A novel intervention for wound bed preparation in severe extremity trauma: Highly concentrated carbon dioxide bathing

Introduction

In severe extremity trauma involving large tissue defects, early closure (e.g., free-flap surgery) of the defects is an essential step for good functional reconstruction; however, in some cases, early closure may be difficult. Highly concentrated carbon dioxide bathing, used to improve blood flow in ischemic limbs and skin ulcers, can also be applied in wound bed preparation for severe limb trauma.

Patients and Methods

The three cases in this study required an average of 13 weeks of highly concentrated carbonated bathing, which led to significantly better wound bed preparation, even in the exposed bone and tendon regions.

Results

We successfully achieved good functional limb reconstruction in patients with deep burns and severe open fractures by reducing wound infection and facilitating good wound bed preparation.

Conclusions

Highly concentrated carbon dioxide bathing was sufficient to prevent frequent wound infections, even in severe extremity trauma involving large soft-tissue defects such as deep crush burns and Gustilo Anderson classification ≥3b open fractures of the extremities. To our knowledge, such interventions have not been reported in the past and are valuable as new procedures for wound bed preparation in severe extremity trauma from both cost and wound infection control perspectives.

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.

Cost effectiveness analysis for commonly used human cell and tissue products in the management of diabetic foot ulcers

Background and Aims

This study considers the cost-effectiveness of commonly used cellular, acellular, and matrix‑like products (CAMPs) of human origin also known as human cell and tissue products (HCT/Ps) in the management of diabetic foot ulcers.

Methods

We developed a 1-year economic model assessing six CAMPs [cryopreserved placental membrane with viable cells (vCPM), bioengineered bilayered living cellular construct (BLCC), human fibroblast dermal substitute (hFDS), dehydrated human amnion chorion membrane (dHACM), hypothermically stored amniotic membrane (HSAM) and human amnion membrane allograft (HAMA) which had randomized controlled trial evidence compared with standard of care (SoC). CAMPs were compared indirectly and ranked in order of cost-effectiveness using SoC as the baseline, from a CMS/Medicare's perspective.

Results

The mean cost, healed wounds (hw) and QALYs per patient for vCPM is $10,907 (0.914 hw, 0.783 QALYs), for HAMA $11,470 (0.903 hw, 0.780 QALYs), for dHACM $15,862 (0.828 hw, 0.764 QALYs), for BLCC $18,430 (0.816 hw, 0.763 QALYs), for hFDS $19,498 (0.775 hw, 0.757 QALYs), for SoC $19,862 (0.601 hw, 0.732 QALYs) and $24, 214 (0.829, 0.763 QALYs) for HSAM respectively. Over 1 year, vCPM results in cheaper costs overall and better clinical outcomes compared to other CAMPs. Following probabilistic sensitivity analysis, vCPM has a 60%, HAMA 40% probability of being cost-effective then dHACM, hFDS, BLCC, and lastly HSAM using a $100,000/healed wound or QALY threshold.

Conclusions

All CAMPs were shown to be cost-effective when compared to SoC in managing DFUs. However, vCPM appears to be the most cost-effective CAMP over the modelled 52 weeks followed by HAMA, dHACM, hFDS, BLCC, and HSAM. We urge caution in interpreting the results because we currently lack head-to-head evidence comparing all these CAMPs and therefore suggest that this analysis be updated when more direct evidence of CAMPs becomes available.

Advanced Biomaterials and Topical Medications for Treating Diabetic Foot Ulcers: A Systematic Review and Network Meta-Analysis

Significance: With the increasing diabetic population worldwide, diabetic foot ulcers (DFUs) are a significant concern. This study aimed to compare the efficacy of skin substitutes, biomaterials, and topical agents with standard care. Recent Advances: A meta-analysis was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, EMBASE, and Web of Science were searched using the following keywords: diabetes mellitus AND skin graft OR tissue replacement OR dressing OR drug. Two independent reviewers performed data collection and quality assessment of the eligible studies. The primary outcome was the 12- to 16-week healing rates and the secondary outcome was recurrence rates. Critical Issues: Thirty-eight randomized controlled trials, including 3,862 patients, were analyzed. The studies exhibited low heterogeneity (τ2 = 0.10) without significant asymmetry (Egger's test, p = 0.8852). After pooling direct and indirect estimates, placenta-based tissue products exhibited the best wound healing probability (p-score = 0.90), followed by skin substitutes with living cells (p-score = 0.70), acellular skin substitutes (p-score = 0.56), and advanced topical dressings (p-score = 0.34) compared with standard of care. The recurrence analysis showed significant improvement in the intervention group compared with the control group (11.21% vs. 15.15%). Future Directions: This network meta-analysis provides the relative effectiveness and rank of biomaterials and topical dressings in DFU healing. The results could help clinical decision making.

