Continuous diffusion of oxygen improves diabetic foot ulcer healing when compared with a placebo control: a randomised, double-blind, multicentre study

The efficacy of topical oxygen therapy for wound healing: A meta-analysis of randomized controlled trials and observational studies

In preclinical studies, topical oxygen treatment (TOT) was shown to enhance wound healing by applying supplemental oxygen topically to the surface of a moist wound at normobaric conditions. The objective of this systematic review and meta-analysis is to provide a thorough evaluation of published RCTs and observational studies that compare supplemental TOT with standard wound care. A total of 1077 studies were obtained from a variety of databases, including PubMed, ScienceDirect, Web of Science, ProQuest, Scopus, ClinicalTrials.gov, EU Clinical Trial Registers, and Preprints.org. The Jadad scale was employed to assess the reliability of RCT studies, while the Newcastle-Ottawa Scale (NOS) was employed to assess the quality of observational studies. Seven RCT studies (n = 692) and two controlled observational studies (n = 111) were analysed. The rate of healed wounds was 25.8% in the control group and 43.25% in the adjuvant TOT group, which shows the use of TOT significantly increased the number of healed wounds (RR = 1.77; 95% CI 1.18-2.64; p = 0.005). A significant decrease in the percentage of wound area was found in the TOT group in RCT studies (mean difference = 15.64; 95% CI 5.22-26.06; p = 0.003). In observational studies, the rate of healed wounds was 37.5% in the standard care group and 80.95% in the adjuvant TOT group, which shows a significant increase in the number of healed wounds in the adjuvant TOT group (RR = 2.15; 95% CI 1.46-3.15; p < 0.00001). Topical oxygen therapy is considered a great adjuvant therapy for chronic wound healing, particularly wounds with vascular compromise such as diabetic ulcers and pressure ulcers. Further studies on this topic are still needed as there are a lot of potential uses for this technology in various types of wounds.

Recent advances in the adjunctive management of diabetic foot ulcer: Focus on noninvasive technologies

Diabetic foot ulcer (DFU) is one of the most costly and serious complications of diabetes. Treatment of DFU is usually challenging and new approaches are required to improve the therapeutic efficiencies. This review aims to update new and upcoming adjunctive therapies with noninvasive characterization for DFU, focusing on bioactive dressings, bioengineered tissues, mesenchymal stem cell (MSC) based therapy, platelet and cytokine-based therapy, topical oxygen therapy, and some repurposed drugs such as hypoglycemic agents, blood pressure medications, phenytoin, vitamins, and magnesium. Although the mentioned therapies may contribute to the improvement of DFU to a certain extent, most of the evidence come from clinical trials with small sample size and inconsistent selections of DFU patients. Further studies with high design quality and adequate sample sizes are necessitated. In addition, no single approach would completely correct the complex pathogenesis of DFU. Reasonable selection and combination of these techniques should be considered.

An Observational Clinical Trial Examining the Effect of Topical Oxygen Therapy (Natrox™) on the Rates of Healing of Chronic DiAbetic Foot Ulcers (OTONAL Trial)

Natrox™ topical oxygen therapy (TOT) (Inotec AMD Ltd, Cambridgeshire, UK) employs a small battery-powered "oxygen generator" to concentrate atmospheric oxygen and feeds pure, moist, oxygen through a fine, soft tube to a dressing-like "oxygen distribution system", which is placed over the wound and is held in place by a conventional dressing. The aim was to determine the effectiveness of Natrox™ for non-healing diabetic foot ulcers (DFU) over a 3-month period.Longitudinal, single-arm, open prospective registry study using 12 weeks of TOT using a 4 week run-in period. 20 patients recruited to OTONAL had chronic DFU greater than 3 months duration or minor amputation sites with less than 50% healing in 4 weeks.There were 13 (65%) males and the mean age was 65.7 (±11.6) years. The mean glycated haemoglobin (HbA1c) was 6.9 (±1.3) mmol mol-1 and mean wound duration before TOT was 114 (±79.1) days. 18/20 (90.0%) patients had concomitant lower limb revascularization angioplasty for chronic limb threatening ischaemia. The mean size of the foot ulcer at baseline was 11.3 ± 14.8 cm2 and mean transcutaneous oxygen measurement value was 34.1 (±19.6) mm Hg. Wound closure of >75% was observed in 14/20 (70.0%) patients. There was a 91.3% (±14.9%) wound area reduction by 3 months (P = .001) and mean time for 100% closure was 77.6 ± 32.5 days. Mean pain scores reduced from 2.4 (±1.8) at baseline to .5 (±1.0) at 3 months (P = .008). All patients were very satisfied using the ambulatory device. Use of TOT in chronic diabetic foot wounds stimulates a healing state, underpinning the concept that oxygen plays a central role in wound healing. Our results are more compelling if you consider they started with relatively large-sized DFUs and majority of patients were frail with underlying peripheral artery disease. (NCT03863054).

Recent advances in molecular mechanisms of skin wound healing and its treatments

The skin, being a multifaceted organ, performs a pivotal function in the complicated wound-healing procedure, which encompasses the triggering of several cellular entities and signaling cascades. Aberrations in the typical healing process of wounds may result in atypical scar development and the establishment of a persistent condition, rendering patients more vulnerable to infections. Chronic burns and wounds have a detrimental effect on the overall quality of life of patients, resulting in higher levels of physical discomfort and socio-economic complexities. The occurrence and frequency of prolonged wounds are on the rise as a result of aging people, hence contributing to escalated expenditures within the healthcare system. The clinical evaluation and treatment of chronic wounds continue to pose challenges despite the advancement of different therapeutic approaches. This is mainly owing to the prolonged treatment duration and intricate processes involved in wound healing. Many conventional methods, such as the administration of growth factors, the use of wound dressings, and the application of skin grafts, are used to ease the process of wound healing across diverse wound types. Nevertheless, these therapeutic approaches may only be practical for some wounds, highlighting the need to advance alternative treatment modalities. Novel wound care technologies, such as nanotherapeutics, stem cell treatment, and 3D bioprinting, aim to improve therapeutic efficacy, prioritize skin regeneration, and minimize adverse effects. This review provides an updated overview of recent advancements in chronic wound healing and therapeutic management using innovative approaches.

Effects of Oxygen Therapy on Patients with a Chronic Wound: A Systematic Review and Meta-analysis

OBJECTIVE

To synthesize the effects of oxygen-based therapy on patients with a chronic wound.

DATA SOURCES

The authors searched PubMed, EMBASE, and Cochrane Central Register of Controlled Trials for relevant randomized controlled trials from database inception. Investigators measured risk of bias using the Cochrane Collaboration's Risk of Bias tool.

STUDY SELECTION

The included randomized controlled trials focused on the effects (short- or long-term wound healing, amputation rate, percentage of reduction in ulcer size, and poststudy transcutaneous oxygen measurement [TcPO2]) of oxygen-based therapy (including hyperbaric oxygen therapy, topical oxygen therapy, and continuous diffusion of oxygen) on patients with a chronic wound.

