Systematic review of economic evaluations of human cell-derived wound care products for the treatment of venous leg and diabetic foot ulcers

Improving Diabetic Wound-Healing Outcomes With Topical Growth Factor Therapies

CONTEXT

Diabetes mellitus is associated with morbid complications such as diabetic foot ulcers (DFUs) that may lead to amputations or mortality if not managed adequately.

OBJECTIVE

New adjunctive interventions to treat diabetic wounds include topical biologics and growth factors. This study aims to evaluate their efficacy in improving wound-healing outcomes and safety.

METHODS

Comprehensive database searches of MEDLINE via PubMed, EMBASE, and Cochrane were performed from inception to December 2022. Three independent researchers selected the studies. Randomized controlled trials that compared the use of a topical biologic growth factor-containing regimen to other biologics or standard of care (SOC) were included. This review followed PRISMA guidelines. Risk of bias analysis was performed using the Jadad scale. Network meta-analysis was performed. Treatments were grouped into common nodes based on the type of biologic agent. Primary outcomes of interest were healing rate and time to wound closure. Secondary outcomes included wound infection, serious adverse events (AEs), and amputation rate.

RESULTS

Human umbilical cord (HUC) was associated with the highest cure, followed by recombinant human epidermal growth factor (hEGF). A significantly greater reduction in the time to cure DFUs was seen in HUC, hEGF, and fibroblast growth factor (FGF). There was a significantly lower risk of AEs when platelet-rich plasma (PRP) was administered.

CONCLUSION

HUC, hEGF, and FGF are promising topical biologics with statistically significant primary outcomes compared to SOC, while PRP is effective in reducing ulcer-related AEs. HUC has been found to be the most effective in terms of cure rate and a reduction in time to cure.

Artificial Skin Therapies; Strategy for Product Development

Significance: Tissue-engineered artificial skin for clinical reconstruction can be regarded as an established practice. Bi-layered skin equivalents are available as established allogenic or autologous therapy, and various acellular skin replacements can support tissue repair. Moreover, there is considerable commonality between the skin and other soft tissue reconstruction products. This article presents an attempt to create a comprehensive global landscape review of advanced replacement materials and associated strategies for skin and soft tissue reconstruction. Recent Advances: There has been rapid growth in the number of commercial and pre-commercial products over the past decade. In this survey, 263 base products for advanced skin therapy have been identified, across 8 therapeutic categories, giving over 350 products in total. The largest market is in the United States, followed by the E.U. zone. However, despite these advances, and the investment of resources in each product development, there are key issues concerning the clinical efficacy, cost-benefit of products, and clinical impact. Each therapeutic strategy has relative merits and limitations. Critical Issues: A critical consideration in developing and evaluating products is the therapeutic modality, associated regulatory processes, and the potential for clinical adoption geographically, determined by regulatory territory, intellectual property, and commercial distribution factors. The survey identifies an opportunity for developments that improve basic efficacy or cost-benefit. Future Directions: The economic pressures on health care systems, compounded by the demands of our increasingly ageing population, and the imperative to distribute effective health care, create an urgent global need for effective and affordable products.

Surgical Time and Postoperative Symptoms Study in Pterygium Excision and Amniotic Membrane Graft Using Celularity Triple Layer Dehydrated Amniotic Membrane

Purpose

To evaluate a novel sutureless glueless technique using a triple-layer dehydrated amniotic membrane (TLDAM) for pterygia excisions in surgical time, postoperative pain, epiphora, irritation, and FBS.

Methods

Twenty eyes with pterygia underwent excision with mitomycin C. The conjunctival defect was closed with TLDAM placed on the dried scleral bed with the edges of the amniotic membrane tucked under the edges of the conjunctival defect. Surgical times were measured from injection of lidocaine to final placement of bandage contact lens. After a bandage contact lens was placed, the eye was patched until POD1. Patients graded self-administered questionnaires to rate pain, FBS, irritation, and epiphora on a scale of 1-5 (1-none; 5-severe) at POD1 and POW1.

