Peripheral arterial disease in diabetic and nondiabetic patients: a comparison of severity and outcome

Epidemiology in diabetes mellitus and cardiovascular disease

As one of the leading causes of death in the USA, diabetes mellitus (DM) has become an epidemic over the past few decades. Despite the high prevalence of diagnosed DM, close to half of all people with DM are unaware of their disease. The risk of type 2 DM is determined by interplay of genetic and metabolic factors. Patients with type 2 DM have a higher risk of death from cardiovascular causes compared with their nondiabetic counterparts, and the mortality rate of DM associated cardiovascular disease is different among ethnicity groups and sex groups. Because of its adverse effect on people's health, DM also imposes an economic burden on individuals and households affected, as well as on the healthcare system. Current guidelines for cardiovascular disease prevention have focused on lifestyle management, blood pressure control, lipid control, blood glucose control, antiplatelet agent use, and tobacco use cessation.

Non-invasive lower limb small arterial measures co-segregate strongly with foot complications in people with diabetes

AIMS

It is unclear how well non-invasive lower-limb vascular assessments can identify those at risk of foot complications in people with diabetes. We aimed to investigate the relationship between a history of foot complication (ulceration or amputation) and non-invasive vascular assessments in people with diabetes.

METHODS

Bilateral ankle-brachial index (ABI), toe brachial index (TBI) and continuous wave Doppler (CWD) were performed in 127 adults with diabetes (97% type 2; age 66.08±11.4years; 55% men; diabetes duration 8.8±7.6years; 28% on insulin therapy; 31% with foot complication history. Correlations were performed between known risk factors for, and documented history of, foot complication. Regression analysis was used to determine the effect of TBI on the likelihood of a prior foot complication.

RESULTS

By logistic regression, the likelihood of foot complication history was highest in those with TBI <0.6 (OR=7.74, p=0.001); then longer diabetes duration (OR=1.06, p=0.05). HbA1c did not independently predict history of foot complications (OR=1.10, p=0.356).

CONCLUSIONS

Likelihood of previous foot complication in this population was ~8 times higher when TBI was <0.6. Such clinical risk profiling was not shown by other non-invasive measures. Prioritizing TBI as a measure of lower-limb vascular disease may be useful to prospectively identify those at risk of diabetic foot complications.

Cross-sectional correlations between the toe brachial index and lower limb complications in older people

The aim of the study was to investigate the relationship between the toe brachial index (TBI) and foot ulceration and amputation in older people. Two hundred and sixty-one participants meeting guidelines for lower limb vascular assessment had their toe and brachial blood pressure measured, medical records audited and signs and symptoms of peripheral arterial disease (PAD) recorded. Pearson's correlation and linear regression analyses were performed to determine the strength of relationships between variables. Significant correlations were found between the TBI and painful symptoms (r = -0·35, P < 0·05) and foot complications (r = -0·31, P < 0·05). After adjusting for traditional risk factors for foot complications, participants with a TBI <0·70 were 19 times more likely to have a history of foot wounds or amputation (odds ratio = 19·20, 95% confidence interval (CI): 2·36-155·96, P < 0·001) than those with higher TBI values (>0·70). This preliminary study supports a TBI threshold of 0·70 for PAD diagnosis and indicates that lower values are associated with painful symptoms, history of ulceration and amputation. Future longitudinal investigation of the predictive capacity is now warranted.

Pathophysiology of peripheral arterial disease in diabetes mellitus

Peripheral arterial disease (PAD) increases the risk of lower extremity amputation. It is also an independent predictor of cardiovascular and cerebrovascular ischemic events, affecting both the quality and expectancy of life. Many studies have demonstrated that the prevalence of PAD in patients with diabetes mellitus (DM) is higher than in non-diabetic patients. In diabetic patients, PAD occurs early with rapid progression, and is frequently asymptomatic. Multiple metabolic aberrations in DM, such as advanced glycation end-products, low-density lipoprotein cholesterol, and abnormal oxidative stress, have been shown to worsen PAD. However, the role of DM in PAD is not completely understood. The purpose of the present article is to review and discuss the pathophysiology of PAD in DM.

Endovascular Versus Open Revascularization for Peripheral Arterial Disease

OBJECTIVE

The aim of this study was to determine whether endovascular or open revascularization provides an advantageous approach to symptomatic peripheral arterial disease (PAD) over the longer term.

SUMMARY OF BACKGROUND DATA

The optimal revascularization strategy for symptomatic lower extremity PAD is not established.

METHODS

We evaluated amputation-free survival, overall survival, and relative rate of subsequent vascular intervention after endovascular or open lower extremity revascularization for propensity-score matched cohorts of Medicare beneficiaries with PAD from 2006 through 2009.

RESULTS

Among 14,685 eligible patients, 5928 endovascular and 5928 open revascularization patients were included in matched analysis. Patients undergoing endovascular repair had improved amputation-free survival compared with open repair at 30 days (7.4 vs 8.9%, P = 0.002). This benefit persisted over the long term: At 4 years, 49% of endovascular patients had died or received major amputation compared with 54% of open patients (P < 0.001). An endovascular procedure was associated with a risk-adjusted 16% decreased risk of amputation or death compared with open over the study period (hazard ratio: 0.84; 95% confidence interval, 0.79-0.89; P < 0.001). The amputation-free survival benefit associated with an endovascular revascularization was more pronounced in patients with congestive heart failure or ischemic heart disease than in those without (P = 0.021 for interaction term). The rate of subsequent intervention at 30 days was 7.4% greater for the endovascular vs the open revascularization cohort. At 4 years, this difference remained stable at 8.6%.

CONCLUSIONS

Using population-based data, we demonstrate that an endovascular approach is associated with improved amputation-free survival over the long term with only a modest relative increased risk of subsequent intervention.

The impact of gender, level of amputation and diabetes on prosthetic fit rates following major lower extremity amputation

BACKGROUND

Diabetes mellitus is a leading cause of major lower extremity amputation.

OBJECTIVE

To examine the influence of gender, level of amputation and diabetes mellitus status on being fit with a prosthetic limb following lower extremity amputation for peripheral arterial disease.

STUDY DESIGN

Retrospective analysis of the Scottish Physiotherapy Amputee Research Group dataset.

RESULTS

Within the cohort with peripheral arterial disease ( n = 1735), 64% were men ( n = 1112) and 48% ( n = 834) had diabetes mellitus. Those with diabetes mellitus were younger than those without: mean 67.5 and 71.1 years, respectively ( p < 0.001). Trans-tibial amputation:trans-femoral amputation ratio was 2.33 in those with diabetes mellitus, and 0.93 in those without. A total of 41% of those with diabetes mellitus were successfully fit with a prosthetic limb compared to 38% of those without diabetes mellitus. Male gender positively predicted fitting with a prosthetic limb at both trans-tibial amputation ( p = 0.001) and trans-femoral amputation ( p = 0.001) levels. Bilateral amputations and increasing age were negative predictors of fitting with a prosthetic limb ( p < 0.001). Diabetes mellitus negatively predicted fitting with a prosthetic limb at trans-femoral amputation level ( p < 0.001). Mortality was 17% for the cohort, 22% when the amputation was at trans-femoral amputation level.