DATA EXTRACTION

Researchers extracted information regarding participant characteristics and primary and secondary outcomes from the included studies.

DATA SYNTHESIS

Pooled effects of 31 included studies showed that patients treated with oxygen had better short-term wound healing (risk ratio [RR], 1.544; 95% CI, 1.199 to 1.987), a higher percentage reduction in the ulcer area (standardized mean difference [SMD], 0.999; 95% CI, 0.439 to 1. 599), lower amputation rates (RR, 0.529; 95% CI, 0.325 to 0.862), shorter wound healing time (SMD, -0.705; 95% CI, -0.908 to -0.501), and higher poststudy TcPO2 (SMD, 2.128; 95% CI, 0.978 to 3.278) than those in the control group. For long-term wound healing, there was no statistically significant difference (RR, 1.227; 95% CI, 0.976 to 1.542).

CONCLUSIONS

Oxygen-based therapy improves short-term parameters of wound healing in patients with chronic wounds.

Effectiveness of interventions to enhance healing of chronic foot ulcers in diabetes: A systematic review

BACKGROUND

It is critical that interventions used to enhance the healing of chronic foot ulcers in diabetes are backed by high-quality evidence and cost-effectiveness. In previous years, the systematic review accompanying guidelines published by the International Working Group of the Diabetic Foot performed 4-yearly updates of previous searches, including trials of prospective, cross-sectional and case-control design.

AIMS

Due to a need to re-evaluate older studies against newer standards of reporting and assessment of risk of bias, we performed a whole new search from conception, but limiting studies to randomised control trials only.

MATERIALS AND METHODS

For this systematic review, we searched PubMed, Scopus and Web of Science databases for published studies on randomised control trials of interventions to enhance healing of diabetes-related foot ulcers. We only included trials comparing interventions to standard of care. Two independent reviewers selected articles for inclusion and assessed relevant outcomes as well as methodological quality.

RESULTS

The literature search identified 22,250 articles, of which 262 were selected for full text review across 10 categories of interventions. Overall, the certainty of evidence for a majority of wound healing interventions was low or very low, with moderate evidence existing for two interventions (sucrose-octasulfate and leucocyte, platelet and fibrin patch) and low quality evidence for a further four (hyperbaric oxygen, topical oxygen, placental derived products and negative pressure wound therapy). The majority of interventions had insufficient evidence.

CONCLUSION

Overall, the evidence to support any other intervention to enhance wound healing is lacking and further high-quality randomised control trials are encouraged.

Guidelines on interventions to enhance healing of foot ulcers in people with diabetes (IWGDF 2023 update)

AIMS

Principles of wound management, including debridement, wound bed preparation, and newer technologies involving alternation of wound physiology to facilitate healing, are of utmost importance when attempting to heal a chronic diabetes-related foot ulcer. However, the rising incidence and costs of diabetes-related foot ulcer management necessitate that interventions to enhance wound healing of chronic diabetes-related foot ulcers are supported by high-quality evidence of efficacy and cost effectiveness when used in conjunction with established aspects of gold-standard multidisciplinary care. This is the 2023 International Working Group on the Diabetic Foot (IWGDF) evidence-based guideline on wound healing interventions to promote healing of foot ulcers in persons with diabetes. It serves as an update of the 2019 IWGDF guideline.

MATERIALS AND METHODS

We followed the GRADE approach by devising clinical questions and important outcomes in the Patient-Intervention-Control-Outcome (PICO) format, undertaking a systematic review, developing summary of judgements tables, and writing recommendations and rationale for each question. Each recommendation is based on the evidence found in the systematic review and, using the GRADE summary of judgement items, including desirable and undesirable effects, certainty of evidence, patient values, resources required, cost effectiveness, equity, feasibility, and acceptability, we formulated recommendations that were agreed by the authors and reviewed by independent experts and stakeholders.

RESULTS

From the results of the systematic review and evidence-to-decision making process, we were able to make 29 separate recommendations. We made a number of conditional supportive recommendations for the use of interventions to improve healing of foot ulcers in people with diabetes. These include the use of sucrose octasulfate dressings, the use of negative pressure wound therapies for post-operative wounds, the use of placental-derived products, the use of the autologous leucocyte/platelet/fibrin patch, the use of topical oxygen therapy, and the use of hyperbaric oxygen. Although in all cases it was stressed that these should be used where best standard of care was not able to heal the wound alone and where resources were available for the interventions.

CONCLUSIONS

These wound healing recommendations should support improved outcomes for people with diabetes and ulcers of the foot, and we hope that widescale implementation will follow. However, although the certainty of much of the evidence on which to base the recommendations is improving, it remains poor overall. We encourage not more, but better quality trials including those with a health economic analysis, into this area.

Stem cell therapy with CRISPR/Cas9-mediated MALAT1 delivery modulates miR-142 and rescues wound healing in rats with age-associated diabetic foot ulcers

BACKGROUND

Diabetic foot ulcer (DFU) is a serious diabetes complication, significantly impacting the quality of life, particularly in the elderly. Age-associated DFUs pose additional challenges due to impaired healing mechanisms. Our study aims to explore the role of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) as a miR-142 sponge in repairing diabetic rat foot ulcer tissue under age-associated diabetes, offering a new theoretical basis and therapeutic target for preventing and treating diabetic vascular disease in the elderly.

METHODS

Using qPCR, we analyzed MALAT1 and miR-142 expression in EPCs and hUC-MSCs. Targetscan predicted potential interaction targets for MALAT1 and miR-142, confirmed by dual luciferase reporter gene assay. An age-associated diabetic rat model was established using Streptozotocin (STZ) injection. Hypoxia, apoptosis, and angiogenesis-related proteins were assessed through Western Blot. In vitro, miR-142 inhibition and MALAT1 overexpression promoted foot ulcer healing in diabetic rats.

RESULTS

MALAT1 acted as a miR-142 sponge, downregulated in hUC-MSCs under high glucose, relevant to age-associated diabetic foot ulcers. MiR-142 negatively regulated SIRT1 and Nrf2. In vitro experiments demonstrated potential significance for age-related DFU treatment.

CONCLUSIONS

MALAT1 in human umbilical cord mesenchymal stem cells expedited foot ulcer healing in diabetic rats, particularly in age-associated diabetes, through miR-142 sponge activity. These findings offer insights for novel therapeutic strategies targeting elderly diabetic foot ulcers, emphasizing exogenous stem cell transplantation's potential in effective DFU treatment for the elderly.

12. Retinopathy, Neuropathy, and Foot Care: Standards of Care in Diabetes-2024

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Optimizing Tissue Oxygenation in Reduction Mammoplasty: The Role of Continuous Diffusion of Oxygen: A Feasibility Pilot Randomized Controlled Trial

INTRODUCTION

Bilateral reduction mammoplasty (BRM) aims to alleviate macromastia-related symptoms in women. This procedure involves a T-Junction suture at the medial inframammary fold that encompasses 12%-39% of wound breakdowns mainly due to reduced perfusion. Continuous diffusion of oxygen (CDO) may enhance breast tissue oxygenation to prevent such complication. We explored the feasibility of this therapy.

