Biomaterials-Based Strategies to Enhance Angiogenesis in Diabetic Wound Healing

Amidst the present healthcare issues, diabetes is unique as an emerging class of affliction with chronicity in a majority of the population. To check and control its effects, there have been huge turnover and constant development of management strategies, and though a bigger part of the health care area is involved in achieving its control and the related issues such as the effect of diabetes on wound healing and care and many of the works have reached certain successful outcomes, still there is a huge lack in managing it, with maximum effect yet to be attained. Studying pathophysiology and involvement of various treatment options, such as tissue engineering, application of hydrogels, drug delivery methods, and enhancing angiogenesis, are at constantly developing stages either direct or indirect. In this review, we have gathered a wide field of information and different new therapeutic methods and targets for the scientific community, paving the way toward more settled ideas and research advances to cure diabetic wounds and manage their outcomes.

Association Between the Society for Vascular Surgery (SVS)-WIfI (Wound, Ischemia, Foot Infection) Classification, Wagner-Meggitt Classification, and Amputation Rate in Patients With Diabetic Foot Infection

Diabetic foot infection (DFI) is a common problem in patients with diabetic foot disease. Amputations and other complications of DFI lead to significant morbidity and mortality. The Society for Vascular Surgery (SVS)-WIfI (wound, ischemia, and foot infection) classification system can evaluate the benefit from revascularization and the risk of amputation in 1 and 3 years. We aimed to evaluate SVS-WIfI and Wagner-Meggitt (WM) prediction of DFI outcome, and to determine factors associated with major amputation and mortality rate. The patients with diabetes who presented between June 2018 and May 2020 with characteristics suggesting a more serious DFI or potential indications for hospitalization were reviewed in this cohort study. Demographic data, clinical characteristics, and type of revascularization were evaluated. One-year and 3-year amputation and mortality rates were the main outcomes. The grading of WM classification and the SVS-WIfI score were compared between amputation and nonamputation groups. Association between mortality and comorbidity were analyzed. One hundred and thirty-one patients admitted with DFI were included in study. And 73.28% had peripheral arterial disease (PAD). The 1-year and 3-year major amputation rates were 16.03% and 26.23%, respectively. Seventy-eight (59.54%) patients required minor amputation to control infection before revascularization. PAD (risk ratio [RR] 1.47: 95% confidence interval [CI] 1.29-1.67, P = .032), benefit from revascularization clinical stage 3 on SVS-WIfI score (RR 4.56: 95%CI 1.21-17.21, P = 0.007), and high WM classification score (RR 9.46: 95% CI 5.65-15.82, P < 0.001) were associated by multivariate analysis with high amputation rates. 1-year & 3-year amputation risk on SVS-WIfI score were not associated with amputation rates in DFI (P = .263 and .496). Only 9 (6.8%) patients were lost to follow up during the 3-year period. WM classification score, SVS-WIfI score on benefit from revascularization, and PAD were strongly associated with major amputation rates in patients with DFI.

Patterns of use of advanced wound matrices in the Veterans Administration clinics

Chronic wounds are a common and costly health issue affecting millions of individuals in the United States, particularly those with underlying conditions such as diabetes, venous insufficiency, and peripheral artery disease. When standard treatments fail, advanced wound care therapies, such as skin substitutes, are often applied. However, the clinical effectiveness, indications, and comparative benefits of these therapies have not been well established. In this study, we report on the usage of both acellular and cellular, single and bilayer, natural and synthetic, dermal, and epidermal skin substitutes in a VA hospital system. We performed a retrospective chart review to understand the ordering and usage patterns of advanced wound therapies for patients with chronic wounds at the VA Northern California Health Care System. We examined types of products being recommended, categories of users recommending the products, indications for orders, and rate of repeated orders. Neuropathic, venous, or pressure ulcers were the main indications for using advanced wound matrices. Only 15.6% of patients for whom the matrices were ordered had supporting laboratory tests. Exactly 34.3% of the ordered matrices were not applied. And the use of wound matrices resulted in increased costs per patient visit of $1018-$3450. Our study sheds light on the usage patterns of these therapies in a VA healthcare facility and highlights the need for more robust evidence-based studies to determine the true benefits, efficacy, and cost-effectiveness of these innovative treatment options.

Diagnostic accuracy of the maximal systolic acceleration to detect peripheral arterial disease

BACKGROUND

Diagnosing peripheral arterial disease (PAD) can be challenging owing to medial arterial calcification (MAC) in patients with diabetes mellitus (DM) and chronic kidney disease (CKD). Current bedside tests, such as the ankle-brachial index and toe-brachial index, are often insufficient. The maximal systolic acceleration (ACCmax) is a velocimetric Doppler-derived parameter and could be a new promising test in the diagnostic workup of these patients. The primary aim of this study was to evaluate the diagnostic performance of the ACCmax to detect PAD.

METHODS

A retrospective cohort study was performed in a tertiary referral hospital. Patients ≥18 years old with suspected PAD who underwent ACCmax measurement(s) along with computed tomography angiography of the abdominal aorta and lower extremities (reference test) were eligible for inclusion. ACCmax measurements of the posterior tibial artery, anterior tibial artery and peroneal artery were collected. Diagnostic performance was assessed by using sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and area under the curve (AUC).

RESULTS

In total, 340 patients (618 limbs) were included. Approximately 40% suffered from DM and 30% had CKD. Diagnostic performance of the ACCmax to detect PAD for the posterior tibial artery showed a sensitivity of 90%, specificity of 93%, positive likelihood ratio of 12.83, and negative likelihood ratio of 0.11 (AUC, 0.953). For the anterior tibial artery, these results were 94%, 97%, 32.06, and 0.06 (same sequence as presented before) with an AUC of 0.984. The peroneal artery had a performance of 86%, 89%, 7.51, and 0.16, respectively (AUC, 0.893). Diagnostic accuracy of the ACCmax did not diminish in subgroup analysis for patients with DM or CKD.