Results

Surgical times ranged from 6:55 to 12:00, with mean of 8:29. Compared with a previous study of sutureless glueless methodology, the difference in mean surgical time was 11.9 (p < 0.0001). Mean questionnaire scores were as follows: POD1 pain 1.8, FBS 2.3, irritation 1.0, and epiphora 2.6; POW1 pain 1.5, FBS 1.6, irritation 1.6, and epiphora 1.6. Compared to previous studies, this technique showed significantly improved pain at POD1 (p=0.0086, p<0.0001, p<0.0001, p<0.0001) and POW1 (p=0.0002, p=0.0016, p<0.0001). Significant improvement in irritation and FBS was noted at POD1 and POW1. See Table 1 for full analysis.

Conclusion

The sutureless glueless technique using TLDAM is a safe and effective technique compared to current standard methods. There appears to be a significant benefit regarding surgical time and postoperative pain, irritation, epiphora, and FBS compared to previous studies.

Role of small intestinal submucosa extracellular matrix in advanced regenerative wound therapy

Advanced regenerative therapies using cellular and tissue-based products (CTPs) can play an important role in effective management of hard-to-heal wounds. CTPs derived from allogenic or xenogenic tissues use an extracellular matrix (ECM) to provide a therapeutic ECM scaffold in the wound bed to facilitate tissue regeneration. One such example is OASIS Extracellular Matrix (Cook Biotech Incorporated), a porcine small intestinal submucosa extracellular matrix (SIS-ECM) that preclinical and clinical data have shown to be tolerable and effective in promoting tissue regeneration in hard-to-heal wounds.

Role of small intestinal submucosa extracellular matrix in advanced regenerative wound therapy

Advanced regenerative therapies using cellular and tissue-based products (CTPs) can play an important role in effective management of hard-to-heal wounds. CTPs derived from allogenic or xenogenic tissues use an extracellular matrix (ECM) to provide a therapeutic ECM scaffold in the wound bed to facilitate tissue regeneration. One such example is OASIS Extracellular Matrix (Cook Biotech Incorporated), a porcine small intestinal submucosa extracellular matrix (SIS-ECM) that preclinical and clinical data have shown to be tolerable and effective in promoting tissue regeneration in hard-to-heal wounds.

Challenges around quantifying uncertainty in a holistic approach to hard-to-heal wound management: Health economic perspective

Treatment of hard-to-heal wounds involves a holistic approach for choosing between available treatment options. However, evidence for informing these choices is sparse, introducing uncertainty into decisions about the optimum treatment pathways that reflect the vast heterogeneity in this patient population. This paper discusses the existing clinical and health economic literature in order to provide insight into sources of uncertainty in the evaluation of the holistic approach to management of the hard-to-heal wounds, and how this uncertainty can be appropriately reflected in research. We identified three key sources of uncertainty in the evaluation of chronic wound treatments, namely heterogeneity in aetiology and patient populations, heterogeneity in treatment pathways, and challenges around capturing all relevant outcomes. Reflecting these complexities requires sophisticated modelling of treatment sequencing and long-term outcomes. The paper discusses how the scope specification, scenario analyses, and sensitivity analyses can be used to fully characterise analytical uncertainty.

Automated Extraction of Skin Wound Healing Biomarkers From In Vivo Label-Free Multiphoton Microscopy Using Convolutional Neural Networks

BACKGROUND AND OBJECTIVES

Histological analysis is a gold standard technique for studying impaired skin wound healing. Label-free multiphoton microscopy (MPM) can provide natural image contrast similar to histological sections and quantitative metabolic information using NADH and FAD autofluorescence. However, MPM analysis requires time-intensive manual segmentation of specific wound tissue regions limiting the practicality and usage of the technology for monitoring wounds. The goal of this study was to train a series of convolutional neural networks (CNNs) to segment MPM images of skin wounds to automate image processing and quantification of wound geometry and metabolism.

STUDY DESIGN/MATERIALS AND METHODS

Two CNNs with a 4-layer U-Net architecture were trained to segment unstained skin wound tissue sections and in vivo z-stacks of the wound edge. The wound section CNN used 380 distinct MPM images while the in vivo CNN used 5,848 with both image sets being randomly distributed to training, validation, and test sets following a 70%, 20%, and 10% split. The accuracy of each network was evaluated on the test set of images, and the effectiveness of automated measurement of wound geometry and optical redox ratio were compared with hand traced outputs of six unstained wound sections and 69 wound edge z-stacks from eight mice.