METHODS

A 4-wk feasibility-pilot randomized controlled trial of women undergoing BRM was conducted. By internal randomization (left/right side), participants received standard of care (SOC) in one breast using topical skin adhesive, while their other breast received SOC + CDO at the T-junction covered by a silicon sheet (sCDO), or CDO directly to the T-Junction skin (dCDO). Feasibility outcomes included protocol delivery, outcome measurement, device-related adverse events, and device acceptability. Exploratory outcomes were T-Junction SatO2 and deoxyhemoglobin assessed with near-infrared spectroscopy and wound dehiscence.

RESULTS

Sixteen participants (age = 33 ± 8 y; body mass index = 34.34 ± 5.85 kg/m2) were recruited, conforming n = 32 breasts (SOC, n = 16; dCDO, n = 10, sCDO, n = 6). At 4 wk, protocol delivery was 93.7%, outcome measuring 100%, and device-related adverse events 0%. Device acceptability showed an 85.4% strong agreement for attitude toward use, 78.2% perceived ease of use, and 77.7% perceived usefulness. Breasts undergoing sCDO showed higher SatO2 (P < 0.001), whereas lower deoxyhemoglobin (P < 0.001) compared to all other breast groups. However, wound dehiscence was not different between groups (P = 0.66).

CONCLUSIONS

Self-applied CDO to the T-Junction is feasible, safe, and acceptable, in patients undergoing BRM. In a proper wound environment, CDO may enhance breast tissue oxygenation. However, it is unclear whether CDO leads to decreased wound dehiscence. This study showed reproducibility for larger randomized trials.

Consenso de expertos sobre la eficacia clínica y directrices sobre la terapia de oxígeno transdérmico continuo para la cicatrización de las heridas complejas o difíciles de cicatrizar

INTRODUCTION

Oxygen is pivotal for wound healing. Its lack or hypoxia can delay this process, especially in individuals with comorbidities, potentially resulting in complex or hard-to-heal wounds. The Colombian Association of Diabetes (ACD) and the Colombian Association of Internal Medicine (ACMI) collaborated with a diverse group of experts to provide recommendations on the efficacy and best practices of continuous transdermal oxygen therapy (TOTc) in the care of such wounds.

METHOD

A modified Delphi technique was employed to obtain controlled feedback and responses. Experts from various disciplines engaged in reviewing and discussing numerous relevant scientific studies, focusing on the role of TOTc in treating chronic ulcers.

RESULTS

Continuous transdermal oxygen therapy has proven to be an effective and safe treatment for chronic and/or hard-to-heal ulcers. This therapy directly addresses the wound's oxygen deficiency, providing an environment conducive to healing. Significant benefits were observed, including the acceleration of the healing process, wound size reduction, and an enhancement in patient quality of life. Its efficacy was found across various ulcer etiologies, underscoring its therapeutic versatility.

CONCLUSIONS

Continuous transdermal oxygen therapy is effective and safe for treating chronic and hard-to-heal ulcers. It's crucial to address each case individually and through a multidisciplinary approach to maximize this therapy's benefits. Both evidence and clinical experience back its utility across a variety of ulcer etiologies.

Detection, management, and prevention of diabetes-related foot disease in the Australian context

Diabetes-related foot disease (DFD) is a widely feared complication among people who live with diabetes. In Australia and globally, rates of disability, cardio-vascular disease, lower extremity amputation, and mortality are significantly increased in patients with DFD. In order to understand and prevent these outcomes, we analyse the common pathogenetic processes of neuropathy, arterial disease, and infection. The review then summarises important management considerations through the interdisciplinary lens. Using Australian and international guidelines, we offer a stepwise, evidence-based practical approach to the care of patients with DFD.

Efficacy of Topical Wound Oxygen Therapy in Healing Chronic Diabetic Foot Ulcers: Systematic Review and Meta-Analysis

Objective: To conduct a systematic review and meta-analysis of recently published randomized controlled trials (RCTs) that employed the use of topical oxygen therapy (TOT) as an adjunct therapy in the treatment of Wagner 1 and 2 diabetic foot ulcers. Approach: Following a literature search of eligible studies from 2010 onward, four RCTs were included. Studies were analyzed for patient and wound characteristics, outcomes, risk of bias, and quality of the evidence assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. A random-effects meta-analysis for complete wound healing was carried out due to statistical heterogeneity of included studies. Results: Risk of bias judgment (RoB2 analysis) resulted in one low-risk trial and three trials with some risk. One study was determined to be the origin of the statistical heterogeneity. Pooled results showed statistical significance with a risk ratio (RR) of 1.59 (95% confidence interval [CI]: 1.07-2.37; p = 0.021). Sensitivity analysis, based on imputed values for missing outcomes, demonstrated that both the RR and 95% CIs changed little. The GRADE ratings for each domain were as follows: (a) risk of bias: moderate (3); (b) imprecision: moderate (2), high (1); (c) inconsistency: low (2), high (1); (d) indirectness: moderate (2), high (1); and (e) publication bias: moderate (1), high (2). Overall, the evidence was moderate. Innovation: Our study shows that TOT is a viable diabetic foot ulcer therapy. Conclusions: These data support the use of TOT for the treatment of chronic Wagner 1 or 2 diabetic foot ulcers in the absence of infection and ischemia.

Venous, Arterial, and Neuropathic Leg Ulcers With Emphasis on the Geriatric Population

Leg ulcers are a common and often serious problem in older adults. Underlying conditions that increase risk include age-related increases in chronic venous insufficiency, peripheral artery disease, connective tissue and autoimmune conditions, reduced mobility, and diabetes mellitus (DM). Geriatric patients have a higher risk of multiple wound-related complications including infection, cellulitis, ischemia, and gangrene, any of which may lead to further complications including amputation. The very presence of these lower extremity ulcers in the elderly negatively impacts their quality of life and ability to function. Understanding and early identification of the underlying conditions and wound features are important for effective ulcer healing and complication mitigation. This targeted review focuses on the three most common types of lower extremity ulcers: venous, arterial, and neuropathic. The goal of this paper is to characterize and discuss the general and specific aspects of these lower extremity ulcers and their relevancy and impact on the geriatric population. The top five main results of this study can be summarized as follows. (1) Venous ulcers, caused by inflammatory processes secondary to venous reflux and hypertension, are the most common chronic leg ulcer in the geriatric population. (2) Arterial-ischemic ulcers are mainly due to lower extremity vascular disease, which itself tends to increase with increasing age setting the stage for an age-related increase in leg ulcers. (3) Persons with DM are at increased risk of developing foot ulcers mainly due to neuropathy and localized ischemia, both of which tend to increase with advancing age. (4) In geriatric patients with leg ulcers, it is important to rule out vasculitis or malignancy as causes. (5) Treatment is best made on a case-by-case basis, considering the patient's underlying condition, comorbidities, overall health status, and life expectancy.