CONCLUSION

Of those with lower extremity amputation as a result of peripheral arterial disease, those with diabetes mellitus were younger, and more had trans-tibial amputation. Although both age and amputation level are good predictors of fitting with a prosthetic limb, successful limb fit rates were no better than those without diabetes mellitus. Clinical relevance This is of clinical relevance to those who are involved in the decision-making process of prosthetic fitting following major amputation for dysvascular and diabetes aetiologies.

Angiopoietin-related growth factor is independently associated with lower extremity peripheral arterial disease

AIMS

The present study investigated the association of serum levels of angiopoietin-related growth factor (AGF) with lower extremity peripheral arterial disease (LEPAD).

METHODS

The study group is comprised of 105 patients with lower extremity peripheral arterial disease. The control group consisted of 80 individuals without lower extremity peripheral arterial disease. Serum AGF concentrations were determined by enzyme-linked immunosorbent assay. The relationship between AGF and clinical and biochemical parameters was studied. Besides, this study analyzed AGF levels in LEPAD patients according to disease severity and evaluated the prognostic value of AGF for amputation and mortality in LEPAD patients after a follow-up period of 1.7years.

RESULTS

Median serum AGF levels were significantly higher in LEPAD group (103.70±64.69ng/mL) as compared with control group (53.83±37.87ng/mL) (P<0.001). In addition, T2DM patients with LEPAD exhibited markedly higher serum AGF concentrations (118.7±60.90ng/mL) than those without LEPAD (60.23±32.62ng/mL) (P<0.0001). Moreover, LEPAD positively predicted AGF concentrations in multivariate linear regression analysis (P<0.0001). Serum AGF levels were independently associated with LEPAD in binary logistic regression analysis model. Among LEPAD patients, those with critical limb ischemia (n=43) showed higher AGF levels (124.9±73.9 vs. 88.98±53.26ng/mL, P=0.01) compared with those with intermittent claudication (n=62). Furthermore, patients with the highest AGF tertile had an increased all-cause mortality and cardiovascular mortality (P=0.033 and P=0.025, respectively).

CONCLUSIONS

Our results suggested that lower extremity peripheral artery disease was positively associated with AGF serum levels. High serum AGF level was a potential risk factor for LEPAD and associates with disease severity and poor outcome in LEPAD patients.

Comparison of the severity of lower extremity arterial disease in smokers and patients with diabetes using a novel duplex Doppler scoring system

Purpose

The aim of this study was to validate the diagnostic feasibility of a novel scoring system of peripheral arterial disease (PAD) in smokers and patients with diabetes depending on duplex Doppler sonographic features.

Methods

Patients presenting with the symptomatology of PAD were divided into three groups: diabetes only, smoking only, and smokers with diabetes. The patients were clinically examined, a clinical severity score was obtained, and the subjects were categorized into the three extrapolated categories of mild, moderate, and severe. All 106 subjects also underwent a thorough duplex Doppler examination, and various aspects of PAD were assessed and tabulated. These components were used to create a novel duplex Doppler scoring system. Depending on the scores obtained, each individual was categorized as having mild, moderate, or severe illness. The Cohen kappa value was used to assess interobserver agreement between the two scoring systems.

Results

Interobserver agreement between the traditional Rutherford clinical scoring system and the newly invented duplex Doppler scoring system showed a kappa value of 0.83, indicating significant agreement between the two scoring systems (P<0.001).

Conclusion

Duplex Doppler imaging is an effective screening investigation for lower extremity arterial disease, as it not only helps in its diagnosis, but also in the staging and grading of the disease, providing information that can be utilized for future management and treatment planning.

[The diabetic foot]

These are the guidelines for preventive care, diagnosis and treatment of the diabetic foot syndrome. Diabetic periphery neuropathy, peripheral vascular disease, bone deformity and altered biomechanics are foot-related risk conditions. The position statement is focused on screening methods and recommendations for clinical care for diabetics, who currently have no foot ulcers. A decision pathway is offered with respect to diagnosis and management of diabetic patients at an increased risk or manifest injuries.

Impact of diabetes on mortality in peripheral artery disease: a meta-analysis

BACKGROUND

There are accumulating studies showing the association between diabetes and all-cause mortality in peripheral vascular disease. However, the results in these studies are conflicting regarding the impact of diabetes on outcome.

HYPOTHESIS

Diabetes is associated with increased risk of mortality in peripheral artery disease.

METHODS

Using MEDLINE and Scopus, we searched for studies published before January 2016. Additionally, studies were identified by manual search of references of original articles or review studies on this topic. Of the 1072 initially identified records, 21 studies with 15,857 patients were included in the final analysis.

RESULTS

Diabetes was associated with a statistically significant increased risk of all-cause mortality (odds ratio: 1.89, 95% confidence interval: 1.51-2.35, P < 0.001), without detected publication bias (Egger bias = 0.75, P = 0.631). The stronger effect on outcome was obtained in patients with critical limb ischemia (odds ratio: 2.38, 95% confidence interval: 1.22-4.63, P < 0.001) as the most severe form of peripheral vascular disease.

CONCLUSIONS

Diabetes is associated with an increased risk of mortality in peripheral vascular disease, and the effect is even more pronounced in patients with critical limb ischemia.

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.

Below-knee endovascular interventions have better outcomes compared to open bypass for patients with critical limb ischemia

Both open surgery and endovascular peripheral interventions have been shown to effectively improve outcomes in patients with peripheral artery disease, but minimal data exist comparing outcomes performed at and below the knee. The purpose of this study was to compare outcomes following infrageniculate lower extremity open bypass (LEB) versus peripheral vascular intervention (PVI) in patients with critical limb ischemia. Using data from the 2008-2014 Vascular Quality Initiative, 1-year primary patency, major amputation, and mortality were compared among all patients undergoing LEB versus PVI at or below the knee for rest pain or tissue loss. Overall, 2566 patients were included (LEB=500, PVI=2066). One-year primary patency was significantly worse following LEB (73% vs 81%; p<0.001). One-year major amputation (14% vs 12%; p=0.18) and mortality (4% vs 6%; p=0.15) were similar regardless of revascularization approach. Multivariable analysis adjusting for baseline differences between groups confirmed inferior primary patency following LEB versus PVI (HR 0.74; 95% CI, 0.60-0.90; p=0.004), but no significant differences in 1-year major amputation (HR 1.06; 95% CI, 0.80-1.40; p=0.67) or mortality (HR 0.71; 95% CI, 0.44-1.14; p=0.16). Based on these data, we conclude that endovascular revascularization is a viable treatment approach for critical limb ischemia resulting from infrageniculate arterial occlusive disease.

