Peripheral arterial disease: therapeutic confidence of CT versus digital subtraction angiography and effects on additional imaging recommendations

International Union of Angiology Position Statement on no-option chronic limb threatening ischemia

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.

Computed Tomography Angiography in Peripheral Arterial Disease: Comparison of Three Image Acquisition Techniques to Optimize Vascular Enhancement-Randomized Controlled Trial

Objectives: To prospectively compare three image acquisition techniques in lower extremity CT angiography: the “standard” anterograde technique (SA), the adaptive anterograde technique (AA), and the retrograde acquisition technique (RA).

Materials and Methods: Sixty consecutive patients were prospectively enrolled and randomized into three acquisition groups: 20 patients were evaluated with SA, 20 with AA as described by Qanadli et al., and 20 with caudocranial acquisition from the feet to the abdominal aorta (RA). Quantitative image quality was assessed by measuring the intraluminal attenuation at different levels of interest, with a total of 536 levels. Qualitative image quality was assessed by two radiologists in consensus using a Likert scale to rate the arterial enhancement and venous return. For each patient and limb, the presence of occlusive or aneurysmal disease was documented.

Results: In quantitative analysis, RA showed lower attenuation values than SA and AA (p < 0.01). AA showed the highest and most homogeneous attenuation along the arterial tree. In qualitative analysis, AA had the lowest rate of non-diagnostic vascular segments (3.9%) compared to SA and RA (4.7 and 13.1%, respectively, p < 0.01). The influence of venous return was significantly different among the different techniques; venous contamination was particularly prevalent at the aortic level with RA (9.4% of patients, 0% with SA and AA, p < 0.01). The presence of stenosis or occlusion had no significant influence on the attenuation values across all levels and acquisition techniques. Conversely, the presence of aneurysmal disease had a significant effect on the luminal attenuation in AA (higher attenuation) and RA (lower attenuation) at the iliac (p = 0.03 and 0.04, respectively) and femoral levels (p = 0.02 and <0.01, respectively).

Conclusion: Considering both quantitative and qualitative analysis, AA performed better than SA and RA, providing the highest percentage of optimal vascular enhancement. AA should be recommended as the technique of choice, specifically in the presence of aneurysmal disease. Alternatively, SA can be useful in case of renal failure, as the test bolus is unnecessary. Finally, the increasing availability of fast CT systems will likely overcome the limitations of RA.

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

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

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

GUIDELINE SUMMARY

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

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

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

Detection of thrombosis in microvessels with indocyanine green videoangiography

Atherosclerosis is a systemic condition that is responsible for many diseases, and becomes a problem in cases where plaques form at several sites. The formation of a thrombotic embolus may jeopardise vascular operations, including microvascular anastomoses in replantation procedures or free tissue transfers. A mobile imaging tool for the detection of thrombosis preoperatively or intraoperatively would be valuable. An intimal injury, simulating removal of atherosclerotic plaques, was made microsurgically in 60 rat aortas, and results were analysed macroscopically, histologically, and with intraoperative indocyanine green (ICG) videoangiography immediately postoperatively. The Spearman and Pearson correlation tests were used to compare the three techniques. The sensitivity and specificity of ICG videoangiography was calculated in relation to both macroscopic and histological results. Detection of thrombosis was possible in 25 cases, and in 18 cases no thrombosis was correctly diagnosed by all methods used. In 31 of 60 specimens formation of thrombus was detected histologically, and in 29 of 60 examinations it was detected clinically, which yielded a correlation of 93.5% between the two examinations. Macroscopic analysis correlated better with ICG videoangiography (sensitivity 86.2% and specificity 64.5%) than histological observations (sensitivity 80.6% and specificity 62.1%). There was a significant correlation among all comparisons (each p≤0.001) with correlation indexes of 0.94, 0.52, and 0.44 for macroscopic/histological, clinical/ICG videoangiographic, and ICG videoangiographic/histological results, respectively. Our results show that ICG videoangiography is an important method for the detection of formation of acute thrombi and may be an important tool in vascular procedures.

Combined Static and Dynamic Computed Tomography Angiography of Peripheral Artery Occlusive Disease: Comparison with Magnetic Resonance Angiography

PURPOSE

To compare in patients with known peripheral artery occlusive disease (PAOD), image quality of a combined CTA to a combined MRA protocol, including both static and dynamic acquisitions.

MATERIALS AND METHODS

Twenty-two patients with PAOD were examined with a combined CTA and MRA protocol consisting of static acquisitions (s-CTA, s-MRA) of the entire runoff and dynamic acquisitions (d-CTA, d-MRA) of the calves. Two radiologists compared image quality of the s-MRA versus s-CTA as well as d-MRA versus d-CTA. Image quality was assessed on a segmental basis using a 4-point Likert scale.

RESULTS

For s-CTA, 76% of segments were rated as excellent or good. For s-MRA, 50% of segments were rated as excellent or good (p < 0.0001). For d-CTA, median image quality score for all segments was rated as excellent for both readers. For d-MRA, median image quality for the different segments ranged from moderate to good. For both d-CTA and d-MRA, the median image quality scores were significantly higher for all segments of the lower limb compared with the static examinations of the lower limb segments (all p values < 0.0001). In patients with PAOD category 4-6, 80% of segments were rated as excellent or good for d-CTA, while 45% of segments were rated as poor or non-diagnostic for d-MRA.

CONCLUSION

In patients with known PAOD, a combined static and dynamic CTA examination improves image quality relative to static and dynamic MRA and should be considered as an alternative to MRA, particularly in patients with advanced stage PAOD.

Association of the KLK1 rs5516 G allele and the ACE D allele with aortic aneurysm and atherosclerotic stenosis

OBJECTIVE

Atherosclerosis underlies aortic aneurysm (AA) and atherosclerotic stenosis (AS). Kallikrein-1 (KLK1) and angiotensin-converting enzyme (ACE) are 2 key molecules in kallikrein-kinin systems and renin-angiotensin systems, respectively, which are responsible for maintaining vascular balance and stability, playing important roles in atherosclerosis. We aimed to assess the involvement of single nucleotide polymorphism rs5516 in KLK1 as well as the insertion/deletion rs4646994 polymorphism in ACE in the development of AA and AS.

