Angiographic distribution of lower extremity atherosclerosis in patients with and without diabetes

Lower Extremity Reconstruction with Anterolateral Thigh Free-Flap Anastomoses: A Computational Fluid Dynamic Analysis

BACKGROUND

 The anterolateral thigh free flap is an option for repairing soft tissue defects of the distal lower extremity. This flap uses the descending branch of the lateral circumflex femoral (LCF) artery as the flap vessel. The recipient vessel in these flaps is often the anterior tibial (AT), posterior tibial (PT), or peroneal (P) arteries. Computational fluid dynamic (CFD) evaluation of anastomoses between these vessels can optimize outcomes.

METHODS

 Thirty-eight CFD models were created to model end-to-side (ETS) and end-to-end (ETE) anastomoses for lower extremity reconstruction. Seven out of thirty-eight models represented ETS anastomoses between the LCF and AT arteries with varying anastomotic angles. Nine out of thirty-eight models represented 45-degree ETS anastomoses between varying diameters of the LCF and AT, PT, and P arteries. Nine out of thirty-eight models represented stenosis on the flap vessel and recipient vessel, pre- and post-bifurcation. Nine out of thirty-eight models represented ETE anastomoses, rather than ETS, with varying vessel diameters. Four out of thirty-eight models represented ETE anastomoses with varying regions and levels of stenosis.

RESULTS

 Stasis of blood flow in ETS models increased as anastomotic angle increased in a logarithmic relationship (R 2 = 0.918). Flow was optimized overall as flap and recipient vessel diameters approached one another. In ETS models, flap vessel and postbifurcation recipient vessel stenosis were found to substantially increase stasis.

CONCLUSION

 Selection of flap and recipient vessels with similar diameters can optimize outcomes in microvascular anastomoses. In the context of lower extremity reconstruction with the ALT flap, the PT artery can be recommended as a first-line recipient vessel due to its similar vessel caliber to the LCF and relative ease of surgical access compared with the P artery. Avoidance of areas of stenosis is recommended to ensure laminar flow and reduce the operative difficulty associated with performing anastomoses on nonpliable arteries. Striving for increased acuity of anastomotic angles is recommended to optimize the flow in ETS microvascular anastomoses.

Contemporary Medical Management of Peripheral Arterial Disease

PURPOSE

Peripheral arterial disease (PAD) is characterized by atherosclerotic arterial occlusive disease of the lower extremities and is associated with an increased risk of major adverse cardiovascular events (MACE) in addition to disabling clinical sequelae, including intermittent claudication and chronic limb-threatening ischemia (CLTI). Given the growing burden of disease, knowledge of modern practices to prevent MACE and major adverse limb events (MALE) is essential. This review article examines evidence for medical management of PAD and its associated risk factors, as well as wound prevention and care.

METHODS

A thorough review of the literature was performed, with attention to evidence for the management of modifiable atherosclerotic risk factors, claudication symptoms, wound prevention, and wound care.

RESULTS

Contemporary management of PAD requires a multi-faceted approach to care, with medical optimization of smoking, hypertension, hyperlipidemia, and diabetes mellitus. The use of supervised exercise therapy for intermittent claudication is highlighted. The anatomic disease patterns of smoking and diabetes mellitus are discussed further, and best practices for diabetic foot ulcer prevention, including offloading footwear, are described. Quality wound care is essential in this patient population and involves strategic use of debridement, wound-healing adjuncts, and skin substitutes, when appropriate.

CONCLUSION

The objective of medical management of PAD is to reduce the risk of MACE and MALE. Atherosclerotic risk factor optimization, appropriate wound care, and management of diabetic foot ulcers, foot infections, gangrene, and chronic, non-healing wounds are critical components of PAD care. Interdisciplinary care is essential to coordinate care, leverage expertise, and improve outcomes.

The relation of anatomical distribution of symptomatic peripheral arterial disease (PAD) with HbA1c level in patients with type 2 diabetes mellitus

AIMS

Increased level of glycated hemoglobin (HbA1c) is associated with an increased prevalence of peripheral arterial disease (PAD). This study aimed to assess the relationship between the anatomical distribution of symptomatic PAD lesions in patients with type 2 diabetes and HbA1c levels at the time of PAD diagnosis.

PATIENTS AND METHODS

A retrospective study was conducted at King Abdullah University Hospital during the period August 2011 to December 2015. Consecutive patients with type 2 diabetes presented with symptomatic PAD confirmed by computed tomography-angiography (CTA) were included in this study. CTA images were reviewed. Relevant information including demographic data, PAD symptoms, comorbidities, HbA1c level, lipid profile, C-reactive protein and the mean platelets volume were retrieved from medical records.

RESULTS

A total of 332 patients with type 2 diabetes (255 males and 77 females) were included in this study. The mean HbA1c at the time of PAD diagnosis was 8.68% (±2.06%). The prevalence of hemodynamic relevant atherosclerotic lesions of the superficial femoral artery, popliteal artery, leg vessels, femoro-popliteal, and crural segments was significantly higher in patients with HbA1c >7.5% compared with patients with HbA1c ⩽7.5%.

CONCLUSION

The anatomical distribution of symptomatic PAD in patients with type 2 diabetes mellitus differed significantly according to HbA1c level at the time of PAD diagnosis.

Use of perfusional CBCT imaging for intraprocedural evaluation of endovascular treatment in patients with diabetic foot: a concept paper

Diabetes mellitus (DM) is one of the most common metabolic diseases worldwide; its global burden has increased rapidly over the past decade, enough to be considered a public health emergency in many countries. Diabetic foot disease and, particularly diabetic foot ulceration, is the major complication of DM: through a skin damage of the foot, with a loss of epithelial tissue, it can deepen to muscles and bones and lead to the amputation of the lower limbs. Peripheral arterial disease (PAD) in patients with diabetes, manifests like a diffuse macroangiopathic multi-segmental involvement of the lower limb vessels, also connected to a damage of collateral circulation; it may also display characteristic microaneurysms and tortuosity in distal arteries. As validation method, Bold-MRI is used. The diabetic foot should be handled with a multidisciplinary team approach, as its management requires systemic and localized treatments, pain control, monitoring of cardiovascular risk factors and other comorbidities. CBCT is an emerging medical imaging technique with the original feature of divergent radiation, forming a cone, in contrast with the spiral slicing of conventional CT, and has become increasingly important in treatment planning and diagnosis: from small anatomical areas, such as implantology, to the world of interventional radiology, with a wide range of applications: as guidance for biopsies or ablation treatments. The aim of this project is to evaluate the usefulness of perfusion CBCT imaging, obtained during endovascular revascularization, for intraprocedural evaluation of endovascular treatment in patients with diabetic foot. (www.actabiomedica.it).