CONCLUSIONS

The ACCmax showed excellent diagnostic performance to detect PAD, independent of patients prone to medial arterial calcification.

Diabetic foot ulcer: Challenges and future

Diabetic foot ulcers (DFUs) have become one of the important causes of mortality and morbidity in patients with diabetes, and they are also a common cause of hospitalization, which places a heavy burden on patients and society. The prevention and treatment of DFUs requires multidisciplinary management. By controlling various risk factors, such as blood glucose levels, blood pressure, lipid levels and smoking cessation, local management of DFUs should be strengthened, such as debridement, dressing, revascularization, stem cell decompression and oxygen therapy. If necessary, systemic anti-infection treatment should be administered. We reviewed the progress in the clinical practice of treating DFUs in recent years, such as revascularization, wound repair, offloading, stem cell transplantation, and anti-infection treatment. We also summarized and prospectively analyzed some new technologies and measurements used in the treatment of DFUs and noted the future challenges and directions for the development of DFU treatments.

Reliability of bedside tests for diagnosing peripheral arterial disease in patients prone to medial arterial calcification: A systematic review

BACKGROUND

Medial arterial calcification (MAC), frequently associated with diabetes mellitus (DM) and chronic kidney disease (CKD), is a systemic vascular disorder leading to stiffness and incompressible arteries. These changes impede the accuracy of bedside tests to diagnose peripheral arterial disease (PAD). This review aimed to evaluate the reliability of bedside tests for the detection of PAD in patients prone to MAC.

METHODS

A systematic search (Pubmed, Embase, Web of Science, Cochrane, and Emcare) was performed according to the PRISMA guidelines to identify relevant studies providing data on the performance of bedside tests for the detection of PAD in patients prone to MAC. Studies were included when bedside test were compared to a reference standard. Primary endpoints were the positive and negative likelihood ratios (PLR, NLR). Methodological quality and risk of bias were evaluated using the QUADAS-2 tool.

FINDINGS

In total, 23 studies were included in this review. The most commonly evaluated test was the ankle-brachial index (ABI), followed by toe-brachial index (TBI), toe pressure (TP) measurements, and continuous wave Doppler (CWD). The majority of patients were older, male, and had DM. We found that ABI <0·9 was helpful to diagnose PAD, but failed to rule out PAD (NLR >0·2). The same applied for TP (NLR >0·3) and TBI (5 out of 6 studies revealed an NLR >0·2). CWD (loss of triphasic pattern) is reliable to exclude PAD (NLR 0-0·09), but was only validated in two studies. Overall, methodological quality was poor which led to risk of bias in 20 studies.

INTERPRETATION

The diagnosis of PAD in patients prone to MAC remains challenging. The ABI performed reasonably in the diagnosis of PAD, while the CWD (loss of triphasic signal) can be used to rule out PAD. This systematic review showed that test performances were generally poor with serious concerns in methodological quality of the included studies. We therefore counsel against the use of a single bedside test.

FUNDING

None to declare.

Role of neurotransmitters in the regulation of cutaneous wound healing

Wound healing is a highly coordinated and dynamic process of tissue repair after injury. The global burden of disease associated with wounds, both acute and chronic, is a significantly rising health concern. Upon skin wounding, neurons have the ability to sense the disruption to mediate the release of neurotransmitters into the wound microenvironment. Serotonin that has long been recognised as a potential vasoconstrictor is now also being contemplated to play a role in re-epithelialisation of wounds. While the role of neuropeptides in stimulating diabetic wound healing is being increasingly emphasised, on the other hand, dopamine is being widely studied for its dual role in mediating both pro- and antiangiogenic effects at the site of the wounds. Similarly, epinephrine levels that are known to be elevated during stress is now recognised as a contributing factor towards delayed wound closure, thereby serving as an inhibitor of wound healing. Thus, each neurotransmitter regulates wound repair and their active regeneration in a typical way. Strengthening our understanding of the molecular pathways via which the neurotransmitter modulates the immune system to control wound healing can yield potential therapeutic measures. Further investigations regarding the safety, efficacy, and cost-effectiveness of these processes are a prerequisite for their possible translation into clinical trials.

Doppler Ultrasonography Derived Maximal Systolic Acceleration: Value Determination With Artificially Induced Stenosis

In diagnosing peripheral arterial disease (PAD), medial arterial calcification (MAC) hampers arterial compression and could lead to unreliable ankle brachial index (ABI), toe brachial index (TBI) and toe pressure (TP). Doppler ultrasonography (DUS) derived maximal systolic acceleration (ACCmax) might be more accurate to diagnose PAD. In an in vitro study, a strong correlation between ACCmax and the severity of stenotic disease was determined. The aim of this study was to investigate the ACCmax in correlation with conventional non-invasive diagnostics in an in vivo setting. Methods: In twelve healthy individuals, an arterial stenosis was mimicked by compression on the common femoral artery by an ultrasounds probe, creating a local stenosis of 50%, 70% and 90%. The ABI, TBI, TP and several DUS parameters (including ACCmax) were assessed at the ankle during these different degrees of stenosis. All DUS parameters were measured separately by two observers to determine the interobserver variability. Results: Overall the ABI, TBI, TP, ACCmax, ACCsys and PSV decreased significantly when the degree of stenosis increased. The ACCmax showed the highest correlation with the degree of stenosis (r −.884), compared to ABI (r −.726), TBI (r −.716) and TP (r −.758). Furthermore, the interobserver variability of ACCmax was excellent, with an intraclass correlation coefficient (ICC) of .97. Conclusion: ACCmax is an accurate non-invasive DUS parameter to diagnose and assess the severity of a mimicked arterial stenosis in healthy individuals. Further prospective assessment of the clinical value of ACCmax and its potential benefits in patients with PAD is needed.

