Assessment of foot perfusion in patients with a diabetic foot ulcer

A portable optical pulsatile flowmetry demonstrates strong clinical relevance for diabetic foot perfusion assessment

We present a robust, cost-effective (<2000 USD), and portable optical diffuse speckle pulsatile flowmetry (DSPF) device with a flexible handheld probe for deep tissue blood flow measurement in the human foot as well as a first-in-man observational clinical study using the proposed optical device for tissue ischemia assessment and peripheral artery disease (PAD) diagnosis. Blood flow in tissue is inherently pulsatile in nature. However, most conventional methods cannot measure deep tissue-level pulsatile blood flow noninvasively. The proposed optical device can measure tissue-level pulsatile blood flow ∼6 mm underneath the skin surface. A new quantitative tissue perfusion index (TPIDSPF) based on frequency domain analysis of the pulsatile blood flow waveform is defined to assess tissue ischemia status. Through a clinical study involving 66 subjects, including healthy individuals and diabetes patients with and without PAD, TPIDSPF demonstrated strong correlations of 0.720 with transcutaneous tissue partial oxygen pressure (TcPO2) and 0.652 with toe-brachial index (TBI). Moreover, among the three methods, TPIDSPF demonstrated the highest area under the curve for PAD diagnosis among diabetes patients, with a notable value of 0.941. The promising clinical results suggest that the proposed optical method has the potential to be an effective clinical tool for identifying PAD among the diabetic cohort.

Repeatability of [15O]H2O PET imaging for lower extremity skeletal muscle perfusion: a test-retest study

BACKGROUND

[15O]H2O PET/CT allows noninvasive quantification of tissue perfusion and can potentially play a future role in the diagnosis and treatment of peripheral artery disease. We aimed to evaluate the reliability of dynamic [15O]H2O PET imaging for measuring lower extremity skeletal muscle perfusion. Ten healthy participants underwent same-day test-retest study with six dynamic [15O]H2O PET scans of lower legs and feet. Manual volume-of-interests were drawn in skeletal muscles, and PET time activity curves were extracted. K1 values (mL/min/100 mL) were estimated using a single-tissue compartment model (1TCM), autoradiography (ARG), and parametric imaging with blood input functions obtained from separate heart scans.

RESULTS

Resting perfusion values in the muscle groups of the lower legs ranged from 1.18 to 5.38 mL/min/100 mL (ARG method). In the muscle groups of the feet, perfusion values ranged from 0.41 to 3.41 mL/min/100 mL (ARG method). Test-retest scans demonstrated a strong correlation and good repeatability for skeletal muscle perfusion with an intraclass correlation coefficient (ICC) of 0.88 and 0.87 and a repeatability coefficient of 34% and 53% for lower legs and feet, respectively. An excellent correlation was demonstrated when comparing volume-of-interest-based methods (1TCM and ARG) (lower legs: ICC = 0.96, feet: ICC = 0.99). Parametric images were in excellent agreement with the volume-of-interest-based ARG method (lower legs: ICC = 0.97, feet: ICC = 0.98).

CONCLUSION

Parametric images and volume-of-interest-based methods demonstrated comparable resting perfusion values in the lower legs and feet of healthy individuals. The largest variation was seen between individuals, whereas a smaller variation was seen between muscle groups. Repeated measurements of resting blood flow yielded a strong overall correlation for all methods.

Incoherent optical fluctuation flowmetry for detecting limbs with hemodynamically significant stenoses in patients with type 2 diabetes

INTRODUCTION

The development of new highly accurate, inexpensive and accessible methods for the detection of lower-extremity peripheral artery disease (LE-PAD) in diabetic patients is required. The aim of this study was to evaluate the accuracy of a new incoherent optical fluctuation flowmetry (IOFF) method in detecting legs with hemodynamically significant stenoses compared to ankle brachial index (ABI) and transcutaneous oximetry (TcPO2) in patients with diabetes mellitus (DM).

MATERIALS AND METHODS

Patients were recruited into 2 groups. Group 1 included patients with DM without LE-PAD and/or diabetic foot syndrome; Group 2 included patients with DM and LE-PAD. All patients underwent the following measurements: ultrasound (reference method), ABI, TcPO2, and the new IOFF method.

RESULTS

The new IOFF method showed a sensitivity of 79.5% and a specificity of 89.8% in detecting limbs with hemodynamically significant stenosis (AUC 0.890, CI 0.822-0.957). TcpO2 allows the diagnosis of LE-PAD with 69.2% sensitivity and 86.2% specificity (AUC 0.817, CI 0.723-0.911). Using a standard ABI cut-off of less than 0.9, the sensitivity and specificity for this parameter were 34.5% and 89.7%, respectively. Increasing the diagnostic cut-off of the ABI on the study group to 0.99 improved sensitivity to 84.6% and specificity to 78% (AUC,0.824 CI 0.732-0.915).

CONCLUSIONS

The new IOFF technique has demonstrated high sensitivity and specificity in the detection of LE-PAD in patients with DM. The high accuracy, rapid measurement, and potential availability suggest that the new IOFF method has a high potential for clinical application in the detection of PAD.

Diabetic Soft Tissue Infections

Diabetes is a systemic illness that can cause a broad range of physiologic effects. Infection rates and wound healing are both affected through multiple mechanisms. Other physiologic changes increase risk for wounds as well as complex soft tissue infections ranging from simple cellulitis to necrotizing soft tissue infections. Clinicians and surgeons need to have a low index of suspicion for severe infection in a patient presenting with diabetes, and even more so in patients with uncontrolled diabetes.

Does the advantage of transcutaneous oximetry measurements in diabetic foot ulcer apply equally to free flap reconstruction?

BACKGROUND

Transcutaneous oxygen pressure (TcpO₂) is a precise method for determining oxygen perfusion in wounded tissues. The device uses either electrochemical or optical sensors.