[Reconstruction of lower limbs in old age-an interdisciplinary approach : Strategies for trauma surgery, vascular surgery and plastic surgery]

The treatment of complex injuries of the lower extremities in geriatric and/or multimorbid patients requires optimized preoperative and perioperative management as well as differentiated and interdisciplinary surgical approaches. Timely and definitive treatment should be strived for to avoid longer periods of immobilization. Temporary external stabilization of complex fractures, when necessary, should be followed by permanent loading stable internal osteosynthesis as soon as possible. Accompanying soft tissue defects are reconstructed after wound débridement using the full armamentarium of plastic and reconstructive surgical procedures, including microvascular free flap. In the context of perfusion compromised soft tissue situations, negative pressure wound therapy can provide sterile temporary defect coverage and aid in preconditioning poorly vascularized tissue before definitive reconstruction. A clarification of the vascular status in geriatric patients is paramount and relevant perfusion disorders should be treated either by intervention or open surgery before complex reconstructive interventions. Close interdisciplinary coordination of the various surgical procedures is imperative in order to guarantee an optimized stable reconstructive outcome with acceptable patient risk. Taking these principles into account, the reconstruction of complex trauma to the extremities can be carried out even in geriatric or multimorbid patients in specialized interdisciplinary surgical centers with excellent functional results.

Subclinical Peripheral Arterial Disease in Patients with Acute Ischemic Stroke: A Study with Ultrasonography

BACKGROUND

Peripheral arterial disease (PAD) is an advanced form of atherosclerosis defined by an abnormal ankle-brachial index (ABI). However, the ABI provides no information about the location of atherosclerosis. We investigated the clinical implication of PAD confirmed using lower-extremity ultrasonography (LEUS), with consideration of the atherosclerosis location.

METHODS

Patients with acute ischemic stroke who underwent LEUS were enrolled. Patients with PAD were further divided into those with PAD at the proximal (above-popliteal artery, PADP) and distal (below-tibialis artery, PADD) segments. The clinical outcome was compared between patients with and without PAD, and between PADP and PADD. The atherosclerosis location in the cerebral artery was also compared between groups.

RESULTS

Among 289 patients, PAD was observed in 108 (37.4%) patients (43 had PADP and 65 had PADD). Patients with PAD were slightly older (P < .001) and had more significant carotid artery stenosis (30.6% versus 12.7%, P < .001) than those without. Patients with PAD had poor 3-month functional outcome than those without (modified-Rankin Scale score: 3 [interquartile range, 1-4] versus 2 [1-3], respectively, P = .003). Diabetes, high-stroke severity, and the presence of PADP (odds ratio, 3.893; 95% confidence interval, 1.454-10.425; P = .007) were independently associated with poor functional outcome at 3 months. Patients with PADP showed higher prevalence of extracranial stenosis than those with PADD (41.9% versus 23.1%; P = .038).

CONCLUSIONS

Our study suggests that subclinical PAD, especially PADP, is associated with poor functional outcome at 3 months after stroke onset. Interestingly, the location of cerebral atherosclerosis differed according to the location of PAD.

Carotid intima-media thickness and plaques in internal carotid artery as surrogate markers of lower limb arterial lesions in Chinese patients with diabetic foot

Peripheral arterial disease (PAD) can impair healing of diabetic foot (DF) in patients with diabetes mellitus. To determine whether carotid intima-media thickness (CIMT) can predict lower limb arterial lesions in patients with DF, this cross-sectional study enrolled patients with DF at West China Hospital (China) between January 2012 and December 2015. Ultrasonography was used to measure CIMT, assess the internal carotid arteries (ICA) for plaques, and evaluate lower limb segmental arteries for stenosis. The optimal CIMT cutoff for detecting lower limb PAD was determined by receiver operating characteristic (ROC) curve analysis. Factors associated with PAD were identified by logistic regression analyses. A total of 167 patients (mean age: 69.7±10.3 years; 102 men) were included. Patients with PAD were older and had higher levels of total cholesterol and low-density lipoprotein than patients without PAD (P<0.05). The area under the ROC curve was 0.747 (P<0.001). At the optimal CIMT cutoff of 0.71 mm, the sensitivity, specificity, positive predictive value, and negative predictive value were 79.65, 61.11, 81.08, and 58.93%, respectively. Compared with those without PAD, more patients with PAD had CIMT ≥0.71 mm (79.65 vs 38.89%; P<0.001) and ICA plaques (66.37vs 11.11%; P<0.001). Multivariate logistic regression revealed that age (odds ratio [OR]: 1.118; 95% confidence interval [95%CI]: 1.056–1.183; P<0.001), ICA plaques (OR: 13.452; 95%CI: 4.450–40.662; P<0.001), and CIMT ≥0.71 mm (OR: 2.802; 95%CI: 1.092–7.188; P=0.032) were associated with PAD.CIMT may be a surrogate marker of PAD in patients with DF.

Site and Burden of Lower Limb Atherosclerosis Predicts Long-term Mortality in a Cohort of Patients With Peripheral Arterial Disease

OBJECTIVE/BACKGROUND

Lower limb peripheral arterial disease (PAD) is becoming increasingly common. Lower limb perfusion, as determined by the ankle brachial pressure index (ABPI), is a recognised predictor of overall mortality. The increasing role of non-invasive imaging in patient assessment may aid in the ability to predict poor patient outcomes.

METHODS

This study included all patients undergoing a lower limb arterial duplex over a period of 20 months. The site and burden of atherosclerosis within the lower limb was determined using the well validated Bollinger score. Patient demographic data were also collated. The primary outcome measure was all cause mortality.

RESULTS

A total of 678 patients were included (median age 74 years). The overall median follow up period was 69.9 months. Of these, 307 patients reached the primary end point, which was death. Independent predictors of all cause mortality included total Bollinger score (odds ratio [OR] 1.11, 95% confidence interval [CI] 1.05-1.18 [p < .001]; OR per 10 points), femoropopliteal Bollinger score (OR 1.34, 95% CI 1.11-1.08 [p = .05]; OR per 10 points), and crural Bollinger score (OR 1.03, 95% CI 1.01-1.03 [p = .03]). There was also a significant association between mortality and age, a prior history of ischaemic heart disease, a history of congestive cardiac failure and chronic renal failure (chronic kidney disease ≥ 3). Statin and antiplatelet therapy were protective.

CONCLUSION

This contemporary study confirms poor long-term outcomes still exist in patients with PAD. The site and severity of lower limb atherosclerosis are independent predictors of long-term mortality.

A Review of Distribution of Atherosclerosis in the Lower Limb Arteries of Patients With Diabetes Mellitus and Peripheral Vascular Disease

OBJECTIVE

There is a generally accepted hypothesis that patients with diabetes mellitus (DM) have a higher burden of atherosclerotic disease below the knee compared to patients without DM (NDM). The aim of this review was to summarize the evidence regarding this hypothesis.

METHODS

The literature was searched for papers that compared the anatomical distribution of atherosclerotic disease in patients with DM and those without using radiological imaging. Search terms used included "diabetes mellitus," "peripheral vascular disease," "distribution of disease," "angiography," "computed tomography angiography," and "magnetic resonance angiography." Where possible, the number of patients with disease in each arterial segment was extracted and included in a forest plot. A descriptive approach was taken when this was not possible or a scoring system was used.

RESULTS

Fourteen studies were included in the review and it was possible to summarize data from 9 of these in a forest plot. Fifteen different arterial segments were described; however, the most commonly used segments that differentiated between proximal and distal disease were aortoiliac (A-I; DM = 466 patients, NDM = 458), femoropopliteal (F-P; DM = 568, NDM = 585), tibial (DM = 306, NDM = 417). The resulting forest plot showed that those with DM were significantly less likely to have disease in the A-I segment (odds ratio [OR]: 0.25 [0.15-0.42]) and significantly more likely to have disease in the tibial segment (OR 1.94 [1.27-2.96]). In the DM group, there was a trend toward relative sparing in the F-P segment, but this does not reach significance (0.66 [0.33-1.31]).