RESULTS

The MPM wound section CNN had an overall accuracy of 92.83%. Measurements of epidermal/dermal thickness, wound depth, wound width, and % re-epithelialization were within 10% error when evaluated on six full wound sections from days 3, 5, and 10 post-wounding that were not included in the training set. The in vivo wound z-stack CNN had an overall accuracy of 89.66% and was able to isolate the wound edge epithelium in z-stacks from eight mice across post-wound time points to quantify the optical redox ratio within 5% of what was recorded by manual segmentations.

CONCLUSION

The CNNs trained and presented in this study can accurately segment MPM imaged wound sections and in vivo z-stacks to enable automated and rapid calculation of wound geometry and metabolism. Although MPM is a noninvasive imaging modality well suited to imaging living wound tissue, its use has been limited by time-intensive user segmentation. The use of CNNs for automated image segmentation demonstrate that it is possible for MPM to deliver near real-time quantitative readouts of tissue structure and function. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

Skin Substitutes for Adults With Diabetic Foot Ulcers and Venous Leg Ulcers: A Health Technology Assessment

BACKGROUND

Wounds may be caused in a variety of ways. Some wounds are difficult to heal, such as diabetic foot ulcers and venous leg ulcers. We conducted a health technology assessment of skin substitutes for adults with neuropathic diabetic foot ulcers and venous leg ulcers, which included an evaluation of effectiveness, safety, cost-effectiveness, the budget impact of publicly funding skin substitutes, and patient preferences and values.

METHODS

We performed a systematic literature search of the clinical evidence. We assessed the risk of bias of each included study using the Cochrane risk-of-bias tool for randomized studies (version 2), and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature search and conducted a cost-utility analysis with a 26-week time horizon from a public payer perspective. We also analyzed the budget impact of publicly funding skin substitutes in adults with diabetic foot ulcers and venous leg ulcers in Ontario. We explored the underlying values, needs, and priorities of those who have lived experience with diabetic leg ulcers and venous leg ulcers, as well as their preferences for and perceptions of skin substitutes.

RESULTS

We included 40 studies in the clinical evidence review. Adults with difficult-to-heal neuropathic diabetic foot ulcers who used dermal (GRADE: High) or multi-layered (GRADE: Moderate) skin substitutes as an adjunct to standard care were more likely to experience complete wound healing than those whose who used standard care alone. Adults with difficult-to-heal venous leg ulcers who used dermal (GRADE: Moderate) or multi-layered (GRADE: High) skin substitutes as an adjunct to standard care were more likely to experience complete wound healing than those who used standard care alone. The evidence for the effectiveness of epidermal skin substitutes was inconclusive for venous leg ulcers because of the small size of the individual studies (GRADE: Very low). We found no studies on epidermal skin substitutes for diabetic foot ulcers. We could not evaluate the safety of skin substitutes versus standard care, because the number of adverse events was either very low or zero (because sample sizes were too small).In our economic analysis, the use of skin substitutes as an adjunct to standard care was more costly and more effective than standard care alone for the treatment of difficult-to-heal diabetic foot ulcers and venous leg ulcers. For diabetic foot ulcers, the incremental cost-effectiveness ratio (ICER) of skin substitutes plus standard care compared with standard care alone was $48,242 per quality-adjusted life-year (QALY), and the cost per ulcer-free week was $158. For venous leg ulcers, the ICER was $1,868,850 per QALY, and the cost per ulcer-free week was $3,235. At the commonly used willingness-to-pay of $50,000 per QALY, the cost-effectiveness of skin substitutes plus standard care versus standard care alone was uncertain (47% probability of being cost-effective) for diabetic foot ulcers and highly unlikely (0% probability of being cost-effective) for venous leg ulcers. At the commonly used willingness-to-pay of $100,000 per QALY, the cost-effectiveness of skin substitutes plus standard care versus standard care alone was moderately likely (71% probability of cost-effectiveness) for people with diabetic foot ulcers and highly unlikely (0% probability of being cost-effective) for people with venous leg ulcers. The annual budget impact of publicly funding skin substitutes in Ontario over the next 5 years would range from an additional $0.17 million in year 1 to $1.2 million in year 5 for people with diabetic foot ulcers, and from $1 million in year 1 to $7.7 million in year 5 for people with venous leg ulcers.Direct patient engagement consisted of three participants for this assessment and 51 from previous health technology assessments that addressed interventions for diabetic foot ulcers and venous leg ulcers. Participants spoke of the negative impact on their quality of life with regard to mobility, employment, social activities, and emotional and mental health. No participants had direct experience using skin substitutes, but participants were open to this treatment option. Barriers to access included the limited use of skin substitutes across Ontario, lack of knowledge of skin substitutes among people with diabetic foot ulcers and venous leg ulcers, and cost.