Vascular Assessment in Patients With a Lower Limb Wound: A Correlational Study of Photoplethysmography and Laser Doppler Flowmetry Toe Pressure Techniques

BACKGROUND

Vascular assessment of the lower limbs is essential in patients with diabetes. In the presence of noncompressible arteries, the ankle brachial index (ABI) can either be inconclusive or provide false-positive results. Toe pressure measurement has been suggested as an alternative as a noninvasive method for detecting peripheral arterial disease (PAD). Toe pressure measurement can be performed either by photoplethysmography (PPG) or by Laser Doppler flowmetry (LDF). The aim of this study was to determine correlations between the two techniques in order to promote the use of PPG in clinical practice.

METHODS

This was a prospective correlational study of 108 consecutive recruited adult patients, with and without diabetes, with at least one lower limb wound from a University-affiliated hospital wound care clinic. Toe pressure measurements were both performed with PPG and LDF devices.

RESULTS

Mean toe pressure values for PPG and LDF were, respectively, 83.7 (SD 35.4) and 79.5 (SD 32.0) mmHg (with a paired t-test 3.969, P < 0.01). In patients with at least one lower limb wound, a strong linear relation was found between PPG and LDF toe pressure techniques with a Pearson's r correlation coefficient of 0.920 (P < 0.001).

CONCLUSIONS

PPG and LDF toe pressure techniques are equivalent in patients with at least one lower limb wound, irrespective of the presence of diabetes. Therefore, in the presence of an ABI with inconclusive results, such as in a patient with noncompressible vessels, both toe pressure techniques can be used for assessing the vascular supply of the lower limb with a wound.

Overcoming ischemia in the diabetic foot: Minimally invasive treatment options

As the global burden of diabetes is rapidly increasing, the incidence of diabetic foot ulcers is continuously increasing as the mean age of the world population increases and the obesity epidemic advances. A significant percentage of diabetic foot ulcers are caused by mixed micro and macro-vascular dysfunction leading to impaired perfusion of foot tissue. Left untreated, chronic limb-threatening ischemia has a poor prognosis and is correlated with limb loss and increased mortality; prompt treatment is required. In this review, the diagnostic challenges in diabetic foot disease are discussed and available data on minimally invasive treatment options such as endovascular revascularization, stem cells, and gene therapy are examined.

Retrospective observational study of characteristics of persons with amputations accessing International Committee of the Red Cross (ICRC) rehabilitation centres in five conflict and postconflict countries

OBJECTIVES

Limb amputation incidence is particularly high in fragile contexts due to conflict, accidents and poorly managed diabetes. The study aim was to analyse (1) demographic and amputation characteristics of persons with any type of acquired amputation (PwA) and (2) time between amputation and first access to rehabilitation in five conflict and postconflict countries.

DESIGN

A retrospective, observational study analysing differences in demographic and clinical factors and time to access rehabilitation between users with traumatic and non-traumatic amputations.

SETTING

Five countries with the highest numbers of PwA in the global International Committee of the Red Cross database (Afghanistan, Cambodia, Iraq, Myanmar, Sudan). Cleaned and merged data from 2009 to 2018 were aggregated by sex; age at amputation and registration; cause, combination and anatomical level of amputation(s); living environment.

PARTICIPANTS

All PwA newly attending rehabilitation.

RESULTS

Data for 28 446 individuals were included (4329 (15.2%) female). Most were traumatic amputations (73.4%, 208 90); of these, 48.6% (138 01) were conflict related. Average age at traumatic amputation for men and women was 26.9 and 24.1 years, respectively; for non-traumatic amputation it was 49.1 years and 45.9 years, respectively. Sex differences in age were statistically significant for traumatic and non-traumatic causes (p<0.001, p=0.003). Delay between amputation and rehabilitation was on average 8.2 years for those with traumatic amputation, significantly higher than an average 3 years for those with non-traumatic amputation (p<0.001).

CONCLUSIONS

Young age for traumatic and non-traumatic amputations indicates the devastating impact of war and fragile health systems on a society. Long delays between amputation and rehabilitation reveal the mismatch of needs and resources. For rehabilitation service providers in fragile settings, it is an enormous task to manage the diversity of PwA of various causes, age, sex and additional conditions. Improved collaboration between primary healthcare, surgical and rehabilitation services, a prioritisation of rehabilitation and increased resource provision are recommended to ensure adequate access to comprehensive rehabilitation care for PwA.

Effect of Exercise on Risk Factors of Diabetic Foot Ulcers: A Systematic Review and Meta-Analysis

The objectives of this study were to examine the effectiveness of different types of exercise on risk factors of diabetic foot ulcers, including glycated hemoglobin, peripheral arterial disease, and diabetic peripheral neuropathy, in people with type 2 diabetes mellitus. PubMed, Web of Science, Cochrane Library, Scopus, and CINAHL were searched from inception to January 2018 for relevant articles. Eligible studies were randomized controlled trials that examined effects of exercise on the selected risk factors. Twenty randomized controlled trials with 1357 participants were included in the meta-analyses. The differences in postintervention values of glycated hemoglobin and ankle brachial index between exercise and control groups were synthesized, yielding mean differences of -0.45% (P < 0.00001) and 0.03 (P = 0.002), respectively; the differences in within-group changes in glycated hemoglobin were synthesized, yielding mean differences of -0.19% (P = 0.1), -0.25% (P = 0.0006), and -0.64% (P = 0.006) for aerobic versus resistance, combined versus aerobic, and combined versus resistance exercise, respectively. Exercise has a significant effect on reducing glycated hemoglobin, whereas combined exercise is more effective compared with aerobic or resistance exercise alone. Exercise also improves ankle brachial index. However, evidence regarding the association between exercise and peripheral neuropathy and risks of diabetic foot ulcers in people with type 2 diabetes mellitus remains insufficient.