CONCLUSIONS

These results support the hypothesis that patients with DM are more likely to have atherosclerotic disease in the tibial vessels than NDM. There is however limited information on how individual vessels are affected. Further information on this and a greater understanding of why the distal vessels are more affected are avenues for future research.

Influence of micro- and macro-vascular disease and Tumor Necrosis Factor Receptor 1 on the level of lower-extremity amputation in patients with type 2 diabetes

BACKGROUND

Patients with type 2 diabetes (T2D) face a high amputation rate. We investigated the relationship between the level of amputation and the presence of micro or macro-vascular disease and related circulating biomarkers, Tumor Necrosis Factor Receptor 1 (TNFR1) and Angiopoietin like-2 protein (ANGPTL2).

METHODS

We have analyzed data from 1468 T2D participants in a single center prospective cohort (the SURDIAGENE cohort). Our outcome was the occurrence of lower limb amputation categorized in minor (below-ankle) or major (above ankle) amputation. Microvascular disease was defined as a history of albuminuria [microalbuminuria: uACR (urinary albumine-to-creatinine ratio) 30-299 mg/g or macroalbuminuria: uACR ≥ 300 mg/g] and/or severe diabetic retinopathy or macular edema. Macrovascular disease at baseline was divided into peripheral arterial disease (PAD): peripheral artery revascularization and/or major amputation and in non-peripheral macrovascular disease: coronary artery revascularization, myocardial infarction, carotid artery revascularization, stroke. We used a proportional hazard model considering survival without minor or major amputation.

RESULTS

During a median follow-up period of 7 (0.5) years, 79 patients (5.5%) underwent amputation including 29 minor and 50 major amputations. History of PAD (HR 4.37 95% CI [2.11-9.07]; p < 0.001), severe diabetic retinopathy (2.69 [1.31-5.57]; p = 0.0073), male gender (10.12 [2.41-42.56]; p = 0.0016) and serum ANGPTL2 concentrations (1.25 [1.08-1.45]; p = 0.0025) were associated with minor amputation outcome. History of PAD (6.91 [3.75-12.72]; p < 0.0001), systolic blood pressure (1.02 [1.00-1.03]; p = 0.004), male gender (3.81 [1.67-8.71]; p = 0.002), and serum TNFR1 concentrations (HR 13.68 [5.57-33.59]; p < 0.0001) were associated with major amputation outcome. Urinary albumin excretion was not significantly associated with the risk of minor and major amputation.

CONCLUSIONS

This study suggests that the risk factors associated with the minor vs. major amputation including biomarkers such as TNFR1 should be considered differently in patients with T2D.

Critical Limb Ischemia: A Practical Up-To-Date Review

Critical limb ischemia (CLI) is the most advanced form of peripheral artery disease. It is associated with significant morbidity and mortality and high management costs. It carries a high risk of amputation and local infection. Moreover, cardiovascular complications remain a major concern. Although it is a well-known entity and new technological and therapeutic advances have been made, this condition remains poorly addressed, with significantly heterogeneous management, especially in nonexperienced centers. This review, from a third-level dedicated inpatient and outpatient cardioangiology structure, aims to provide an updated summary on the topic of CLI of its complexity, encompassing epidemiological, social, economical and, in particular, diagnostic/imaging issues, together with potential therapeutic strategies (medical, endovascular, and surgical), including the evaluation of cardiovascular risk factors, the diagnosis, and treatment together with prognostic stratification.

Open and Endovascular Treatment of Trans-Atlantic Inter-Society Consensus II D Aortoiliac Occlusive Lesions: What Determines the Rate of Restenosis?

Background:

Open surgery is the preferred approach for the treatment of type D lesions according to the Trans-Atlantic Inter-Society Consensus (TASC) II guideline, but endovascular solutions also appear to be a valid option in selected patients. The study aimed to identify the risk factors of restenosis after open and endovascular reconstruction of symptomatic TASC II D aortoiliac occlusive lesions (AIOLs).

Methods:

Fifty-six patients (82 limbs) who underwent open repair and endovascular treatment (ET) for symptomatic TASC ΙΙ D AIOLs between March 2005 and December 2012 were retrospectively reviewed. Baseline characteristics, preoperative and postoperative imaging, and operation procedure reports were reviewed and analyzed. Restenosis after revascularization was assessed by duplex ultrasound or computed tomography angiogram. Kaplan-Meier survival analysis, Log-rank test, and multivariate Cox regression were used to evaluate the relevance between risk factors and patency.

Results:

The mean duration of follow-up was 42.8 ± 23.5 months (ranging from 3 to 90 months). Primary patency rates at 1-, 3-, 5-, and 7-year were 93.6%, 89.3%, 87.0%, and 70.3%, respectively. Restenosis after revascularization occurred in 11 limbs. Kaplan-Meier survival analysis and the Log-rank test revealed that diabetes, Rutherford classification ≥5^th and concurrent femoropopliteal TASC II type C/D lesions were significantly related to the duration of primary patency. According to the result of Cox regression, diabetes and femoropopliteal TASC ΙΙ type C/D lesions were identified as the risk factors for restenosis after revascularization.

Conclusion:

This study demonstrated that diabetes and femoropopliteal TASC ΙΙ type C/D lesions are risk factors associated with restenosis after open and ET of TASC II D AIOLs.

The diabetic foot in 2015: an overview

In 2015, it can be said that the diabetic foot is no longer the Cinderella of diabetic complications. Thirty years ago there was little evidence-based research taking place on the diabetic foot, and there were no international meetings addressing this topic. Since then, the biennial Malvern Diabetic Foot meetings started in 1986, the American Diabetes Association founded their Foot Council in 1987, and the European Association for the Study of Diabetes established a Foot Study Group in 1998. The first International Symposium on the Diabetic Foot in The Netherlands was convened in 1991, and this was soon followed by the establishment of the International Working Group on the Diabetic Foot that has produced useful guidelines in several areas of investigation and the management of diabetic foot problems. There has been an exponential rise in publications on diabetic foot problems in high impact factor journals, and a comprehensive evidence-base now exists for many areas of treatment. Despite the extensive evidence available, it, unfortunately, remains difficult to demonstrate that most types of education are efficient in reducing the incidence of foot ulcers. However, there is evidence that education as part of a multi-disciplinary approach to diabetic foot ulceration plays a pivotal role in incidence reduction. With respect to treatment, strong evidence exists that offloading is the best modality for healing plantar neuropathic foot ulcers, and there is also evidence from two randomized controlled trials to support the use of negative-pressure wound therapy in complex post-surgical diabetic foot wounds. Hyperbaric oxygen therapy exhibits the same evidence level and strength of recommendation. International guidelines exist on the management of infection in the diabetic foot. Many randomized trials have been performed, and these have shown that the agents studied generally produced comparable results, with the exception of one study in which tigecycline was shown to be clinically inferior to ertapenem ± vancomycin. Similarly, there are numerous types of wound dressings that might be used in treatment and which have shown efficacy, but no single type (or brand) has shown superiority over others. Peripheral artery disease is another major contributory factor in the development of ulceration, and its presence is a strong predictor of non-healing and amputation. Despite the proliferation of endovascular procedures in addition to open revascularization, many patients continue to suffer from severely impaired perfusion and exhaust all treatment options. Finally, the question of the true aetiopathogenesis of Charcot neuroarthropathy remains enigmatic, although much work is currently being undertaken in this area. In this area, it is most important to remember that a clinically uninfected, warm, insensate foot in a diabetic patient should be considered as a Charcot foot until proven otherwise, and, as such, treated with offloading, preferably in a cast.