Application of extracorporeal shockwave therapy to improve microcirculation in diabetic foot ulcers: A prospective study

Extracorporeal shockwave therapy (ESWT) can induce wound healing by increasing tissue microcirculation. However, studies on the effect of ESWT on enhancing tissue microcirculation in diabetic foot ulcer (DFU), particularly on when the microcirculation increases after ESWT application, are still lacking. Therefore, we aimed to examine the effectiveness of ESWT in promoting microcirculation in DFU patients in a time-dependent manner. We included 50 feet of 25 patients with type 2 diabetes mellitus and Wagner grade I to II DFU in this study. The affected feet were used as the ESWT group and the unaffected contralateral feet were used as the control group. ESWT was performed in 3 sessions per week for a total of 3 weeks. Transcutaneous partial oxygen pressure (TcPO2) was used to evaluate the tissue microcirculation. The TcPO2 level (>43 mm Hg) in the ESWT group was recovered by the 2nd week of treatment, and statistical significance (P < .05) was demonstrated at the same time. From the 2nd week of ESWT, a significant increase in TcPO2 was observed in Wagner grade I and II DFU. These findings imply that the ESWT may improve microcirculation in patients with Wagner grades I to II DFU. However, this impact requires at least 2 weeks or more than 6 sessions. For better comparison, further studies with larger clinical groups and extended period are needed.

12. Retinopathy, Neuropathy, and Foot Care: Standards of Care in Diabetes-2023

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Reduced Hospitalizations and Amputations in Patients with Diabetic Foot Ulcers Treated with Cyclical Pressurized Topical Wound Oxygen Therapy: Real-World Outcomes

Background: This study sought to examine the real-world impact of multimodality cyclical-pressure topical wound oxygen therapy (TWO2) on hospitalizations and amputations in patients with diabetic foot ulcer (DFU) compared with patients without TWO2. Methods: We conducted a retrospective review of deidentified patient medical records at 2 U.S. Veterans Affairs hospitals between January 2012 and January 2020. DFU patients were assigned to TWO2 or NO TWO2 cohorts based on their treatment records. Patients received appropriate standard of care and may have received other advanced wound treatments, including skin substitutes, negative pressure wound therapy, and growth factors. Primary study outcomes were patients requiring hospitalization and/or amputation within 360 days of initial wound documentation. Findings: Among unmatched cohorts of 202 patients with DFU (91 TWO2, 111 NO TWO2), 6.6% and 12.1% of TWO2 patients had hospitalizations and amputations, respectively, compared with 54.1% and 41.4% of NO TWO2 patients within 360 days (p < 0.0001, p < 0.0001), representing 88% and 71% reductions. Among propensity score-matched cohorts of 140 DFU patients (70 TWO2, 70 NO TWO2), compared with NO TWO2, 82% fewer TWO2 patients were hospitalized (7.1% vs. 40.0%, p < 0.0001) and 73% fewer TWO2 patients had amputations (8.6% vs. 31.4%, p = 0.0007). Logistic regression among matched cohorts demonstrated nearly ninefold and fivefold higher risk of hospitalization and amputation, respectively, for NO TWO2 versus TWO2. Interpretation: This retrospective cohort study demonstrates that treating patients with DFU with TWO2 is associated with significant reductions in hospitalizations and amputations in the real-world setting.

Efficacy and safety of topical oxygen therapy for diabetic foot ulcers: An updated systematic review and meta-analysis

To evaluate the efficacy and safety of topical oxygen therapy (TOT) in diabetic foot ulcers (DFUs), researchers systematically retrieved relevant studies from PubMed, EMBASE, Web of Science, CENTRAL and ClinicalTrials.gov. Relevant studies were searched from database inception to January 2022. Two researchers independently screened the literature, extracted data and assessed the quality of the included studies. Statistical analysis was performed in Stata 16.0. A total of seven RCTs involving 614 participants were included. Compared with the control group, the TOT group had a higher healing rate (RR = 1.63, 95% CI [1.33, 2.00]). According to descriptive analysis, TOT reduced the ulcer area and improved healing durability and quality of life. Furthermore, it had no effect on the occurrence of adverse events. However, it was unclear whether it would be able to reduce the healing time. The existing evidence suggests that TOT is effective and safe for chronic DFUs. Further studies are warranted to validate our findings.

Australian guideline on wound healing interventions to enhance healing of foot ulcers: part of the 2021 Australian evidence-based guidelines for diabetes-related foot disease

BACKGROUND

Diabetes-related foot ulceration (DFU) has a substantial burden on both individuals and healthcare systems both globally and in Australia. There is a pressing need for updated guidelines on wound healing interventions to improve outcomes for people living with DFU. A national expert panel was convened to develop new Australian evidence-based guidelines on wound healing interventions for people with DFU by adapting suitable international guidelines to the Australian context.

METHODS

The panel followed National Health and Medical Research Council (NHMRC) procedures to adapt suitable international guidelines by the International Working Group of the Diabetic Foot (IWGDF) to the Australian context. The panel systematically screened, assessed and judged all IWGDF wound healing recommendations using ADAPTE and GRADE frameworks for adapting guidelines to decide which recommendations should be adopted, adapted or excluded in the Australian context. Each recommendation had their wording, quality of evidence, and strength of recommendation re-evaluated, plus rationale, justifications and implementation considerations provided for the Australian context. This guideline underwent public consultation, further revision and approval by ten national peak bodies.

RESULTS

Thirteen IWGDF wound healing recommendations were evaluated in this process. After screening, nine recommendations were adopted and four were adapted after full assessment. Two recommendations had their strength of recommendations downgraded, one intervention was not currently approved for use in Australia, one intervention specified the need to obtain informed consent to be acceptable in Australia, and another was reworded to clarify best standard of care. Overall, five wound healing interventions have been recommended as having the evidence-based potential to improve wound healing in specific types of DFU when used in conjunction with other best standards of DFU care, including sucrose-octasulfate impregnated dressing, systemic hyperbaric oxygen therapy, negative pressure wound therapy, placental-derived products, and the autologous combined leucocyte, platelet and fibrin dressing. The six new guidelines and the full protocol can be found at: https://diabetesfeetaustralia.org/new-guidelines/ CONCLUSIONS: The IWGDF guideline for wound healing interventions has been adapted to suit the Australian context, and in particular for geographically remote and Aboriginal and Torres Strait Islander people. This new national wound healing guideline, endorsed by ten national peak bodies, also highlights important considerations for implementation, monitoring, and future research priorities in Australia.