METHODS

We enrolled Chinese Han patients with AA (N = 408) and AS (N = 432), as well as healthy controls (N = 408). Clinical and demographic characteristics were assessed. Genotypes were analyzed with recessive and dominant models.

RESULTS

The rs5516 G allele of KLK1 was significantly associated with AA (P < 0.001), and the D allele of ACE was significantly associated with both AA (P < 0.001) and AS (P < 0.001). The GG and DD genotypes were significantly associated with both AA (P = 0.013) and AS (P < 0.001) in a recessive model, and were synergistic with hypertension in AA patients, but not in AS. Patients with CC/DD, CG/ID, or GG/II genotypes, which were synergistic with hypertension, had a greater risk of developing AA, while CC/DD, CG/DD, GG/ID, or GG/DD genotypes, which were not synergistic with hypertension, contributed to the development of AS.

CONCLUSION

The KLK1 rs5516 G allele is closely associated with AA, and the ACE D allele is closely related to AA and AS.

Lowering iodinated contrast concentration in infrainguinal endovascular interventions: a three-armed randomized controlled non-inferiority trial

Objectives

To determine the influence of lowering iodinated contrast concentration on confidence of interventional radiologists in diagnosing and treating lesions during endovascular interventions in patients with symptomatic peripheral arterial disease (PAD).

Methods

A randomized controlled non-inferiority trial was performed in 60 patients. Intervention was performed with contrast concentrations (in mg of iodine per mL, mgI/mL) of 300 (standard), 240, or 140 mgI/mL. Primary outcome was confidence (score 0-100 %) of radiologists in diagnosing and treating arterial lesions. Secondary outcomes were procedural iodine load and image quality (i.e. non-diagnostic, limited, diagnostic, exemplary).

Results

Median confidence scores in diagnosing lesions were 100 % (range 81-100 %) for the 300 group (n = 21), 100 % (range 82-100 %) for the 240 group (n = 19), and 100 % (range 91-100 %) for the 140 group (n = 20) (both p = 1.00 compared to the 300 group). Median scores for treating lesions in the 240 and 140 groups, 100 % (range 79-100 %, p = 0.40), and 100 % (range 63-100 %, p = 0.25), respectively, were not lower compared to the 300 group (median 100 %, range 78-100 %). Procedural iodine load was lower in the 240 (24.3 ± 7.6 g, p = 0.022) and 140 groups (17.8 ± 5.6 g, p < 0.001) compared to the 300 group (29.7 ± 6.3 g). Image quality was diagnostic for all groups.

Conclusion

Using iodine contrast of 140 mgI/mL for diagnosis and interventions in PAD patients significantly reduces administered iodine load without compromising image quality. Future use of lower iodine dose is recommended.

Key Points

• Lower iodinated contrast concentration during endovascular intervention does not decrease radiologist’s confidence.

• Image quality of standardized angiographies remains diagnostic using 140 mgI/mL iodinated contrast concentration.

• Iodine load during intervention can be decreased by >40 % when using 140 mgI/mL.

• Implementing the use of a lower iodinated contrast concentration will reduce the costs of the procedure.

Diagnostic confidence of run-off CT-angiography as the primary diagnostic imaging modality in patients presenting with acute or chronic peripheral arterial disease

Objectives

To investigate the reliability of CT-angiography of the lower extremities (run-off CTA) to derive a treatment decision in patients with acute and chronic peripheral artery disease (PAD).

Materials and Methods

314 patients referred for run-off CTA were includ-ed in this retrospective study. First, diagnostic confidence of run-off CTA to derive a treat-ment decision was assessed in an interdisciplinary vascular conference using a 2 point scale (sufficient or not sufficient diagnostic confidence) and compared with the image quality eval-uated by two readers in consensus in four different levels (abdominopelvic, thigh, calf, foot arteries). Second, reliability of treatment decision was verified in all patients undergoing re-vascularization therapy.

Results

Diagnostic confidence of run-off CTA to derive a treatment deci-sion was sufficient in all patients with acute and in 97% of patients (215/221) with chronic PAD, whereas the rate of run-off CTA with non-diagnostic image quality was considerably higher in the calf and foot level (acute vs. chronic; calf: 28% vs.17%; foot: 52% vs. 20%). Reliability of treatment decision was superior for patients with chronic (123/133 = 92%) than for patients with acute PAD (64/78 = 82%, P = 0.02).

Conclusion

Run-off CTA is a reliable imaging modality for primary diag-nostic work-up of patients with acute and chronic PAD.

Society for Vascular Surgery practice guidelines for atherosclerotic occlusive disease of the lower extremities: management of asymptomatic disease and claudication

Peripheral arterial disease (PAD) continues to grow in global prevalence and consumes an increasing amount of resources in the United States health care system. Overall rates of intervention for PAD have been rising steadily in recent years. Changing demographics, evolution of technologies, and an expanding database of outcomes studies are primary forces influencing clinical decision making in PAD. The management of PAD is multidisciplinary, involving primary care physicians and vascular specialists with varying expertise in diagnostic and treatment modalities. PAD represents a broad spectrum of disease from asymptomatic through severe limb ischemia. The Society for Vascular Surgery Lower Extremity Practice Guidelines committee reviewed the evidence supporting clinical care in the treatment of asymptomatic PAD and intermittent claudication (IC). The committee made specific practice recommendations using the GRADE (Grades of Recommendation Assessment, Development and Evaluation) system. There are limited Level I data available for many of the critical questions in the field, demonstrating the urgent need for comparative effectiveness research in PAD. Emphasis is placed on risk factor modification, medical therapies, and broader use of exercise programs to improve cardiovascular health and functional performance. Screening for PAD appears of unproven benefit at present. Revascularization for IC is an appropriate therapy for selected patients with disabling symptoms, after a careful risk-benefit analysis. Treatment should be individualized based on comorbid conditions, degree of functional impairment, and anatomic factors. Invasive treatments for IC should provide predictable functional improvements with reasonable durability. A minimum threshold of a >50% likelihood of sustained efficacy for at least 2 years is suggested as a benchmark. Anatomic patency (freedom from restenosis) is considered a prerequisite for sustained efficacy of revascularization in IC. Endovascular approaches are favored for most candidates with aortoiliac disease and for selected patients with femoropopliteal disease in whom anatomic durability is expected to meet this minimum threshold. Conversely, caution is warranted in the use of interventions for IC in anatomic settings where durability is limited (extensive calcification, small-caliber arteries, diffuse infrainguinal disease, poor runoff). Surgical bypass may be a preferred strategy in good-risk patients with these disease patterns or in those with prior endovascular failures. Common femoral artery disease should be treated surgically, and saphenous vein is the preferred conduit for infrainguinal bypass grafting. Patients who undergo invasive treatments for IC should be monitored regularly in a surveillance program to record subjective improvements, assess risk factors, optimize compliance with cardioprotective medications, and monitor hemodynamic and patency status.