Paramalleolar Arterial Bollinger Score in the Era of Diabetes and End-Stage Renal Disease - Usefulness for Predicting Operative Outcome of Critical Limb Ischemia

BACKGROUND

The aim of this study was to evaluate the usefulness of paramalleolar arterial Bollinger score (PBS) for predicting postoperative outcome of infra-popliteal bypass surgery for critical limb ischemia (CLI).

METHODS AND RESULTS

A total of 104 consecutive patients (118 limbs) who underwent infra-popliteal (tibial or paramalleolar) arterial bypass surgery with an autologous vein conduit for the treatment of CLI (Rutherford 4-6) between January 2002 and December 2012 were classified according to PBS ≤45 or >45. Postoperative outcome was compared between these groups. Primary outcomes were major adverse limb events plus perioperative death, and amputation-free survival (AFS). The secondary outcomes were overall survival, limb salvage and secondary graft patency. More than 80% of patients had either diabetes mellitus (DM) or end-stage renal disease (ESRD) and 30 patients with 36 limbs had PBS >45. Compared with the PBS ≤45 group, the PBS >45 group had higher CVD and carotid stenosis rate, poor nutrition status and lower malignancy rate. On overall analysis, the PBS >45 group had worse outcome for AFS and survival but this was not statistically significant (P=0.12, NS). In DM or ESRD patients, the PBS >45 group had significantly worse outcome for both AFS (P=0.04, 0.02) and overall survival rate (P=0.04, 0.03).

CONCLUSIONS

PBS successfully classified CLI patients with DM or ESRD who had worse outcome after infra-popliteal bypass surgery.

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

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

Peripheral arterial disease and revascularization of the diabetic foot

Diabetes is a complex disease with many serious potential sequelae, including large vessel arterial disease and microvascular dysfunction. Peripheral arterial disease is a common large vessel complication of diabetes, implicated in the development of tissue loss in up to half of patients with diabetic foot ulceration. In addition to peripheral arterial disease, functional changes in the microcirculation also contribute to the development of a diabetic foot ulcer, along with other factors such as infection, oedema and abnormal biomechanical loading. Peripheral arterial disease typically affects the distal vessels, resulting in multi-level occlusions and diffuse disease, which often necessitates challenging distal revascularisation surgery or angioplasty in order to improve blood flow. However, technically successful revascularisation does not always result in wound healing. The confounding effects of microvascular dysfunction must be recognised--treatment of a patient with a diabetic foot ulcer and peripheral arterial disease should address this complex interplay of pathophysiological changes. In the case of non-revascularisable peripheral arterial disease or poor response to conventional treatment, alternative approaches such as cell-based treatment, hyperbaric oxygen therapy and the use of vasodilators may appear attractive, however more robust evidence is required to justify these novel approaches.

Management of Atherosclerotic Aortoiliac Occlusive Disease

Development of aortoiliac occlusive disease (AIOD) is associated with classic risk factors for atherosclerotic disease such as hyperlipidemia, hypertension, diabetes, or smoking. Risk factor modification, smoking cessation, and prevention of cardiovascular events remain the cornerstones of AIOD management. Symptom improvement and limb loss prevention are considered secondary goals of therapy. Continuous technological advances, new devices, as well as new revascularization techniques are constantly changing the landscape of AIOD management. Surgical interventions, which were considered a gold standard therapy for nearly 50 years, currently give way to newer and less invasive endovascular techniques.

Comparison of lower extremity atherosclerosis in diabetic and non-diabetic patients using multidetector computed tomography

Background

Lower extremity atherosclerosis (LEA) is among the most serious diabetic complications and leads to non-traumatic amputations. The recently developed dual-source CT (DSCT) and 320- multidetector computed tomography (MDCT) may help to detect plaques more precisely. The aim of our study was to evaluate the differences in LEA between diabetic and non-diabetic patients using MDCT angiography.

Methods

DSCT and 320-MDCT angiographies of the lower extremities were performed in 161 patients (60 diabetic and 101 non-diabetic). The plaque type, distribution, shape and obstructive natures were compared.

Results

Compared with non-diabetic patients, diabetic patients had higher peripheral neuropathy, history of cerebrovasuclar infarction and hypertension rates. A total of 2898 vascular segments were included in the analysis. Plaque and stenosis were detected in 681 segments in 60 diabetic patients (63.1%) and 854 segments in 101 non-diabetic patients (46.9%; p <0.05). Regarding these plaques, diabetic patients had a higher incidence of mixed plaques (34.2% vs. 27.1% for non-diabetic patients). An increased moderate stenosis rate and decreased occlusion rate were observed in diabetic patients relative to non-diabetic patients (35.8% vs. 28.3%; and 6.6% vs. 11.4%; respectively). In diabetic patients, 362 (53.2%) plaques were detected in the distal lower leg segments, whereas in non-diabetic patients, 551 (64.5%) plaques were found in the proximal upper leg segments. The type IV plaque shape, in which the full lumen was involved, was detected more frequently in diabetic patients than in non-diabetic patients (13.1% vs. 8.2%).

Conclusion

Diabetes is associated with a higher incidence of plaque, increased incidence of mixed plaques, moderate stenosis and localisation primarily in the distal lower leg segments. The advanced and non-invasive MDCT could be used for routine preoperative evaluations of LEA.

Octogenarians develop infrapopliteal arterial occlusive disease in the absence of traditional risk factors

BACKGROUND

With increasing longevity, a growing proportion of patients who present with lower extremity peripheral arterial disease (LE-PAD) are ≥80 years old. While smoking and diabetes mellitus (DM) have traditionally been the main risk factors associated with PAD, we noted a pattern of severe infrapopliteal PAD in patients ≥80 years old in the absence of these traditional risk factors. As recognition of patterns of disease affects decisions regarding diagnostic and therapeutic approach, we sought to confirm this observation.

METHODS

A single-center retrospective review was performed on all patients who underwent lower extremity arteriography between March 2007 and September 2009. Arteriograms were scored in a blinded fashion. Any infrapopliteal PAD was defined as one or more infrapopliteal arteries with either >50% stenosis or total occlusion. Severe infrapopliteal PAD was defined as 2 or more infrapopliteal arteries with >50% stenosis or total occlusion. Fisher's exact test and 2-sample t-test or Wilcoxon rank-sum test were used for analysis.