A multicenter clinical trial evaluating the durability of diabetic foot ulcer healing in ulcers treated with topical oxygen and standard of care versus standard of care alone 1 year post healing

Multiple clinical trials and real‐world studies have demonstrated accelerated healing in diabetic foot ulcers (DFU) treated with advanced modalities, such as topical oxygen therapy (TOT). In addition to healing, the durability of wound closure is a crucial long‐term endpoint for DFU clinical trials: an advanced treatment that does not confer a reasonable ulcer‐free period will have limited clinical benefit and modest economic value. Preclinical studies suggest that DFUs receiving topical oxygen therapy will experience improved quality of healing: increased collagen deposition and angiogenesis. It is postulated that these changes will translate into a more long‐lasting closure for ulcers treated with TOT and SOC compared to ulcers treated with SOC alone. At the conclusion of a recently completed randomised controlled DFU clinical trial evaluating the efficacy of TOT and SOC compared to SOC alone, patients with healed ulcers were asked to enrol in a long‐term follow‐up study. Healed patients completed four questionnaires through text messages or phone calls within 1‐year post completion of the trial. Twenty‐nine patients consented to participate in the long‐term follow‐up trial (17 TOT/SOC and 12 SOC). Only seven subjects were lost to follow up (5 TOT and 2 SOC). This is a surprisingly low number when factoring in the disruption caused by the COVID‐19 pandemic that continued throughout the entire follow‐up period. In the remaining patients, 85% of the TOT patients and 60% of the SOC remained healed at 1 year. There was one major amputation, which occurred in an SOC‐treated patient. The numbers in the long‐term follow‐up were too small to reach statistical significance; however, there is a strong trend toward more durable closure in ulcers treated with TOT.

Guidelines for the use of topical oxygen therapy in the treatment of hard-to-heal wounds based on a Delphi consensus

A growing body of evidence supports the use of topical oxygen therapy (TOT) in the treatment of diabetic foot ulcers (DFUs). In addition, anecdotal evidence suggests that topical oxygen may be effective in the treatment of other wound types. In May 2021, experts in the field of wound healing from across the US assembled in New Orleans for the inaugural Leaders in Wound Healing conference. In an interactive session dedicated to TOT, several physicians presented and debated the evidence for TOT. Experts in the audience also shared their experiences in treating patients with TOT. The consensus of the experts recommended the use of TOT in DFUs and supported payer reimbursement for the modality. However, they stressed the need for a guidance document on the use of TOT in patients with hard-to-heal wounds. Following the conference, a Delphi method was employed to establish consensus guidelines for prescribing TOT. A multidisciplinary panel of 24 wound experts (15 wound specialists, six vascular surgeons, one plastic surgeon, one critical care provider and one PhD researcher) participated in two rounds of questionnaires. The Delphi survey questions focused on the indications for topical oxygen, when to prescribe the therapy, pretreatment work-up, visit frequency and length of therapy. A clinical workflow algorithm was also included as part of the Delphi. After two rounds, the Delphi participants were able to reach consensus of >77% on when to prescribe topical oxygen, the wound types that may benefit from the therapy, pretreatment wound preparation and work-up and length of therapy. The goal of the guidelines is to standardise the use of topical oxygen and inform further research efforts.

Topical oxygen treatment relieves pain from hard-to-heal leg ulcers and improves healing: a case series

Managing painful hard-to-heal leg ulcers is challenging with current therapeutic options. Wounds are prone to being hypoxic, and the subsequent pain is often related to hypoxia. Hyperbaric oxygen therapy (HBOT) is used to treat hard-to-heal leg wounds by delivering 100% oxygen at a pressure 2-3 times higher than atmospheric pressure. Unfortunately, most patients cannot be offered HBOT because it is costly and needs to be applied at specialised centres. Therefore, topical continuous oxygen therapy (TCOT) is a novel alternative for continuous local oxygen delivery to wounds and is associated with improved wound healing; however, its effect on painful wounds is unknown. This retrospective study was conducted on 20 patients, of whom 17 had painful hard-to-heal leg ulcers. In 13 patients (76%) with painful ulcers, TCOT was associated with rapid and substantial pain alleviation. Also, eight (40%) of the patients' wounds healed entirely with TCOT. This study suggests that TCOT may represent a novel pain management device for hard-to-heal wounds.

Effectiveness of Lower-Extremity Electrical Stimulation to Improve Skin Perfusion

BACKGROUND

Although numerous studies suggest the benefit of electrical stimulation (E-Stim) therapy to accelerate wound healing, the underlying mechanism of action is still debated. In this pilot study, we examined the potential effectiveness of lower-extremity E-Stim therapy to improve tissue perfusion in patients with diabetic foot ulcers.

METHODS

Thirty-eight patients with diabetic foot ulcers underwent 60 min of active E-Stim therapy on acupuncture points above the level of the ankle joint using a bioelectric stimulation technology platform. Perfusion changes in response to E-Stim were assessed by measuring skin perfusion pressure (SPP) at baseline and during 30 and 60 min of therapy; retention was assessed 10 min after therapy. Tissue oxygen saturation (SatO2) was measured using a noninvasive near-infrared camera.

RESULTS

Skin perfusion pressure increased in response to E-Stim therapy (P = .02), with maximum improvement observed at 60 min (11%; P = .007) compared with baseline; SPP reduced 10 min after therapy but remained higher than baseline (9%; P = .1). Magnitude of improvement at 60 min was negatively correlated with baseline SPP values (r = -0.45; P = .01), suggesting that those with lower perfusion could benefit more from E-Stim therapy. Similar trends were observed for SatO2, with statistically significant improvement for a subsample (n = 16) with moderate-to-severe peripheral artery disease.

CONCLUSIONS

This study provides early results on the feasibility and effectiveness of E-Stim therapy to improve skin perfusion and SatO2. The magnitude of benefit is higher in those with poorer skin perfusion. Also, the effects of E-Stim could be washed out after stopping therapy, and regular daily application might be required for effective benefit in wound healing.

Topical Wound Oxygen Therapy in the Treatment of Chronic Diabetic Foot Ulcers

Oxygen is a critical component of many biological processes and is essential for wound healing. Chronic wounds are typically characterized as being hypoxic in that the partial pressure of oxygen (pO2) in the center of the wound is often below a critical threshold necessary to fully support those enzymatic processes necessary for tissue repair. Providing supplemental oxygen can effectively raise pO2 levels to better optimize functioning of these essential enzymes. While hyperbaric oxygen therapy has been well studied in this regard, comparative clinical studies have fallen short of providing clear evidence in support of this modality for healing chronic diabetic foot ulcers (DFU). Topical oxygen therapy (TOT) has been in clinical use for over 50 years with encouraging pre-clinical and clinical studies that have shown improved healing rates when compared to standard care. Nonetheless, TOT has heretofore been discounted as an unproven wound healing modality without theoretical or clinical evidence to support its use. This review shall provide a brief summary of the role of oxygen in wound healing and, specifically, discuss the different types of topical oxygen devices and associated studies that have convincingly shown their efficacy in healing chronic DFUs. The time has come for topical oxygen therapy to be embraced as a proven adjunctive modality in this regard.

Continuous Diffusion of Oxygen Adjunct Therapy to Improve Scar Reduction after Cervicotomy - A Proof of Concept Randomized Controlled Trial

BACKGROUND

Dressing materials are known to influence post-operative surgical wound healing and scar formation (SF). A particular dressing that could promote wound hydration is essential to ensure quick epithelialization and reduce SF. This study examined the effectiveness of a novel Continuous Diffusion of Oxygen (CDO) dressing to reduce scar length post cervicotomy.

METHODS

A randomized controlled trial was performed in patients undergoing cervicotomy, either for thyroid or parathyroid disease. Patients were randomized to either control (CG) or intervention (IG) groups. The IG received a portable CDO system (TransCu O2, EO2 Concepts Inc., TX, USA), whereas the CG received a standard dressing for a 4-week period. The primary outcome was >10% of scar length reduction and %change in scar length.