AIM

To evaluate the usefulness of TcpO₂ measurements on free flaps (FFs) in diabetic foot ulcers (DFUs).

METHODS

TcpO₂ was measured in 17 patients with DFUs who underwent anterolateral thigh (ALT)-FF surgery and compared with 30 patients with DFU without FF surgery.

RESULTS

Significant differences were observed in the ankle-brachial index; duration of diabetes; and haemoglobin, creatinine, and C-reactive protein levels between the two groups. TcpO₂ values were similar between two groups except on postoperative days 30 and 60 when the values in the ALT-FF group remained < 30 mmHg and did not increase > 50 mmHg.

CONCLUSION

Even if the flap is clinically stable, sympathectomy due to adventitia stripping during anastomosis and arteriovenous shunt progression due to diabetic polyneuropathy could lead to low TcpO₂ values in the ALT-FF owing to its thick fat tissues, which is supported by the slow recovery of the sympathetic tone following FF. Therefore, TcpO₂ measurements in patients with DFU who underwent FF reconstruction may be less accurate than in those who did not.

Correlation of leg pain responses with ankle-brachial index and peripheral sensory responses in foot of type 2 diabetes mellitus

Introduction: Type 2 Diabetes Mellitus (T2DM) is associated with changes that occur in the peripheral circulation that affect foot functions. Therefore, there is a need for a risk prediction test on foot abnormalities using the leg pain response parameters in T2DM patients with ankle-brachial index (ABI) and peripheral sensory changes as a preventive effort to manage foot care. Design and Methods: This study employed a cross-sectional design in which 63 T2DM patients in a Public Health Center (PHC) in Malang were investigated. The instruments used include visual analog scale (VAS), monofilament, and foot doppler. Results: The Pearson correlation test showed no relationship between the responses to leg pain and the ABI of the right and left feet (p-values = 0.217 and 0.692), but there was a significant relationship between the left foot ABI and sensory status (p-value 0.002; left foot r = 0.383). Meanwhile, the Pearson's correlation and linear regression test also showed a relationship between the right foot ABI and sensory status (p-value = 0.007; r = 0.338). Furthermore, a multiple linear regression test showed a relationship between the leg pain response and sensory perception of the right and left feet (p-value = 0.035; r = 0.325). Conclusions: The relationship between the sensory status of the right and left feet and the response to leg pain in T2DM patients were moderate with a negative direction. It, therefore, implies that a decrease in the sensory responses increased the leg pain. Meanwhile, the moderate relationship and positive direction between the ABI and sensory status of the feet of T2DM patients indicates that a higher ABI score led to an increase in the sensory status of the foot.

Effect of the human endotoxin challenge on tedizolid tissue penetration

The effects of the human endotoxin challenge on tissue pharmacokinetics are unknown. In the present study, we aimed to assess the effect of the endotoxin challenge on interstitial fluid pharmacokinetics of tedizolid in healthy volunteers using intramuscular microdialysis. Eight healthy male subjects were treated with 200 mg of tedizolid phosphate for 6 days. On Day 6, an intravenous bolus of lipopolysaccharide (LPS) (2 ng/kg body weight) was administered. LPS infusion did not affect plasma pharmacokinetics of tedizolid. In contrast, following LPS infusion, median muscle tissue fAUC (0.83 [0.75-1.15] vs. 1.14 [1.11-1.43] mg × h/L, P = .0078) and muscle tissue fC_max (0.15 [0.14-0.19] vs. 0.19 [0.18-0.24] mg/L, P = .0078) were significantly increased by 38% and 24%, respectively. The human endotoxin challenge was associated with increased tissue concentrations of tedizolid, without affecting its plasma concentration-time profile. The human endotoxin challenge combined with microdialysis may be used to investigate the influence of systemic inflammation on tissue pharmacokinetics.

[Evaluation of tissue perfusion by indocyanine green fluorescein angiography in patients with neuroischemic diabetic foot syndrome after endovascular treatment]

OBJECTIVE

To evaluate the fluorescence angiography (FA) parameters with Indocyanine green (ICG) and their dynamics in diabetic foot patients after endovascular treatment.

MATERIAL AND METHODS

A single-center prospective non-blinded study was conducted with the inclusion of 47 diabetic foot patients with Chronic limb-threatening ischemia (CLTI). TcPO2 and FA-ICG were done before and after angioplasty. Zones of interest were selected for FA-ICG: the area of minimum and maximum fluorescence, the area of of the largest part of the foot. Also presented are the parameters of FA ICG: Tstart (sec) - the time of occurrence of min fluorescence (Istart, unit) in the zone of interest after the introduction of ICG; Tmax (sec) - the time to achieve max fluorescence (Imax, unit) after the introduction of ICG; Tmax -Tstart (sec) - the difference in the time of reaching Imax and Istart.

RESULTS

The median TcPO2 values indicated the presence of CLTI before revascularization. Technical success of revascularization was achieved in 45 patients. In the postoperative period, statistically significant changes in TcPO2 and Tstart, Tmax, Tmax-Tstar were obtained. A reduction in the time to reach the ICZ to the zones of interest was noted.

CONCLUSION

FA-ICG evaluate the visual and quantitative characteristics of perfusion of soft tissues of the foot. Reducing the time to reach the fluorescent substance in the areas of interest makes it possible to assume the restoration of the main blood flow to the foot. Further investigations are warranted to determine threshold values to predict wound healing and indications for revascularization.