RESULTS

Two hundred ninety-seven patients comprised the study population. Eighty-two percent (= 145/176) of those ≤70 years old versus 96% (= 46/48) of those ≥80 years old had any infrapopliteal PAD (P = 0.02). Thirty percent of patients ≥80 years old with infrapopliteal PAD had no history of DM or smoking, while only 5% of younger patients had infrapopliteal PAD in the absence of DM or smoking (P < 0.0001). A similar pattern was seen for severe infrapopliteal PAD. Tissue loss was an indication for lower extremity arteriography in 45% of those ≤70 years of age versus 65% of those ≥80 (P = 0.022).

CONCLUSIONS

A significant proportion of patients ≥80 years of age with PAD develop arterial disease in the infrapopliteal pattern in the absence of the traditional risk factors of smoking and DM. Our data also showed that this pattern of disease is significantly associated with tissue loss and critical limb ischemia, particularly in patients ≥80 years of age. Primary care providers need to be educated to suspect ischemic etiology for foot pain and ulcers in elderly patients not otherwise thought to have risk factors associated with PAD. Vascular specialists need to anticipate this pattern of disease when planning interventions. As smoking becomes less prevalent and as the population ages, octogenarians with severe infrapopliteal arterial occlusive disease will become a larger proportion of the patients treated by vascular specialists.

Patterns of disease distribution of lower extremity peripheral arterial disease

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

Disease location is associated with survival in patients with peripheral arterial disease

BACKGROUND

We investigated whether disease location influences survival in patients with peripheral arterial disease.

METHODS AND RESULTS

Patients (n = 12,731; mean age, 67.5 ± 12.7 years; 57.4% male) who underwent outpatient noninvasive lower extremity arterial evaluation were followed up for 5.9 ± 3.1 years for all-cause mortality. Peripheral arterial disease (n = 8930) was defined as a resting or postexercise ankle-brachial index (ABI) ≤ 0.90, and normal ABI (n = 3,801) was defined as a resting and postexercise ABI of 1.00 to 1.30. Presence or absence of disease at the proximal location or distal location was determined on the basis of Doppler signals in leg arteries; 42% had no PD or DD, 45% had proximal (14% postexercise PD only), 30% had distal disease, 17% had both proximal and distal disease, 28% had proximal only and 14% had distal only. We performed multivariable logistic regression to identify factors associated with disease location, and Cox proportional hazard regression to assess the respective effects of proximal or distal disease on survival. Older age, male sex, diabetes, heart failure, and critical limb ischemia were associated with distal disease, whereas female sex, smoking, hypertension, dyslipidemia, coronary heart disease, cerebrovascular disease, chronic obstructive pulmonary disease, and critical limb ischemia were associated with proximal disease. Over a mean follow-up of 5.9 ± 3.1 years, 3039 patients (23.9%) died. After adjustment for potential confounders, the hazard ratios (HRs) of death associated with PD only and DD only were 1.3 (1.3 to 1.4) and 1.5 (1.4 to 1.6), respectively. After additional adjustment for resting ABI, there was no significant association between proximal disease and death, whereas the association of distal disease with death remained significant (HR, 1.2; 95% CI, 1.1 to 1.3).

CONCLUSIONS

In patients with peripheral arterial disease, proximal and distal disease locations were associated with distinctive risk factor and comorbidity profiles. Distal disease was associated with worse survival even after adjustment for risk factors, comorbidities, and resting ABI.

A solution to ankle-brachial index limitations in peripheral transluminal angioplasty

PURPOSE

We evaluated the limitations of the ankle-brachial index (ABI) in the revascularisation of diabetic patients with critical limb ischaemia (CLI) who were undergoing peripheral transluminal angioplasty (PTA) compared with the degree of arterial stenosis and with transcutaneous oxygen tension (TcpO2).

MATERIALS AND METHODS

This prospective study assessed 250 consecutive diabetic patients in whom we evaluated results of posterior tibial and dorsalis pedis Doppler, ABI, TcpO2, and duplex scans. In total, 104 patients were considered suitable candidates for PTA.

RESULTS

In 42% of the patients studied, ABI could either not be used (9.34% due to no signal; 14.02% because the artery could not be compressed) or was incorrect (18.7% before PTA; 15.9% after PTA). In contrast, TcpO2 was determined in all cases. After PTA, vessel stenosis decreased from 58.33±20.07% to 21.87±13.57% (p<0.001), whereas ABI increased from 0.79±0.57 to 0.95±0.47 (p<0.001) and TcpO2 from 27.37±10.40 mmHg to 38.23±10.25 mmHg (p<0.001). A statistical analysis revealed scant correlation between techniques (TcpO2 and ABI) (r=0.14).

CONCLUSIONS

ABI shows significant limitations for the diagnosing and treating CLI patients compared with TcpO2.

Features analysis of lower extremity arterial lesions in 162 diabetes patients

Objective. This study aimed to investigate the angiographic manifestations of lower extremity atherosclerotic steno-occlusive disease in patients with diabetes. Materials and Methods. A total of 162 patients with diabetes were enrolled in this study. The angiographic findings of lower extremity arterial lesions were evaluated according to location (iliac, femoral, popliteal, and crural artery), type (stenosis or occlusion), and length (<5 cm, 5-10 cm, and >5 cm). Results. A total of 131 of 162 (80.9%) diabetics showed multiple segmental lesions, and 19.1% (31/162) presented single segmental lesions in the lower extremity artery. Crural artery was the mainly involved location (39/162, 85.8%). Among the recorded 660 lesions of 162 cases, 437 (66.2%) were occlusion lesions, while 223 (33.8%) were stenosis lesions. Of 437 occlusion lesions, 308 lesions (70.5%) were in crural artery. More than 10 cm occlusion lesion (242/392, 61.7%) was the main manifestation in crural artery, especially in anterior (92/127, 67.2%) and posterior tibial arteries (91/124, 73.4%), which was higher than that in iliac artery (8/33, 24.2%), popliteal artery (53/157, 33.8%), and femoral artery (11/78, 14.1%). Conclusion. In diabetic subjects with lower limb artery ischemia, the vascular involvement is extremely diffuse and particularly severe in crural arteries, with high prevalence of more than 10 cm occlusion lesions.

Revascularization by angioplasty of type D femoropopliteal and long infrapopliteal lesion in diabetic patients with critical limb ischemia: are TASC II recommendations suitable? A population-based cohort study

Feasibility of revascularization of type D femoropopliteal and long infrapopliteal lesions by angioplasty (peripheral translumenal angioplasty [PTA]) in diabetic patients with critical limb ischemia (CLI) according to the TransAtlantic Inter-Society Consensus (TASC) II recommendations was studied. A total of 292 diabetic patients were admitted for CLI; 308 limbs underwent a PTA. Out of 211 femoropopliteal lesions treated with PTA, 44 were TASC II type A, 45 type B, 48 type C, and 76 type D lesions. In 44 of the 76 patients with type D lesions revascularized by PTA, no artery was patent down to the foot before the PTA. In 172 limbs with all infrapopliteal arteries occluded, revascularization was carried out down to the foot in 167 limbs. Follow-up was 3.1 ± 0.3 years. A first episode of restenosis occurred in 66/308 limbs with an incidence/year of 7.9. PTA procedures were successfully repeated in 57/66 restenosis episodes: secondary patency was 97.1%. The incidence/year of type D femoropopliteal lesions was 5.4, the incidence/year in others was 5.0, without statistically significant differences: P = .417. The only variable found significantly associated with restenosis occurrence on logistic analysis was the presence of lesions in both femoropopliteal and infrapopliteal axes. A total of 26/308 above-the-ankle amputations were performed, with an incidence/year of 2.5. Multivariate analysis showed the independent role of only crural artery occlusion after PTA. These data show that the choice to refer to angioplasty diabetic patients with type D and/or long infrapopliteal lesions without good run-off at the foot and/or high surgical risk allowed high revascularization feasibility, with an optimal amputation outcome.