A multicenter, randomized controlled clinical trial evaluating the effects of a novel autologous heterogeneous skin construct in the treatment of Wagner one diabetic foot ulcers: Final analysis

A novel autologous heterogeneous skin construct (AHSC) was previously shown to be effective versus standard of care (SOC) treatment in facilitating complete wound healing of Wagner 1 diabetic foot ulcers in an interim analysis of 50 patients previously published. We now report the final analysis of 100 patients (50 per group), which further supports the interim analysis findings. Forty-five subjects in the AHSC treatment group received only one application of the autologous heterogeneous skin construct, and five received two applications. For the primary endpoint at 12 weeks, there were significantly more diabetic wounds closed in the AHSC treatment group (35/50, 70%) than in the SOC control group (17/50, 34%) (p = 0.00032). A significant difference in percentage area reduction between groups was also demonstrated over 8 weeks (p = 0.009). Forty-nine subjects experienced 148 adverse events: 66 occurred in 21 subjects (42%) in the AHSC treatment group versus 82 in 28 SOC control group subjects (56.0%). Eight subjects were withdrawn due to serious adverse events. Autologous heterogeneous skin construct was shown to be an effective adjunctive therapy for healing Wagner 1 diabetic foot ulcers.

Tissue Engineering-Based Strategies for Diabetic Foot Ulcer Management

Significance: Diabetic foot ulcers (DFU) are a mounting problem with the increasingly frail population. Injuries that would otherwise heal are kept open by risk factors such as diabetes, obesity, and age-related conditions, which interferes with the natural wound healing processes. Recent Advances: This review summarizes recent advancements in the field of tissue engineering for the treatment of DFUs. FDA-approved approaches, including signaling-based therapies, stem cell therapies, and skin substitutes are summarized and cutting-edge experimental technologies that have the potential to manage chronic wounds, such as skin printing, skin organogenesis, skin self-assembly, and prevascularization, are discussed. Critical Issues: The standard of care for chronic wounds involves wound debridement, wound dressings, and resolving the underlying cause such as lowering the glycemic index and reducing wound pressure. Current DFU treatments are limited by low wound closure rates and poor regrown skin quality. New adjuvant therapies that facilitate wound closure in place of or in conjunction with standard care are critically needed. Future Directions: Tissue engineering strategies are limited by the plasticity of adult human cells. In addition to traditional techniques, genetic modification, although currently an emerging technology, has the potential to unlock human regeneration and can be incorporated in future therapeutics.

Reactive oxygen species-degradable polythioketal urethane foam dressings to promote porcine skin wound repair

Porous, resorbable biomaterials can serve as temporary scaffolds that support cell infiltration, tissue formation, and remodeling of nonhealing skin wounds. Synthetic biomaterials are less expensive to manufacture than biologic dressings and can achieve a broader range of physiochemical properties, but opportunities remain to tailor these materials for ideal host immune and regenerative responses. Polyesters are a well-established class of synthetic biomaterials; however, acidic degradation products released by their hydrolysis can cause poorly controlled autocatalytic degradation. Here, we systemically explored reactive oxygen species (ROS)-degradable polythioketal (PTK) urethane (UR) foams with varied hydrophilicity for skin wound healing. The most hydrophilic PTK-UR variant, with seven ethylene glycol (EG7) repeats flanking each side of a thioketal bond, exhibited the highest ROS reactivity and promoted optimal tissue infiltration, extracellular matrix (ECM) deposition, and reepithelialization in porcine skin wounds. EG7 induced lower foreign body response, greater recruitment of regenerative immune cell populations, and resolution of type 1 inflammation compared to more hydrophobic PTK-UR scaffolds. Porcine wounds treated with EG7 PTK-UR foams had greater ECM production, vascularization, and resolution of proinflammatory immune cells compared to polyester UR foam-based NovoSorb Biodegradable Temporizing Matrix (BTM)-treated wounds and greater early vascular perfusion and similar wound resurfacing relative to clinical gold standard Integra Bilayer Wound Matrix (BWM). In a porcine ischemic flap excisional wound model, EG7 PTK-UR treatment led to higher wound healing scores driven by lower inflammation and higher reepithelialization compared to NovoSorb BTM. PTK-UR foams warrant further investigation as synthetic biomaterials for wound healing applications.

