The bacteriology of diabetic foot ulcers and infections and incidence of Staphylococcus aureus Small Colony Variants.

Introduction. Uninfected diabetes-related foot ulcer (DFU) progression to diabetes-related foot infection (DFI) is a prevalent complication for patients with diabetes. DFI often progresses to osteomyelitis (DFI-OM). Active (growing) Staphylococcus aureus is the most common pathogen in these infections. There is relapse in 40-60 % of cases even when the initial treatment at the DFI stage apparently clears infection.Hypothesis. S. aureus adopts the quasi-dormant Small Colony Variant (SCV) state during DFU and consequently infection, and when present in DFI cases also permits survival in non-diseased tissues as a reservoir to cause relapse.Aim. The aim of this study was to investigate the bacterial factors that facilitate persistent infections.Methodology. People with diabetes were recruited from two tertiary hospitals. Clinical and bacterial data was taken from 153 patients with diabetes (51 from a control group with no ulcer or infection) and samples taken from 102 patients with foot complications to identify bacterial species and their variant colony types, and then compare the bacterial composition in those with uninfected DFU, DFI and those with DFI-OM, of whom samples were taken both from wounds (DFI-OM/W) and bone (DFI-OM/B). Intracellular, extracellular and proximal 'healthy' bone were examined.Results. S. aureus was identified as the most prevalent pathogen in diabetes-related foot pathologies (25 % of all samples). For patients where disease progressed from DFU to DFI-OM, S. aureus was isolated as a diversity of colony types, with increasing numbers of SCVs present. Intracellular (bone) SCVs were found, and even within uninfected bone SCVs were present. Wounds of 24 % of patients with uninfected DFU contained active S. aureus. All patients with a DFI with a wound but not bone infection had previously had S. aureus isolated from an infection (including amputation), representing a relapse.Conclusion. The presence of S. aureus SCVs in recalcitrant pathologies highlights their importance in persistent infections through the colonization of reservoirs, such as bone. The survival of these cells in intracellular bone is an important clinical finding supporting in vitro data. Also, there seems to be a link between the genetics of S. aureus found in deeper infections compared to those only found in DFU.

Use of Biodegradable Temporising Matrix (BTM) in the reconstruction of diabetic foot wounds: A pilot study.

Introduction: Complex diabetes-related foot wounds are at high risk of infection and subsequent major amputation unless healed expediently. Biodegradable Temporising Matrix (BTM) is a synthetic matrix that facilitates the organisation of the extracellular matrix, resulting in a neodermis layer over these difficult-to-heal areas. The aim of this study was to evaluate the efficacy of using BTM in the reconstruction of challenging diabetic foot wounds. Methods: Eighteen patients with complex diabetic foot wounds (exposed tendon, fascia, joint, bone), or chronic ulcers at high shear stress locations had BTM applied. Indications for BTM application were high shear stress location (66.6%), exposed bone (16.6%), exposed fascia (5.6%), exposed tendon (5.6%) and chronic non-healing wound (5.6%). The time to complete healing, infection rate and incidence of subsequent wound breakdown was analysed. Discussion: Thirteen of 18 patients completed the BTM treatment regime with all these patients achieving complete wound healing at a median time of 13 weeks. One patient had partial treatment with BTM and four patients were withdrawn from the study following BTM application. The rate of infection and re-ulceration were both 15.4%. Conclusion: This is the first prospective cohort pilot study evaluating the use of BTM for complex diabetic foot wounds. BTM demonstrates potential in healing uninfected, non-ischaemic diabetic foot wounds with exposed deep structures and chronic wounds subject to high shear stress. The re-ulceration and infection rates were relatively low for this high-risk population. BTM may also offer promise as an alternative to free flaps. Lay Summary: The prevalence of diabetes and its complications, including foot ulcers and wounds, have significantly increased worldwide over the last 40 years. Increasingly patients are admitted to hospital for antibiotics, debridements and subsequent amputations from these wounds. Complex diabetes-associated wounds are those at highest risk of these complications or necessitating more extensive, complex operations such as free flaps. These wounds may have exposed deep structures, be at risk of high shear stress or be chronic non-healing wounds.Temporisers are a type of material which integrates into the wound and promotes in-growth of tissue, ideal for healing over these difficult to heal areas. Biodegradable Temporising Matrix (BTM) is a synthetic temporising matrix which has demonstrated positive outcomes in facilitating healing in burns and plastics wounds, but its effectiveness in diabetic foot wounds has not yet been proven. This is the first prospective cohort pilot study evaluating the use of BTM for complex diabetic foot wounds. BTM demonstrates potential in healing uninfected, non-ischaemic complex diabetic foot wounds and potentially avoiding more complex operations.