Limb revascularization feasibility in diabetic patients with critical limb ischemia: results from a cohort of 344 consecutive unselected diabetic patients evaluated in 2009

AIMS

To evaluate the feasibility of peripheral revascularization by angioplasty (PTA) or bypass grafting (BPG) in diabetic patients with critical limb ischemia (CLI).

METHODS

All diabetic patients referred to our Diabetic Foot Centre for foot lesion or rest pain were assessed for the presence of CLI as assessed by the TASC criteria. All patients underwent angiography that was evaluated jointly by an interventional radiologist, a vascular surgeon and a diabetologist of the diabetic foot care team.

RESULTS

During 2009, 344 diabetics were admitted because of CLI in a total of 360 limbs. PTA was performed in 308 (85.6%) limbs, and BPG was performed in 40 (11.1%) limbs in which PTA was not feasible. Revascularization could not be carried out in 12 (3.3%) limbs due to the lack of target vessel (9 limbs) or high surgical risk (3 limbs). According to the judgement of the vascular surgeon, BPG was anatomically feasible in 180 (58.4%) of the 308 limbs that underwent PTA. Therefore, considering also the 40 limbs that underwent BPG, surgical revascularization was judged anatomically possible in a total of 220 (61.1%) limbs. At 30 days, 19 (5.3%) above-the-ankle amputations were performed: 8 (66.7%) amputations were performed in the 12 non-revascularized limbs, 8 (2.6%) amputations were performed in the 308 limbs treated with PTA and 3 (7.5%) amputations were performed in the 40 limbs treated with BPG.

CONCLUSIONS

Revascularization by PTA is highly feasible in diabetics with CLI. The feasibility of revascularization by BPG is lower but nonetheless consistent. In centres where both revascularization procedures are available, it is possible to revascularize more than 96% of diabetics with CLI.

Progression of asymptomatic peripheral artery disease over 1 year

The pathophysiology and time course of an individual converting from asymptomatic peripheral artery disease (PAD) to symptomatic claudication is unclear. The objectives of this study were: (1) to characterize the extent of atherosclerotic disease in individuals with an abnormal ankle–brachial index (ABI), but without claudication; and over 1 year of follow-up to (2) evaluate the progression of PAD using ultrasound imaging, (3) determine changes in the ABI and leg pain symptoms, and (4) correlate PAD progression with changes in the ABI and leg symptoms. We hypothesized that PAD progression would be associated with the development of claudication and changes in the ABI, 6-minute walk distance (6-MWD), and walking quality of life. Individuals with a reduced ABI but without typical intermittent claudication noted on community screening were invited to undergo baseline and 1-year follow-up assessment, including duplex ultrasound. The initial and repeat evaluations included measurement of the ABI, lower extremity duplex arterial mapping, and assessment of leg pain and functional status. Of the 50 people studied, 44 (88%) had significant atherosclerotic lesions in the lower extremity arteries, affecting 80 legs. A total of 33 of 50 individuals (66%) returned for the 1-year follow-up visit. On ultrasound examination, two of 18 normal legs developed PAD, and in 48 legs with PAD at baseline, 17 legs (35%) developed new or progressive lesions. Thirteen legs developed new claudication. Overall, there was no significant worsening in the ABI, 6-MWD, or the Walking Impairment Questionnaire (WIQ). However, legs with new lesions or lesion progression were significantly more likely to develop claudication, and the 13 legs (seven subjects) developing claudication showed a significant decline in the 6-MWD. In conclusion, these data indicate that a significant number of people with asymptomatic PAD show progression over 1 year, that such individuals are more likely to develop claudication, and that those developing claudication have a significant decrease in their 6-MWD.

What the radiologist needs to know about the diabetic patient

Diabetes mellitus (DM) is recognised as a major health problem. Ninety-nine percent of diabetics suffer from type 2 DM and 10% from type 1 and other types of DM. The number of diabetic patients worldwide is expected to reach 380 millions over the next 15 years. The duration of diabetes is an important factor in the pathogenesis of complications, but other factors frequently coexisting with type 2 DM, such as hypertension, obesity and dyslipidaemia, also contribute to the development of diabetic angiopathy. Microvascular complications include retinopathy, nephropathy and neuropathy. Macroangiopathy mainly affects coronary arteries, carotid arteries and arteries of the lower extremities. Eighty percent of deaths in the diabetic population result from cardiovascular incidents. DM is considered an equivalent of coronary heart disease (CHD). Stroke and peripheral artery disease (PAD) are other main manifestations of diabetic macroangiopathy. Diabetic cardiomyopathy (DC) represents another chronic complication that occurs independently of CHD and hypertension. The greater susceptibility of diabetic patients to infections completes the spectrum of the main consequences of DM. The serious complications of DM make it essential for physicians to be aware of the screening guidelines, allowing for earlier patient diagnosis and treatment.

Variations in the anatomical distribution of peripheral vascular disease according to gender

BACKGROUND

While large epidemiological studies have suggested that the male gender is more frequently afflicted with intermittent claudication, there is little data whether there are gender differences in the distribution of peripheral vascular disease (PVD). The aim of this study was to clarify this issue on the basis of angiographic findings in patients presenting with claudication.

PATIENTS AND METHODS

The radiology department computerised database was used to identify all lower limb angiograms performed for investigation of PVD. Patients undergoing incomplete assessment and those with normal angiograms were excluded. Demographic details for each patient were collected together with details of uni- or bilaterality of disease, the number of lesions present and their anatomical distribution according to the major named vessels. Only lesions reported as radiologically significant were included in the analysis.

RESULTS

Five hundred consecutive angiograms fitting the defined study criteria were assessed. There were 310 males and 190 females giving a male to female ratio of 1.6:1. The most common distribution for both genders was multiple bilateral lesions. There were no significant differences in the number of stenoses in terms of ratio of bilateral to unilateral (2.39 vs 2.77) or ratio of multiple to single lesions (1.5 vs 1.7) between the female and male groups. Disease was more common in males at all anatomical locations, the most significant differences being for lesions of the common femoral and profunda femoris arteries.

CONCLUSIONS

PVD is more commonly diagnosed in males than females. The disease process is more commonly bilateral in both genders and PVD affects more numerous sites in the male claudicant than in the female claudicant. Nevertheless, there does not appear to be any difference in the anatomical distribution of disease between genders.

One-year outcome after percutaneous rotational and aspiration atherectomy in infrainguinal arteries in patient with and without type 2 diabetes mellitus

BACKGROUND

To compare the safety and efficacy of a rotational aspiration atherectomy system (Jetstream) for the treatment of infrainguinal arteries in diabetic versus nondiabetic patients.