RESULTS

21 patients were recruited (Age: 53 ± 16 years; 90% female; CG = 9, IG = 12). 5 patients were lost to follow-up. At 4 weeks, 88.8% of the IG significantly achieved >10% of scar reduction (versus CG = 28.5%, d = 0.48, P = 0.049), showing a 40.4% smaller scar (15.7% versus 11.2%, d = 0.13, P = 0.72) compared to the CG. However, the difference was not significant. A sub-sample of patients undergoing thyroidectomy showed a significant scar reduction using CDO (IG = 11.6% versus CG = 5.1%, d = 2.96, P = 0.009).

CONCLUSIONS

This is the first study to assess scar reduction using CDO adjunct therapy after cervicotomy. Advanced CDO dressings may assist wound healing showing improved outcomes for scar visualization in patients undergoing thyroidectomy. A larger sample is required to validate this observation.

Topical oxygen therapy for diabetes-related foot ulcers: A systematic review and meta-analysis

INTRODUCTION

Topical oxygen therapy (TOT) has been suggested as a treatment for diabetes-related foot ulcer (DFU) but no prior meta-analyses of randomised clinical trials (RCT) have been reported. This systematic review and meta-analysis examined the randomised evidence for the benefit of TOT in healing DFU.

METHODS

Publicly available databases were searched for RCTs investigating the effect of TOT on wound healing in participants with a DFU. The primary outcome was ulcer healing defined as full epithelialisation. Meta-analyses were performed using random effect models and reported as risk ratios (RR) and 95% confidence intervals (CI). Study quality and publication bias were assessed using a modified version of the Cochrane Collaboration's tool and funnel plots, respectively.

RESULTS

Six RCTs involving 530 participants with a DFU testing TOT were included. Meta-analysis suggested that TOT significantly increased the likelihood of ulcer healing compared to controls (Risk ratio [RR] 1.94; 95% CI 1.19, 3.17; I²  = 57%; NNT = 5.33) and findings were robust in sensitivity analyses. Risk of bias was high, moderate and low in two, one and three studies, respectively. Analysis of the three trials judged to be at low risk of bias suggested that TOT increased the likelihood of ulcer healing compared to controls (RR 2.37; 95% CI 1.52, 3.68; I²  = 0%). Funnel plots suggested the possibility of publication bias. Data on amputation were too limited for meta-analysis.

CONCLUSION

This meta-analysis suggests that TOT improves the likelihood of DFU healing; however, its effect on amputation and cost-effectiveness are unclear.

Topical oxygen treatment relieves pain from hard-to-heal leg ulcers and improves healing: a case report

Pain from hard-to-heal wounds is common and challenging to manage with current therapies. Most hard-to-heal wounds show some degree of hypoxia that impairs healing and contributes to pain. Regular oxygen therapy is given in hyperbaric oxygen chambers and is costly, time-consuming and cannot be offered to most patients. Moreover, hyperbaric oxygen therapy (HBOT) only increases tissue oxygen for a short time and is given only for a few hours per week. Topical oxygen therapy (TOT) was introduced as an alternative and in this report we focus on topical continuous oxygen therapy (TCOT), which has been shown to be associated with healing of hard-to-heal ulcers. We report on a patient with type 1 diabetes with a painful hard-to-heal lower leg ulcer that failed to heal with standard wound dressings and that had insufficient response to pharmacological analgesia. The patient was on three different analgesics before treating the wound with TCOT. As the wound was considered hypoxic, due to longstanding diabetes and probable microangiopathy, TCOT was commenced. Within one week of treatment starting, the patient spontaneously ceased all his analgesics as he was free of pain; and after 2.5 months, the ulcer healed. The patient reported no adverse effects. In addition to promoting healing, TCOT may also be considered for its potential analgesic effects in hard-to-heal wound management.

Topical oxygen therapy in the treatment of diabetic foot ulcers: a multicentre, open, randomised controlled clinical trial

OBJECTIVES

Perfusion and blood oxygen levels are frequently insufficient in patients with hard-to-heal wounds due to poor circulation, vascular disruption and vasoconstriction, reducing the wound's capacity to heal. This study aimed to investigate the effect of topical oxygen on healing rates in patients with hard-to-heal diabetic foot ulcers (DFUs) (i.e., non-responsive over four weeks).

METHOD

This multicentre, open-label, community-based randomised clinical trial compared standard care (SOC) with or without continuous topical oxygen therapy (TOT) for 12 weeks in patients with DFUs or minor amputation wounds. SOC included debridement, offloading with total contact casting (TCC) and appropriate moisture balance. Primary endpoints were the number of patients to achieve complete wound closure and percentage change in ulcer size. Secondary endpoints were pain levels and adverse events.

RESULTS

For the study, 145 patients were randomised with index ulcers graded Infectious Diseases Society of America (IDSA) 1 or 2, or Wagner 1 or 2. In the intention-to-treat analysis, 18/64 (28.1%) patients healed in the SOC group at 12 weeks compared with 36/81 (44.4%) in the SOC plus TOT group (p=0.044). There was a statistically significant reduction in wound area between the groups: SOC group mean reduction: 40% (standard deviation (SD) 72.1); SOC plus TOT group mean reduction: 70% (SD 45.5); per protocol p=0.005). There were no significant differences in changes to pain levels or adverse events.

CONCLUSION

This study suggests that the addition of TOT to SOC facilitates wound closure in patients with hard-to-heal DFUs.

Molecular Biomarkers of Oxygen Therapy in Patients with Diabetic Foot Ulcers

Hyperbaric oxygen therapy (HBOT) and topical oxygen therapy (TOT) including continuous diffuse oxygen therapy (CDOT) are often utilized to enhance wound healing in patients with diabetic foot ulcerations. High pressure pure oxygen assists in the oxygenation of hypoxic wounds to increase perfusion. Although oxygen therapy provides wound healing benefits to some patients with diabetic foot ulcers, it is currently performed from clinical examination and imaging. Data suggest that oxygen therapy promotes wound healing via angiogenesis, the creation of new blood vessels. Molecular biomarkers relating to tissue inflammation, repair, and healing have been identified. Predictive biomarkers can be used to identify patients who will most likely benefit from this specialized treatment. In diabetic foot ulcerations, specifically, certain biomarkers have been linked to factors involving angiogenesis and inflammation, two crucial aspects of wound healing. In this review, the mechanism of how oxygen works in wound healing on a physiological basis, such as cell metabolism and growth factor signaling transduction is detailed. Additionally, observable clinical outcomes such as collagen formation, angiogenesis, respiratory burst and cell proliferation are described. The scientific evidence for the impact of oxygen on biomolecular pathways and its relationship to the outcomes in clinical research is discussed in this narrative review.

Therapeutic effect of continuous diffusion of oxygen therapy combined with traditional moist wound dressing therapy in the treatment of diabetic foot ulcers

AIMS

To investigate the therapeutic effect of continuous diffusion of oxygen (CDO) combined with traditional moist wound dressing (MWD) on the diabetic foot ulcers (DFUs) inpatients.

