validation and establishment of uniform criteria for DUS parameters.

Do Doppler waveforms at the common femoral artery accurately predict iliac stenosis?

OBJECTIVE

Evaluate whether common femoral artery (CFA) Doppler waveform assessment predicted the presence of significant iliac artery stenosis as visualised on magnetic resonance angiography (MRA).

METHOD

Three-year retrospective study of patients investigated using CFA Doppler waveforms and MRA. The patients were identified from vascular/radiology databases. Waveforms were reported real time as monophasic, biphasic or triphasic. Results were compared with MRA findings.

RESULTS

In 76 patients, 119 waveforms were assessed. MRA demonstrated 37 iliac vessels with significant stenosis. 32 (86%) had abnormal waveforms (monophasic/biphasic), 5 were triphasic. In 82 cases where MRA showed no significant stenosis, waveforms were abnormal in 35 (43%). Abnormal CFA waveforms have sensitivity of 86% and specificity of 57%. Monophasic waveforms alone were more specific (88%) but less sensitive (57%) for predicting iliac lesions.

CONCLUSION

Whilst CFA waveform morphology is a useful adjunct in detection of iliac disease, normal triphasic waveforms do not exclude iliac stenosis.

Duplex ultrasound scanning of peripheral arterial disease of the lower limb

OBJECTIVES

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).

DESIGN

A prospective, blinded, comparative study.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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 criteria for determination of in-stent stenosis after angioplasty and stenting of the superficial femoral artery

OBJECTIVE

Endovascular intervention is considered first-line therapy for most superficial femoral artery (SFA) occlusive disease. Duplex ultrasound (DU) criteria for SFA in-stent stenosis and correlation with angiographic data remain poorly defined. This study evaluated SFA-specific DU criteria for the assessment of SFA in-stent stenosis.

METHODS

From May 2003 to May 2008, 330 limbs underwent SFA angioplasty and stenting and were monitored by serial DU imaging. Suspected stenotic lesions underwent angiography and intervention when appropriate. Data pairs of DU and angiographically estimated stenosis <or=30 days of each other were analyzed. Seventy-eight limbs met these criteria, and 59 underwent reintervention. In-stent peak systolic velocity (PSV), the ratio of the stented SFA velocity/proximal SFA velocity, changes in ankle-brachial indices (ABIs), and the percentage of angiographic stenosis were examined. Linear regression and receiver operator characteristic (ROC) curve analyses were used to compare angiographic stenosis with PSV and velocity ratios (Vrs) to establish optimal criteria for determining significant in-stent stenosis.

RESULTS

Mean follow-up was 16.9 +/- 8.3 months. Of the 59 limbs that underwent reintervention, 37 (63%) were symptomatic, and 22 (37%) underwent reintervention based on DU findings alone. Linear regression models of PSV and Vr vs degree of angiographic stenosis showed strong adjusted correlation coefficients (R(2) = 0.60, P < .001 and R(2) = 0.55, P < 0.001, respectively). ROC curve analysis showed that to detect a >or=50% in-stent stenosis, a PSV >or=190 had 88% sensitivity, 95% specificity, a 98% positive predictive value (PPV), and a 72% negative predictive value (NPV); for Vr, a ratio of >1.50 had 93% sensitivity, 89% specificity, a 96% PPV, and a 81% NPV. To detect >or=80% in-stent stenosis, a PSV >or=275 had 97% sensitivity, 68% specificity, a 67% PPV, and a 97% NPV; a Vr ratio >or=3.50 had 74% sensitivity, 94% specificity, a 77% PPV, and a 88% NPV. Combining a PSV >or=275 and a Vr >or=3.50 to determine >or=80% in-stent stenosis had 74% sensitivity, 94% specificity, a 88% PPV, and a 85% NPV; odds ratio was 42.17 (95% confidence interval, 10.20-174.36, P < .001) to predict >or=80% in-stent stenosis. A significant drop in ABI (>0.15) correlated with a >62% in-stent stenosis, although the adjusted correlation coefficients was low (R(2) = 0.31, P = .02).