Healing of Diabetic Neuroischemic Foot Wounds With vs Without Wound-Targeted Revascularization: Preliminary Observations From an 8-Year Prospective Dual-Center Registry

Purpose: To assess the clinical efficacy of endovascular angiosome-oriented wound-targeted revascularization (WTR) vs indirect (wound-indifferent) revascularization (IR) in diabetic patients with neuroischemic foot ulcers. Materials and Methods: Between April 2009 and July 2017, 167 diabetic patients (mean age 72.8 years; 137 men) with chronic limb-threatening ischemia (Rutherford category 5) and foot wounds (Wagner 2-4) in 194 limbs were prospectively registered and scheduled for primary infragenicular endovascular treatment. Specific angiosome source artery reperfusion sustained by patent foot arches or arterial-arterial connections was attempted initially. If this approach failed, topographic revascularization via available collaterals (WTRc) and IR were sequentially attempted. Results: Reperfusion was successful in 176 (91%) of 194 limbs (113 with WTR, 28 with WTRc, and 35 with IR); the global angiosome-oriented technical success (WTR and WTRc) was 73% (141/194). The mean follow-up was 10.9±0.7 months (range 3-12.5). Over 1 year, 102 (58%) of the 176 successfully treated limbs experienced wound healing [79/113 (70%) in the WTR group, 15/28 (54%) in the WTRc group, and 7/35 (20%) in the IR group; p=0.011]. The mean time to healing was 6.8±0.4 months in the WTR group, 7.9±0.6 months in the WTRc group, and 9.8±0.7 months in the IR group (p=0.001). Relapses were noted in 18 (16%) WTR limbs, 5 (18%) WTRc limbs, and 6 (17%) IR limbs. Comparison between WTR and IR and WTRc vs IR showed improved cicatrization in the angiosome-oriented groups (p<0.05). Major adverse limb events (MALE) and limb salvage were different between WTR and WTRc and between WTR and IR groups (p<0.05), while WTRc vs IR was not. Amputation-free survival was not influenced by the revascularization strategy (p=0.093). Conclusion: Wound healing in diabetic patients with chronic limb-threatening ischemia appeared to be improved by intentional wound-targeted revascularization, but no uniform benefit concerning MALE or limb preservation was observed. IR still represents an alternative for limb salvage in cases in which angiosome-guided revascularization fails.

A case of mistaken identity: classic Kaposi sarcoma misdiagnosed as a diabetic foot ulcer in an atypical patient

Background

The presentation of Kaposi sarcoma is divided into four known clinical subtypes. In this case report we describe classic Kaposi sarcoma in an African-American heterosexual, diabetic, seronegative human immunodeficiency virus male. Classic Kaposi sarcoma is rare in this patient demographic and can be easily misdiagnosed.

Case presentation

The patient presented with a lesion between the fourth and fifth digits of his right foot which was initially diagnosed as a diabetic foot ulcer. Despite local wound care, the lesion did not resolve. A shave biopsy was performed and histopathology findings were consistent with classic Kaposi sarcoma.

Conclusions

The patient tolerated local radiotherapy well and had complete resolution of his pedal lesion. There have been emerging associations between diabetes and Kaposi sarcoma. As such, clinicians should have a low threshold when considering the biopsy of suspicious pedal lesions in patients with diabetes. The utilization of appropriate biopsy technique may lead to the diagnosis of classic KS tumors in populations outside of the current four widely accepted clinical subtypes.

Contemporary critical limb ischemia: Asian multidisciplinary consensus statement on the collaboration between endovascular therapy and wound care

The burden of peripheral artery disease (PAD) and diabetes in Asia is projected to increase. Asia also has the highest incidence and prevalence of end-stage renal disease (ESRD) in the world. Therefore, most Asian patients with PAD might have diabetic PAD or ESRD-related PAD. Given these pandemic conditions, critical limb ischemia (CLI) with diabetes or ESRD, the most advanced and challenging subset of PAD, is an emerging public health issue in Asian countries. Given that diabetic and ESRD-related CLI have complex pathophysiology that involve arterial insufficiency, bacterial infection, neuropathy, and foot deformity, a coordinated approach that involves endovascular therapy and wound care is vital. Recently, there is increasing interaction among cardiologists, vascular surgeons, radiologists, orthopedic surgeons, and plastic surgeons beyond specialty and country boundaries in Asia. This article is intended to share practical Asian multidisciplinary consensus statement on the collaboration between endovascular therapy and wound care for CLI.

Prospective study on microangiopathy in type 2 diabetic foot ulcer

AIMS/HYPOTHESIS

We investigated the significance of microangiopathy in the development of foot ulcer, which is still disputed.

METHODS

We assessed microangiopathy by histological analysis of the capillary ultrastructure using transmission electron microscopy and capillary density and arteriolar morphology in paraffin-embedded sections from the skin of type 2 diabetic patients: 30 neuroischaemic patients (Isc) revascularised with peripheral angioplasty and 30 neuropathic patients (Neu) with foot ulcer, compared with ten non-diabetic volunteers.