Effect of diabetes mellitus on walking distance parameters after supervised exercise therapy for intermittent claudication: A systematic review

Some believe that certain patients with intermittent claudication may be unsuitable for supervised exercise therapy (SET), based on the presence of comorbidities and the possibly increased risks. We conducted a systematic review (MEDLINE, EMBASE and CENTRAL) to summarize evidence on the potential influence of diabetes mellitus (DM) on the response to SET. Randomized and nonrandomized studies that investigated the effect of DM on walking distance after SET in patients with IC were included. Considered outcome measures were maximal, pain-free and functional walking distance (MWD, PFWD and FWD). Three articles met the inclusion criteria ( n = 845). In one study, MWD was 111 meters (128%) longer in the non-DM group compared to the DM group after 3 months of follow-up ( p = 0.056). In a second study, the non-DM group demonstrated a significant increase in PFWD (114 meters, p ⩽ 0.05) after 3 months of follow-up, whereas there was no statistically significant increase for the DM group (54 meters). On the contrary, the largest study of this review did not demonstrate any adverse effect of DM on MWD and FWD after SET. In conclusion, the data evaluating the effects of DM on SET were inadequate to determine if DM impairs the exercise response. While trends in the data do not suggest an impairment, they are not conclusive. Practitioners should consider this limitation when making clinical decisions.

Factors associated with lower extremity atherosclerotic disease in Chinese patients with type 2 diabetes mellitus: A case-control study

Early detection and treatment of lower extremity atherosclerotic disease (LEAD), and controlling its risk factors are critical in preventing amputation and death in diabetic patients. This study aimed to investigate the factors associated with LEAD in Chinese diabetic patients.In this case-control study, patients with type 2 diabetes mellitus (T2DM) (N = 1289) were divided into 2 groups according to the ultrasonic Doppler examination: with (LEAD+, n = 737) and without (LEAD-, n = 552) LEAD. In subgroup analysis, the LEAD+ group was divided based on the diameter of lower-extremity arteries: LEAD+A (1%-49% reduction) and LEAD+B (≥50% reduction). Clinical and demographic data of patients were analyzed.Compared with the LEAD- group, serum creatinine levels were significantly increased (P < 0.001), whereas glomerular filtration rate (GFR) was significantly decreased (P < 0.001) in the LEAD+ group. Multivariate analysis results showed that GFR (odds ratio [OR] 0.991, 95% confidence interval [CI] 0.986-0.997, P = 0.003), diabetes duration (OR 1.055, 95% CI 1.026-1.084, P < 0.001), age (OR 1.123, 95% CI 1.104-1.142, P < 0.001), and uric acid (OR 1.002, 95% CI 1.000-1.004, P = 0.031) were independently associated with LEAD in patients with T2DM. Furthermore, multivariate analysis showed that age (OR 1.078, 95% CI 1.048-1.109, P < 0.001) and GFR (OR 0.985, 95% CI 0.975-0.994, P = 0.002) were independently associated with the severity of arterial lesions in patients with T2DM and LEAD.The risk factors of LEAD in Chinese patients with T2DM include age, course of disease, uric acid, and GFR. Patients with T2DM, high uric acid levels, and declined GFR could be listed in the high-risk group for LEAD.

Wound Closure in Smoking Peripheral Arterial Disease Patients With Treatment-Refractory Ulcerations: A 12-Month Follow-up Case Series

Despite ongoing smoking cessation efforts and optimized perfusion, failed wound closure in the presence of peripheral arterial disease (PAD) and diabetes are common. A clinical effectiveness review was conducted in actively smoking diabetic patients diagnosed with PAD, treated with serial applications of a viable intact cryopreserved human placental membrane (vCPM) (Grafix, Osiris Therapeutics Inc, Columbia, MD) for recalcitrant lower extremity ulcerations (n = 6). More than half of the patients were not candidates for revascularization. Baseline vascular status in 5 of 6 lower-extremity wounds remained unchanged throughout the entire course of vCPM treatment. Daily cigarette consumption averaged 18 cigarettes per patient. Mean wound duration and mean surface area was 53 weeks and 4.6 cm2, respectively. Mean number of vCPM applications and time to closure was 7.0 grafts in 7.8 weeks. There were no wound-related infections or amputations and no vCPM-related adverse events. All 6 wounds remained closed at the 12-month follow-up visit. In conclusion, vCPM demonstrated clinically effective outcomes in 6 previously nonhealing ulcerations despite ongoing smoking habits in the presence of PAD and diabetes.

Influence of genetic variations in platelet glycoproteins and eNOS in the development of arterial ischaemia of lower limbs in type 2 diabetes mellitus patients

Endothelial and platelet dysfunction increase the atherothrombotic risk in diabetes mellitus patients. Therefore, arterial ischaemia of lower limbs is an important complication in diabetes mellitus. In the present work, type 2 diabetic patients were classified by a podiatrist into presence or absence of arterial ischaemia of lower limbs. Several polymorphisms in platelet glycoproteins and eNOS genes were evaluated. Our results suggest that the -5CC genotype in Kozak sequence of GPIbα may be associated with a higher risk of developing arterial ischaemia of lower limbs in type 2 diabetes mellitus patients.

Peripheral artery disease: epidemiology and global perspectives

Global populations are undergoing a major epidemiological transition in which the burden of atherosclerotic cardiovascular diseases is shifting rapidly from high-income to low-income and middle-income countries (LMICs). Peripheral artery disease (PAD) is no exception, so that greater focus is now required on the prevention and management of this disease in less-advantaged countries. In this Review, we examine the epidemiology of PAD and, where feasible, take a global perspective. However, the dearth of publications in LMICs means an unavoidable over-reliance on studies in high-income countries. Research to date suggests that PAD might affect a greater proportion of women than men in LMICs. Although factors such as poverty, industrialization, and infection might conceivably influence the development of PAD in such settings, the ageing of the population and increase in traditional cardiovascular risk factors, such as smoking, diabetes mellitus, and hypertension, are likely to be the main driving forces.

Microvascular and Macrovascular Disease and Risk for Major Peripheral Arterial Disease in Patients With Type 2 Diabetes

OBJECTIVE

Peripheral arterial disease (PAD) is a common manifestation of atherosclerosis in type 2 diabetes, but the relationship between other vascular diseases and PAD has been poorly investigated. We examined the impact of previous microvascular and macrovascular disease on the risk of major PAD in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

We analyzed 10,624 patients with type 2 diabetes free from baseline major PAD in the Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation (ADVANCE) clinical trial. The primary composite outcome was major PAD defined as PAD-induced death, peripheral revascularization, lower-limb amputation, or chronic ulceration. The secondary end points were the PAD components considered separately.