Impact of choice of imaging modality accompanying outpatient exercise stress testing on outcomes and resource use after revascularization for acute coronary syndromes

BACKGROUND

Exercise stress testing is commonly obtained after percutaneous coronary intervention (PCI) performed for acute coronary syndromes (ACS). We compared the relationships between exercise echocardiography and nuclear testing after ACS-related PCI on outcomes and resource use.

METHODS

Longitudinal observational study using fee-for-service Medicare claims to identify patients undergoing outpatient exercise stress testing with imaging within 15 months after PCI performed for ACS between 2003 and 2004.

RESULTS

Of 63,100 patients undergoing stress testing 3 to 15 months post-PCI, 31,731 (50.3%) underwent an exercise stress test with imaging. Among 29,279 patients undergoing exercise stress testing with imaging, 15.5% received echocardiography. Echocardiography recipients had higher rates of repeat stress testing (adjusted hazard ratio [HR] 2.60, CI 2.19-3.10) compared with those undergoing nuclear imaging in the 90 days after testing, but lower rates of revascularization (adjusted HR 0.87, CI 0.76-0.98) and coronary angiography (adjusted HR 0.88, CI 0.80-0.97). None of these differences persisted subsequent to 90 days after stress testing. Rates of death and readmission for myocardial infarction rates were similar. Total Medicare payments were lower initially after echocardiography (incremental difference $498, CI 488-507), an effect attributed primarily to lower reimbursement for the stress test itself, but not significantly different after 14 months after testing.

CONCLUSIONS

In this study using administrative data, echocardiography recipients initially had fewer invasive procedures but higher rates of repeat testing than nuclear testing recipients. However, these differences between echo and nuclear testing did not persist over longer time frames.

Dual-energy CT: vascular applications

OBJECTIVE

Dual-energy CT permits a variety of image reconstructions for the depiction and characterization of vascular disease. Techniques include visualization of low- and high-peak-kilovoltage spectra image datasets and also material-specific reconstructions combining both low- and high-peak-kilovoltage data.

CONCLUSION

This article focuses on four main vascular areas: the aorta, the major visceral, lower limb, and cervical arteries. For each territory, the current status, potential advantages, and limitations of these techniques are described.

Downstream testing and subsequent procedures after coronary computed tomographic angiography following coronary stenting in patients ≥65 years of age

Limited data are available on the use of coronary computed tomographic angiography (CCTA) in patients who have received percutaneous coronary intervention (PCI). To evaluate patterns of cardiac testing including CCTA after PCI, we created a retrospective observational dataset linking National Cardiovascular Data Registry CathPCI Registry baseline data with longitudinal inpatient and outpatient Medicare claims data for patients who received coronary stenting from November 1, 2005 through December 31, 2007. In 192,009 patients with PCI (median age 74 years), the first test after coronary stenting was CCTA for 553 (0.3%), stress testing for 89,900 (46.8%), and coronary angiography for 22,308 (11.6%); 79,248 (41.3%) had no further testing. Patients referred to CCTA first generally had similar or lower baseline risk than those referred for stress testing or catheterization first. Compared to patients with stress testing first after PCI, patients who underwent CCTA first had higher unadjusted rates of subsequent noninvasive testing (10% vs 3%), catheterization (26% vs 15%), and revascularization (13% vs 8%) within 90 days of initial testing after PCI (p <0.0001 for all comparisons). In conclusion, despite similar or lesser-risk profiles, patients initially evaluated with CCTA after PCI had more downstream testing and revascularization than patients initially evaluated with stress testing. It is unclear whether these differences derive from patient selection, performance of CCTA compared to other testing strategies, or the association of early adoption of CCTA with distinct patterns of care.

Atherosclerosis in sickle cell disease - a review

Acute, vaso-occlusive crises are the most common and earliest clinical manifestations of sickle cell disease. Recent thoughts about development of atherosclerosis as a result of this disease are presented. Current insights into the pathogenesis of atherosclerosis in sickle cell disease are reviewed, in particular the role of endothelial dysfunction, homocysteine and platelets. Common and uncommon sites of atherosclerosis are described. Radiological assessment and potential therapeutic agents to slow the progression of atherosclerosis are discussed. Finally, treatment of atherosclerosis in certain sites is evaluated and reviewed.