CONCLUSION

PSV and Vr appear to have a significant role in predicting in-stent stenosis. To determine >or=80% stenosis, combining PSV >or=275 cm/s and Vr >or=3.50 is highly specific and predictive.

A Prospective Feasibility Study of Duplex Ultrasound Arterial Mapping, Digital-Subtraction Angiography, and Magnetic Resonance Angiography in Management of Critical Lower Limb Ischemia by Endovascular Revascularization

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.

Critical limb ischemia

Critical limb ischemia (CLI) is the most severe manifestation of peripheral artery disease (PAD). Without timely recognition, appropriate diagnosis, and revascularization, patients with CLI are at risk for amputation or potentially fatal complications. The past decade has seen substantial growth in endovascular CLI therapies and options now exist for treating long-segment lower-extremity arterial occlusive disease, but surgical bypass may yield more durable results. Patients who are younger, more active, and at low risk for surgery may have better outcomes with an operation. Surgical treatment is also indicated for failures of endovascular therapy, which may include early technical failures or later occlusion after placement of stents or other interventions.

Gadolinium-enhanced Magnetic Resonance Angiography, Colour Duplex and Digital Subtraction Angiography of the Lower Limb Arteries from the Aorta to the Tibio-peroneal Trunk in Patients with Intermittent Claudication

OBJECTIVES

To evaluate the sensitivity, specificity, positive and negative predictive value of contrast-enhanced (gadolinium) magnetic resonance imaging (CE-MRA) and colour duplex ultrasound (CDU) of lower limb arteries.

DESIGN

Prospective, single centre study.

MATERIAL AND METHODS

A consecutive series of 58 patients with intermittent claudication (IC) were examined with CE-MRA and CDU from the infrarenal aorta to the tibio-peroneal trunk with digital subtraction angiography (DSA) as reference. The arterial tree was divided into 15 segments, pooled into three regions; suprainguinal, thigh and knee. Sensitivity, specificity, positive and negative predictive values for significant obstructions were calculated. Cohen Kappa statistics was used to establish agreement between the three methods.

RESULTS

The sensitivity (specificity in parentheses) for significant obstructions in the suprainguinal region were 96% (94%) for CE-MRA and 91% (96%) for CDU, in the thigh region 92% (95%) for CE-MRA and 76% (99%) for CDU, and in the knee region 93% (96%) for CE-MRA and 33% (98%) for CDU. CDU failed to visualize 10% of suprainguinal, 2% of thigh and 13% of knee-region arterial segments.

CONCLUSIONS

Both CE-MRA and CDU are good alternatives to DSA in the suprainguinal- and thigh-region. In the knee region only CE-MRA can be relied upon as an alternative to DSA. Imaging by CDU is not suited to situations were evaluation of runoff vessels is important.

Aortoiliac and Lower Extremity Arteries Assessed with 16–Detector Row CT Angiography: Prospective Comparison with Digital Subtraction Angiography

PURPOSE

To prospectively compare the accuracy of 16-detector row computed tomographic (CT) angiography with conventional digital subtraction angiography (DSA) as the reference standard in the assessment of aortoiliac and lower extremity arteries in patients with peripheral arterial disease.

MATERIALS AND METHODS

This study was approved by the institutional review board, and informed consent was obtained. A total of 39 consecutive patients (27 men [mean age, 66 years] and 12 women [mean age, 64 years]) with peripheral arterial disease underwent both conventional DSA and 16-detector row CT angiography. For data analysis, the arterial vascular system was divided into 35 segments. A total of 1365 arterial segments were analyzed for arterial stenosis by two independent blinded readers using a four-point grading system (grade 1, <10% luminal narrowing; grade 2, 10%-49% luminal narrowing; grade 3, 50%-99% luminal narrowing; grade 4, occlusion). Interobserver agreements were calculated by using kappa statistics. A third independent blinded reader assessed possible reasons for disagreements between 16-detector row CT angiographic findings and conventional DSA findings. Effective radiation dose was calculated for both imaging modalities.