RESULTS

In the diabetic patients, capillaries in the dermal papillary layer were fewer (-22.2%, 159 ± 43 vs 205 ± 52 mm(2) in non-diabetic volunteers, p < 0.01). They also showed detrimental remodelling, with a 2.2-fold increase in capillary basement membrane thickness (3.44 ± 1.19 vs 1.53 ± 0.34 μm in non-diabetic volunteers, p < 0.001) and a 57.7% decrease in lumen area (14.6 ± 11.1 vs 34.7 ± 27.5 μm(2), p < 0.001). No differences were observed between the diabetic Isc or Neu patients. Isc were more prone to develop arteriolar occlusion than Neu (16.8 ± 6.9% vs 6.7 ± 3.7%, respectively, p < 0.001). No patient had been amputated at 30 days and healing time was significantly longer in Isc (180 ± 120 vs 64 ± 50 days in Neu, p < 0.001).

CONCLUSIONS/INTERPRETATION

Capillary microangiopathy is present in equal measure in neuroischaemic and neuropathic diabetic foot skin. The predominance of arteriolar occlusions with neuroischaemia indicated the existence of an additional 'small vessel disease' that did not affect an effective revascularisation and did not worsen the prognosis of major amputations but slowed the healing process of the neuroischaemic foot ulcer.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02610036.

Multivalent Conjugates of Sonic Hedgehog Accelerate Diabetic Wound Healing

Despite their preclinical promise, few recombinant growth factors have been fully developed into effective therapies, in part, due to the short interval of therapeutic activity after administration. To address this problem, we developed nanoscale polymer conjugates for multivalent presentation of therapeutic proteins that enhance the activation of targeted cellular responses. As an example of this technology, we conjugated multiple Sonic hedgehog (Shh) proteins onto individual hyaluronic acid biopolymers to generate multivalent protein clusters at defined ratios (i.e., valencies) that yield enhanced Shh pathway activation at equivalent concentrations relative to unconjugated Shh. In this study, we investigated whether these multivalent conjugates (mvShh) could be used to improve the therapeutic function of Shh. We found that a single treatment with mvShh significantly accelerated the closure of full-thickness wounds in diabetic (db/db) mice compared to either an equivalent dose of unconjugated Shh or the vehicle control. Furthermore, we identified specific indicators of wound healing in fibroblasts and endothelial cells (i.e., transcriptional activation and cell migration) that were activated by mvShh in vitro and at concentrations approximately an order of magnitude lower than the unconjugated Shh. Taken together, our findings suggest that mvShh conjugates exhibit greater potency to activate the Shh pathway, and this multivalency advantage improves its therapeutic effect to accelerate wound closure in a diabetic animal model. Our strategy of multivalent protein presentation using nanoscale polymer conjugates has the potential to make a significant impact on the development of protein-based therapies by improving their in vivo performance.

Prevalence of Peripheral Arterial Disease in Patients With Diabetic Charcot Neuroarthropathy

Charcot neuroarthropathy (CN) is a serious complication of diabetes mellitus (DM) that can lead to pedal ulceration, infection, hospitalization, and amputation. Peripheral arterial disease (PAD) is also found in patients with diabetic foot disease; however, its prevalence in patients with CN has not been extensively evaluated. The aim of the present study was to evaluate the prevalence of PAD in a group of patients with CN (with and without ulceration) and compare this to a group of patients with diabetic foot ulceration (DFU) and no CN. We compared the lower extremity noninvasive arterial testing results of 85 patients with DM and CN with those from a group of 126 patients with DFU and no CN. No statistically significant differences were found in age, gender, type of DM (1 versus 2), insulin use, duration of DM, or history of dialysis between our study and control groups. The prevalence of PAD in the patients with CN was 40%. Compared with patients with DFUs, the patients with CN were less likely to have PAD (odds ratio 0.48, 95% confidence interval 0.28 to 0.85; p = .0111), ischemia (odds ratio 0.33, 95% confidence interval 0.16 to 0.69; p = .0033), or the need for revascularization (odds ratio 0.27, 95% confidence interval 0.10 to 0.73; p = .0097). Critical limb ischemia (great toe pressure <30 mm Hg) was 82% less likely in patients with CN than in patients with DFU. PAD in patients with CN is not uncommon; however, ischemia and the need for revascularization were significantly less likely than in patients with DFU without CN.

Lower limb ischaemia in patients with diabetic foot ulcers and gangrene: recognition, anatomic patterns and revascularization strategies

The confluence of several chronic conditions--in particular ageing, peripheral artery disease, diabetes, and chronic kidney disease--has created a global wave of lower limbs at risk for major amputation. While frequently asymptomatic or not lifestyle limiting, at least 1% of the population has peripheral artery disease of sufficient severity to be limb threatening. To avoid the critical error of failing to diagnose ischaemia, all patients with diabetic foot ulcers and gangrene should routinely undergo physiologic evaluation of foot perfusion. Ankle brachial index is useful when measurable, but may be falsely elevated or not obtainable in as many as 30% of patients with diabetic foot ulcers primarily because of medial calcinosis. Toe pressures and skin perfusion pressures are applicable to such patients.