Incoherent Optical Fluctuation Flowmetry: A New Method for the Assessment of Foot Perfusion in Patients with Diabetes-Related Lower-Extremity Complications

(1) Background: To date, there are no studies evaluating the ability of the incoherent optical fluctuation flowmetry (IOFF) method to assess foot tissue perfusion. The aim of this study was to evaluate the correlation between perfusion values measured by IOFF and TcPO2 in patients with diabetes-related lower-extremity complications. (2) Methods: This was an observational, cross-sectional, two-center study. Diabetic patients with peripheral artery disease and/or diabetic foot ulcers were studied (n = 27, examinations were carried out on 54 legs). Perfusion in the foot tissues was assessed using TcPO2 (reference standard for this study) and the IOFF method. (3) Results: High correlation coefficients of all perfusion parameters measured by IOFF with TcPO2 (Rs 0.7 to 0.76) were shown. The study demonstrated that the IOFF method allows, with a sensitivity of 85.7% and a specificity of 90.0%, the identification of patients with a critical decrease in TcPO2 < 20 mmHg. (4) Conclusions: The high correlation of IOFF parameters with TcPO2 and the moderately high sensitivity and specificity in detecting patients with severe ischemia of foot tissues shows the promise of the method for assessing a tissue perfusion in patients with diabetes-related lower-extremity complications.

Analysis of peripheral arterial disease (PAD) patients by laser speckle measurement techniques

Diabetic foot is a well-known problem among patients suffering from peripheral arterial diseases (PAD). This article presents an optical sensor for contactless measurement of the anatomical site based on laser speckle techniques. The sensor illuminates the inspected tissue and analyzes the captured back-reflected light from the time-changing speckle patterns. An occlusion test was implemented to provide a statistical parameter to differentiate between a low perfused and a healthy foot. A clinical study of 15 subjects was conducted. The video was analyzed by two methods: dynamic laser speckle (DLS) and laser speckle contrast analysis (LASCA). Data analysis included several classification models, where the KNN model exhibited maximum performance. These findings suggest that a simple and inexpensive system for PAD monitoring can be designed for home use and/or in community clinics.

Overcoming severe calcified lower extremity artery in lower limb salvage operation by using the Fogarty catheter and vein graft

BACKGROUND

With severe vascular calcifications, vascular clamp application and utilizing the vessel for free flap recipient vessel becomes impossible. These obstacles can be overcome with the Fogarty catheter and vein graft.

PATIENTS AND METHODS

When unclampable artery was encountered intraoperatively, a vein graft was used to make a clampable recipient site for six diabetic foot patients (ages from 42 to 80). The end of the Fogarty catheter was inserted into the proximal end of the vein graft and the transected calcified vessel in sequence, and the balloon of the catheter was used as an intraluminal tourniquet. The remaining end of the vein graft was connected to the distal vessel with a vascular clamp.

RESULTS

Five short vein graft revascularization for segmental arterial occlusion, one long vein graft for recipient artery elongation was done (lengths from 2 to 13.8 cm). Three delayed, and two immediate anterolateral thigh flaps (sizes from 15 to 150 cm² ) were performed, and one patient received vein graft revascularization surgery only. Postoperative vascular sonography of all six patients showed well-maintained patency. Minor flap marginal disruption occurred at two patients but healed with conservative care. Postoperative follow-up was done for 1-18 months (average 7.17). Limb salvage was achieved for five patients and all five free flaps survived. However, for one patient, arterial restenosis at popliteal artery a month later lead to major amputation.

CONCLUSION

Using a Fogarty catheter and a vein graft may obtain perfect hemostasis during micro-anastomosis and achieve successful microvascular reconstruction in patients with severely calcified vessels.

Protocol for a prospective observational study: the Australia and New Zealand Diabetic and Ischaemic Foot Outcomes Study (ANZ-DIFOS)

INTRODUCTION

Diabetic foot disease is a common condition globally and is over-represented in indigenous populations. The propensity for patients with diabetic foot disease to undergo minor or major limb amputation is a concern. Diabetic foot disease and lower limb amputation are debilitating for patients and have a substantial financial impact on health services. The purpose of this multicentre study is to prospectively report the presentation, management and outcomes of diabetic foot disease, to validate existing scoring systems and assess long term outcomes for these patients particularly in relation to major limb amputation.

METHODS AND ANALYSIS

This is a multisite, international, prospective observational study, being undertaken at Waikato Hospital, New Zealand (NZ); Sir Charles Gairdner Hospital, the Royal Adelaide Hospital and the Queen Elizabeth Hospital, Australia. Consecutive participants with diabetic foot disease that meet inclusion criteria and agree to participate will be recruited from multidisciplinary team diabetic foot clinic, vascular clinic, dialysis and admission to hospital. Follow-up of participants will occur at 1, 3, 6 and 12 months. At recruitment and follow-up reviews, information about service details, demographic and clinical history, wound data and discharge information will be recorded. The primary outcomes are the time to wound healing, major amputation, overall mortality and amputation-free survival at 12 months. This study started in NZ in August 2020 and will commence in Australian sites in early 2021.

ETHICS AND DISSEMINATION

New Zealand Central Health and Disability Ethics Committee (20/CEN/122), Waikato DHB Research Department (RDO020044), Quality Improvement HoD Sir Charles Gairdner Hospital (39715) and the Central Adelaide Local Health Network (CALHN) Human Research Ethics Committee (13928). Results will be presented at international conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12621000337875).