RESULTS

Sixteen-detector row CT angiographic and conventional DSA findings were diagnostic in all vascular segments. Compared with conventional DSA, the sensitivity and specificity of 16-detector row CT angiography with regard to detection of hemodynamically significant stenosis in all 35 arterial segments were 96% and 97%, respectively, for both readers. Readers 1 and 2 overestimated arterial stenosis in 42 (3%) and 34 (2%) arterial segments, respectively, and underestimated arterial stenosis in 13 (1%) and 10 (1%) arterial segments, respectively. Interobserver agreement was excellent (kappa = 0.84-1.00). Presence of anteroposteriorly located luminal narrowing and extensive vascular wall calcification were considered main reasons for disagreements between imaging modalities. Effective radiation dose was lower for 16-detector row CT angiography (1.6-3.9 mSv) than for conventional DSA (6.4-16.0 mSv).

CONCLUSION

Sixteen-detector row CT angiography is an accurate and reliable noninvasive alternative to conventional DSA in the assessment of aortoiliac and lower extremity arteries in patients with peripheral arterial disease.

Les explorations non invasives de l’AOMI

FOR THE DIAGNOSIS OF AN ARTERIOPATHY: The approach is basically clinical, and vascular explorations are represented by the measurement of ankle blood pressure and calculation of the pressure index, a simple test that should systematically complete the examination. THE SEARCH FOR LOCAL LESIONS OF POTENTIALLY POOR PROGNOSIS: These are principally aneurysm and stenosis of the derivation routes that should be searched for using a Doppler in order to localise them and, completed by measurement of ankle blood pressure, specify the upstream impact and the ultrasound-Doppler analysis of certain selected areas. BEFORE REVASCULARISATION: The arteriography, examination of reference until recently, has certain limits that explain its more restricted use and the widened use of ultrasound-Doppler explorations, combined with magnetic resonance imaging and scanning.

Preoperative vascular assessment of the lower limb for harvest of a fibular flap: the views of vascular surgeons in the United Kingdom

Adequate preoperative vascular assessment of the lower limb is essential before harvesting fibular free flaps to prevent ischaemic complications or failure of the flap. The best method of assessment remains controversial. Clinical examination, conventional angiography, colour flow Doppler, and magnetic resonance angiography have all been advocated. We asked 206 UK vascular surgeons for their opinions on preoperative assessment and potential issues of negligence and 85 (42%) completed the questionnaire. All respondents thought that further imaging should be done in addition to clinical examination, most of whom (n = 70) favoured colour flow Doppler (82%). In addition 75 (88%) considered that the surgeon would be judged to be negligent if clinical examination was the only preoperative assessment. In the light of these findings, we suggest that an objective assessment of the vasculature of the leg should be obtained before a fibular flap is harvested.

Color Doppler US findings in the diagnosis of arterial occlusive disease of the lower limb

Peripheral arterial occlusive disease (PAOD) of the lower limb is a widely spread disease at the present time. After clinical examination, which includes a comprehensive history of the patient, different imaging modalities are competitive in the exact assessment of PAOD. Besides digital subtraction angiography and MR -angiography, color Doppler US is an established imaging modality in the diagnosis of PAOD. This article illustrates the typical color Doppler US findings in PAOD of the lower limb. Duplex images of normal and pathological findings are presented, and the limitations of the method are pointed out. Color Doppler US examination strategies in patients suffering of PAOD are outlined.

Blinded comparison of preoperative duplex ultrasound scanning and contrast arteriography for planning revascularization at the level of the tibia

PURPOSE

We examined whether preoperative duplex ultrasound scanning (DU) could replace contrast material-enhanced arteriography (CA) in selecting the recipient artery of tibial or peroneal artery bypass grafts.

METHODS

In patients who underwent tibial or peroneal artery bypass grafting because of critical ischemia, images were obtained of the lower extremity arterial circulation with both DU and CA. Vascular surgeons, blinded to the operation performed, reviewed either DU or CA images for arterial visualization and patency. The tibial or peroneal artery best suited to receive the bypass graft was selected by surgeons using only data from either DU or CA images. This selection was compared with the artery actually used at bypass surgery.