Organization of wound healing services: The impact on lowering the diabetes foot amputation rate in a ten-year review and the importance of early debridement

Diabetes foot ulceration (DFU) has a negative impact on the quality of life and leads to disabling morbidity, such as lower extremity amputation (LEA). This study aimed to evaluate the LEA trend before and after the establishment of the diabetes foot team, an on-time debridement, on-site screening, and multidisciplinary integration with standardizing care, in Chang Gung Memorial Hospital, Chia Yi, Taiwan, starting in 2010. The study retrospectively investigated the non-traumatic LEA rate in diabetes foot (identified by using ICD-9-Clinical Modification (CM) codes, 250.70-250.83) and whole patients with diabetes (ICD-9 250.XX) yearly from 2004 to 2013. Patients were enrolled from hospitalization, emergency room (ER), or outpatient departments, respectively. Despite the overall incidence of diabetes foot in patients with diabetes remaining constant, from 3.47% in 2004 to 3.58% in 2013, the incidence of hospitalized diabetes foot from diabetes reduced, from 2.83% in 2004 to 1.51% in 2013. Introduction of integrated wound care also led to a reduction of the average LEA rate in hospitalized patients, from 15.27% (2004-2009) to 6.08% (2010-2013) (P<0.001). A similar decline of the LEA rate was observed for patients from hospitalization, ER and outpatient departments together with an average LEA rate from 7.99% (2004-2009) down to 3.02% (2010-2013) (P<0.001). In trend analysis, the curve estimation revealed a quadratic trend in the relationship between LEA rate and time (R-square=0.869, P=0.001) for hospitalized patients as well as a linear (R-square=0.819, P<0.001) and quadratic (R-square=0.845, P=0.001) trend in the relationship between LEA rate and time for hospitalization, ER, and outpatient departments together. The LEA rate for DM patients declined from 372.72/100,000 in 2004 to 61.74/100,000 in 2013. With establishment of an organizing, standardized wound care protocol and integrated multidisciplinary team, we demonstrated a significant decline in the LEA rate both in diabetes foot patients and all patients with diabetes. These improvements can be attributed to introducing an efficient pathway with on-time debridement and early intervention of diabetes foot ulcers.

Underrecognized Peripheral Arterial Disease in Patients With Diabetes Mellitus in Thailand: We Must Consider Neuroischemic Foot Ulcers From This Fallout

A range of prevalence of peripheral artery disease in diabetic patients has been estimated using the measurement of ankle brachial pressure index and clinical features in Asian countries. These data may be underestimates and hence underrecognized, raising questions about the numbers of patients with neuroischemic feet who are also at risk of diabetic foot ulcers. Underrecognition of these lesions may well increase the high levels of chronic wound burden resulting from peripheral artery disease as well as neuroischemic foot lesions. Improved education and training of clinical staff (nurses and family physicians) is required to combat these serious issues.

Update and validation of the Society for Vascular Surgery wound, ischemia, and foot infection threatened limb classification system

The diagnosis of critical limb ischemia, first defined in 1982, was intended to delineate a patient cohort with a threatened limb and at risk for amputation due to severe peripheral arterial disease. The influence of diabetes and its associated neuropathy on the pathogenesis-threatened limb was an excluded comorbidity, despite its known contribution to amputation risk. The Fontaine and Rutherford classifications of limb ischemia severity have also been used to predict amputation risk and the likelihood of tissue healing. The dramatic increase in the prevalence of diabetes mellitus and the expanding techniques of arterial revascularization has prompted modification of peripheral arterial disease classification schemes to improve outcomes analysis for patients with threatened limbs. The diabetic patient with foot ulceration and infection is at risk for limb loss, with abnormal arterial perfusion as only one determinant of outcome. The wound extent and severity of infection also impact the likelihood of limb loss. To better predict amputation risk, the Society for Vascular Surgery Lower Extremity Guidelines Committee developed a classification of the threatened lower extremity that reflects these important clinical considerations. Risk stratification is based on three major factors that impact amputation risk and clinical management: wound, ischemia, and foot infection. This classification scheme is relevant to the patient with critical limb ischemia because many are also diabetic. Implementation of the wound, ischemia, and foot infection classification system in critical limb ischemia patients is recommended and should assist the clinician in more meaningful analysis of outcomes for various forms of wound and arterial revascularizations procedures required in this challenging, patient population.

Transformation of the Multidisciplinary Diabetic Foot Clinic Into a Multidisciplinary Diabetic Foot Day Unit

The natural history of the diabetic foot is aggressive and complex. To counteract this, we describe the transformation of a Multidisciplinary Diabetic Foot Clinic into a Multidisciplinary Diabetic Foot Day Unit, which delivers an emergency open access system for patients, with a “one-stop,” same day service in which investigations are performed, results reviewed and treatment implemented. It also provides joint clinics with vascular, orthopaedic, and plastic surgeons and specialized clinics for casting of complex neuropathic feet and for the administration of intravenous or intramuscular antibiotics on the same day. The aim was to document these increasingly wide-ranging facilities by undertaking a retrospective evaluation over a 6-week period, with analysis of notes, investigations, and an anonymous patient satisfaction survey. The clinic was visited by 597 patients who attended in 1076 appointments, of which 112 (10.4%) were emergency visits; these patients attended the clinic without a booked appointment but via an open access policy, 93 of whom were known to the clinic, but 19 were new self-referred patients to the service. Furthermore, 197 (18%) were seen in a Joint Vascular Diabetic Foot Clinic and 98 (9%) were seen in a Joint Orthopaedic Plastic Diabetic Foot Clinic, 570 (53%) were seen in an Active Ulcer Clinic and 97 (9%) in a Total Contact Casting Clinic. Forty-five percent of patients were prescribed antibiotics, including 188 (76%) as oral and 45(18%) as intravenous antibiotics and 15(6%) as intramuscular injections. Of the 1076 appointments, 150 (14%) patients were in the foot clinic for more than 4 hours. Sixty (10%) patients were reviewed 4 or more times over the 6-week period. Only 22 (2%) were admitted to hospital. Of the 125 survey responders, 98% were satisfied with this service, which has evolved from a Diabetic Foot Clinic into a Multidisciplinary Diabetic Foot Day Unit.