Nicotinamide Riboside Enhances Endothelial Precursor Cell Function to Promote Refractory Wound Healing Through Mediating the Sirt1/AMPK Pathway

Lack of vascularization is directly associated with refractory wound healing in diabetes mellitus (DM). Enrichment of endothelial precursor cells (EPCs) is a promising but challenging approach for the treatment of diabetic wounds. Herein, we investigate the action of nicotinamide riboside (NR) on EPC function for improved healing of diabetic wounds. Db/db mice that were treated with NR-supplemented food (400 mg/kg/d) for 12 weeks exhibited higher wound healing rates and angiogenesis than untreated db/db mice. In agreement with this phenotype, NR supplementation significantly increased the number of blood EPCs and bone marrow (BM)-derived EPCs of db/db mice, as well as the tube formation and adhesion functions of BM-EPCs. Furthermore, NR-supplemented BM-EPCs showed higher expression of sirtuin 1 (Sirt1), phosphorylated adenosine monophosphate–activated protein kinase (p-AMPK), and lower expression of acetylated peroxisome proliferator–activated receptor γ coactivator (PGC-1α) than BM-EPCs isolated from untreated db/db mice. Knockdown of Sirt1 in BM-EPCs significantly abolished the tube formation and adhesion function of NR as well as the expression of p-AMPK and deacetylated PGC-1a. Inhibition of AMPK abolished the NR-regulated EPC function but had no effect on Sirt1 expression, demonstrating that NR enhances EPC function through the Sirt1-AMPK pathway. Overall, this study demonstrates that the oral uptake of NR enhances the EPC function to promote diabetic wound healing, indicating that NR supplementation might be a promising strategy to prevent the progression of diabetic complications.

Pilot study of contrast-free MRI reveals significantly impaired calf skeletal muscle perfusion in diabetes with incompressible peripheral arteries

Patients with diabetes mellitus (DM) are more likely to have densely calcified lesions in the below-the-knee tibial arteries. However, the relationship between peripheral arterial calcification and local skeletal muscle perfusion has not been explored. Thirty subjects were prospectively recruited into three groups in this pilot study: (1) Non-DM: 10 people without DM; (2) DM, ABI < 1.3: 10 people with DM and normal ankle-brachial index (ABI) (0.9-1.3); and (3) DM, ABI ⩾ 1.3: 10 people with DM and ABI ⩾ 1.3. All subjects underwent calf perfusion measurements at rest and during an isometric plantarflexion contraction exercise within the magnetic resonance imaging (MRI) system. The noncontrast MRI techniques were applied to quantitatively assess skeletal muscle blood flow (SMBF) and oxygen extraction fraction (SMOEF) in medial gastrocnemius and soleus muscles. Both SMBF and SMOEF reserves were calculated as the ratio of the exercise value to the resting value. Exercise SMBF and SMOEF values in the medial gastrocnemius muscle were lower in the two DM groups than in the non-DM group (p < 0.05). The SMBF reserve in medial gastrocnemius was significantly lower in the DM, ABI ⩾ 1.3 group compared to the DM, ABI < 1.3 group (p < 0.05). This study demonstrates that people with DM and calcified arteries had lower perfusion in gastrocnemius muscle compared to those without DM and those with DM and a normal ABI.

The Efficacy of Cone-Beam CT-Based Perfusion Mapping in Evaluation of Tissue Perfusion in Peripheral Arterial Disease

This study investigated the use of cone-beam computed tomography (CBCT)-based perfusion mapping during percutaneous transluminal angioplasty (PTA) to predict clinical outcome in the peripheral arterial disease (PAD). From January 2016 to March 2020, 43 patients (28 male, 15 female; mean age, 69) with 51 limbs, who underwent PTA with CBCT-based foot perfusion mapping for PAD were included. Parenchymal blood volume (PBV) of foot was measured. Clinical response was investigated based on medical records. Predictive value for clinical success was evaluated using multiple logistic regression with C-statistics. Two reviewers visually assessed the improvement on angiography and CBCT-based foot perfusion mapping; inter-observer agreement of clinical success between the two were measured. Technical and clinical success rate of PTA was 90.8% and 68.6%, respectively. In multiple logistic regression, the maximum value of PBV (PBV_max) on perfusion mapping after PTA was significant (p = 0.03) for evaluating clinical success with the highest C-statistic (0.84). Using a cutoff of 235.7 mL/L for PBV_max after PTA, area under curve for prediction of clinical success was 0.664, and sensitivity and specificity were 71.4% and 68.8%, respectively. Consistency in prediction of clinical success between the two reviewers was almost perfect for CBCT-based foot perfusion mapping.

Diabetic foot and peripheral arterial disease. Single centre experience

OBJECTIVES

To determine the prevalence of vasculopathic diabetic foot and the associated factors in a Saudi tertiary center. Methods: This retrospective chart review included adult patients (≥18 years) diagnosed with diabetic foot between May 2015 and July 2019 in King Saud University Medical City, Riyadh, Kingdom of Saudi Arabia. Based on clinical presentation and laboratory results, the patients were categorized into 2 groups namely, "vascular induced diabetic foot group" and "non-vascular induced diabetic foot group".

RESULTS

A total of 404 diabetic patients were enrolled in the study. The mean age of the patients was 62.03±12.30 years; 61.9% were males. Most of the diabetic foot cases had a non-vascular etiology (n=327, 80.9%), while 77 cases (19.1%) were due to vasculopathy. Patient in the vascular group had a significantly higher incidence of coronary artery disease (32.5% versus 14.4%; p greater than 0.001), and a higher incidence of peripheral artery disease (PAD) in the unaffected limb (22.1% versus 2.1%; p less than 0.001). Conclusion: Most cases of diabetic foot were due to non-vascular causes. Old age, history of coronary artery disease, or PAD in the unaffected limb were factors that were significantly associated with diabetic foot due to arterial disease.

Hyperspectral imaging in wound care: A systematic review

Multispectral and hyperspectral imaging (HSI) are emerging imaging techniques with the potential to transform the way patients with wounds are cared for, but it is not clear whether current systems are capable of delivering real-time tissue characterisation and treatment guidance. We conducted a systematic review of HSI systems that have been assessed in patients, published over the past 32 years. We analysed 140 studies, including 10 different HSI systems. Current in vivo HSI systems generate a tissue oxygenation map. Tissue oxygenation measurements may help to predict those patients at risk of wound formation or delayed healing. No safety concerns were reported in any studies. A small number of studies have demonstrated the capabilities of in vivo label-free HSI, but further work is needed to fully integrate it into the current clinical workflow for different wound aetiologies. As an emerging imaging modality for medical applications, HSI offers great potential for non-invasive disease diagnosis and guidance when treating patients with both acute and chronic wounds.