RESULTS

Major PAD occurred in 620 (5.8%) participants during 5 years of follow-up. Baseline microvascular and macrovascular disease were both associated with subsequent risk of major PAD after adjustment for age, sex, region of origin, and randomized treatments. However, only microvascular disease remained significantly associated with PAD after further adjustment for established risk factors. The highest risk was observed in participants with a history of macroalbuminuria (hazard ratio 1.91 [95% CI 1.38-2.64], P < 0.0001) and retinal photocoagulation therapy (1.60 [1.11-2.32], P = 0.01). Baseline microvascular disease was also associated with a higher risk of chronic lower-limb ulceration (2.07 [1.56-2.75], P < 0.0001) and amputation (1.59 [1.15-2.22], P = 0.006), whereas baseline macrovascular disease was associated with a higher rate of angioplasty procedures (1.75 [1.13-2.73], P = 0.01).

CONCLUSIONS

Microvascular disease, particularly macroalbuminuria and retinal photocoagulation therapy, strongly predicts major PAD in patients with type 2 diabetes, but macrovascular disease does not.

Presentations of major peripheral arterial disease and risk of major outcomes in patients with type 2 diabetes: results from the ADVANCE-ON study

Background

Peripheral arterial disease (PAD) is known to be associated with high cardiovascular risk, but the individual impact of PAD presentations on risk of macrovascular and microvascular events has not been reliably compared in patients with type 2 diabetes. We aimed to evaluate the impact of major PAD, and its different presentations, on the 10-year risk of death, major macrovascular events, and major clinical microvascular events in these patients.

Methods

Participants in the action in diabetes and vascular disease: PreterAx and DiamicroN modified-release controlled evaluation (ADVANCE) trial and the ADVANCE-ON post-trial study were followed for a median of 5.0 (in-trial), 5.4 (post-trial), and 9.9 (overall) years. Major PAD at baseline was subdivided into lower-extremity chronic ulceration or amputation secondary to vascular disease and history of peripheral revascularization by angioplasty or surgery.

Results

Among 11,140 participants, 516 (4.6 %) had major PAD at baseline: 300 (2.7 %) had lower-extremity ulceration or amputation alone, 190 (1.7 %) had peripheral revascularization alone, and 26 (0.2 %) had both presentations. All-cause mortality, major macrovascular events, and major clinical microvascular events occurred in 2265 (20.3 %), 2166 (19.4 %), and 807 (7.2 %) participants, respectively. Compared to those without PAD, patients with major PAD had increased rates of all-cause mortality (HR 1.35, 95 % CI 1.15–1.60, p = 0.0004), and major macrovascular events (1.47 [1.23–1.75], p < 0.0001), after multiple adjustments for region of origin, cardiovascular risk factors and treatments, peripheral neuropathy markers, and randomized treatments. We have also observed a trend toward an association of baseline PAD with risk of major clinical microvascular events [1.31 (0.96–1.78), p = 0.09]. These associations were comparable for patients with a lower-extremity ulceration or amputation and for those with a history of peripheral revascularization. Furthermore, the risk of retinal photocoagulation or blindness, but not renal events, increased in patients with lower-extremity ulceration or amputation [1.53 (1.01–2.30), p = 0.04].

Conclusions

Lower-extremity ulceration or amputation, and peripheral revascularization both increased the risks of death and cardiovascular events, but only lower-extremity ulceration or amputation increased the risk of severe retinopathy in patients with type 2 diabetes. Screening for major PAD and its management remain crucial for cardiovascular prevention in patients with type 2 diabetes (ClinicalTrials.gov number, NCT00949286).

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0446-x) contains supplementary material, which is available to authorized users.

Targeted Expression of Catalase to Mitochondria Protects Against Ischemic Myopathy in High-Fat Diet-Fed Mice

Patients with type 2 diabetes respond poorly to treatments for peripheral arterial disease (PAD) and are more likely to present with the most severe manifestation of the disease, critical limb ischemia. The underlying mechanisms linking type 2 diabetes and the severity of PAD manifestation are not well understood. We sought to test whether diet-induced mitochondrial dysfunction and oxidative stress would increase the susceptibility of the peripheral limb to hindlimb ischemia (HLI). Six weeks of high-fat diet (HFD) in C57BL/6 mice was insufficient to alter skeletal muscle mitochondrial content and respiratory function or the size of ischemic lesion after HLI, despite reducing blood flow. However, 16 weeks of HFD similarly decreased ischemic limb blood flow, but also exacerbated limb tissue necrosis, increased the myopathic lesion size, reduced muscle regeneration, attenuated muscle function, and exacerbated ischemic mitochondrial dysfunction. Mechanistically, mitochondrial-targeted overexpression of catalase prevented the HFD-induced ischemic limb necrosis, myopathy, and mitochondrial dysfunction, despite no improvement in limb blood flow. These findings demonstrate that skeletal muscle mitochondria are a critical pathological link between type 2 diabetes and PAD. Furthermore, therapeutically targeting mitochondria and oxidant burden is an effective strategy to alleviate tissue loss and ischemic myopathy during PAD.

Glyoxalase-1 Overexpression Reverses Defective Proangiogenic Function of Diabetic Adipose-Derived Stem Cells in Streptozotocin-Induced Diabetic Mice Model of Critical Limb Ischemia

Adipose‐derived stem cell (ADSC)‐based therapy is promising for critical limb ischemia (CLI) treatment, especially in patients with diabetes. However, the therapeutic effects of diabetic ADSCs (D‐ADSCs) are impaired by the diabetes, possibly through intracellular reactive oxygen species (ROS) accumulation. The objective of the present study was to detect whether overexpression of methylglyoxal‐metabolizing enzyme glyoxalase‐1 (GLO1), which reduces ROS in D‐ADSCs, can restore their proangiogenic function in a streptozotocin‐induced diabetic mice model of CLI. GLO1 overexpression in D‐ADSCs (G‐D‐ADSCs) was achieved using the lentivirus method. G‐D‐ADSCs showed a significant decrease in intracellular ROS accumulation, increase in cell viability, and resistance to apoptosis under high‐glucose conditions compared with D‐ADSCs. G‐D‐ADSCs also performed better in terms of migration, differentiation, and proangiogenic capacity than D‐ADSCs in a high‐glucose environment. Notably, these properties were restored to the same level as that of nondiabetic ADSCs under high‐glucose conditions. G‐D‐ADSC transplantation induced improved reperfusion and an increased limb salvage rate compared D‐ADSCs in a diabetic mice model of CLI. Histological analysis revealed higher microvessel densities and more G‐D‐ADSC‐incorporated microvessels in the G‐D‐ADSC group than in the D‐ADSC group, which was comparable to the nondiabetic ADSC group. Higher expression of vascular endothelial growth factor A and stromal cell‐derived factor‐1α and lower expression of hypoxia‐induced factor‐1α were also detected in the ischemic muscles from the G‐D‐ADSC group than that of the D‐ADSC group. The results of the present study have demonstrated that protection from ROS accumulation by GLO1 overexpression is effective in reversing the impaired biological function of D‐ADSCs in promoting neovascularization of diabetic CLI mice model and warrants the future clinical application of D‐ADSC‐based therapy in diabetic patients. Stem Cells Translational Medicine2017;6:261–271

Rearfoot Transcutaneous Oximetry is a Useful Tool to Highlight Ischemia of the Heel

PURPOSE

To demonstrate the usefulness of rearfoot transcutaneous oximetry to assess the peripheral arterial disease in diabetic patients with heel ulcer.