Chapter V: Diabetic foot

Ulcerated diabetic foot is a complex problem. Ischaemia, neuropathy and infection are the three pathological components that lead to diabetic foot complications, and they frequently occur together as an aetiologic triad. Neuropathy and ischaemia are the initiating factors, most often together as neuroischaemia, whereas infection is mostly a consequence. The role of peripheral arterial disease in diabetic foot has long been underestimated as typical ischaemic symptoms are less frequent in diabetics with ischaemia than in non-diabetics. Furthermore, the healing of a neuroischaemic ulcer is hampered by microvascular dysfunction. Therefore, the threshold for revascularising neuroischaemic ulcers should be lower than that for purely ischaemic ulcers. Previous guidelines have largely ignored these specific demands related to ulcerated neuroischaemic diabetic feet. Any diabetic foot ulcer should always be considered to have vascular impairment unless otherwise proven. Early referral, non-invasive vascular testing, imaging and intervention are crucial to improve diabetic foot ulcer healing and to prevent amputation. Timing is essential, as the window of opportunity to heal the ulcer and save the leg is easily missed. This chapter underlines the paucity of data on the best way to diagnose and treat these diabetic patients. Most of the studies dealing with neuroischaemic diabetic feet are not comparable in terms of patient populations, interventions or outcome. Therefore, there is an urgent need for a paradigm shift in diabetic foot care; that is, a new approach and classification of diabetics with vascular impairment in regard to clinical practice and research. A multidisciplinary approach needs to implemented systematically with a vascular surgeon as an integrated member. New strategies must be developed and implemented for diabetic foot patients with vascular impairment, to improve healing, to speed up healing rate and to avoid amputation, irrespective of the intervention technology chosen. Focused studies on the value of predictive tests, new treatment modalities as well as selective and targeted strategies are needed. As specific data on ulcerated neuroischaemic diabetic feet are scarce, recommendations are often of low grade.

Peripheral arterial disease in diabetic patients with renal insufficiency: a review

Peripheral arterial disease is common among diabetic patients with renal insufficiency, and most of the diabetic patients with end-stage renal disease (ESRD) have peripheral arterial disease. Ischaemia is probably overrepresented as an etiological factor for a diabetic foot ulcer in this group of patients compared with other diabetic patients. ESRD is a strong risk factor for both ulceration and amputation in diabetic patients. It increases the risk of nonhealing of ulcers and major amputation with an OR of 2.5-3. Renal disease is a more important predictor of poor outcome after revascularizations than commonly expected. Preoperative vascular imaging is also affected by a number of limitations, mostly related to side effects of contrast agents poorly eliminated because of kidney dysfunction. Patients with renal failure have high perioperative morbidity and mortality. Persistent ischaemia, extensive infection, forefoot and heel gangrene, poor run-off, poor cardiac function, and the length of dialysis-dependent renal failure all affect the outcome adversely. Despite dismal overall outcome, recent data indicate that by proper selection, favourable results can be obtained even in ESRD patients, with the majority of studies reporting 1-year limb salvage rates of 65-75% after revascularization among survivors. High 1-year mortality of 38% reported in a recent review has to be taken into consideration, though. The preferential use of endovascular-first approach is attractive in this vulnerable multimorbid group of patients, but the evidence for endovascular treatment is very scarce. The need for complete revascularization of the foot may be even more important than in other patients with ischaemic ulcerated diabetic foot because there are a number of factors counteracting healing in these patients. Typically, half of the patients are reported to lose their legs despite open bypass. To control tissue damage and improve chances of ulcer healing, one should understand that early referral to vascular consultation is necessary.

Evaluation of peripheral arterial disease with nonenhanced quiescent-interval single-shot MR angiography

PURPOSE

To assess the diagnostic performance of quiescent-interval single-shot (QISS) magnetic resonance (MR) angiography, a nonenhanced two-dimensional electrocardiographically gated single-shot balanced steady-state free precession examination for the evaluation of symptomatic chronic lower limb ischemia.

MATERIALS AND METHODS

For this prospective institutional review board-approved, HIPAA-compliant study, the institutional review board waived the requirement for informed patient consent. The QISS nonenhanced MR angiography technique was evaluated in a two-center trial involving 53 patients referred for lower extremity MR angiography for suspected or known chronic peripheral arterial disease (PAD), with contrast material-enhanced MR angiography serving as the noninvasive reference standard. The accuracy of stenosis assessments performed with the nonenhanced MR angiography sequence was evaluated relative to the reference standard. Per-segment, per-region, and per-limb sensitivities and specificities were calculated, and assessments were considered correct only if they were in exact agreement with the reference standard-derived assessments. Generalized estimating equation (GEE) modeling with use of an unstructured binomial logit analysis was used to account for clustering of multiple measurements per case. The sensitivity and specificity of QISS MR angiography for the determination of nonsignificant (<50%) versus significant (50%-100%) stenosis were compared with the sensitivity and specificity of the reference standard.

RESULTS

The diagnostic performance of nonenhanced MR angiography was found to be nearly equivalent to the diagnostic performances of contrast-enhanced MR angiography and digital subtraction angiography. Non-GEE segment-based analysis revealed that for the two reviewers, nonenhanced MR angiography had sensitivities of 89.7% (436 of 486 segments) and 87.0% (423 of 486 segments) and specificities of 96.5% (994 of 1030 segments) and 94.6% (973 of 1028 segments).

CONCLUSION

QISS nonenhanced MR angiography offers an alternative to currently used imaging tests for symptomatic chronic lower limb ischemia, for which the administration of iodinated or gadolinium-based contrast agents is contraindicated.

Multidetector CT angiography versus arterial duplex USG in diagnosis of mild lower extremity peripheral arterial disease: is multidetector CT a valuable screening tool?

OBJECTIVE

To prospectively compare the efficacy of 40-row multidetector computed tomography angiography (MDCTA) and duplex ultrasonography (DUS) to diagnose mild peripheral arterial occlusive disease (PAOD) in lower leg and to search whether MDCTA can be used as a screening tool.

METHODS

Forty-three patients with intermittent claudication and leg pain, diagnosed as mild PAOD, had undergone DUS and MDCTA of lower limb. The arteries of lower leg were initially scanned by DUS, followed by MDCTA. Both modalities were compared for detecting the obstructed and stenotic segments.

RESULTS

A total of 774 vessel segments were imaged by both modalities. When all arteries were considered, MDCTA detected obstructed or stenotic lesions in 16.8% of arteries, versus 11.1% compared to DUS. When suprapopliteal arteries alone were considered, MDCTA detected lesions in 15.0% of arteries, versus 11.0% with DUS. When infrapopliteal arteries only were considered, MDCTA detected lesions in 19.6% of arteries, versus 11.3% with DUS. MDCTA showed 5.7% (95% CI: [3.5%, 7.9%]) more lesions than DUS when all arteries were considered together, 8.3% (95% CI: [4.6%, 12.0%]) more lesions when only the infrapopliteal arteries were compared, and 4.0% (95% CI: [1.3%, 6.8%]) more lesions when only suprapopliteal arteries were compared (p<0.01 for all comparisons).