Hyperspectral imaging in wound care: A systematic review

Multispectral and hyperspectral imaging (HSI) are emerging imaging techniques with the potential to transform the way patients with wounds are cared for, but it is not clear whether current systems are capable of delivering real-time tissue characterisation and treatment guidance. We conducted a systematic review of HSI systems that have been assessed in patients, published over the past 32 years. We analysed 140 studies, including 10 different HSI systems. Current in vivo HSI systems generate a tissue oxygenation map. Tissue oxygenation measurements may help to predict those patients at risk of wound formation or delayed healing. No safety concerns were reported in any studies. A small number of studies have demonstrated the capabilities of in vivo label-free HSI, but further work is needed to fully integrate it into the current clinical workflow for different wound aetiologies. As an emerging imaging modality for medical applications, HSI offers great potential for non-invasive disease diagnosis and guidance when treating patients with both acute and chronic wounds.

Single snapshot spatial frequency domain imaging for risk stratification of diabetes and diabetic foot

Diabetic foot is one of the major complications of diabetes. In this work, a real-time Single Snapshot Multiple-frequency Demodulation (SSMD) - Spatial Frequency Domain Imaging (SFDI) system was used to image the forefoot of healthy volunteers, diabetes, and diabetic foot patients. A layered skin model was used to obtain the 2D maps of optical and physiological parameters, including cutaneous hemoglobin concentration, oxygen saturation, scattering properties, melanin content, and epidermal thickness, from every single snapshot. We observed a strong correlation between the measured optical and physiological parameters and the degree of diabetes. The cutaneous hemoglobin concentration, oxygen saturation, and epidermal thickness decrease, whereas the melanin content increases with the progress of diabetes. The melanin content further increases, and the reduced scattering coefficient and scattering power are lower for diabetic foot patients than those of both healthy and diabetic subjects. High accuracies (AUC) of 97.2% (distinguishing the diabetic foot patients among all subjects), 95.2% (separating healthy subjects from the diabetes patients), and 87.8% (classifying mild vs severe diabetes), respectively, are achieved in binary classifications in sequence using the SSMD-SFDI system, demonstrating its applicability to risk stratification of diabetes and diabetic foot. The prognostic value of the SSMD-SFDI system in the prediction of the occurrence of the diabetic foot and other applications in monitoring tissue microcirculation and peripheral vascular disease are also addressed.

Toe pressure should be part of a vascular surgeon's first-line investigation in the assessment of lower extremity artery disease and cardiovascular risk of a patient

OBJECTIVE

Toe pressure (TP) is an accurate indicator of the peripheral vascular status of a patient and thus cardiovascular risk, with less susceptibility to errors than ankle-brachial index (ABI). This study aimed to analyze how ABI and TP measurements associate with overall survival and cardiovascular death and to analyze the TP of patients with ABI of 0.9 to 1.3.

METHODS

The first ABI and TP measurements of a consecutive 6784 patients treated at the Helsinki University Hospital vascular surgery clinic between 1990 and 2009 were analyzed. Helsinki University Vascular Registry and the national Cause of Death Registry provided the data.

RESULTS

The poorest survival was in patients with ABI >1.3 (10-year survival, 15.3%; hazard ratio, 2.2; 95% confidence interval, 1.9-2.6; P < .0001; reference group, ABI 0.9-1.3), followed by the patients with TP <30 mm Hg (10-year survival, 19.6%; hazard ratio, 2.0; 95% confidence interval, 1.7-2.2; P < .0001; reference group, TP ≥80 mm Hg). The best 10-year survival was in patients with TP ≥80 mm Hg (43.9%). Of the 642 patients with normal ABI (0.9-1.3), 18.7% had a TP <50 mm Hg. The highest cardiovascular death rate (64.6%) was in the patients with TP <30 mm Hg, and it was significantly lower than for the patients with TP >50 mm Hg.

CONCLUSIONS

Low TP is associated significantly with survival and cardiovascular mortality. Patients with a normal ABI may have lower extremity artery disease (LEAD) and a considerable risk for a cardiovascular event. If only the ABI is measured in addition to clinical examination, a substantial proportion of patients may be left without LEAD diagnosis or adequate treatment of cardiovascular risk factors. Thus, especially if ABI is normal, LEAD is excluded only if TPs are also measured and are normal.

Assessment of foot perfusion: Overview of modalities, review of evidence, and identification of evidence gaps

Patients with critical limb ischemia have nonhealing wounds and/or ischemic rest pain and are at high risk for amputation and mortality. Accurate evaluation of foot perfusion should help avoid unnecessary amputation, guide revascularization strategies, and offer efficient surveillance for patency. Our aim is to review current modalities of assessing foot perfusion in the context of the practical clinical management of patients with critical limb ischemia.

Fast pulsatile blood flow measurement in deep tissue through a multimode detection fiber

SIGNIFICANCE

Noninvasive in vivo fast pulsatile blood flow measurement in deep tissue is important because the blood flow waveform is correlated with physiological parameters, such as blood pressure and elasticity of blood vessels. Compromised blood flow may cause diseases, such as stroke, foot ulcer, and myocardial ischemia. There is great clinical demand for a portable and cost-effective device for noninvasive pulsatile blood flow measurement.

AIM

A diffuse-optics-based method, diffuse speckle pulsatile flowmetry (DSPF), was developed for fast measurement (∼300  Hz) of deep tissue blood flow noninvasively. To validate its performance, both a phantom experiment and in vivo demonstration were conducted.

APPROACH

Over the past two decades, single-mode fibers have been used as detection fibers in most diffuse-optics-based deep tissue blood flow measurement modalities. We used a multimode (MM) detection fiber with a core size of 200  μm for diffused speckle pattern detection. A background intensity correction algorithm was implemented for speckle contrast calculation. The MM detection fiber helped to achieve a level of deep tissue blood flow measurement similar to that of conventional modalities, such as diffuse correlation spectroscopy and diffuse speckle contrast analysis, but it increases the measurement rate of blood flow to 300 Hz.