RESULTS

Preoperative DU and CA data for 40 lower extremities in 38 patients undergoing bypass grafting at the level of the tibia provided 110 arteries: 38 anterior tibial arteries, 32 peroneal arteries, and 40 posterior tibial arteries. Ten arteries (8 peroneal, 2 anterior tibial) were not identified with DU, and 1 artery (anterior tibial) was not identified with CA. DU enabled prediction of the artery actually used in 88% of patients (35 of 40), whereas CA enabled prediction of the artery actually used in 93% of patients (37 of 40; P =.59). Duplicate findings at DU and CA enabled selection of 85% of arteries actually used (95% confidence interval, 71%-93%). Arteries used for bypass grafting had significantly higher peak systolic velocity (35 cm/s vs 25 cm/s; P =.04), higher end-diastolic velocity (15 cm/s vs 9 cm/s; P =.005), and greater diameter (2.4 mm vs 1.7 mm; P =.003) compared with arteries not selected for bypass grafting.

CONCLUSION

Findings at DU and CA typically agree when used to select tibial or peroneal arteries for bypass grafting. With DU there is occasional difficulty in identification of the peroneal artery, but selection of the actual artery used is accurate. Peak systolic velocity, end-diastolic velocity, and diameter characteristics correlate with arteriographic criteria for tibial bypass target artery selection. If DU enables adequate identification of a target artery for bypass grafting, and especially if the peroneal artery is seen, findings at CA are not likely to alter bypass execution.

Ankle-arm index versus angiography for the preassessment of the fibula free flap

Peripheral arterial occlusive disease or congenital anomalies of the major crural arteries may limit the use of the fibula free flap and should be detected preoperatively. Conventional selective angiography is the definitive standard imaging method for making this diagnosis, but it has drawbacks. A safer, cheaper, more accurate, and noninvasive alternative is desirable. The authors sought to test the hypothesis that the ankle-arm index of each of the three crural arteries, combined with pencil Doppler examination of the peroneal skin perforators, would provide adequate information to restrict the use of angiography to cases in which the outcomes of either or both of these options are insufficient. The ankle-arm index data of each of the three crural arteries, as well as pencil Doppler examination of the peroneal skin perforators of both legs of nine prospectively included patients and the nonoperated legs of 13 retrospectively included patients, were compared statistically in four different ways with the preoperative angiographic findings. A combined ankle-arm index and pencil Doppler examination is not accurate enough to detect legs or arteries with subclinical peripheral arterial occlusive disease or vascular variation and, hence, is not a sufficient basis on which to develop the surgical plan for a fibula free flap.

The additional value of angiography after colour-coded duplex on decision making in patients with critical limb ischaemia. A prospective study

OBJECTIVE

to investigate prospectively the additional value of intra arterial digital subtraction arteriography (IADSA) for decision making in patients with critical limb ischemia (CLI). Treatment plans based on colour-duplex imaging (CDI) were compared with treatment plans based on IADSA.

METHODS

ninety-eight consecutive patients with 112 legs with CLI were investigated by CDI and IADSA. Treatment plans based on CDI and IADSA were made separately during a multidisciplinary meeting. Both plans were retrospectively analysed with the outcome of the operation or the endovascular procedure as a reference.

RESULTS

eighty-eight patients with 101 legs could be analysed. In 91 out of the 101 legs (90%) CDI offered the same strategy as the IADSA. In 10 legs IADSA provided additional information. Most of the additional information concerned the crural vessels.

CONCLUSION

the preoperative planning of treatment in patients with chronic critical ischaemia of the lower limbs can be based on CDI alone in most patients. For planning crural revascularisation additional information may be needed. If severe calcification prevents adequate visualisation of the crural vessels or no patent anterior or posterior tibial artery with outflow across the ankle is present, IADSA should be performed.