CONCLUSION

40-row MDCTA may be used as a screening tool in patients with mild lower extremity PAOD as it is a non-invasive and more accurate modality when compared to DUS.

Technical considerations for lower limb multidetector computed tomographic angiography

Multidetector computed tomography (MDCT) enables imaging of the entire arterial tree non-invasively. Optimal technical considerations for performing MDCT angiography (MDCTA) are essential for accurate diagnosis and atherosclerotic disease stratification. This review article focuses on the various technical aspects necessary for peripheral computed tomographic angiography (CTA) acquisition. Common clinical indications for peripheral MDCTA and the latest scan protocols are described. The essential issue of radiation dose reduction is discussed, along with methods of optimal contrast bolus detection and delivery. Post-processing techniques are also presented. Previously, digital subtraction angiography was the only established reliable imaging technique to quantify atherosclerotic disease load; however, MDCTA may now challenge this old gold standard, along with other non-invasive techniques such as magnetic resonance angiography (MRA).

Comparison between 64-row CT angiography and digital subtraction angiography in the study of lower extremities: personal experience

PURPOSE

This study was undertaken to evaluate the potential of 64-row multislice computed tomography (CT) versus digital subtraction angiography (DSA) in detecting significant lesions of lower-extremity inflow and runoff arteries.

MATERIALS AND METHODS

Fifty-three patients underwent 64-row multislice CT and DSA over a mean of 36 days. The vascular tree was divided into 33 segments. Three readers independently reviewed the axial CT scans and multiplanar oblique and two- and three-dimensional reconstructions (maximum intensity projection and volume rendering) images to assess degree of stenosis according to four categories: 1 (0%-49% stenosis); 2 (50%-99% stenosis); 3 (occluded); 4 (not evaluable). In all cases, DSA was performed by arterial catheterisation.

RESULTS

In 53 patients, 1,440 segments were evaluated (infrarenal aorta and 16 arterial segments for each leg; 42 bilateral studies, 11 unilateral studies). Compared with DSA, CT angiography yielded 97.2% sensitivity, 97% specificity, 92.5% positive predictive value, 98.9% negative predictive value, 97.1% diagnostic accuracy and 95.4% concordance on the degree of stenosis.

CONCLUSIONS

Sixty-four-row multislice CT proved to be helpful in detecting haemodynamically significant lesions in peripheral arterial occlusive disease and improved the results obtained with 4- and 16-slice multidetector CT. In addition, owing to the high spatial resolution and rigorous technique, no variations in the data obtained below the knee were detected, overcoming a limitation of earlier generations of CT scanners.

Defining optimal research study design for cardiovascular imaging using computed tomography angiography as a model

Patients, physicians, and payers are facing a significant increase in cardiovascular (CV) imaging use, resulting in skyrocketing societal costs, without clear improvement in patient outcomes. The need for studies evaluating the effects of CV imaging that assess appropriate end points is critical to address continued concerns over the lack of well-designed clinical studies. Thus, the investigators propose a framework, using computed tomographic angiography as a model, that should be considered in the optimal design of future imaging research and would potentially provide payers with data to make appropriate reimbursement decisions. The inclusion of risk stratification, randomization, multiple-site participation, and multigeography site enrollment are key elements in the construction of such studies. Meaningful end points with regard to operating characteristics, downstream testing, CV event rates, outcomes, and costs are essential to appropriately evaluate any new imaging technology. Only once better level evidence is formed to support CV imaging can the central issues of quality and appropriateness of CV imaging truly be evaluated. If the CV community does not embrace this type of scientific evaluation of CV imaging modalities and fails to adequately identify the value in these techniques, it may ultimately lose the ability to use them to provide optimal care to its patients.

Outcomes of patients who participate in randomized controlled trials compared to similar patients receiving similar interventions who do not participate

BACKGROUND

Some people believe that patients who take part in randomised controlled trials (RCTs) face risks that they would not face if they opted for non-trial treatment. Others think that trial participation is beneficial and the best way to ensure access to the most up-to-date physicians and treatments. This is an updated version of the original Cochrane review published in Issue 1, 2005.

OBJECTIVES

To assess the effects of patient participation in RCTs ('trial effects') independent both of the effects of the clinical treatments being compared ('treatment effects') and any differences between patients who participated in RCTs and those who did not. We aimed to compare similar patients receiving similar treatment inside and outside of RCTs.

SEARCH STRATEGY

In March 2007, we searched The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, The Cochrane Methodology Register, SciSearch and PsycINFO for potentially relevant studies. Our search yielded 7586 new references. In addition, we reviewed the reference lists of relevant articles.

SELECTION CRITERIA

Randomized studies and cohort studies with data on clinical outcomes of RCT participants and similar patients who received similar treatment outside of RCTs.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed studies for inclusion, assessed study quality and extracted data.

MAIN RESULTS

We identified 30 new non-randomized cohort studies (45 comparisons): no new RCTs were found. This update now includes five RCTs (yielding 6 comparisons) and 80 non-randomized cohort studies (130 comparisons), with 86,640 patients treated in RCTs and 57,205 patients treated outside RCTs. In the randomised studies, patients were invited to participate in an RCT or not; these comparisons provided limited information because of small sample sizes (a total of 412 patients) and the nature of the questions they addressed. When the results of RCTs and non-randomized cohorts that reported dichotomous outcomes were combined, there were 98 comparisons; there was also heterogeneity (P < 0.00001, I(2) = 42.2%) between studies. No statistical significant differences were found for 85 of the 98 comparisons. Eight comparisons reported statistically significant better outcomes for patients treated within RCTs, and five comparisons reported statistically significant worse outcomes for patients treated within RCTs. There was significant heterogeneity (P < 0.00001, I(2) = 58.2%) among the 38 continuous outcome comparisons. No statistically significant differences were found for 30 of the 38 comparisons. Three comparisons reported statistically significant better outcomes for patients treated within RCTs, and five comparisons reported statistically significant worse outcomes for patients treated within RCTs.