RESULTS

The design and implementation of the DSPF system were introduced. The theory of the background intensity correction for the diffused speckle pattern detected by the MM fiber was explained. A flow phantom was built for validation of the performance of the DSPF system. An in vivo cuff-induced occlusion experiment was performed to demonstrate the capability of the proposed DSPF system.

CONCLUSIONS

An MM detection fiber can help to achieve fast (∼300  Hz) pulsatile blood flow measurement in the proposed DSPF method. The cost-effective device and the fiber-based flexible probe increase the usability of the DSPF system significantly.

Imaging in Chronic Wound Diagnostics

Significance: Chronic wounds affect millions of patients worldwide, placing a huge burden on health care resources. Although significant progress has been made in the development of wound treatments, very few advances have been made in wound diagnosis. Recent Advances: Standard imaging methods like computed tomography, single-photon emission computed tomography, magnetic resonance imaging, terahertz imaging, and ultrasound imaging have been widely employed in wound diagnostics. A number of noninvasive optical imaging modalities like optical coherence tomography, near-infrared spectroscopy, laser Doppler imaging, spatial frequency domain imaging, digital camera imaging, and thermal and fluorescence imaging have emerged over the years. Critical Issues: While standard diagnostic wound imaging modalities provide valuable information, they cannot account for dynamic changes in the wound environment. In addition, they lack the capability to predict the healing outcome. Thus, there remains a pressing need for more efficient methods that can not only indicate the current state of the wound but also help determine whether the wound is on track to heal normally. Future Directions: Many imaging probes have been fabricated and shown to provide real-time assessment of tissue microenvironment and inflammatory responses in vivo. These probes have been demonstrated to noninvasively detect various changes in the wound environment, which include tissue pH, reactive oxygen species, fibrin deposition, matrix metalloproteinase production, and macrophage accumulation. This review summarizes the creation of these probes and their potential implications in wound monitoring.

The prevalence and predictors of diabetes distress in elderly with type 2 diabetes mellitus

AIMS

Diabetes distress (DD) leads to damaging consequences in patients with type 2 diabetes mellitus (T2DM). Few studies have been carried out on the DD among elderly in Iran. The aim of the current study was to investigate the prevalence of DD and some of its related factors on the elderly living in Qom, Iran.

METHODS

This study was cross-sectional, in design. It lasted for three months (December to February 2018). 519 community dwelling(aged 60 and over) participated in the study. Participants' distress measured by diabetes distress scale (DDS). The cut of 3(≥3) was considered as the presence of distress. In addition, socio-demographic information was assessed. In order to determine predictors factors of DD, the logistic regression analysis was applied.

RESULTS

The mean age (±SD) of the participants was 68.38 (SD:6.78) with the majority being female (53.6%). Among them, 48.6% were identified with DD. A multi-variable logistic regression analysis showed that being female (OR = 1.94, [ 1.30-2.31]), sedentary lifestyle (OR = 3.59, [1.43-9.03]), complications (OR = 3.10, [2.06-4.67]), body mass index (BMI) of 25 or more (OR = 2.46, [1.54-3.94]), duration of disease below 10 years (OR = 2.60, [ 1.56-4.31]), two comorbidity (OR = 2.07, [ 1.19-3.61]) and three or more comorbidity (OR = 3.51, [ 1.20-10.27]) are the predictors of DD.

CONCLUSIONS

DD is notably prevalent among the elderly with T2DM. Attention to psychological aspects of diabetes is a health priority, especially among women and other high-risk groups.

Study protocol for a comparative diagnostic accuracy study of bedside tests used to detect arterial disease in diabetes: TEsting for Arterial disease in Diabetes (TrEAD) study

INTRODUCTION

In the UK, over 7000 amputations are performed each year because of diabetes. Up to 80% of these are preceded by a foot ulcer and could therefore be prevented with improvements in ulcer care. Peripheral arterial disease is an important risk factor for the development of diabetic foot ulceration. However, its diagnosis in diabetes is challenging due to the presence of neuropathy and arterial calcification. Commonly used bedside tests either have low sensitivities or little supporting evidence to justify their use. Duplex ultrasound (DUS) has good correlation to angiography findings but a full scan is difficult to learn and time consuming to perform. We have previously demonstrated that a focused DUS of the distal anterior and posterior tibial arteries at the ankle (podiatry ankle duplex scan (PAD-scan)) can be readily learnt by novices and performed rapidly and accurately. The primary aim of this study is to determine the diagnostic accuracy of the PAD-scan and other commonly used bedside tests in detecting arterial disease in diabetes.

METHODS AND ANALYSIS

The study will include 305 patients presenting to diabetic foot clinics at two centres. Arterial assessment will be performed using the following index tests: the PAD-scan, pulse palpation, audible handheld Doppler, Ankle Brachial Pressure Index, Toe Brachial Pressure Index and transcutaneous pressure of oxygen. Patients will then undergo a full lower limb arterial DUS by a blinded vascular scientist as a reference test.

ETHICS AND DISSEMINATION

Approval was gained from NRES Committee London (REC reference 17/LO/1447). Findings will be disseminated by various methods including international presentations and publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT04058626).

A systematic review of the use of near-infrared fluorescence imaging in patients with peripheral artery disease

OBJECTIVE

In the diagnosis of peripheral artery disease (PAD), the ankle-brachial index plays an important role. However, results of the ankle-brachial index are unreliable in patients with severe media sclerosis. Near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) can provide information about tissue perfusion and has already been studied in oncologic, reconstructive, and cardiac surgery. For patients with PAD, this technique might give insight into skin perfusion and thereby guide treatment. We performed a systematic review of the literature on the use of NIR fluorescence imaging in patients with PAD.