METHODS

From our database of 550 critical limb ischemia diabetic patients followed after a percutaneous transluminal angioplasty, we have selected patients with below the knee arterial disease. Patients were grouped according to the dorsal transcutaneous oximetry value (Group A < 30 mmHg; Group B ≥ 30 mmHg). Patients of Group B had a second oximetry performed at the rearfoot, close to the lesion localized in all cases at the heel. Finally, the analysis of the arterial pattern disease has been done.

RESULTS

We selected 191 patients: Group A (151 patients), dorsal transcutaneous oximetry of 11.8 ± 0.7 mmHg; Group B (40 patients), dorsal transcutaneous oximetry of 44.2 ± 10.1 mmHg. In Group B, rearfoot oximetry was 20.5 ± 5 mmHg, significantly lower than dorsal oximetry (p = 0.0179). The anterior tibial artery was involved in all patients of Group A. In Group B, the anterior tibial artery was involved in 15 subjects and never alone; the posterior tibial artery was involved in 20 subjects and in 11 cases alone. The peroneal artery was affected in 20 subjects and in 14 patients alone.

CONCLUSION

When a heel lesion is present and the transcutaneous oximetry recorded on the dorsum of the foot does not confirm the presence of critical limb ischemia (not ≤30 mmHg), a second oximetry recorded on the rearfoot is useful to point out ischemia of the peroneal artery and/or of the posterior tibial artery.

Amputations and mortality in in-hospital treated patients with peripheral artery disease and diabetic foot syndrome

AIMS

The prevalence of diabetes mellitus (DM) and its associated complications such as peripheral artery disease (PAD) and diabetic foot syndrome (DFS) are increasing worldwide. We aimed to determine the contemporary acute and long-term outcome of patients with PAD and DFS in Germany.

METHODS

Nationwide, anonymized data of 40,335 patients hospitalized for PAD and/or DFS from the years 2009-2011 were analyzed and followed up until 2013. Patients were classified into 3 groups: DFS, PAD+DM and PAD without DM. In-hospital and long-term outcome (1156days, 95% CI 1.151-1.161) regarding major and minor amputation and mortality was assessed. Cumulative amputation-free survival and overall survival rates were calculated using Kaplan-Meier analysis.

RESULTS

The proportion of DFS, PAD+DM and PAD only was 17.3%, 21.5% and 61.2%, respectively. At index-hospitalization, DFS patients had the highest amputation (31.9% vs. 11.1% vs. 6.0%), yet the lowest revascularization rate (18.2% vs. 67.8% vs. 71.6%) compared to patients with PAD only and PAD+DM (P<0.001). Cumulative 4-year survival (57.4%, 60.8% and 70.0%) and amputation-free-survival (45.4%, 74.4% and 86.5%) were lowest for DFS followed by PAD+DM and PAD only (P<0.001).

CONCLUSIONS

Patients with diabetes, particularly those with DFS, have persistent high rates of limb amputation and of mortality in a real-world setting. Our data emphasize the need for further dedicated research to identify and target the underlying causes of the extraordinary poor outcome in this high risk population.

Interobserver Reliability of Three Validated Scoring Systems in the Assessment of Diabetic Foot Ulcers

Scoring systems for diabetic foot ulcers may be used for clinical purposes, research or audit, to help assess disease severity, plan management, and even predict outcomes. While many have been validated in study populations, little is known about their interobserver reliability. This prospective study aimed to evaluate interobserver reliability of 3 scoring systems for diabetic foot ulceration. After sharp debridement, diabetic foot ulcers were classified by a multidisciplinary pool of trained observers, using the PEDIS (Perfusion, Extent, Depth, Infection, Sensation), SINBAD (Site, Ischemia, Neuropathy, Bacterial infection, Depth), and University of Texas (UT) wound classification systems. Interobserver reliability was assessed using intraclass correlations (0 = no agreement; 1 = complete agreement). Thirty-seven patients (78.4% male) were assessed by a pool of 12 observers. Single observer reliability was slight to moderate for all scoring systems (UT 0.53; SINBAD 0.44; PEDIS 0.23-0.42), but multiple observer reliability was almost perfect (UT 0.94; SINBAD 0.91; PEDIS 0.80-0.90). The worst agreement for single observers was when scoring infection (SINBAD 0.28; PEDIS 0.28), ischemia (SINBAD 0.26; PEDIS 0.23), or both (UT 0.25); however, this improved to almost perfect agreement for multiple observers (infection: 0.83; ischemia: 0.80-0.82; both: 0.81). These classification systems may be reliably used by multiple observers, for example, when conducting research and audit. However, they demonstrate only slight to moderate reliability when used by a single observer on an individual subject and may therefore be less helpful in the clinical setting, when documenting ulcer characteristics or communicating between colleagues.

Epidemiology and Pathophysiology of Lower Extremity Peripheral Arterial Disease

Peripheral arterial disease (PAD), a major cause of disability, loss of work, and lifestyle changes in the United States, is defined as obstruction of blood flow into an arterial tree excluding the intracranial or coronary circulations. PAD is mostly silent in its early stages, but when lesion obstruction exceeds 50%, it may cause intermittent claudication with ambulation. Further disease progression typically leads to rest pain or frank tissue loss. However, some patients may remain asymptomatic with severe disease because of extensive collateralization in the lower extremity. Estimates of the prevalence of intermittent claudication vary by population, from 0.6% to nearly 10%; the rate increases dramatically with age. Approximately 20% to 25% of patients will require revascularization, while fewer than 5% will progress to critical limb ischemia. Limb loss, although rare, is associated with severe disability and an overall poor prognosis, with 30% to 40% mortality in the first 24 months after limb loss. As with coronary artery disease, the most common cause of symptomatic obstruction in the peripheral arterial tree is atherosclerosis, a systemic inflammatory process in which cholesterol-laden plaque builds up in the artery and eventually blocks the lumen. Typical risk factors include age, gender, diabetes, tobacco abuse, hypertension, and hyperlipidemia.