METHODS

The inpatients from May 2016 to April 2018 were enrolled and randomly divided into MWD, CDO and combination treatment groups (n = 40 each group). The moist dressing was used in the MWD group while a micro-oxygen supply device was used in the CDO group. The combination treatment group was given both MWD and CDO. All patients were treated for 8 weeks. The wound healing, amputation rate, and inflammatory control were evaluated.

RESULTS

Compared with MWD and CDO groups, the combination group showed a higher wound healing rate (P < 0.05), lower white blood cell count (P < 0.05) and lower high-sensitivity C-reactive protein level (P < 0.05). During 1-year follow-up, the amputation rate was 0% in combination group, which was significantly lower than that in other two groups (P < 0.05).

CONCLUSIONS

The combination of MWD and CDO was effective in promoting healing and preventing infection of DFUs, which holds a potential to be a new strategy for the treatment of this critical clinical condition.

Managing Diabetic Foot Ulcers: Pharmacotherapy for Wound Healing

Historically, there has been a scarcity of evidence-based topical therapy to hasten the healing of diabetic foot ulcers. But recently new evidence-based treatments have emerged from multicentre, randomised, controlled trials. This article highlights those trials, and describes the current pharmacological management of the diabetic foot ulcer and the advances that have been made in wound therapy to date. It provides an overview of topical and systemic pharmacotherapies in current use and those in development for future use in managing the diabetic foot. For each treatment, proposed mechanisms of action and evidence available to support their clinical use are presented. There is supporting randomised, controlled evidence for sucrose octasulfate in the treatment of neuro-ischaemic ulcers, and multi-layered patch of autologous leucocytes, platelets and fibrin in ulcers with or without ischaemia. There is also evidence for placentally derived products and for topical and systemic oxygen therapy in the healing of diabetic foot ulcers. Growth factors, bio-engineered tissues, stem cell therapy, gene therapy and peptide therapy also have some supporting evidence in the healing of diabetic foot ulcers. Nonsurgical debriding agents may be useful when the optimum approach of sharp debridement is not possible, and immunomodulators may be helpful for their antimicrobial effects, but robust data is still required to strengthen the case for general use. The review does not cover antimicrobials as their primary role are as anti-infectives and not in wound healing. The development of nanotechnology has created a means of prolonging the bioavailability of target molecules at the wound site, with the use of glass/hydrogel nanoparticles, polyethylene glycol and hyaluronic acid. Looking forward, novel therapies, including traction force-activated payloads, local delivery of short-interfering RNA and finally hydrogels incorporating bioactive agents or cells may provide possibilities for pharmacotherapy in the future.

An economic evaluation examining the cost-effectiveness of continuous diffusion of oxygen therapy for individuals with diabetic foot ulcers

Continuous delivery of oxygen therapy has been observed to improve healing for individuals with an advanced diabetic foot ulcer (DFU). However, this intervention requires the purchasing of an oxygen delivery device and moist dressings. It is unknown whether this upfront financial investment represents good value for money. Thus the aim of this project is to evaluate the cost-effectiveness of treating advanced DFU using continuous delivery of oxygen compared with negative pressure wound therapy from the perspective of the public health care payer in Ontario, Canada. A microsimulation model was constructed with inputs from peer-reviewed journal publications and publicly available reports. The 5-year costs and quality-adjusted life-years were compared between treatment and comparator. Sensitivity analyses were conducted to evaluate the robustness of results. The model predicted that continuous delivery of oxygen would cost $4800 less compared with negative pressure wound therapy and increased quality-adjusted life years by 0.025. Lower cost and improved outcomes were observed in most scenario analyses. The results of this economic evaluation suggest that CDO therapy may reduce health care economic burden with a modest increase in quality of life outcomes. Health care decision-makers should consider the inclusion of CDO for the treatment of DFU.

The effect of continuous diffusion of oxygen treatment on cytokines, perfusion, bacterial load, and healing in patients with diabetic foot ulcers

To evaluate continuous diffusion of oxygen therapy (CDO) on cytokines, perfusion, and bacterial load in diabetic foot ulcers we evaluated 23 patients for 3 weeks. Tissues biopsies were obtained at each visit to evaluate cytokines and quantitative bacterial cultures. Perfusion was measured with hyperspectral imaging and transcutaneous oxygen. We used paired T tests to compare continuous variables and independent T tests to compare healers and nonhealers. There was an increase from baseline to week 1 in TGF-β (P = .008), TNF-α (P = .014), VEGF (P = .008), PDGF (P = .087), and IGF-1 (P = .058); baseline to week 2 in TGF-β (P = .010), VEGF (P = .051), and IL-6 (P = .031); and baseline to week 3 with TGF-β (P = .055) and IL-6 (P = .054). There was a significant increase in transcutaneous oxygen after 1 week of treatment on both medial and lateral foot (P = .086 and .025). Fifty-three percent of the patients had at least a 50% wound area reduction (healers). At baseline, there were no differences in cytokines between healers and nonhealers. However, there was an increase in CXCL8 after 1 week of treatment (P = .080) and IL-6 after 3 weeks of treatment in nonhealers (P = .099). There were no differences in quantitative cultures in healers and nonhealers.

Comparing near infrared spectroscopy and transcutaneous oxygen measurement in hard-to-heal wounds: a pilot study

Objective:

Oxygen plays an integral role in all phases of the wound healing process and tissue oxygenation is a key determinant of wound healing. A comprehensive evaluation of patients with hard-to-heal wounds must include measurement of oxygenation in and around the area of skin breakdown. The current gold standard, transcutaneous oxygen measurement (TCOM), has numerous drawbacks and as a result has fallen into disuse.

Method:

This study compared measurement of tissue oxygenation of near infrared spectroscopy (NIRS) with TCOM in patients with acute and hard-to-heal wounds. The Shapiro-Wilk test was used to evaluate the normality of the data. The level of agreement between NIRS and TCOM was determined using Bland-Altman analysis. The relationship between TCOM and NIRS was examined using Pearson correlation.

Results:

A total of 24 observations were obtained from 10 patients using TCOM and NIRS. The weighted mean partial pressure of oxygen (pO2) in the study population was 39.54mmHg (8.96 standard deviation). Bland–Altman analysis showed that mean difference was positive (18.75), suggesting an overestimation of oxygen measurements using TCOM compared with NIRS. The oxygen levels measured by TCOM and NIRS showed a strong correlation (r=0.74).

Conclusion:

The wound and hyperbaric community would benefit from a simplified procedure for measuring tissue oxygenation. These findings suggest a strong trend toward correlation between NIRS and TCOM. A further study in a larger population is recommended. NIRS offers several advantages over TCOM. Clinicians have immediate point-of-care visualisation of tissue oxygenation using a handheld device. The procedure takes minutes to perform and is less operator-dependent than TCOM. Finally, NIRS allows measurement of oxygenation in the wound bed, while TCOM does not.