The Society for Vascular Surgery Lower Extremity Threatened Limb Classification System: risk stratification based on wound, ischemia, and foot infection (WIfI)

Critical limb ischemia, first defined in 1982, was intended to delineate a subgroup of patients with a threatened lower extremity primarily because of chronic ischemia. It was the intent of the original authors that patients with diabetes be excluded or analyzed separately. The Fontaine and Rutherford Systems have been used to classify risk of amputation and likelihood of benefit from revascularization by subcategorizing patients into two groups: ischemic rest pain and tissue loss. Due to demographic shifts over the last 40 years, especially a dramatic rise in the incidence of diabetes mellitus and rapidly expanding techniques of revascularization, it has become increasingly difficult to perform meaningful outcomes analysis for patients with threatened limbs using these existing classification systems. Particularly in patients with diabetes, limb threat is part of a broad disease spectrum. Perfusion is only one determinant of outcome; wound extent and the presence and severity of infection also greatly impact the threat to a limb. Therefore, the Society for Vascular Surgery Lower Extremity Guidelines Committee undertook the task of creating a new classification of the threatened lower extremity that reflects these important considerations. We term this new framework, the Society for Vascular Surgery Lower Extremity Threatened Limb Classification System. Risk stratification is based on three major factors that impact amputation risk and clinical management: Wound, Ischemia, and foot Infection (WIfI). The implementation of this classification system is intended to permit more meaningful analysis of outcomes for various forms of therapy in this challenging, but heterogeneous population.

Adjunct methods of the standard diabetic foot ulceration therapy

The outcome of management of diabetic foot ulceration (DFU) is poor and insufficient. DFU therapy includes the standard management as debridement of the wound, revascularization procedures, off-loading of the ulcer and antibacterial actions, and supplementation of growth factors and cytokines, leading to stimulation of granulation, epidermization, and angiogenesis. The aim of the present review is to summarize the adjunct methods of the standard DFU therapy as hyperbaric oxygen therapy (HBOT), maggot therapy (MT), and platelet-rich plasma therapy (PRPT). The results of preclinical and clinical trials indicated that the methods may reduce time of therapy, short-term morbidity, and the risk of major amputation.

Health service pathways for patients with chronic leg ulcers: identifying effective pathways for facilitation of evidence based wound care

BACKGROUND

Chronic leg ulcers cause long term ill-health for older adults and the condition places a significant burden on health service resources. Although evidence on effective management of the condition is available, a significant evidence-practice gap is known to exist, with many suggested reasons e.g. multiple care providers, costs of care and treatments. This study aimed to identify effective health service pathways of care which facilitated evidence-based management of chronic leg ulcers.

METHODS

A sample of 70 patients presenting with a lower limb leg or foot ulcer at specialist wound clinics in Queensland, Australia were recruited for an observational study and survey. Retrospective data were collected on demographics, health, medical history, treatments, costs and health service pathways in the previous 12 months. Prospective data were collected on health service pathways, pain, functional ability, quality of life, treatments, wound healing and recurrence outcomes for 24 weeks from admission.

RESULTS

Retrospective data indicated that evidence based guidelines were poorly implemented prior to admission to the study, e.g. only 31% of participants with a lower limb ulcer had an ABPI or duplex assessment in the previous 12 months. On average, participants accessed care 2-3 times/week for 17 weeks from multiple health service providers in the twelve months before admission to the study clinics. Following admission to specialist wound clinics, participants accessed care on average once per week for 12 weeks from a smaller range of providers. The median ulcer duration on admission to the study was 22 weeks (range 2-728 weeks). Following admission to wound clinics, implementation of key indicators of evidence based care increased (p < 0.001) and Kaplan-Meier survival analysis found the median time to healing was 12 weeks (95% CI 9.3-14.7). Implementation of evidence based care was significantly related to improved healing outcomes (p < 0.001).

CONCLUSIONS

This study highlights the complexities involved in accessing expertise and evidence based wound care for adults with chronic leg or foot ulcers. Results demonstrate that access to wound management expertise can promote streamlined health services and evidence based wound care, leading to efficient use of health resources and improved health.

Pressure-relieving interventions for treating diabetic foot ulcers

BACKGROUND

Diabetes-related foot ulceration is a major contributor to morbidity in diabetes. Diabetic foot ulcers are partly a consequence of abnormal foot pressures and pressure relief is a widely used treatment for healing diabetes-related plantar foot ulcers, but the most effective method for healing is unclear.

OBJECTIVES

To determine the effects of pressure-relieving interventions on the healing of foot ulcers in people with diabetes.

SEARCH METHODS

For this update we searched the Cochrane Wounds Group Specialised Register (searched 2 November 2012); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 10); Ovid MEDLINE (1950 to October Week 4 2012); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, October 31, 2012); Ovid EMBASE (1980 to 2012 Week 43); and EBSCO CINAHL (1982 to 1 November 2012). There were no restrictions based on language or publication status.

SELECTION CRITERIA

Randomised controlled trials evaluating the effects of pressure-relieving interventions on the healing of foot ulcers in people with diabetes.

DATA COLLECTION AND ANALYSIS

Data from eligible trials were extracted, and summarised using a data extraction sheet, by two review authors independently.

MAIN RESULTS

Fourteen trials (709 participants) met the inclusion criteria for the review. One study compared two different types of non-removable casts with no discernable difference between the groups. Seven studies (366 participants) compared non-removable casts with removable pressure-relieving devices. In five of those studies non-removable casts were associated with a statistically significant increase in the number of ulcers healed compared with the removable device (RR 1.17 95% CI 1.01 to 1.36: P value = 0.04).Two studies (98 participants) found that significantly more ulcers healed with non-removable casts than with dressings alone. Achilles tendon lengthening combined with a non-removable cast in one study resulted in significantly more healed ulcers at 7 months than non-removable cast alone (RR 2.23; 95% CI 1.32 to 3.76). More ulcers remained healed at two years in this group (RR 3.41; 95% CI 1.42 to 8.18).Other comparisons included surgical debridement of ulcers; felt fitted to the foot; felted foam dressings and none of these showed a statistically significant treatment effect in favour of the intervention.