Critical Limb Ischemia

Patients with critical limb ischemia (CLI) present with ischemic rest pain or with tissue loss. Tissue loss, in its mildest presentation, includes focal ischemic ulceration or nonhealing wounds. Gangrene is the manifestation of severe chronic ischemia. Without revascularization, patients with CLI are at risk for limb loss and for potentially fatal complications from the progression of gangrene and the development of sepsis. The best patient outcomes are achieved when the diagnosis and appropriate treatment for CLI are not delayed. Simple noninvasive tests, such as measurement of ankle-to-brachial indices or toe Doppler pressures, take only minutes to provide sufficient information to confirm the diagnosis of peripheral artery disease (PAD) and to document the severity of limb ischemia. Subsequent diagnostic imaging studies, such as arteriography, magnetic resonance angiography, or ultrasound duplex scanning, provide the detailed information needed to plan revascularization therapy. Balloon angioplasty and stenting work best for focal segments of narrowing or short occlusions of the iliac arteries, but endovascular treatments yield progressively poorer results with longer and more distal lesions. Long segments of occlusion, especially those distal to the common femoral artery, are best treated with surgical bypass. Pharmacotherapy and adjunctive therapies, such as topical therapies or hyperbaric oxygen treatment, may have a limited role in patients in whom revascularization procedures have failed or for those in whom revascularization is not technically possible--particularly when amputation is the only alternative. Prostanoids are the best-studied class of drugs for such applications, but their use is still investigational in the United States. Though other medical approaches, such as use of other vasoactive agents, drugs that treat claudication, or gene-induced angiogenesis may prove useful, they do not yet have demonstrated roles in the treatment of patients with CLI.

[Doppler echocardiography and lower limb arteriopathy obliterans]

Duplex Doppler ultrasonography became the first line investigation in patients with lower limb arterial disease. It use the ultrasonic technology coupled to computer. Constant progress of duplex Doppler ultrasonography, as color flow imaging or power Doppler and more simply continuous refinements in grey scale image resolution, associated with the expansion of the interventional endovascular processing explains its significant development these last years. This simple non invasive technique is now an essential complement of physical examination. It is thus an usual tool use in common practice by vascular physicians and surgeons from tracking till processing while passing by the diagnosis. Duplex Doppler ultrasonography gives accurate informations about both structural and dynamic anomalies in the peripheral lower limb. It thus allows the evaluation, the quantification and the follow-up of the arterial diseases by carrying out a precise vascular mapping that can guides the radiological or surgical processing if necessary. Duplex Doppler ultrasonography remains however "operator depending" and moreover cannot replace the appropriate clinical decision making and medical therapeutic strategy.

Can ultrasound replace arteriography in the management of chronic arterial occlusive disease of the lower limb?

OBJECTIVES

to investigate whether colour duplex scanning can be used as the sole diagnostic investigation prior to lower limb revascularisation.

PATIENTS AND METHODS

the results of angiography and duplex were compared in 80 limbs (69 claudication, 11 critical limb ischaemia [CLI]) from 68 patients.

RESULTS

excellent diagnostic agreement (kappa value 0.89, 95% CI 0.85-0.93) was achieved at the femoropopliteal segment. Agreement was good for the aorto-iliac segment (kappa value 0.69, 95% CI 0.61-0.77) and moderate for the infrapopliteal segment (kappa value 0.59, 95% CI 0.55-0.63). Similarly, in the decision-making process excellent agreement was achieved for the femoropopliteal segment (kappa value 0.91, 95% CI 0.88-0.94), good for the aortoiliac segment (kappa value 0.62, 95% CI 0.56-0.68), and moderate for the infrapopliteal segment (kappa value 0.46, 95% CI 0.42-0.50). Duplex detected patent 12 tibial arteries in 10 limbs that were not opacified on arteriography. In four limbs duplex revealed significant disease in the above knee popliteal artery that was missed on arteriography.

CONCLUSIONS

treatment of femoropopliteal disease can be based upon duplex alone in the great majority of cases. However, where there is disease in the aortoiliac segment, or where infrapopliteal revascularisation is long considered both duplex and angiography should be performed to maximise pre-operative information.