CONCLUSIONS

Dermal and multi-layered skin substitutes, when used as an adjunct to standard care, were more effective than standard care alone in completely healing difficult-to-heal neuropathic diabetic foot ulcers and venous leg ulcers in adults. Using skin substitutes as an adjunct to standard care was more costly and more effective than standard care alone for the treatment of difficult-to-heal neuropathic diabetic foot ulcers and venous leg ulcers. For adults with diabetic foot ulcers, the likelihood of skin substitutes being cost-effective compared with standard care depends on the willingness to pay. The likelihood of skin substitutes being cost-effective compared with standard care is uncertain at $50,000 per QALY and moderately likely at $100,000 per QALY. For adults with venous leg ulcers, skin substitutes were highly unlikely to be cost-effective compared with standard care. We estimated that publicly funding skin substitutes in Ontario would result in additional costs of $3 million and $20 million over the next 5 years for people with diabetic foot ulcers and venous leg ulcers, respectively. The people with diabetic foot ulcers and venous leg ulcers we spoke with were open to using skin substitutes as a treatment option.

The Development of Tissue Engineering Scaffolds Using Matrix from iPS-Reprogrammed Fibroblasts

Tissue engineering solutions have been widely explored for enhanced healing of skin wounds. Diabetic foot ulcers (DFU) are particularly challenging wounds to heal for a variety of reasons, including aberrant ECM, dysregulation of vascularization, and persistent inflammation. Tissue engineering approaches, such as porous collagen-based scaffolds, have shown promise in replacing the current treatments of surgical debridement and topical treatments. Collagen-glycosaminoglycan scaffolds, which are FDA approved for diabetic foot ulcers, can benefit from further functionalization by incorporation of additional signaling factors or extracellular matrix molecules. One option for this is to incorporate matrix from a rejuvenated cell source, as wounds in younger patients heal more quickly. Induced pluripotent stem cells (iPS) are generated from somatic cells and share many functional similarities with embryonic stem cells (ES), while avoiding the ethical concerns. Fibroblasts differentiated from iPS cells have been shown to enrich their ECM with glycosaminoglycan (GAGs), collagen Type III and fibronectin, to have an increased ECM production, and to be pro-angiogenic. Here we describe a technique to grow matrix from post-iPS fibroblasts, and to develop a scaffold from this matrix, in combination with collagen, with the goal of enhancing wound healing. By activating scaffolds with extracellular matrix (ECM) from fibroblasts derived from an iPS source (post-iPSF), the scaffolds are enriched with beneficial elements like GAGs, collagen type III, fibronectin, and VEGF. We believe these scaffolds can enhance skin regeneration and that the techniques can be modified for other tissue engineering applications.

Optimization of extracellular matrix production from human induced pluripotent stem cell-derived fibroblasts for scaffold fabrication for application in wound healing

Extracellular matrix is a key component of all tissues, including skin and it plays a crucial role in the complex events of wound healing. These events are impaired in chronic wounds, with chronic inflammation and infection often present in these non-healing wounds. Many tissue engineering approaches for wound healing provide a scaffold to mimic the native matrix. Fibroblasts derived from iPS cells (iPSF) represent a novel source of matrix rich in pro-regenerative components, which can be used for scaffold fabrication to improve wound healing. However, in vitro production of matrix by cells for scaffold fabrication requires long cell culturing times which increases cost. The aim of this work is to optimize the iPSF matrix production by boosting matrix deposition, without affecting its composition. A good candidate technique to achieve this goal is macromolecular crowding, which is known to promote conversion of procollagen into mature collagen and its accumulation. We tested two molecular crowders, Ficoll and Carrageenan-in combination with ascorbic acid-over a prolonged period of time. Ficoll in combination with ascorbic acid notably increased collagen deposition and matrix dry weight compared to ascorbic acid alone, and did not affect matrix composition as measured by RT-PCR. Interestingly, Carrageenan did not affect collagen quantity, but it significantly increased glycosaminoglycan deposition. Finally, we successfully fabricated scaffolds from harvested matrix and confirmed their ability for cell growth and viability. This work lays the foundation for development of a time and cost effective protocol for novel iPSF ECM production for tissue engineering scaffolds.