Frail patients having vascular surgery during the early COVID-19 pandemic experienced high rates of adverse perioperative events and amputation.

BACKGROUND: Frailty predicts adverse perioperative outcomes and increased mortality in patients having vascular surgery. Frailty assessment is a potential tool to inform resource allocation, and shared decision-making about vascular surgery in the resource constrained COVID-19 pandemic environment. This cohort study describes the prevalence of frailty in patients having vascular surgery and the association between frailty, mortality and perioperative outcomes. METHODS: The COVID-19 Vascular Service in Australia (COVER-AU) prospective cohort study evaluates 30-day and six-month outcomes for consecutive patients having vascular surgery in 11 Australian vascular units, March-July 2020. The primary outcome was mortality, with secondary outcomes procedure-related outcomes and hospital utilization. Frailty was assessed using the nine-point visual Clinical Frailty Score, scores of 5 or more considered frail. RESULTS: Of the 917 patients enrolled, 203 were frail (22.1%). The 30 day and 6 month mortality was 2.0% (n = 20) and 5.9% (n = 35) respectively with no significant difference between frail and non-frail patients (OR 1.68, 95%CI 0.79-3.54). However, frail patients stayed longer in hospital, had more perioperative complications, and were more likely to be readmitted or have a reoperation when compared to non-frail patients. At 6 months, frail patients had twice the odds of major amputation compared to non-frail patients, after adjustment (OR 2.01; 95% CI 1.17-3.78), driven by a high rate of amputation during the period of reduced surgical activity. CONCLUSION: Our findings highlight that older, frail patients, experience potentially preventable adverse outcomes and there is a need for targeted interventions to optimize care, especially in times of healthcare stress.

Factors Associated With Key Outcomes in Diabetes Related Foot Disease: A Prospective Observational Study.

OBJECTIVE: Diabetic foot disease is a serious and common complication of diabetes mellitus. The aim of this study was to assess limb and patient factors associated with key clinical outcomes in diabetic patients with foot ulcers. METHODS: This was a prospective observational study of diabetic patients with foot wounds admitted to a major tertiary teaching hospital in South Australia or seen at associated multidisciplinary foot clinics between February 2017 and December 2018. Patient demographic and clinical data were collected, including limb status severity assessed by the WIfI system and grip strength. Participants were followed up for 12 months. The primary outcomes were major amputation, death, amputation free survival, and completion of healing of the index wound within one year. RESULTS: A total of 153 participants were recruited and outcome data were obtained for 152. Forty-two participants underwent revascularisation during the research period. Eighteen participants (11.8%) suffered major amputation of the index limb and 16 (10.5%) died during follow up. Complete wound healing was achieved in 106 (70%) participants. There was a statistically significant association between WIfI stage and major amputation (subdistribution hazard ratio [SHR] 2.75), mortality (hazard ratio [HR] 2.60), amputation free survival (odds ratio [OR] 0.32), and wound healing (SHR 0.69). There was also a statistically significant association between time to healing and grip strength (SHR 0.50), and previous amputations (major or minor) (SHR 0.57). CONCLUSION: This prospective study supports the ability of the WIfI classification system to predict one year key clinical outcomes in a diabetic population with foot ulcers. It also demonstrated that grip strength may be a useful predictor of wound healing.

Assessment of a smartphone-based application for diabetic foot ulcer measurement.