Assessment of arterial stenosis in a flow model with power Doppler angiography: accuracy and observations on blood echogenicity

The objective of the project was to study the influence of various hemodynamic and rheologic factors on the accuracy of 3-D power Doppler angiography (PDA) for quantifying the percentage of area reduction of a stenotic artery along its longitudinal axis. The study was performed with a 3-D power Doppler ultrasound (US) imaging system and an in vitro mock flow model containing a simulated artery with a stenosis of 80% area reduction. Measurements were performed under steady and pulsatile flow conditions by circulating, at different flow rates, four types of fluid (porcine whole blood, porcine whole blood with a US contrast agent, porcine blood cell suspension and porcine blood cell suspension with a US contrast agent). A total of 120 measurements were performed. Computational simulations of the fluid dynamics in the vicinity of the axisymmetrical stenosis were performed with finite-element modeling (FEM) to locate and identify the PDA signal loss due to the wall filter of the US instrument. The performance of three segmentation algorithms used to delineate the vessel lumen on the PDA images was assessed and compared. It is shown that the type of fluid flowing in the phantom affects the echoicity of PDA images and the accuracy of the segmentation algorithms. The type of flow (steady or pulsatile) and the flow rate can also influence the PDA image accuracy, whereas the use of US contrast agent has no significant effect. For the conditions that would correspond to a US scan of a common femoral artery (whole blood flowing at a mean pulsatile flow rate of 450 mL min(-1)), the errors in the percentages of area reduction were 4.3 +/- 1.2% before the stenosis, -2.0 +/- 1.0% in the stenosis, 11.5 +/- 3.1% in the recirculation zone, and 2.8 +/- 1.7% after the stenosis, respectively. Based on the simulated blood flow patterns obtained with FEM, the lower accuracy in the recirculation zone can be attributed to the effect of the wall filter that removes low flow velocities. In conclusion, the small errors reported in vitro may support the clinical use of this technique.

Peripheral arterial disease: gadolinium-enhanced MR angiography versus color-guided duplex US--a meta-analysis

PURPOSE

To summarize and compare the published data on gadolinium-enhanced magnetic resonance (MR) angiography and color-guided duplex ultrasonography (US) for the work-up for peripheral arterial disease.

MATERIALS AND METHODS

Studies published between January 1984 and November 1998 were included if (a) gadolinium-enhanced MR angiography and/or color-guided duplex US were performed for evaluation of arterial stenoses and occlusions in the work-up for peripheral arterial disease of the lower extremities, (b) conventional angiography was the reference standard, and (c) absolute numbers of true-positive, false-negative, true-negative, and false-positive results were available or derivable.

RESULTS

With a random effects model, pooled sensitivity for MR angiography (97.5% [95% CI: 95.7%, 99.3%]) was higher than that for duplex US (87.6% [95% CI: 84.4%, 90.8%]). Pooled specificities were similar: 96.2% (95% CI: 94.4%, 97.9%) for MR angiography and 94.7% (95% CI: 93.2%, 96.2%) for duplex US. Summary receiver operating characteristic analysis demonstrated better discriminatory power for MR angiography than for duplex US. Regression coefficients for MR angiography versus US were 1.67 (95% CI: -0.23, 3.56) with adjustment for covariates, 2.11 (95% CI: 0.12, 4.09) without such adjustment, and 1.73 (95% CI: 0.44, 3.02) with a random effects model.

CONCLUSION

Gadolinium-enhanced MR angiography has better discriminatory power than does color-guided duplex US and is a highly sensitive and specific method, as compared with conventional angiography, for the work-up for peripheral arterial disease.

Effect of homocysteine-lowering treatment with folic acid plus vitamin B6 on progression of subclinical atherosclerosis: a randomised, placebo-controlled trial

BACKGROUND

A high plasma homocysteine concentration is associated with increased risk of atherothrombotic disease. We investigated the effects of homocysteine-lowering treatment (folic acid plus vitamin B6) on markers of subclinical atherosclerosis among healthy siblings of patients with premature atherothrombotic disease.