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.

Scaffolds Functionalized with Matrix from Induced Pluripotent Stem Cell Fibroblasts for Diabetic Wound Healing

Diabetic foot ulcers (DFUs) are chronic wounds, with 20% of cases resulting in amputation, despite intervention. A recently approved tissue engineering product-a cell-free collagen-glycosaminoglycan (GAG) scaffold-demonstrates 50% success, motivating its functionalization with extracellular matrix (ECM). Induced pluripotent stem cell (iPSC) technology reprograms somatic cells into an embryonic-like state. Recent findings describe how iPSCs-derived fibroblasts ("post-iPSF") are proangiogenic, produce more ECM than their somatic precursors ("pre-iPSF"), and their ECM has characteristics of foetal ECM (a wound regeneration advantage, as fetuses heal scar-free). ECM production is 45% higher from post-iPSF and has favorable components (e.g., Collagen I and III, and fibronectin). Herein, a freeze-dried scaffold using ECM grown by post-iPSF cells (Post-iPSF Coll) is developed and tested vs precursors ECM-activated scaffolds (Pre-iPSF Coll). When seeded with healthy or DFU fibroblasts, both ECM-derived scaffolds have more diverse ECM and more robust immune responses to cues. Post-iPSF-Coll had higher GAG, higher cell content, higher Vascular Endothelial Growth Factor (VEGF) in DFUs, and higher Interleukin-1-receptor antagonist (IL-1ra) vs. pre-iPSF Coll. This work constitutes the first step in exploiting ECM from iPSF for tissue engineering scaffolds.

Open-label Venous Leg Ulcer Pilot Study Using a Novel Autolologous Homologous Skin Construct

Venous leg ulcers (VLUs) are often refractory to compression therapy, and their prevalence is increasing. An autologous homologous skin construct (AHSC) that uses the endogenous regenerative capacity of healthy skin has been developed to treat cutaneous defects, with a single application. The ability of AHSC to close VLUs with a single treatment was evaluated in an open-label, single-arm feasibility study to test the hypothesis that AHSC treatment will result in wound closure by providing healthy autologous tissue to the wound bed.

METHODS

Ten VLUs were treated with a single application of AHSC. A 1.5 cm2 full-thickness skin harvest from the proximal calf was collected and sent to a Food and Drug Administration-registered facility, where it was processed into AHSC and returned to the provider within 48 hours. AHSC was spread evenly across the wound and dressed with silicone. The primary endpoint was wound closure rate at 12 weeks. Wound closure was followed with 3-dimensional planimetry, and closure was confirmed by a panel of plastic surgeons. Additional endpoints followed for 12 weeks included graft take, harvest site closure, adverse event rate, complications, and patient-reported pain.

RESULTS

All 10 VLUs demonstrated successful graft take as evidenced by graft persisting in wound and harvest site closure. Eight VLUs exhibited complete closure within 12 weeks. One VLU that failed to heal with a prior split thickness skin graft closed within 13.5 weeks with AHSC. The mean time of closure was 34 days (95% confidence interval, 14-53). Pain improved by closure confirmation visit. There was 1 serious adverse event unrelated to the product or procedure.

CONCLUSION

This pilot study demonstrated that AHSC may be a viable single-application topical intervention for VLUs and warrants further investigation in larger, controlled studies.

A Systematic Review of Model-Based Economic Evaluations of Treatments for Venous Leg Ulcers

OBJECTIVE

The aim of this review was to identify, and assess the quality of, published model-based economic evaluations relating to treatments for patients with venous leg ulcers to help inform future decision-analytic models in this clinical area.

METHODS

A systematic literature search was performed on six electronic databases, from database inception until 21 May 2018. Search results were screened against predefined criteria by two independent reviewers. Data was then extracted from the included studies using a standardised form, whilst the decision-analytic model-specific Philips Checklist was used to assess quality and to inform model critique.