METHODS

A total of 172 patients with Rutherford stage 1-5 lower limb ischemia were treated with rotational aspiration atherectomy between February 2006 and February 2007. Of these, 80 patients with type 2 diabetes mellitus (DM: 46.5%) were compared with 92 nonDM (53.5%) patients. Overall, 210 target lesions (99 DM; 111 nonDM) were treated, located in the superficial femoral (67% DM; 61% nonDM), popliteal (25% DM; 30% nonDM), and tibial (8% DM; 9% nonDM) arteries. Lesion characteristics were comparable in both groups, mean lesion length was 28.5 mm (DM) and 26.2 mm (nonDM); total occlusions were present in 29% (DM) and 32% (nonDM), and 15% (DM) and 14% (nonDM) were restenotic.

RESULTS

In the entire cohort, device success was 99% (all but two lesions). The major adverse event (MAE) rate (death, index limb amputation, myocardial infarction, target lesion revascularization [TLR] and target vessel revascularization) in DM at 30 days was 2.5% (n = 2 planned amputations) and 0% in nonDM. At 6 and 12 months, MAE in DM was seen in 13.8% (11/80) and 25% (20/80) compared with 21.7% (20/92) and 31.5% (29/92) in nonDM, respectively. TLR rate through 12 months was 20% (16/80) in DM and 28% in nonDM (26/92). Overall, 1 year restenosis rate was 38.2% based on duplex. The ankle-brachial index, mean Rutherford categories, and walking impairment questionnaire did not differ between groups at baseline and were increased significantly in both study cohorts at 12 months.

CONCLUSION

Jetstream-assisted atherectomy in infrainguinal arteries is safe and effective in DM compared with nonDM patients. In this short-lesion cohort, vessel patency in diabetics was as good as for non-DM at 1 year. TLR and MAE were higher by trend in nonDM, although planned amputations were seen only in DM. The clinical benefit was similar in both groups.

Influence of obesity and metabolic dysfunction on the endothelial control in the coronary circulation

Diseases of the coronary circulation remain the leading cause of death in Western society despite impressive advances in diagnosis, pharmacotherapy and post-event management. Part of this statistic likely stems from a parallel increase in the prevalence of obesity and metabolic dysfunction, both significant risk factors for coronary disease. Obesity and diabetes pose unique challenges for the heart and their impact on the coronary vasculature remains incompletely understood. The vascular endothelium is a major interface between arterial function and the physical and chemical components of blood flow. Proper function of the endothelium is necessary to preserve hemostasis, maintain vascular tone and limit the extent of vascular diseases such as atherosclerosis. Given its central role in vascular health, endothelial dysfunction has been the source of considerable research interest in diabetes and obesity. In the current review, we will examine the pathologic impact of obesity and diabetes on coronary function and the extent to which these two factors impact endothelial function. This article is part of a Special Issue entitled "Coronary Blood Flow".

Characteristics of peripheral arterial disease and its relevance to the diabetic population

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

An angiographic analysis of atherosclerosis progression in below-the-knee arteries after femoropopliteal angioplasty in claudicants

PURPOSE

To report an angiographic investigation of midterm atherosclerotic disease progression in below-the-knee (BTK) arteries of claudicants.

METHODS

Angiograms were performed in 58 consecutive claudicants (35 men; mean age 68.3+/-8.7 years) with endovascular treatment of femoropopliteal arteries in 58 limbs after a mean follow-up of 3.6+/-1.2 years. Angiograms were reviewed in consensus by 2 experienced readers blinded to clinical data. Progression of atherosclerosis in 4 BTK arterial segments (tibioperoneal trunk, anterior and posterior tibial arteries, and peroneal artery) was assessed according to the Bollinger score. The composite per calf Bollinger score represented the average of the 4 BTK arterial segment scores. The association of the Bollinger score with cardiovascular risk factors and gender was scrutinized.

RESULTS

A statistically significant increase in atherosclerotic burden was observed for the mean composite per calf Bollinger score (5.7+/-8.3 increase, 95% CI 3.5 to 7.9, p<0.0001), as well as for each single arterial segment analyzed. In multivariate linear regression analysis, diabetes mellitus was associated with a more pronounced progression of atherosclerotic burden in crural arteries (beta: 5.6, p = 0.035, 95% CI 0.398 to 10.806).

CONCLUSION

Progression of infrapopliteal atherosclerotic lesions is common in claudicants during midterm follow-up. Presence of diabetes mellitus was confirmed as a major risk factor for more pronounced atherosclerotic BTK disease progression.

Evaluation of Feasibility of Ankle Pressure and Foot Oxymetry Values for the Detection of Critical Limb Ischemia in Diabetic Patients

A total of 261 diabetic patients were admitted because of rest pain and/or foot ulcer in 1 limb. Ankle pressure (AP) and transcutaneous oxygen tension (TcPO2) were measured, and digital subtraction arteriography was performed. Transcutaneous oxygen tension was <30 mm Hg in 213 patients and ≥30<50 mm Hg in 48 patients. Ankle pressure could not be measured in 109 patients. In 50 patients, AP was <70 mm Hg and in 102 patients, it was ≥70 mm Hg. Arteriography showed evidence of stenoses >50% of vessel lumen diameter in all patients. Major amputation was performed in 16 patients; AP was <70 mm Hg in 4 patients and ≥70 mm Hg in 6. It was not practicable in the remaining 6 patients. Transcutaneous oxygen tension was <30 mm Hg in 15 patients and ≥30 mm Hg in 1 patient. For diagnosis of critical limb ischemia (CLI) in diabetic patients presenting with rest pain or foot ulcer, measurement of TcPO 2 is essential not only when AP is not measurable but also when this value is ≥70 mm Hg.

Application of serial analysis of gene expression to the study of human genetic disease

Sequence tag analysis using serial analysis of gene expression (SAGE) is a powerful strategy for the quantitative analysis of gene expression in human genetic disorders. SAGE facilitates the measurement of mRNA transcripts and generates a non-biased gene expression profile of normal and pathological disease tissue. In addition, the SAGE technique has the capacity of detecting the expression of novel transcripts allowing for the identification of previously uncharacterised genes, thus providing a unique advantage over the traditional microarray-based approach for expression profiling. The technique has been successful in providing pathological gene expression profiles in a number of common genetic disorders including diabetes, cardiovascular disease, Parkinson disease and Down syndrome. When combined with next generation sequencing platforms, SAGE has the potential to become a more powerful and sensitive technique making it more amenable for diagnostic use. This review will therefore discuss the application of SAGE to several common genetic disorders and will further evaluate its potential use in diagnosing human genetic disease.

[The vascular surgeon's role in interdisciplinary treatment of diabetic foot syndrome]

There are more than 6 million diabetes patients in Germany. Due to long-term neuropathic and angiopathic sequelae, the number of patients with "diabetic foot syndrome" has increased dramatically in recent years. Diabetic foot ulcers have become one of the most common pathologies in interdisciplinary wound care centers. Because of its complex pathogenesis, diabetic foot syndrome needs a multidisciplinary therapeutic approach. More than 150,000 diabetics per year develop foot ulcers that often heal slowly and progress into chronic wounds. Despite all efforts at prevention, early diagnosis, and adequate therapy, more than 20,000 diabetics suffer major limb amputation in Germany every year. Applying stringent standards of care in interdisciplinary wound care centers, the amputation rate in patients with diabetic foot syndrome can be reduced to less than 50%. This article describes the complexity of diabetic foot syndrome with respect to pathogenesis, diagnostics, and therapy from a vascular surgeon's point of view. The importance of an interdisciplinary approach is emphasized.