Oxygen therapy: evidence base

The evidence base for the different methods of oxygen therapy ranges from systematic reviews and meta-analyses to case series evaluations. A common thread running through the assorted evidence is that oxygen therapy accelerates healing and reduces healing times. This article summarises the clinical evidence produced on this therapy.

Effectiveness of interventions to enhance healing of chronic foot ulcers in diabetes: a systematic review

The management of diabetic foot ulcers (DFU) remains a challenge, and there is continuing uncertainty concerning optimal approaches to wound healing. The International Working Group of the Diabetic Foot (IWGDF) working group on wound healing has previously published systematic reviews of the evidence in 2008, 2012 and 2016 to inform protocols for routine care and to highlight areas which should be considered for further study. The working group has now updated this review by considering papers on the interventions to improve the healing of DFU's published between June 2014 and August 2018. Methodological quality of selected studies was independently assessed by a minimum of two reviewers using the recently published 21-point questionnaire as recommended by IWGDF/European Wound Management Association, as well as the previously incorporated Scottish Intercollegiate Guidelines Network criteria. Of the 2275 papers identified, 97 were finally selected for grading following full text review. Overall, there has been an improvement in study design and a significant rise in the number of published studies. While previous systematic reviews did not find any evidence to justify the use of newer therapies, except for negative pressure wound therapy in post-surgical wounds, in this review we found additional evidence to support some interventions including a sucrose-octasulfate dressing, the combined leucocyte, fibrin and platelet patch as well as topical application of some placental membrane products, all when used in addition to usual best care. Nonetheless, the assessment and comparison of published trials remains difficult with marked clinical heterogeneity between studies: in patient selection, study duration, standard of usual care provision and the timing and description of the clinical endpoints.

A Multinational, Multicenter, Randomized, Double-Blinded, Placebo-Controlled Trial to Evaluate the Efficacy of Cyclical Topical Wound Oxygen (TWO2) Therapy in the Treatment of Chronic Diabetic Foot Ulcers: The TWO2 Study

OBJECTIVE

Topical oxygen has been used for the treatment of chronic wounds for more than 50 years. Its effectiveness remains disputed due to the limited number of robust high-quality investigations. The aim of this study was to assess the efficacy of multimodality cyclical pressure Topical Wound Oxygen (TWO2) home care therapy in healing refractory diabetic foot ulcers (DFUs) that had failed to heal with standard of care (SOC) alone.

RESEARCH DESIGN AND METHODS

Patients with diabetes and chronic DFUs were randomized (double-blind) to either active TWO2 therapy or sham control therapy-both in addition to optimal SOC. The primary outcome was the percentage of ulcers in each group achieving 100% healing at 12 weeks. A group sequential design was used for the study with three predetermined analyses and hard stopping rules once 73, 146, and ultimately 220 patients completed the 12-week treatment phase.

RESULTS

At the first analysis point, the active TWO2 arm was found to be superior to the sham arm, with a closure rate of 41.7% compared with 13.5%. This difference in outcome produced an odds ratio (OR) of 4.57 (97.8% CI 1.19, 17.57), P = 0.010. After adjustment for University of Texas Classification (UTC) ulcer grade, the OR increased to 6.00 (97.8% CI 1.44, 24.93), P = 0.004. Cox proportional hazards modeling, also after adjustment for UTC grade, demonstrated >4.5 times the likelihood to heal DFUs over 12 weeks compared with the sham arm with a hazard ratio of 4.66 (97.8% CI 1.36, 15.98), P = 0.004. At 12 months postenrollment, 56% of active arm ulcers were closed compared with 27% of the sham arm ulcers (P = 0.013).

CONCLUSIONS

This sham-controlled, double-blind randomized controlled trial demonstrates that, at both 12 weeks and 12 months, adjunctive cyclical pressurized TWO2 therapy was superior in healing chronic DFUs compared with optimal SOC alone.

Guidelines on use of interventions to enhance healing of chronic foot ulcers in diabetes (IWGDF 2019 update)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the prevention and management of diabetic foot disease since 1999. In conjunction with advice from internal and external reviewers and expert consultants in the field, this update is based on a systematic review of the literature centred on the following: the Population (P), Intervention (I), Comparator (C) and Outcomes (O) framework; the use of the SIGN guideline/Cochrane review system; and the 21 point scoring system advocated by IWGDF/EWMA. This has resulted in 13 recommendations. The recommendation on sharp debridement and the selection of dressings remain unchanged from the last recommendations published in 2016. The recommendation to consider negative pressure wound therapy in post-surgical wounds and the judicious use of hyperbaric oxygen therapy in certain non-healing ischaemic ulcers also remains unchanged. Recommendations against the use of growth factors, autologous platelet gels, bioengineered skin products, ozone, topical carbon dioxide, nitric oxide or interventions reporting improvement of ulcer healing through an alteration of the physical environment or through other systemic medical or nutritional means also remain. New recommendations include consideration of the use of sucrose-octasulfate impregnated dressings in difficult to heal neuro-ischaemic ulcers and consideration of the use of autologous combined leucocyte, platelet and fibrin patch in ulcers that are difficult to heal, in both cases when used in addition to best standard of care. A further new recommendation is the consideration of topical placental derived products when used in addition to best standard of care.

Therapeutic advances in wound healing

Wound healing is a complex physiological process that occurs in the human body involving the sequential activation of multiple cell types and signaling pathways in a coordinated manner. Chronic wounds and burns clearly decrease quality of life of the patients since they are associated with an increase in physical pain and socio-economical complications. Furthermore, incidence and prevalence of chronic wounds (unlike burns) have been increasing mainly due to population aging resulting in increased costs for national health systems. Thus, the development of new and more cost-effective technologies/therapies is not only of huge interest but also necessary to improve the long-term sustainability of national health systems. This review covers the current knowledge on recent technologies/therapies for skin regeneration, such as: wound dressings; skin substitutes; exogenous growth factor based therapy and systemic therapy; external tissue expanders; negative pressure; oxygen; shock wave, and photobiomodulation wound therapies. Associated benefits and risks as well as the clinical use and availability are all addressed for each therapy. Moreover, future trends in wound care including novel formulations using metallic nanoparticles and topical insulin are herein presented. These novel formulations have shown to be promising therapeutic options in the near future that may change the wound care paradigm.

Editorial and Mini-Review: Topical Oxygen Therapy for Diabetic Foot Ulcerations - Avenue Towards New Hope?

Diabetic foot complications now represent the 10th leading cause of disease burden and disability. Wound healing is impaired, leading to chronic ulceration. Local high oxygen concentration is required by the metabolically active cells in the wound, which may render the region hypoxic, even in the absence of peripheral arterial disease. Therefore, the contribution of hyperbaric oxygen to improved healing rates has been extensively investigated. More recent developments include products delivering topical oxygen therapy (TOT) directly at the wound site, either by continuous delivery or by pressurized systems. A very recent systematic review has found that TOT increases wound healing rates in chronic, less severe diabetic foot ulcers (DFUs), and it promotes high rates of healing in more severe ulcers. Thus, TOT appears to be very promising to improve healing in DFUs. We now need more experience regarding its therapeutic place in the algorithm of DFU management and in relation to optimal patient selection.