AUTHORS' CONCLUSIONS

This review indicates that participation in RCTs is associated with similar outcomes to receiving the same treatment outside RCTs. These results challenge the assertion that the results of RCTs are not applicable to usual practice.

Anatomical variations of the coeliac trunk and the mesenteric arteries evaluated with 64-row CT angiography

PURPOSE

This study was undertaken to evaluate the accuracy of 64-row computed tomography angiography (CTA) in the study of vascular anatomy by assessing the incidence of anatomical variations of the origin of the coeliac trunk, mesenteric arteries and collateral branches.

MATERIALS AND METHODS

Sixty patients were evaluated with 64-row CTA (VCT, General Electric Healthcare, Milwaukee, WI, USA) with a collimation of 0.625 mm after the injection of iodinated nonionic contrast material (4 ml/s). Exclusion criteria were the presence of any pathological condition likely to affect normal vascular anatomy.

RESULTS

The coeliac trunk had a normal trifurcation in 56.7% of cases. The common hepatic artery was normal in 60% of patients. The inferior pancreaticoduodenal arteries were either absent or not assessable in 8.3% of cases and there was a double trunk in 5%, a common trunk in 83.3% and a single vessel in 3.3%. The number of jejunal and ileal arteries ranged from a minimum of six to a maximum of 13 (mean value 8.7+/-1.34). The Riolan arcade was assessable in 31.7% and developed in 68.4% of these.

CONCLUSIONS

The 64-row CTA enables visualisation of small vessels and accessory arteries that are difficult to identify with other techniques. The technique's high sensitivity allowed us to observe that the prevalence of vascular abnormalities is higher than that reported in the literature.

Multipath curved planar reformation of the peripheral arterial tree in CT angiography

The study was approved by the institutional review board, and informed consent was obtained. The purpose of the study was to prospectively quantify the angular visibility range, determine the existence of orthogonal viewing pairs, and characterize the conditions that cause artifacts in multipath curved planar reformations (MPCPRs) of the peripheral arterial tree in 10 patients (eight men and two women; mean age, 69 years; range, 54-80 years) with peripheral arterial occlusive disease. Percentage of segments with the maximal possible visibility score of 1 was significantly greater (odds ratio, 1.42; P<.001) for MPCPRs than for maximum intensity projections. One or more orthogonal viewing pairs were identified for all above-knee arterial segments, and artifactual vessel distortion was observed when the vessel axis approached a horizontal course in MPCPRs.

[Chronic critical ischemia of the lower leg: pretherapeutic imaging and methods for revascularization]

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.

Diagnostic Accuracy of Multislice CT Angiography in Peripheral Arterial Disease

A systematic search of the PubMed and Medline databases of English literature was performed to determine the diagnostic accuracy of multislice computed tomographic (CT; MSCT) angiography in peripheral arterial disease (PAD) compared with digital subtraction angiography (DSA). Studies comparing MSCT angiography with DSA in peripheral vascular disease were included, and the diagnostic value of MSCT angiography in terms of sensitivity, specificity, and diagnostic accuracy was compared and analyzed. Ten studies (19 comparisons) met the criteria and were included for analysis. The pooled sensitivity, specificity, and accuracy rates were 92%, 91%, and 91%, respectively, at all arterial levels; 92%, 94%, and 93%, respectively, at aortoiliac arteries; 96%, 85%, and 92%, respectively, at femoropopliteal arteries; and 91%, 85%, and 87%, respectively, at infrapopliteal arteries. A significant difference was found in the sensitivity of MSCT angiography in PAD between four-slice CT and 16-slice CT, between aortoiliac and femoropopliteal arterial segments, and between femoropopliteal and infrapopliteal arterial segments (P<.05). This review demonstrates that MSCT angiography has a high diagnostic value and could be a reliable alternative to DSA in the diagnosis of PAD.

Imaging of peripheral arteries by 16-row multidetector computed tomography angiography: a feasible tool?

OBJECTIVE

To evaluate the efficacy of multidetector (16-row) computed tomography (MDCT) in imaging the upper and lower limb arterial tree in trauma and peripheral arterial occlusive disease (PAOD).

METHODS

Thirty-three patients underwent MDCT angiography (MDCTA) of the upper or the lower limb on 16-row MDCT scanner between November, 2004 and July, 2005. The findings were compared with the surgical outcome in cases with trauma and suspected arterial injuries or color Doppler correlation was obtained for patients of PAOD.

RESULTS

MDCTA allowed a comprehensive diagnostic work-up in all trauma cases with suspected arterial injuries. In the 23 cases of PAOD, MDCT adequately demonstrated the presence of stenosis or occlusion, its degree and extent, the presence of collaterals and plaques.

CONCLUSION

Our experience of CT angiography (CTA) with 16-row MDCT scanner has clearly demonstrated its efficacy as a promising, new, fast, accurate, safe and non-invasive imaging modality of choice in cases of trauma with suspected arterial injuries and as a useful screening modality in cases of PAOD for diagnosis and for grading.

[CTA and MRA in peripheral arterial disease--is DSA out?]

New developments in technique and postprocessing have led to further improvement in diagnosing and evaluating peripheral arterial disease (PAD) by noninvasive computed tomographic angiography (CTA) and magnetic resonance angiography (MRA). Under clinical conditions diagnostic conventional angiography (DSA) will be increasingly replaced by CTA and MRA. The radiologist has to become familiar with the field of indications, the different techniques, postprocessing tools, and effective visualization. In consideration of the current literature some methodological aspects and the role of CTA and MRA in PAD will be discussed.

Vessel wall calcifications at multi-detector row CT angiography in patients with peripheral arterial disease: effect on clinical utility and clinical predictors

PURPOSE

To evaluate retrospectively the effect of vessel wall calcifications on the clinical utility of multi-detector row computed tomographic (CT) angiography performed in patients with peripheral arterial disease and to identify clinical predictors for the presence of vessel wall calcifications.