RESULTS

A total of 23 models were identified, 12 studies used a Markov modelling approach, five used decision trees and six studies did not detail the model type. Studies were predominantly from the National Health Service (NHS)/payer perspective, with only two taking a societal perspective. Interventions were wide ranging, but dressing technologies (11/23) were most common. The intervention studied was found to be dominant in 22/23 studies. The reporting quality of papers was mostly low, with evidence behind model structures, time horizons and data selection consistently underreported across the included papers.

CONCLUSIONS

This review has identified a sizeable literature of model-based economic evaluations, evaluating treatments for venous leg ulcers. However, the methods used to conduct such studies were generally poorly reported. In particular, the reporting of evidence surrounding the model structure, justification of the time horizon used and the rationale for selecting data inputs should be focused on in any future models developed.

The Safety and Effectiveness of the Percutaneous Flexor Tenotomy in Healing Neuropathic Apical Toe Ulcers in the Outpatient Setting

Percutaneous flexor tenotomy is a minimally invasive procedure that involves cutting one or both flexor digitorum tendons underneath the toe. It is an alternative to open surgical procedures performed in an operating theatre. This project is a prospective case series investigating the utility, effectiveness, and participant satisfaction of the percutaneous flexor tenotomy when performed in the outpatient setting. People with diabetes, digital flexion deformity, and loss of protective sensation with an apical ulcer or preulcerative lesion presenting to the Austin Health Foot Ulcer Specialist Outpatient Clinic were enrolled in the study. The procedure was performed under sterile technique with an 18-gauge needle or fine scalpel blade. Participants were reviewed weekly until the incision and/ or ulcer healed. Participants were then followed up at 3 and 6 months. Time to ulcer healing, reulceration rate, frequency of complications, and patient satisfaction were recorded. There were 11 toe ulcers and 41 preulcerative lesions. A total of 76 tenotomy procedures were performed on the 23 participants across 35 episodes of care. The mean time to ulcer healing following tenotomy was 10.2 ± 4.3 days. There were no recurrences of ulceration. The infection rate per episode of care was 2.8%. There were 11 toes (14.5%) that sustained a transfer lesion post the index procedure. The mean time to development of a transfer lesion was 95.5 ± 98.1 days. All participants strongly agreed that they were satisfied with the outcome of the procedure. The flexor tenotomy is an effective procedure to expedite the healing of apical toe ulcers in people with loss of protective sensation and flexion digital deformity. It has a low infection rate and high patient satisfaction rate when performed in the outpatient setting. There is a moderate risk of transfer preulcerative lesions to an adjacent digit. Levels of Evidence: Level IV: Prospective case series.

A retrospective matched-cohort study of 3994 lower extremity wounds of multiple etiologies across 644 institutions comparing a bioactive human skin allograft, TheraSkin, plus standard of care, to standard of care alone

Most chronic wounds are related to comorbidities, for which no clinical trials are performed. This retrospective propensity matched-cohort study examined data from 2 074 000 lower extremity wounds across 644 institutions to determine the effectiveness of TheraSkin plus standard of care (SOC; n = 1997) versus SOC alone (n = 1997). Multivariate modelling comparing outcomes such as healing rates, percent area reductions (PARs), amputations, recidivism, treatment completion, and medical transfers were evaluated. A higher proportion of wounds in the treatment group compared with the controls were more likely to close (68.3% versus 60.3%), particularly wounds with exposed structures (64% versus 50.4%) and with lower recidivism at 6 months (24.9% versus 28.3%). The control group was 2.75x more likely to require amputation than the treatment group. The combination of propensity matching and logistic regression analysis on a particularly large database demonstrated that wounds treated with TheraSkin had higher healing rates, higher PARs (78.7% versus 68.9%), fewer amputations, lower recidivism, higher treatment completion (61.0% versus 50.6%), and lower medical transfers (16.1% versus 23.5%) than SOC alone. This study considered data from complex wounds typically excluded from controlled trials and supports the idea that real-world evidence studies can be valid and reliable.