METHODS

PubMed, MEDLINE, Embase, and Cochrane were searched for articles and abstracts on the application of NIR fluorescence imaging using ICG as fluorescent dye in patients with PAD. Our search strategy combined the terms "fluorescence," "ICG," or synonyms and "peripheral artery disease" or synonyms. The extracted data included fluorescence parameters and test characteristics for diagnosis of PAD.

RESULTS

Twenty-three articles were found eligible for this review using 18 different parameters for evaluation of the fluorescence signal intensity. NIR fluorescence imaging was used for four main indications: diagnosis, quality control in revascularization, guidance in amputation surgery, and visualization of vascular structures. For the diagnosis of PAD, NIR fluorescence imaging yields a sensitivity ranging from 67% to 100% and a specificity varying between 72% and 100%. Significant increases in multiple fluorescence parameters were found in comparing patients before and after revascularization.

CONCLUSIONS

NIR fluorescence imaging can be used for several indications in patients with PAD. NIR fluorescence imaging seems promising in diagnosis of PAD and guidance of surgeons in treatment, especially in patients in whom current diagnostic methods are not applicable. Further standardization is needed to reliably use this modality in patients with PAD.

Rosiglitazone accelerates wound healing by improving endothelial precursor cell function and angiogenesis in db/db mice

Background & Aims

Endothelial precursor cell (EPC) dysfunction is one of the risk factors for diabetes mellitus (DM) which results in delayed wound healing. Rosiglitazone (RSG) is a frequently prescribed oral glucose-lowering drug. Previous studies have shown the positive effects of RSG on ameliorating EPC dysfunction in diabetic patients. Interestingly, knowledge about RSG with regard to the wound healing process caused by DM is scarce. Therefore, in this study, we investigated the possible actions of RSG on wound healing and the related mechanisms involved in db/db diabetic mice.

Methods

Db/db mice with spontaneous glucose metabolic disorder were used as a type 2 DM model. RSG (20 mg/kg/d, i.g.,) was administered for 4 weeks before wound creation and bone marrow derived EPC (BM-EPC) isolation. Wound closure was assessed by wound area and CD31 staining. Tubule formation and migration assays were used to judge the function of the BM-EPCs. The level of vascular endothelial growth factor (VEGF), stromal cell derived factor-1α (SDF-1α) and insulin signaling was determined by ELISA. Cell viability of the BM-EPCs was measured by CCK-8 assay.

Results

RSG significantly accelerated wound healing and improved angiogenesis in db/db mice. Bioactivities of tube formation and migration were decreased in db/db mice but were elevated by RSG. Level of both VEGF and SDF-1α was increased by RSG in the BM-EPCs of db/db mice. Insulin signaling was elevated by RSG reflected in the phosphorylated-to-total AKT in the BM-EPCs. In vitro, RSG improved impaired cell viability and tube formation of BM-EPCs induced by high glucose, but this was prevented by the VEGF inhibitor avastin.

Conclusion

Our data demonstrates that RSG has benefits for wound healing and angiogenesis in diabetic mice, and was partially associated with improvement of EPC function through activation of VEGF and stimulation of SDF-1α in db/db mice.

Limb salvage in diabetic foot disease: A classification to aid successful reconstruction

Diabetes is a global epidemic. If poorly managed, innocuous injury in a diabetic foot leads to intractable ulceration, bone and joint destruction and subsequent major amputation. It is estimated that every week in the UK there are 100 lower limb amputations of which 80 could have been prevented had diabetes been better managed. It is widely recognised that prevention is critical; nonetheless diabetic foot lesions continue to increase in prevalence. Reconstruction of diabetic foot lesions has a dismal reputation despite promising published work. Reconstruction in the correctly chosen patient can be successful. Multiple classification systems and scores have been published, but these do not guide the clinician as to which lesions are reconstructible, and those in which attempts to salvage are futile. These patients would be better served with primary amputation. A tertiary referral centre's experience of diabetic foot reconstruction over 7 years is presented in a series of 22 consecutive patients who were assessed using a new classification system. Twenty-four flaps were performed all of which were either complex (n = 7) or complicated (n = 17) wounds as per our classification. Five patients (22%) had donor site healing problems, but only one flap (5%) in the series failed. Average follow-up was 23 months (range 4-75 months) and all patients were ambulant at discharge. Our simple classification system and aggressive approach to excision and reconstruction of diabetic foot lesions is a useful adjunct to existing systems, and helps promote the cause that limb salvage is warranted in these challenging cases when appropriately managed.

Vein conduit for end-to-side anastomosis of a calcified vessel in lower extremity free flap reconstruction

BACKGROUND

As the microsurgical and interventional revascularization techniques are evolving, traditionally amputated limbs are now challenged to salvage. However, a calcified recipient vessel is a common but challenging problem encountered in lower extremity reconstruction.

METHODS

An end-to-side anastomosis of a vein graft (1.5-3.5 cm in length) was performed to the recipient vessel when it was difficult to clamp the recipient vessel near the defect because of the inelastic and hard vessel wall. The vascular clamp was applied to the vein graft, and the flap's pedicle was anastomosed to the vein graft.

RESULTS

A total of 18 free flaps (10 ALT cases, 4 TDAP cases, 2 PAP cases, and 2 SCIP cases) were anastomosed with a bridge vein graft to the heavily calcified recipient vessels (7 ATA cases, 3 PTA cases, 7 DPA cases, and 1 MPA case). Overall flap survival rate was 83.3%. Limb salvage rate was 93.7%, and anastomosis patency rate was 94.4% CONCLUSION: Vein conduit in an end-to-side anastomosis of severely calcified recipient vessels shows a reasonable limb salvage rate. It acts as a buffer, which makes microscopic vessel manipulation easier. If vessel calcification is the only drawback for a free flap reconstruction, then a vein graft needs to be prepared instead of an amputation. This method may extend the surgical option to more high-risk patients in lower extremity microsurgical reconstruction and increase the limb salvage rate.