MATERIALS AND METHODS

The study was approved by the hospital institutional review board, and informed consent was obtained from all patients. For this study the authors included patients from two randomized controlled trials that measured the costs and effects of diagnostic imaging in patients with peripheral arterial disease. All patients underwent CT angiography and were followed up for 6 months. Clinical utility was measured on the basis of therapeutic confidence (rated on a 10-point scale) in the results of initial CT angiography and the need for additional vascular imaging. Univariable and multivariable logistic and linear regression analysis and the area under the receiver operating characteristic curve were used to evaluate the effect of vessel wall calcifications on the clinical utility of CT angiography and the use of patient characteristics to predict the number of calcified segments at CT angiography.

RESULTS

A total of 145 patients were included (mean age, 64 years; 70% men). The authors found that the number of calcified segments was a significant predictor of the need for additional imaging (P = .001) and of the confidence scores (P < .001). The number of calcified segments discriminated between patients who required additional imaging after CT angiography and those who did not (area under the receiver operating characteristic curve, 0.66; 95% confidence interval: 0.54, 0.77). Age, diabetes mellitus, and cardiac disease were significant predictors of the number of calcified segments in both the univariable and multivariable analyses (P < .05).

CONCLUSION

Vessel wall calcifications decrease the clinical utility of CT angiography in patients with peripheral arterial disease. Diabetes mellitus, cardiac disease, and elderly age (older than 84 years) are independently predictive for the presence of vessel wall calcifications.

Arteriogenesis: Noninvasive Quantification with Multi–Detector Row CT Angiography and Three-dimensional Volume Rendering in Rodents

PURPOSE

To evaluate two-dimensional (2D) multi-detector row computed tomographic (CT) angiography and three-dimensional (3D) volume rendering for depiction of patterns of arterial growth and quantification of blood vessel density and volume.

MATERIALS AND METHODS

The institutional animal care and use committee approved this study. The right femoral artery and its branches were ligated and excised in 16 inbred Lewis rats; animals were randomly assigned to receive 70 microL Dulbecco's modified Eagle's medium (DMEM) or 1.5 x 10(7) bone marrow-derived mononuclear cells (BMC) from isogenic donor rats in 70 microL DMEM. At 2 weeks, CT angiography was performed with injection of 0.45 mL barium sulfate suspension at 0.7 mL/min, followed by silver staining. Number of blood vessels, area, mean area, volume, and blood vessel size distribution derived from digitally subtracted 2D CT angiographic sections were quantified; 3D images were reconstructed. Two-way analysis of variance and paired and unpaired Student t tests were performed.

RESULTS

CT angiography showed two patterns of arterial growth: collateral arterial formation and branching arteriogenesis. Two-way analysis of variance indicated that differences within subjects (ischemic vs nonischemic legs) and between subjects (BMC vs DMEM treatment) were significant for total blood vessel area, total blood vessel volume, and mean of blood vessel area (P < .001). In the BMC group, there were significantly more arteries (mean, 241.6 +/- 77.0 [standard deviation] vs 196.4 +/- 75.2, P = .028), but mean cross-sectional area of these arteries was smaller in ischemic versus nonischemic legs (5.4 mm(2) +/- 1.2 vs 6.8 mm(2) +/- 1.3, P = .006). Total arterial area and volume did not differ significantly between ischemic and nonischemic legs.

CONCLUSION

BMC injection had a substantial effect on arteriogenesis, with normalization of total arterial area and volume in the BMC group; this effect was successfully depicted.

Balloon angioplasty versus implantation of nitinol stents in the superficial femoral artery

BACKGROUND

Because stent implantation for disease of the superficial femoral artery has been associated with high rates of late clinical failure, percutaneous transluminal angioplasty is preferred for endovascular treatment, and stenting is recommended only in the event of suboptimal technical results. We evaluated whether primary implantation of a self-expanding nitinol (nickel-titanium) stent yielded anatomical and clinical benefits superior to those afforded by percutaneous transluminal angioplasty with optional secondary stenting.

METHODS

We randomly assigned 104 patients who had severe claudication or chronic limb ischemia due to stenosis or occlusion of the superficial femoral artery to undergo primary stent implantation (51 patients) or angioplasty (53 patients). Restenosis and clinical outcomes were assessed at 6 and 12 months.

RESULTS

The mean (+/-SD) length of the treated segment was 132+/-71 mm in the stent group and 127+/-55 mm in the angioplasty group. Secondary stenting was performed in 17 of 53 patients (32 percent) in the angioplasty group, in most cases because of a suboptimal result after angioplasty. At 6 months, the rate of restenosis on angiography was 24 percent in the stent group and 43 percent in the angioplasty group (P=0.05); at 12 months the rates on duplex ultrasonography were 37 percent and 63 percent, respectively (P=0.01). Patients in the stent group were able to walk significantly farther on a treadmill at 6 and 12 months than those in the angioplasty group.

CONCLUSIONS

In the intermediate term, treatment of superficial-femoral-artery disease by primary implantation of a self-expanding nitinol stent yielded results that were superior to those with the currently recommended approach of balloon angioplasty with optional secondary stenting. (ClinicalTrials.gov number, NCT00281060.).

IV Contrast Selection for MDCT: Current Thoughts and Practice

OBJECTIVE

The purpose of this article is to review studies evaluating how contrast concentration affects MDCT of the body and to report IV contrast infusion protocols from MDCT angiography and MDCT of abdominal tumors.

CONCLUSION

Higher concentrations (350 mg I/mL or greater) may improve visualization of small abdominal arteries. However, preliminary data comparing 300 mg I/mL to higher concentrations for MDCT of hypervascular hepatocellular carcinoma and pancreatic cancer have shown that higher concentrations may not increase tumor conspicuity.