Advances in our understanding of the influence of gender on patient outcomes with peripheral arterial disease co-occurring with diabetes

Peripheral arterial disease is an important predictor of cardiovascular morbidity and mortality. Patients with peripheral arterial disease are at a higher risk of myocardial infarction and stroke. The well-known coronary artery disease risk factors such as diabetes, hypertension, smoking and dyslipidemia are also risk factors for peripheral arterial disease. Hyperglycemia is an important mediator in the pathogenesis of this disease in diabetics, more so in women. The morbidity and poor outcomes associated with peripheral arterial disease in women are emerging. Women are more likely to present at an older age are often asymptomatic and have poorer outcomes with revascularization. Women experience specific sex-related challenges in the various diagnostic methods which could lead to a delay in diagnosis. This is a group which needs close attention and aggressive risk factor modification.

Markers of fibrinolysis may predict development of lower extremity arterial disease in patients with diabetes: A longitudinal prospective cohort study with 10 years of follow-up

BACKGROUND

A previous cross-sectional study suggested that tissue plasminogen activator-activity might be an early marker of asymptomatic lower extremity arterial disease, but the long-term relationship is unknown.

SUBJECTS AND METHODS

This study included 96 diabetic (48 type 1/48 type 2) and 62 non-diabetic subjects aged 30-70 years without previously known lower extremity arterial disease (age: 50.3 ± 9.3 years, gender: M/W 47.5/52.5% and body mass index: 26.6 ± 4.5 kg/m(2)). The relationships between asymptomatic lower extremity arterial disease and fibrinolytic markers (tissue plasminogen activator-activity, tissue plasminogen activator-mass, plasminogen activator inhibitor-1 activity) at baseline and after 10 years were assessed by logistic regression analysis adjusting for age, hypertension, statin treatment, HbA1c, triglycerides and low-density lipoprotein cholesterol as fixed covariates.

RESULTS

The tissue plasminogen activator-activity at baseline and at the 10-year follow-up significantly predicted the presence of sign(s) of lower extremity arterial disease (odds ratio = 1.78, 95% confidence interval: 1.02-3.10, p = 0.043 and odds ratio = 1.78, 95% confidence interval: 1.12-2.23, p = 0.014, respectively). In addition, tissue plasminogen activator-mass at the 10-year follow-up was associated with signs of lower extremity arterial disease (odds ratio = 1.07, 95% confidence interval: 1.00-1.15, p = 0.046). Baseline age, hypertension and HbA1c were independently associated with sign(s) of lower extremity arterial disease at 10 years (odds ratio = 1.09, 95% confidence interval: 1.04-1.14, p = < 0.001; odds ratio = 3.68, 95% confidence interval: 1.67-8.12, p = 0.001 and odds ratio = 1.54, 95% confidence interval: 1.21-1.95, p = < 0.001, respectively).

CONCLUSION

This long-term study supports previous findings of a significant association between asymptomatic lower extremity arterial disease and tissue plasminogen activator-activity. Thus, tissue plasminogen activator-activity may be an early marker of lower extremity arterial disease although the mechanism of this relationship remains unclear.

Low 25-Hydroxyvitamin D Level Is Associated with Peripheral Arterial Disease in Type 2 Diabetes Patients

BACKGROUND AND AIMS

Patients with type 2 diabetes have an increased risk of atherosclerosis and vascular disease. Vitamin D deficiency is associated with vascular disease and is prevalent in diabetes patients. We undertook this study to determine the association between 25-hydroxyvitamin D (25[OH]D) levels and prevalence of peripheral arterial disease (PAD) in type 2 diabetes patients.

METHODS

A total of 1028 type 2 diabetes patients were recruited at Nanjing Medical University Affiliated Nanjing Hospital from November 2011 to October 2013. PAD was defined as an ankle-brachial index (ABI) < 0.9. Cardiovascular risk factors (blood pressure, HbA1c, lipid profile), comorbidities, carotid intima-media thickness (IMT) and 25(OH)D were assessed.

RESULTS

Overall prevalence of PAD and of decreased 25(OH)D (<30 ng/mL) were 20.1% (207/1028) and 54.6% (561/1028), respectively. PAD prevalence was higher in participants with decreased (23.9%) than in those with normal (15.6%) 25(OH)D (≥30 ng/mL, p <0.01). Decreased 25(OH)D was associated with increased risk of PAD (odds ratio [OR], 1.69, 95% CI: 1.17-2.44, p <0.001) and PAD was significantly more likely to occur in participants ≥65 years of age (OR, 2.56, 95% CI: 1.51 -4.48, vs. 1.21, 95% CI: 0.80-1.83, p-interaction = 0.027). After adjusting for known cardiovascular risk factors and potential confounding variables, the association of decreased 25(OH)D and PAD remained significant in patients <65 years of age (OR, 1.55; 95% CI: 1.14-2.12, p = 0.006).

CONCLUSIONS

Low serum 25(OH)D levels were significantly associated with a higher prevalence of PAD in type 2 diabetes patients <65 years of age. It may increase the risk of PAD independent of other known cardiovascular risk factors.

Endovascular reconstruction of popliteal and infrapopliteal arteries for limb salvage and wound healing in patients with critical limb ischemia - A retrospective analysis

Background

Advancement in endovascular techniques has led to rapid growth in endovascular revascularization, and it has emerged as a treatment for critical limb ischemia (CLI). Clinical effectiveness of revascularization has been frequently judged by vessel patency and limb salvage, but there is paucity of reports on outcomes of the wound. We present a retrospective analysis of immediate angiographic and 3-month clinical outcome of patients who underwent endovascular reconstruction of popliteal and infrapopliteal arteries for CLI.

Methods

All patients who underwent endovascular reconstruction of popliteal and/or infrapopliteal arteries for CLI and >70% stenosis on digital subtraction angiography between March 2010 and November 2014 and had a clinical follow-up of at least 3 months were selected for analysis.

Results

34 patients underwent endovascular reconstruction. 9 patients (26%) underwent only POBA and remaining 25 (74%) underwent additional stenting. 13 patients (38%) had multiple segmental revascularization. 24 patients (71%) had successful vessel recanalization. Linear flow to foot in at least one artery could be achieved in 20 patients (59%) post revascularization. Successful wound healing occurred in 11 (35%) patients with an additional 7 (21%) patients showing clinical improvement in their wounds. Limb salvage was achieved in 33 patients (97%) at 3-month follow-up.

Conclusion

Endovascular revascularization of popliteal and infrapopliteal arteries is a feasible, safe, and effective procedure for the treatment of CLI. Normal inflow and outflow with at least one of the three infrapopliteal vessels being patent is essential for adequate healing of chronic ulcers and prevention of major amputation.