ADIE - Nursing Interventions of Diabetic Foot Ulcer: An Integrative Review of the Literature

BACKGROUND AND AIMS

Diabetic foot ulcer is recognized as a consequence of peripheral neuropathy and peripheral arterial disease amid individuals with diabetes. As is well known, this situation still remains a crucial problem in nursing practice. Available studies describing an algorithm of inter- related nursing interventions concerned with diabetic foot ulcers are limited. Therefore, this integrative review was aimed to present evidence-based practice for overcoming the complications of diabetic foot ulcer as well as preventing lower extremity amputation.

METHODS

This integrative review retrieved scientific literature from PubMed, CINAHL, ProQuest, SAGE Publishing and ScienceDirect databases as published from 2008 to 2017. Thirty-seven studies that met the inclusion criteria were included in this study.

RESULTS

Our findings present that neurologic and circulatory assessments were considered as primary steps prior to conducting interventions. Formulating a diagnosis based upon the assessment results is a principal part to determine appropriate interventions. Multiple experimental studies displayed the effectiveness of certain interventions consist of applying wound cleansing, advanced modern wound dressing, topical therapy, offloading, intensive diabetes education and advanced treatment modalities. Hemoglobin A1c, high-density lipoprotein, procalcitonin, the potential of hydrogen of wound fluid, wound size, neurological and circulatory status were determined as the outcomes measurement which must be correctly evaluated.

CONCLUSION

This review contributes an algorithm for intervening diabetic foot ulcer thereby generating the given name: ADIE (Assessment, Diagnosis, Interventions, and Evaluation). A collaborative care amid multidisciplinary diabetes team is needed for implementing along with evaluating the feasibility of the study findings. Moreover, active family participation also plays a crucial role to achieve successful management of diabetic foot ulcer at home.

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

OBJECTIVE/BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Current concepts for the evaluation and management of diabetic foot ulcers

The lifetime risk for diabetic patients to develop a diabetic foot ulcer (DFU) is 25%. In these patients, the risk of amputation is increased and the outcome deteriorates.More than 50% of non-traumatic lower-extremity amputations are related to DFU infections and 85% of all lower-extremity amputations in patients with diabetes are preceded by an ulcer; up to 70% of diabetic patients with a DFU-related amputation die within five years of their amputation.Optimal management of patients with DFUs must include clinical awareness, adequate blood glucose control, periodic foot inspection, custom therapeutic footwear, off-loading in high-risk patients, local wound care, diagnosis and control of osteomyelitis and ischaemia. Cite this article: EFORT Open Rev 2018;3:513-525. DOI: 10.1302/2058-5241.3.180010.

Management of peripheral arterial disease in diabetes: a national survey of podiatry practice in the United Kingdom

Background

We aimed to investigate podiatry practice in diagnosing peripheral arterial disease (PAD) in diabetes, decision making once PAD is suspected and limitations of referral pathways.

Methods

A survey, comprising 26 questions was distributed to podiatrists across the UK via mailing lists of collaborating organizations including the College of Podiatry (UK). Response rates were estimated based on NHS workforce data. Analysis of responses from the open-ended questions was performed using inductive content analysis.

Results

Data from 283 respondents were analyzed. Response rate for all NHS podiatrists across the UK was estimated to be 6%. For the detection of arterial disease only 18.8% (n = 49/260) of participants reported using a full combination of history, pulse palpation, Doppler and ABPI assessment. Self-reported confidence in detecting arterial disease was highest amongst podiatrists who felt they had received adequate training compared to podiatrists who felt they had not (median 85 (IQR 75-90) vs 67 (50-77), respectively; p < 0.001) as well as those who see > 20 diabetic patients per week compared to those who see < 20 (median 80 (IQR 70-90) vs 72 (60-82.8), respectively; p < 0.001). Over one third of respondents (35.8%, n = 93/260) were aware of missed cases of PAD in the past year and 17.5% (n = 38/217) believed that this resulted in an amputation in some cases.The survey highlighted a lack of clarity amongst podiatrists regarding referral guidelines. Additionally, 69% (n = 169/242) reported that their patients had to wait longer than 2-weeks for specialist vascular assessment and 67.6% (n = 54/80) reported similar waits for a Duplex Ultrasound scan. There was a statistically significant variation in DUS waiting time across the UK (X² (10, N = 80) = 21.59, p = 0.017). Inability to make a direct referral to vascular services and long delays were reported as major limitations of the referral pathway.

Conclusion

We have identified important targets for further investigation and quality improvement.

Technologies to monitor the health of loaded skin tissues

There are many situations where the skin and underlying soft tissues are compromised by mechanical loading in the form or pressure, or pressure in combination with shear. If sustained, this can lead to damage in the tissues particularly adjacent to bony prominences, resulting in chronic wounds. An array of bioengineering technologies have been adopted to assess the integrity of loaded soft tissues. This paper aims to review these approaches for the quantification, simulation and early detection of mechanically-induced skin damage. The review considers different measurements at the interface between the skin and support surface/medical device, involving pressure, shear, friction and the local microclimate. The potential of the techniques to monitor the physiological response of the skin to these external stimuli including biophysical measurement devices and sampling of biofluids are critically analysed. In addition, it includes an analysis of medical imaging technologies and computational modelling to provide a means by which tissue deformation can be quantified and thresholds for tissue damage defined. Bioengineering measurement and imaging technologies have provided an insight into the temporal status of loaded skin. Despite the advances in technology, to date, the translation to clinical tools which are robust and cost effective has been limited. There is a need to adapt existing technologies and simulation platforms to enable patients, carers and clinicians to employ appropriate intervention strategies to minimise soft tissue damage.