Guidelines for the optimization of microsurgery in atherosclerotic patients

We review the pathogenesis of atherosclerosis and the issues that must be taken into consideration when performing microsurgery in atherosclerotic patients. Atherosclerosis is a systemic disease, and may affect the success of microsurgery. Atherosclerotic patients have a tendency toward thrombosis, because the nature of the arteries is changed. Such patients are usually old and have additional medical problems. To increase the success rate of microsurgery in atherosclerotic patients, special precautions should be considered. Patients must be evaluated properly for the suitability of microsurgery. The microsurgical technique requires a meticulous approach, and various technical tricks can be used to avoid thrombosis. Recipient-vessel selection, anastomotic technique, and the use of vein grafts are all important issues. Prophylactic anticoagulation is recommended in severely atherosclerotic patients. Close monitoring of the patient and flap is necessary after the operation, as with routine microvascular free-tissue transfers. We conclude that atherosclerosis is not a contraindication for microsurgery. If the microsurgeon knows how to deal with the difficulties in atherosclerotic patients, microsurgery can be performed safely.

Imaging Peripheral Arterial Disease: A Randomized Controlled Trial Comparing Contrast-enhanced MR Angiography and Multi–Detector Row CT Angiography

PURPOSE

To prospectively evaluate clinical utility, patient outcomes, and costs of contrast material-enhanced magnetic resonance (MR) angiography compared with multi-detector row computed tomographic (CT) angiography for initial imaging in the diagnostic work-up of patients with peripheral arterial disease.

MATERIALS AND METHODS

Institutional review board approval and informed consent were obtained. Patients referred for diagnostic imaging work-up to evaluate the feasibility of a revascularization procedure were randomly assigned to undergo either MR angiography or CT angiography. Clinical utility was assessed with therapeutic confidence (scale of 0-10) at initial imaging and with the need for additional imaging. Patient outcomes included ankle-brachial index, maximum walking distance, change in clinical status, and health-related quality of life. Actual diagnostic and therapeutic costs were calculated from the hospital perspective. Differences between group means were calculated with unpaired t tests and 95% confidence intervals.

RESULTS

A total of 157 consecutive patients with peripheral arterial disease were prospectively randomized to undergo MR angiography (51 men, 27 women; mean age, 63 years) or CT angiography (50 men, 29 women; mean age, 64 years). For one of the 78 patients in the MR group, no data were available. Mean confidence for MR angiography (7.7) was slightly lower than that for CT angiography (8.0, P = .8). During 6 months of follow-up, 13 patients in the MR group compared with 10 patients in the CT group underwent additional vascular imaging (P = .5). Although not statistically significant, there was a consistent trend of less improvement in the MR group across all patient outcomes. The average cost for diagnostic imaging was 359 ($438) higher in the MR group than in the CT group (95% confidence interval: 209, 511 [$255, $623]; P < .001). Therapeutic costs were higher in the MR group, but the difference was not significant.

CONCLUSION

The results suggest that CT angiography has some advantages over MR angiography in the initial evaluation of peripheral arterial disease.

Computed tomographic angiography allows accurate planning of the setting and technique of open and percutaneous vascular interventions

BACKGROUND

Vascular surgeons can offer patients with arterial and venous disorders a multitude of endovascular and surgical options. Computed tomographic angiography (CTA) has the potential to allow the development of an effective interventional strategy without subjecting patients to invasive diagnostic testing.

METHODS

A prospectively maintained database was reviewed comprising 6 consecutive months of arterial and venous procedures performed using an algorithm emphasizing CTA supplemented with other noninvasive imaging.

RESULTS

Eighty-five patients underwent 90 arterial or venous procedures, the majority of which were based on CTA. Preprocedure plans matched a successful intervention in 35 of 40 (88%) procedures performed in the interventional suite, and 48 of 49 (98%) procedures performed in the surgical suite. Two of 40 patients treated initially in the interventional suite eventually required a surgical vascular procedure. The majority of procedures were therapeutic (86%) rather than diagnostic (14%).

CONCLUSIONS

An algorithm using CTA and supplemented with other noninvasive imaging allows safe and effective planning for open surgical and endovascular procedures.

Purification and properties of liver fructose 1,6-bisphosphatase from C57BL/KsJ normal and diabetic mice

PURPOSE

To prospectively compare therapeutic confidence in, patient outcomes (in terms of quality of life) after, and the costs of digital subtraction angiography (DSA) with those of multi-detector row computed tomographic (CT) angiography as the initial diagnostic imaging test in patients with peripheral arterial disease (PAD).

MATERIALS AND METHODS

Institutional medical ethics committee approval and patient informed consent were obtained. Between April 2000 and August 2001, patients with PAD were randomly assigned to undergo either DSA or multi-detector row CT angiography as the initial diagnostic imaging test. Outcomes were the therapeutic confidence assessed by physicians (on a scale from 0 to 10), the need for additional imaging, the health-related quality of life at 6-month follow-up, diagnostic and therapeutic costs, and the costs for a hospital stay. Costs were computed from a hospital perspective according to Dutch guidelines for cost calculations in health care. Mean outcomes were compared between groups with unpaired t testing and were adjusted for predictive baseline characteristics with multivariable regression analysis.

RESULTS

Among the 145 patients, 72 were randomly allocated to the DSA group and 73 to the CT angiography group. One patient in the DSA group had to be excluded. Mean age was 63 years in the DSA group and 64 years in the CT angiography group. There were 47 men in the DSA group and 58 men in the CT angiography group. Physician confidence in making a correct therapeutic choice was significantly higher at DSA (mean confidence score, 8.2) than at CT angiography (mean score, 7.2; P < .001). During 6-month follow-up, 14% less additional imaging was performed in the DSA group than in the CT angiography group (P = .3). No significant quality-of-life differences were found between groups. The diagnostic cost associated with DSA (564 +/- 210 euro [standard deviation]) was significantly higher than that associated with CT angiography (363 +/- 273 euro), a difference of -201 euro (95% confidence interval: -281 euro, -120 euro; P < .001). Therapeutic and hospitalization costs were similar for both strategies.

CONCLUSION

These results suggest that use of noninvasive multi-detector row CT angiography instead of DSA as the initial diagnostic imaging test for PAD provides sufficient information for therapeutic decision making and reduces imaging costs.