Comparison of Skin Substitutes for Acute and Chronic Wound Management

Chronic and acute wounds, such as diabetic foot ulcers and burns, respectively, can be difficult to treat, especially when autologous skin transplantations are unavailable. Skin substitutes can be used as a treatment alternative by providing the structural elements and growth factors necessary for reepithelialization and revascularization from a nonautologous source. As of 2020, there are 76 commercially available skin substitute products; this article provides a review of the relevant literature related to the major categories of skin substitutes available.

SkinTE for the Treatment of a Complicated Wound after Synovial Sarcoma Resection: A Case Report

Radiation therapy following oncologic resection can result in incisional breakdown, delay or cessation of wound healing, and exposure of structures. Impaired wound healing often mandates free tissue transfer for definitive closure and preservation of function. We present the case of a 16-year-old male patient who had a major incisional dehiscence following resection of a synovial sarcoma of the lower leg after postoperative irradiation. The progressive wound breakdown failed to respond to local wound care or negative pressure therapy and progressed to expose tendons of the distal leg. The patient was successfully treated with SkinTE, an autologous homologous skin graft and casting. Healing was slow but the wound filled with granulation tissue (which covered the tendon), epithelialized, and led to an excellent cosmetic and functional result. This highlights the potential of stem cell therapy and other forms of regenerative methods in healing of complicated wounds.

Wound dressings: curbing inflammation in chronic wound healing

Chronic wounds represent an economic burden to healthcare systems worldwide and a societal burden to patients, deeply impacting their quality of life. The incidence of recalcitrant wounds has been steadily increasing since the population more susceptible, the elderly and diabetic, are rapidly growing. Chronic wounds are characterised by a delayed wound healing process that takes longer to heal under standard of care than acute (i.e. healthy) wounds. Two of the most common problems associated with chronic wounds are inflammation and infection, with the latter usually exacerbating the former. With this in mind, researchers and wound care companies have developed and marketed a wide variety of wound dressings presenting different compositions but all aimed at promoting healing. This makes it harder for physicians to choose the correct therapy, especially given a lack of public quantitative data to support the manufacturers’ claims. This review aims at giving a brief introduction to the clinical need for chronic wound dressings, focusing on inflammation and evaluating how bio-derived and synthetic dressings may control excess inflammation and promote healing.

Dehydrated human amnion and chorion allograft versus standard of care alone in treatment of Wagner 1 diabetic foot ulcers: a trial-based health economics study

AIMS

The aim of this health economics study was to estimate the cost-utility of an aseptically processed, dehydrated human amnion and chorion allograft (dHACA) plus standard of care (SOC) (group 1) versus SOC alone (group 2) based on a published randomized controlled trial in which patients who had an eligible Wagner 1 diabetic foot ulcer wound were randomized to either of these treatments.

MATERIALS AND METHODS

A Markov microsimulation was used to project trial results out to a 1-year horizon time with a third-party payer perspective. The starting health state was an unhealed non-infected ulcer with other health states of healed ulcer, infected non-healed ulcer, cellulitis, osteomyelitis, and absorbing states of dead or amputation. All patients started with unhealed non-infected ulcers at cycle 0. Costs were incurred by patients for procedures at hospital outpatient wound care provider-based departments (PBDs) and hospitals (if complications occurred) and were calculated using time-based activity costing methods. Effectiveness units were quality-adjusted life years (QALYs) computed from literature utility values. One-way and probabilistic sensitivity analysis (PSA) were also conducted.

RESULTS

After 1 year, the calculated incremental cost-effectiveness ratio (ICER) for group 1 versus group 2 was -$4,373 with group 1 (dHACA) being dominant over group 2 (SOC). PSA demonstrated that group 1 had 69.2% lower cost values with increased positive incremental effectiveness for 94.9% of values. A willingness to pay (WTP) curve showed that about 92% of interventions were cost effective for group 1 when $50,000 was paid.

CONCLUSIONS

The results of this study demonstrated that dHACA added to SOC compared to SOC alone was extremely cost-effective in the defined trial population.