METHODS

We did a randomised, placebo-controlled trial among 158 healthy siblings of 167 patients with premature atherothrombotic disease. 80 were assigned placebo and 78 were assigned 5 mg folic acid and 250 mg vitamin B6 daily for 2 years. The primary endpoint was the development or progression of subclinical atherosclerosis as estimated from exercise electrocardiography, the ankle-brachial pressure index, and carotid and femoral ultrasonography.

FINDINGS

Ten participants in the treatment group, and 14 in the placebo group dropped out. Vitamin treatment, compared with placebo, was associated with a decrease in fasting homocysteine concentration (from 14.7 to 7.4 micromol/L vs from 14.7 to 12.0 micromol/L), and in postmethionine homocysteine concentration (from 64.9 to 34.9 micromol/L vs from 64.8 to 50.3 micromol/L). It was also associated with a decreased rate of abnormal exercise electrocardiography tests (odds ratio 0.40 [0.17-0.93]; p=0.035). There was no apparent effect of vitamin treatment on ankle-brachial pressure indices (0.87 [0.56-1.33]), or on carotid and peripheral-arterial outcome variables (1.02 [0.26-4.05] and 0.86 [0.47-1.59], respectively).

INTERPRETATION

Homocysteine-lowering treatment with folic acid plus vitamin B6 in healthy siblings of patients with premature atherothrombotic disease is associated with a decreased occurrence of abnormal exercise electrocardiography tests, which is consistent with a decreased risk of atherosclerotic coronary events.

Correlation of hemodynamic and functional variables with the angiographic extent of peripheral arterial occlusive disease

The aim of the study was to determine whether hemodynamic and functional variables are related to the angiographic extent of lower limb atherosclerosis. In 150 patients with stable intermittent claudication, the Bollinger angiogram score was compared with the resting Doppler pressure values, and the initial claudication distance (ICD) and absolute claudication distance (ACD) with treadmill exercise. The extent of lower limb atherosclerosis correlated significantly with the age of the patients and the duration of the claudication. The angiogram scores of the patients were negatively correlated with the ankle systolic blood pressure (SBP) and the ankle/brachial index (ABI). In a multiple regression analysis, ABI was the most predictive variable for the angiographic severity of disease. ICD, ACD and work on the treadmill failed to correlate with the angiogram summation score. If patients were classified into groups for those with iliac or femoropopliteal disease, a weak correlation between ACD and femoropopliteal angiogram score was found. The comparison between Doppler measurements and treadmill exercise testing showed no significant correlation between SBP/ABI of the more diseased limb and ICD. However, both SBP and ABI did correlate significantly with ACD (r = 0.16, p < 0.05 and r = 0.20, p < 0.01, respectively). In conclusion, SBP and ABI are reliable parameters for indirect assessment of the angiographic extent of lower limb atherosclerosis. In contrast, the walking capacity of claudicant patients is independent of the angiographic severity of the disease.

Use of colour duplex imaging to diagnose and guide angioplasty of lower limb arterial lesions

BACKGROUND

The purpose of this study was to investigate whether colour duplex imaging alone could safely and effectively be used to diagnose lower limb arterial lesions and guide subsequent percutaneous transluminal angioplasty (PTA).

METHODS

Patients with discrete lower limb arterial lesions, preferably stenoses, which could be visualized clearly by colour duplex imaging were selected for duplex-guided PTA. Duplex-guided PTA was performed in an operating theatre using conventional balloon catheters.

RESULTS

Duplex imaging was used to diagnose and guide PTA of 55 arterial lesions in 50 legs of 45 patients. There were 53 stenoses and two occlusions. The median (range) ankle : brachial pressure index was 0. 86 (0.52-1.10) before dilatation and 1.00 (0.83-1.40) immediately after dilatation (P = 0.0001). There were no complications during or after any of the procedures and 46 of the 47 symptomatic legs were markedly improved at a median follow-up of 23 days. Radiographic imaging was not required for any of the procedures.

CONCLUSION

It is possible to diagnose and angioplasty lower limb arterial lesions using colour duplex imaging alone.