The accurate measurement of diabetic foot ulcer (DFU) wound size is essential as the rate of wound healing is a significant prognostic indicator of the likelihood of complete wound healing. Mobile phone photography is often used for surveillance and to aid in telemedicine consultations. However, there remains no accurate and objective measurement of wound size integrated into these photos. The NDKare mobile phone application has been developed to address this need and our study evaluates its accuracy and practicality for DFU wound size assessment. The NDKare mobile phone application was evaluated for its accuracy in two- (2D) and three-dimensional (3D) wound measurement. One hundred and fifteen diabetic foot wounds were assessed for wound surface area, depth and volume accuracy in comparison to Visitrak and the WoundVue camera. Thirty five wounds had two assessors with different mobiles phones utilizing both applications to assess the reproducibility of the measurements. The 2D surface area measurements by NDKare showed excellent concordance with Visitrak and WoundVue measurements (ICC: 0.991 [95% CI: 0.988, 0.993]) and between different users (ICC: 0.98 [95% CI: 0.96, 0.99)]. The 3D NDKare measurements had good agreement for depth and fair agreement for volume with the WoundVue camera. The NDKare phone application can consistently and accurately obtain 2D measurements of diabetic foot wounds with mobile phone photography. This is a quick and readily accessible tool which can be integrated into comprehensive diabetic wound care.

Evaluation of a Novel Three-Dimensional Wound Measurement Device for Assessment of Diabetic Foot Ulcers.

Objective: The initial wound measurement and regular monitoring of diabetic foot ulcers (DFU) is critical to assess treatment response. There is no standardized, universally accepted, quick, reliable, and quantitative assessment method to characterize DFU. To address this need, a novel topographic imaging system has been developed. Our study aims at assessing the reliability and practicality of the WoundVue® camera technology in the assessment of DFU. Approach: The WoundVue system is a prototype device. It consists of two infrared cameras and an infrared projector, and it is able to produce a three-dimensional (3D) reconstruction of the wound structure. Fifty-seven diabetic foot wounds from patients seen in a multidisciplinary foot clinic were photographed from two different angles and distances by using the WoundVue camera. Wound area, volume, and maximum depth were measured for assessment of reliability. Thirty-one of these wounds also had area calculated by using the established Visitrak™ system, and a correlation between the area obtained by using both systems was assessed. Results: WoundVue images analysis showed excellent agreement for area (intraclass correlation coefficient [ICC]: 0.995), volume (ICC: 0.988), and maximum depth (ICC: 0.984). Good agreement was found for area measurement by using the WoundVue camera and Visitrak system (ICC: 0.842). The average percentage differences between measures obtained by using the WoundVue from different angles for assessment of different sizes and shapes of wounds were 2.9% (95% confidence interval [CI]: 0.3-5.4), 12.9% (95% CI: 9.6-35.7), and 6.2% (95% CI: 2.3-14.7) for area, maximum depth, and volume, respectively. Innovation: This is the first human trial evaluating this novel 3D wound measurement device. Conclusion: The WoundVue system is capable of recreating a 3D model of DFU and produces consistent data. Digital images are ideal for monitoring wounds over time, and the WoundVue camera has the potential to be a valuable adjunct in diabetic foot wound care.

Micronutrient Status in Diabetic Patients with Foot Ulcers.

Objective: To explore the prevalence of micronutrient deficiencies in patients with diabetic foot ulcers and correlate this with foot disease severity and other clinical factors. Approach: Prospective cohort study of diabetic patients with foot ulcers seen in multidisciplinary foot clinics across Adelaide or admitted to the Vascular Surgery Unit at the Royal Adelaide Hospital between February 2017 and September 2018. A total of 131 patients were included in the study. Plasma serum levels of vitamins A, C, D, and E, copper, zinc, and ferritin were measured. Demographic and clinical data, including BMI, smoking status, duration of diabetes, HbA1c, and WIfI score, were obtained. Results: The most prevalent nutritional deficiency found was vitamin D affecting 55.7% of patients. Suboptimal levels of vitamin C affected 73% of patients, comprising marginal levels in 22.2% and deficient levels in 50.8%. Zinc deficiency, vitamin A deficiency, and low ferritin levels were present in 26.9%, 10.9%, and 5.9% of patients, respectively. There was no correlation between BMI, grip strength, duration of diabetes, HbA1c, or smoking status with micronutrient deficiency. Increased severity of diabetic foot disease was associated with lower vitamin C levels (p = 0.02). Innovation: This study has demonstrated that the deficiency of micronutrients, especially vitamin D, vitamin C, zinc, and vitamin A, is common in diabetic patients with foot ulcers. Conclusions: The prevalence of micronutrient deficiency is high in a diabetic population with foot ulcers/wounds. Special concerns regarding the high prevalence of vitamin C and zinc deficiency, given their roles in wound healing. Although further research needs to be performed to determine the clinical implications of our findings, micronutrient deficiency should be considered in diabetic patients with foot wounds.