Performance of prognostic markers in the prediction of wound healing or amputation among patients with foot ulcers in diabetes: a systematic review

Prediction of wound healing and major amputation in patients with diabetic foot ulceration is clinically important to stratify risk and target interventions for limb salvage. No consensus exists as to which measure of peripheral artery disease (PAD) can best predict outcomes. To evaluate the prognostic utility of index PAD measures for the prediction of healing and/or major amputation among patients with active diabetic foot ulceration, two reviewers independently screened potential studies for inclusion. Two further reviewers independently extracted study data and performed an assessment of methodological quality using the Quality in Prognostic Studies instrument. Of 9476 citations reviewed, 11 studies reporting on 9 markers of PAD met the inclusion criteria. Annualized healing rates varied from 18% to 61%; corresponding major amputation rates varied from 3% to 19%. Among 10 studies, skin perfusion pressure ≥ 40 mmHg, toe pressure ≥ 30 mmHg (and ≥ 45 mmHg) and transcutaneous pressure of oxygen (TcPO2 ) ≥ 25 mmHg were associated with at least a 25% higher chance of healing. Four studies evaluated PAD measures for predicting major amputation. Ankle pressure < 70 mmHg and fluorescein toe slope < 18 units each increased the likelihood of major amputation by around 25%. The combined test of ankle pressure < 50 mmHg or an ankle brachial index (ABI) < 0.5 increased the likelihood of major amputation by approximately 40%. Among patients with diabetic foot ulceration, the measurement of skin perfusion pressures, toe pressures and TcPO2 appear to be more useful in predicting ulcer healing than ankle pressures or the ABI. Conversely, an ankle pressure of < 50 mmHg or an ABI < 0.5 is associated with a significant increase in the incidence of major amputation.

Non-invasive vascular assessment in the foot with diabetes: sensitivity and specificity of the ankle brachial index, toe brachial index and continuous wave Doppler for detecting peripheral arterial disease

BACKGROUND & AIMS

Non-invasive lower limb vascular assessment in people at risk of peripheral arterial disease (PAD) including those with diabetes is crucial. There is evidence that standard assessment techniques such as the ankle-brachial index (ABI) may be less effective in people with diabetes. However there is limited evidence for other frequently used tests including continuous wave Doppler (CWD), and the toe-brachial index (TBI). The aim of this study was to determine the sensitivity and specificity of, ABI, CWD and TBI in a population with, and without diabetes.

METHODS

Participants with and without diabetes who met current guidelines for vascular screening were recruited, and CWD waveforms, an ABI and a TBI were obtained from the right lower limb. Diagnostic accuracy was determined using colour duplex ultrasound (CFDU). Receiver operating characteristic curves were calculated.

RESULTS

117 participants were recruited, seventy-two with diabetes and forty-five without diabetes. CWD had the highest sensitivity in people with diabetes (74%) and without (84%). CWD also had the highest specificity in people with diabetes (74%) and without (84%) compared to both TBI and ABI. In participants with diabetes, the ABI was a poor test, area under the curve: 0.58 (p=0.27).

CONCLUSIONS

CWD waveform is more likely to detect significant PAD compared to ABI and TBI in people with and without diabetes.

Physical activity, ambulation, and comorbidities in people with diabetes and lower-limb amputation

We characterized physical activity (PA) and its relation to physical function and number of comorbidities in people with diabetes and transtibial amputation (AMP), people with diabetes without AMP, and nondisabled adults without diabetes or AMP. Twenty-two individuals with type 2 diabetes mellitus (DM) and transtibial amputation (DM+AMP), 11 people with DM, and 13 nondisabled participants were recruited for this cross-sectional cohort study. Measures included PA volume and intensity, a Timed Up and Go test, a 2-min walk test, and number of comorbidities. The nondisabled group performed greater amounts of PA than the DM group, who performed greater amounts of PA than the DM+AMP group. PA was related to physical function in the DM group and in the DM+AMP group, whereas no such relationship existed in the nondisabled group. PA was not related to number of comorbidities in any group. These findings suggest the ability to walk may affect overall performance of PA. Alternately, PA may alleviate walking problems. This possibility is of interest because issues with walking may be modifiable by improved levels and intensity of PA. PA's lack of relation to number of comorbidities suggests that factors beyond multiple morbidities account for group differences in PA.

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.

Factors Affecting Penetration of Ciprofloxacin in Lower Extremity Ischemic Tissues

The aims of this study were to evaluate factors influencing the distribution of ciprofloxacin in tissue of patients suffering from varying degrees of peripheral arterial disease (PAD). Blood and tissue samples were collected from patients undergoing debridement or amputation procedures and the amount of ciprofloxacin in them was determined using high-performance liquid chromatography. All patients were administered a 200-mg dose of intravenous ciprofloxacin prior to the debridement or amputation procedure. Data, including patient gender, age, type of diabetes, presence of neuropathy, medications taken, and severity of PAD were collected. These data were then analyzed to determine factors influencing the concentrations of ciprofloxacin in tissue of the lower limbs. The Kruskal-Wallis test, Spearman correlation, and chi-square test were used to relate covariates and fixed factors with the concentration of ciprofloxacin in tissue. Following bivariate analysis, a 3-predictor regression model was fitted to predict tissue concentrations of ciprofloxacin given information about these predictors. Blood and tissue samples were collected from 50 patients having an average age of 68 years. Thirty-three patients were males and 35 patients suffered from type 2 diabetes. The average number of medications that these patients were taking was 10. The majority of patients (n = 35) were suffering from severe PAD. Tissue concentrations of ciprofloxacin were mainly related to plasma concentrations of ciprofloxacin, number of medications that the patients were taking and severity of PAD.

Histopathological Differences of the Pedicle Artery in Commonly Used Free Flaps: The Influence of Age, Gender, and Side

PURPOSE

The increasing use of vascularized free flaps has increased the demand for a specified flap selection. This study investigated histologic differences in the arterial wall of the pedicle for commonly used free flaps and the effect of age, gender, and anatomic side on these differences.

MATERIALS AND METHODS

Light microscopic examinations of vessel walls were performed on 245 specimens of the nourishing artery of commonly used free vascularized flaps in preserved cadavers. The peroneal artery (PA), radial artery (RA), inferior epigastric artery (IEA), deep circumflex iliac artery (DCIA), and circumflex scapular artery (CSA) were examined. Differences of histologic changes in the arterial wall and the effect of age, gender, and body side were investigated.

RESULTS

All examined vessel specimens (age range, 62 to 98 yr; mean age, 83 yr; 15 female and 12 male) displayed mostly Class II changes. PA showed the greatest atherosclerotic changes, followed by the RA, IEA, DCIA, and CSA. Age had a meaningful effect on PA and RA. Anatomic side was important for PA and DCIA, whereas gender had a minor influence on vessel condition.

CONCLUSION

The vessel wall of different flaps showed different atherosclerotic changes depending on age, anatomic side, and gender. These differences should be considered in flap selection.