Patterns of artery disease in 450 patients undergoing revascularization for critical limb ischemia: implications for clinical trial design

OBJECTIVE

The pattern and distribution of arterial occlusions and stenoses in patients with critical limb ischemia presenting at two academic medical centers was described.

METHODS

From January 1998 to December 2006, 450 consecutive critical limb ischemia patients who underwent arteriography and infrainguinal revascularization at the University of Colorado Health Sciences Center or Southern Illinois University were retrospectively evaluated. Demographics, clinical morbidities, and Fontaine stage were recorded. The arterial tree was categorized into three groups: the aorta and iliac arteries (A-I); the common femoral, superficial femoral, and profunda femoral arteries (Fem); and the popliteal and tibial arteries (Pop-Tib). Arterial segments within groups were categorized as subcritical stenoses (patent or <50% stenoses), critical stenoses (single or multiple >50% stenoses), or occluded (segmental occlusions of any length). Patients with diabetes mellitus, end-stage renal disease, and Fontaine stage (III vs IV) were analyzed for differing disease patterns according to their chart history.

RESULTS

Occlusive disease was present in 5% in all arterial segments (A-I + Fem + Pop-Tib), in 1% in the A-I + Fem group, in 2% in the A-I + Pop-Tib group, in 3% in A-I group, in 4% in the Fem group, in 30% in the Fem + Pop-Tib group, and in 55% in the Pop-Tib group. Descriptive comparisons among subgroups demonstrated a 61% to 69% prevalence of popliteal and tibial occlusive patterns in patients with diabetes mellitus, end-stage renal disease, and Fontaine stage IV. Furthermore, 65% of patients with Pop-Tib occlusions had associated critical stenoses in the proximal arterial groups.

CONCLUSION

More than half of critical limb ischemia patients undergoing infrainguinal revascularization have arterial occlusions in the popliteal or tibial arterial segments, or both, with associated critical stenoses in the femoral arterial segments, which is even greater in the subgroups with diabetes mellitus, end-stage renal disease, and Fontaine stage IV. Knowledge of such occlusive patterns is important for the development of novel infrainguinal endovascular and angiogenesis therapies for critical limb ischemia.

Large and Small Vessels Atherosclerosis: Similarities and Differences

Atherosclerosis is a systemic, multifocal disease leading to a various symptoms and clinical events. Beyond disparities related to the organs involved, some differences might exist according to whether the lesions occur in the large (proximal) or small (distal) arteries. Atherosclerotic lesions occur predominantly in the large vessels first, and more distal lesions occur with aging. Proximal lesions are usually more evolving, especially with higher rates of unstable plaques in the proximal segments of coronary arteries. Racial differences regarding lesion distribution exist, with higher rates of distal lesions observed in races other than caucaians. Despite conflicting results found in each vascular territory, there is a suggestion of a stronger association between large vessel disease and smoking and dyslipidemia, whereas diabetes appears more specific for small vessel disease. Hypertension is more frequently reported in intracranial than in extracranial cerebrovascular disease. Preliminary studies report inflammatory markers preferably associated to large-vessel atherosclerosis. Proximal lesions in 1 territory are more frequently associated with concomitant lesions in other territories. Geometric, hemodynamic, and histologic particularities in large and small vessels may at least partially explain these differences, and some recent data point out different biologic properties of the endothelium according to its location.

Predictive Values of Transcutaneous Oxygen Tension for Above-the-ankle Amputation in Diabetic Patients with Critical Limb Ischemia

OBJECTIVE

To assess the values of transcutaneous oxygen tension (TcPO2) capable of predicting above-the-ankle amputation in diabetic patients diagnosed for critical limb ischemia (CLI) according to the criteria of the TransAtlantic Inter-Society Consensus.

DESIGN

Retrospective study.

METHODS

From January 1999 to December 2003, 564 diabetic patients were consecutively hospitalized for CLI in one limb. Revascularization with angioplasty or bypass graft was performed when possible and, if not possible, prostanoid therapy was used. In patients in whom therapies did not relieve the rest pain or the gangrene was extended above the Chopart joint, an above-the-ankle-amputation was performed. After treatment TcPO2 values were evaluated in all patients at the dorsum of the foot.

RESULTS

Fifty-five (9.8%) patients underwent an above-the-ankle amputation: 22 of 420 patients who underwent angioplasty, 17 of 117 patients who underwent bypass (14.5%) and 16 of 27 patients in whom revascularization was not possible. Post-treatment TcPO2, measured by a receiver operating characteristic (ROC) curve, showed a value 34 mmHg as the best threshold for determining the need for revascularization, with an area under the curve of 0.89 (95%CI 0.85-0.94). Using logistic regression analysis the probability of above-the-ankle amputation for this threshold is 9.7% and reduces to 3% for TcPO2 > 40 mmHg.

CONCLUSION

TcPO2 levels<34 mmHg indicate the need for revascularization, while for values >or= 34 < 40 mmHg this need appears less pressing, although there remains a considerable probability of amputation. TcPO2 levels greater than 40 mmHg suggest that revascularization is dependent on the severity of tissue loss and possible morbidity caused by the procedure.

Effect of type 2 diabetes mellitus on exercise intolerance and the physiological responses to exercise in peripheral arterial disease

AIMS/HYPOTHESIS

There are conflicting data about the effect of type 2 diabetes mellitus on exercise tolerance in peripheral arterial disease. To elucidate this problem, we compared the tolerance and physiological responses to treadmill and cycle exercise in 31 patients with peripheral arterial disease and intermittent claudication.

MATERIALS AND METHODS

One group of these patients had type 2 diabetes (n = 12) and its members were matched for sex and age with a group of patients who did not have diabetes (n = 12). Since BMI and body weight were greater in the diabetic group (28.4 +/- 3.7 vs 25.2 +/- 2.4 kg/m(2); 84.0 +/- 14.6 vs 73.8 +/- 8.0 kg), we also studied a third, 'heavy' group of non-diabetic patients with claudication of similar age (n = 7; BMI = 30.9 +/- 5.3 kg/m(2); body weight = 85.2 +/- 8.2 kg).

RESULTS

Compared with the 'light' non-diabetic group, maximum treadmill times were shorter for the diabetic and heavy non-diabetic groups (1,448 vs 845 and 915 s; ANOVA p = 0.01); maximum cycle time also tended to be shorter (ANOVA, p = 0.08) in the diabetic and heavy non-diabetic groups (median = 1,231 vs 730 and 797 s). The majority of physiological responses assessed were not different between the groups, although the time constant of oxygen uptake during submaximal treadmill and cycle exercise was significantly larger (ANOVA p < 0.05) for the diabetic group.

CONCLUSIONS/INTERPRETATION

These data demonstrate that exercise tolerance is lower in diabetic than non-diabetic patients with claudication, but that this difference is due to obesity rather than diabetes itself.