AUTHORS' CONCLUSIONS

Non-removable, pressure-relieving casts are more effective in healing diabetes related plantar foot ulcers than removable casts, or dressings alone. Non-removable devices, when combined with Achilles tendon lengthening were more successful in one forefoot ulcer study than the use of a non-removable cast alone.

A diabetic foot service established by a department of vascular surgery: an observational study

BACKGROUND

The mechanism by which the multidisciplinary approach to diabetic foot disease reduces amputation rates is unclear. Ischemia, sepsis, and necrosis represent aspects of severe diabetic foot disease amenable to intervention. In 2006, a vascular unit introduced a rapid access service for severe foot disease, augmenting the established community provision. This study aimed to determine whether concurrent changes in amputation rates were observed, and to identify areas that may have influenced outcomes.

METHODS

Unit data prospectively collected during 4 years for patients with lower-limb disease were compared with data retrieved over 2 years before the foot service. Outcome measurements were major amputations, foot surgery, vascular interventions, admissions, and length of stay.

RESULTS

Major amputation rates associated with diabetes peaked in 2005 at 24.7/10,000 vs. 1.07/10,000 in 2009; (relative risk = 0.043, 95% confidence interval = 0.006-0.322). The proportion of diabetic to nondiabetic amputations decreased; foot surgery rates also dropped (53.7/10,000 in 2006 vs. 7.5/10,000 in 2009). The number of open revascularization procedures decreased, but the rates of endovascular procedures remained generally constant. Hospital admission rates decreased after initially peaking, and the length of stay was unchanged (16 vs. 15.5 days in 2004 and 2009, respectively).

CONCLUSIONS

The integration of a vascular unit with community care has been associated with improved outcomes for patients with diabetic foot disease. Improvements were not related to the increased number of vascular procedures or hospitalizations, but did coincide with a greater proportion of patients attending the foot unit. The referral of patients to the unit facilitates the rapid management of severe disease, reducing delays deleterious to outcomes.

Neuropathic diabetic foot ulcers - evidence-to-practice

Foot ulcers and their attendant complications are disquietingly high in people with diabetes, a majority of whom have underlying neuropathy. This review examines the evidence base underpinning the prevention and management of neuropathic diabetic foot ulcers in order to inform best clinical practice. Since it may be impractical to ask patients not to weight-bear at all, relief of pressure through the use of offloading casting devices remains the mainstay for management of neuropathic ulcers, whilst provision of appropriate footwear is essential in ulcer prevention. Simple non-surgical debridement and application of hydrogels are both effective in preparing the wound bed for healthy granulation and therefore enhancing healing. Initial empirical antibiotic therapy for infected ulcers should cover the most common bacterial flora. There is limited evidence supporting the use of adjunctive therapies such as hyperbaric oxygen and cytokines or growth factors. In selected cases, recombinant human platelet-derived growth factor has been shown to enhance healing; however, its widespread use cannot be advised due to the availability of more cost-effective approaches. While patient education may be beneficial, the evidence base remains thin and conflicting. In conclusion, best management of foot ulcers is achieved by what is taken out of the foot (pressure, callus, infection, and slough) rather than what is put on the foot (adjuvant treatment).

Efficacy, safety, and tolerability of NGX-4010, capsaicin 8% patch, in an open-label study of patients with peripheral neuropathic pain

AIMS

To assess efficacy, safety, and tolerability of NGX-4010, capsaicin 8% patch, in patients with peripheral neuropathic pain.

METHODS

This open-label, uncontrolled, 12-week study enrolled 25 patients with postherpetic neuralgia (PHN), one with HIV-distal sensory polyneuropathy, and 91 with painful diabetic neuropathy (PDN). Patients received pre-treatment with one of three 4% lidocaine topical anesthetics (L.M.X.4¹, Topicaine Gel², or Betacaine Enhanced Gel 4³) followed by a single 60- or 90-min NGX-4010 application. The primary efficacy variable was the percentage change in Numeric Pain Rating Scale scores from baseline to Weeks 2-12. Adverse events (AEs), laboratory parameters, vital signs, neurosensory examinations, dermal assessments, treatment-related pain scores, and medication use for treatment-related pain were collected.

RESULTS

PDN and PHN patients achieved a 31% and 28% mean pain decrease from baseline during Weeks 2-12, respectively, and 47% and 44%, respectively, were responders (≥30% pain decrease). Mild or moderate treatment-site-related burning and pain were the most common AEs and there was no evidence of impaired neurosensory function.

CONCLUSIONS

NGX-4010 in conjunction with any of the three topical anesthetics tested was generally safe and well tolerated and reduced pain over a 12-week period in patients with PDN and PHN.

Diabetic foot disease in people with advanced nephropathy and those on renal dialysis

Among the spectrum of risk for diabetic foot disease conferred by chronic kidney disease (CKD), end-stage renal disease (ESRD) has emerged as a novel independent risk factor. Apart from the classical triad of neuropathy, infection, and peripheral arterial disease that operate in these individuals, the risk is further compounded by inadequate foot self-care by patients and by dialysis centers not providing onsite foot care, as medical priorities are diverted to the dialysis itself. Consequently, the burden of diabetic foot disease has increased in the CKD and ESRD population as exemplified by high ulceration, amputation, and foot-related mortality rates. Current guidelines on foot care in diabetes should recognize advanced CKD and ESRD/dialysis as a separate risk factor for foot disease to alert professionals and highlight the opportunity for prevention. Recent studies have demonstrated improved foot outcomes when chiropody programs are instituted within dialysis units.