Estudo comparativo do Índice Tornozelo-Braquial em diabéticos e não diabéticos com isquemia crítica

Resumo Contexto A calcificação da camada média arterial pode tornar o Índice Tornozelo-Braquial (ITB) falsamente elevado em diabéticos, dificultando a avaliação da doença arterial. Objetivo Comparar os valores do ITB de diabéticos e não diabéticos com isquemia crítica. Métodos Foram incluídos 140 pacientes (60% de diabéticos) acompanhados no Serviço de Cirurgia Vascular do Complexo Hospitalar Universitário Professor Edgard Santos com isquemia crítica por DAOP infra-inguinal. Comparou-se a média dos valores do ITB dos dois grupos de pacientes, correlacionando o ITB com a gravidade da isquemia, segundo a Classificação de Rutherford. A análise estatística foi realizada pelo EPI-INFO. Resultados A maioria dos 140 pacientes (77%) se encontrava na Categoria 5 da Classificação de Rutherford, 6% na 4 e 17% na 6. Nove diabéticos (11%) e um não diabético (2%) apresentaram ITB > 1,15 (p = 0,02), sendo excluídos da análise das médias do ITB. Considerando os 130 pacientes, os 75 doentes diabéticos apresentaram média do ITB na artéria tibial posterior de 0,26 versus 0,28 dos 55 doentes não diabéticos (p = 0,6); e no ITB da artéria pediosa aqueles apresentaram média de 0,32 versus 0,23 desses (p = 0,06). Estratificando os doentes nas categorias da Classificação de Rutherford, não houve diferença nas médias do ITB nas categorias 4 e 5. Apenas em relação à artéria pediosa e em pacientes na Categoria 6, a média do ITB foi significativamente maior em diabéticos (0,44 versus 0,16; p = 0,03). Conclusão Os diabéticos apresentaram maior prevalência de ITB falsamente elevado. Porém, excluindo-se esses casos, a média dos valores de ITB são semelhantes aos não diabéticos, exceto na artéria pediosa, nos pacientes com isquemia na categoria 6.

Mitochondrial Regulation of the Muscle Microenvironment in Critical Limb Ischemia

Critical limb ischemia (CLI) is the most severe clinical presentation of peripheral arterial disease and manifests as chronic limb pain at rest and/or tissue necrosis. Current clinical interventions are largely ineffective and therapeutic angiogenesis based trials have shown little efficacy, highlighting the dire need for new ideas and novel therapeutic approaches. Despite a decade of research related to skeletal muscle as a determinant of morbidity and mortality outcomes in CLI, very little progress has been made toward an effective therapy aimed directly at the muscle myopathies of this disease. Within the muscle cell, mitochondria are well positioned to modulate the ischemic cellular response, as they are the principal sites of cellular energy production and the major regulators of cellular redox charge and cell death. In this mini review, we update the crucial importance of skeletal muscle to CLI pathology and examine the evolving influence of muscle and endothelial cell mitochondria in the complex ischemic microenvironment. Finally, we discuss the novelty of muscle mitochondria as a therapeutic target for ischemic pathology in the context of the complex co-morbidities often associated with CLI.

Socket Interface Pressure and Amputee Reported Outcomes for Comfortable and Uncomfortable Conditions of Patellar Tendon Bearing Socket: A Pilot Study

The objectives of the current study were to compare intra-socket pressure differences between comfortable and uncomfortable socket conditions, and the usefulness of subject perception of satisfaction, activity limitations, and socket comfort in distinguishing between these two socket conditions. Five unilateral trans-tibial amputees took part in the study. They answered the Socket Comfort Score (SCS) and Trinity Amputation and Prosthetic Experience Scale (TAPES) questionnaires before the interface pressure (in standing and walking) was measured for the uncomfortable socket condition at five regions of the residual limb. Participants were then provided with a comfortable socket and wore it for two weeks. Participants who were satisfied with the socket fit after two weeks repeated the SCS and TAPES questionnaires and interface pressure measurements. The differences between the test results of the two conditions were not statistically significant, except for the interface pressure at the popliteal region during the early stance phase, TAPES socket fit subscale, and the SCS. Due to large variability of the data and the lack of statistical significance, no firm conclusion can be made on the possible relationship between the interface pressure values and the patient-reported outcomes of the two socket conditions. A larger sample size and longer acclimation period are required to locate significant differences.

Contemporary medical management of peripheral arterial disease: a focus on risk reduction and symptom relief for intermittent claudication

Peripheral arterial disease (PAD) is primarily caused by progressive systemic atherosclerosis manifesting in the lower extremities. This review addresses the epidemiology, clinical presentation and evaluation, and medical management of PAD, with a focus on intermittent claudication. Key advances in the recognition of cardiovascular risk in asymptomatic individuals with mildly abnormal ankle-brachial index, newer reflections on exercise therapy, and a review of established and investigational agents for the treatment of symptomatic PAD, such as cilostazol, statins, and angiotensin-converting enzyme inhibitors, are highlighted.

Use of hand-held Doppler ultrasound examination by podiatrists: a reliability study

BACKGROUND

Hand held Doppler examination is a frequently used non-invasive vascular assessment utilised by podiatrists. Despite this, the reliability of hand-held Doppler has not been thoroughly investigated. Given the importance of Doppler in completing a vascular assessment of the lower limb, it is essential to determine the reliability of the interpretation of this testing method in practicing podiatrists.

METHODS

This was a multi-centre inter and intra-rater reliability study. Four podiatrists (the raters) participated in this study, two public and two private practitioners. Three aspects of Doppler use were examined; (i) use of Doppler (i.e., technique and interpretation), (ii) interpretation of Doppler audio sounds, and (iii) interpretation of visual Doppler waveforms (i.e., tracings). Participants meeting current guidelines for vascular screening attended two testing sessions, 1 week apart at either the private practice (n = 32), or the public practice (n = 31). To assess use of Doppler, the raters evaluated the Doppler waveforms that they collected, rating them as mono-phasic or multi-phasic. To assess Doppler audio sounds and visual Doppler waveforms, raters were required to evaluate 30 audio recordings of Doppler sounds and 30 waveform tracings, respectively, that were previously recorded and chosen at random by the researchers. Cohen's kappa (κ) statistics were used to calculate inter and intra-rater reliability using SPSS version 19.

RESULTS

Use of Doppler demonstrated the lowest reliability for both pairs of clinicians (inter-rater reliability κ 0.20 to 0.24 and intra-rater reliability κ 0.27 to 0.42). The public podiatrists showed higher reliability in audio interpretation (inter-tester reliability κ 0.61, intra-tester reliability κ 1.00) compared to the private podiatrists (inter-tester reliability κ 0.31, intra-tester reliability κ 0.53). Evaluation of Doppler waveform tracings demonstrated highest reliability, with inter-rater reliability ranging from κ 0.77 to 0.90 and intra-rater reliability from κ 0.81 to 1.00.

CONCLUSIONS

There is a need for ongoing education for podiatrists using Doppler in clinical practice, as the reliability for the clinical use of the Doppler was low. This indicates that technique could be an issue. There is also a need to further evaluate if hand-held Doppler equipment, using the examinations that we evaluated, is suitable for use in the contexts examined in this study.