Locally Delivered Umbilical Cord Mesenchymal Stromal Cells Reduce Chronic Inflammation in Long-Term Nonhealing Wounds: A Randomized Study

Inflammation is part of a complex biological response to injury that mediates a rapid mobilization of cells and triggers the restoration of tissue homeostasis. The systemic diseases of the connective tissues, repetitive strain injuries, neuropathy, and vascular impairment lead to the development of a chronic inflammatory state. In such cases, a forced intervention is required to trigger tissue regeneration. Mesenchymal stromal cells (MSCs) have been considered a perspective tool for regenerative medicine because of their ability to change the expression and secretory profile under the influence of signals from the microenvironment to perform a regulatory function at the site of tissue damage. In this study, MSCs were isolated from the human umbilical cord (UCMSCs). The ability of UCMSCs to regulate chronic inflammation was investigated in a randomized placebo-controlled pilot study to assess the efficacy and safety of UCMSC therapy in patients with nonhealing wounds. A total of 108 patients with chronic wounds of different etiologies were randomly divided into two groups according to the criteria of inclusion and exclusion. The group (n = 59) that was treated with a single local subcutaneous infusion of UCMSCs around the wound periphery showed a pronounced growth of granulation tissue, improved blood microcirculation, and reduction in wound size compared to the placebo group (n = 49). No prominent adverse events were detected in patients from the UCMSC group during the 1-year follow-up period. This research has demonstrated that locally delivered allogeneic UCMSCs can contribute to chronic wound repair and provide an additional support toward new therapeutic strategies. Registration certificate №FS2006/341 was issued by the Federal Service for Surveillance in Healthcare.

Matrix therapy is a cost-effective solution to reduce amputation risk and improve quality of life: pilot and case studies

Introduction: Chronic, non-healing ulcers remain one of the most challenging clinical situations for health care practitioners. Often, conventional treatments fail and lead to amputation, further decreasing the patient's quality of life and resulting in enormous medical expenditures for healthcare systems. Here we evaluated the use of and cost-effectiveness of the RGTA (ReGeneraTing Agents) medical device CACIPLIQ20 (OTR4120) for chronic lower-extremity ulcers in patients with Leriche and Fontaine Stage IV peripheral arterial disease who were not eligible for revascularization. Methods: This uncontrolled pilot study included 14 chronic lower extremity ulcers in 12 patients in one hospital. The pilot study included 12 patients with TcPO₂ < 20 mm Hg and ABPI < 0.5 who had either a minimum of one chronic lower extremity ulcer or a chronic ulcer related to amputation. OTR4120 was applied twice a week or until complete healing, for up to 12 weeks. Ulcer surface area reduction (%)after 2, 4, 8 and 12 weeks, appearance after 4 weeks, and healing after 12 weeks were measured and recorded. Results: A 35% reduction in ulcer size was achieved after 4 weeks. 7 (50%) out of 14 ulcers completely healed within 1 to 3 months of treatment. Discussion: OTR4120 is an effective therapeutic option for patients with chronic lower extremity ulcers, can provide major improvement of quality of life and has the added benefit of being a significant cost-effective solution for healthcare systems.

Stem cell therapy for chronic skin wounds in the era of personalized medicine: From bench to bedside

With the significant financial burden of chronic cutaneous wounds on the healthcare system, not to the personal burden mention on those individuals afflicted, it has become increasingly essential to improve our clinical treatments. This requires the translation of the most recent benchtop approaches to clinical wound repair as our current treatment modalities have proven insufficient. The most promising potential treatment options rely on stem cell-based therapies. Stem cell proliferation and signaling play crucial roles in every phase of the wound healing process and chronic wounds are often associated with impaired stem cell function. Clinical approaches involving stem cells could thus be utilized in some cases to improve a body's inhibited healing capacity. We aim to present the laboratory research behind the mechanisms and effects of this technology as well as current clinical trials which showcase their therapeutic potential. Given the current problems and complications presented by chronic wounds, we hope to show that developing the clinical applications of stem cell therapies is the rational next step in improving wound care.

Health economics for treatment of diabetic foot ulcers: a cost-effectiveness analysis of eight skin substitutes

Aim:

Skin substitutes are frequently used to treat chronic diabetic foot ulcers (DFU), and many different options are available. While the clinical efficacy of many products has been evaluated, a comprehensive cost-effectiveness analysis comparing the most popular skin substitutes and using the most recent cost data has been lacking.

Methods:

This study compared eight skin substitutes using published efficacy rates combined with the Centers for Medicare and Medicaid Services (CMS) 2018 cost data. The study criteria resulted in the inclusion of seven studies that described efficacy rates for treatment of DFUs using the skin substitutes.

Results:

The results revealed wide discrepancies between these skin substitutes for the costs of treatments and healing rates in hospital outpatient departments and physician office settings. Healing rates for 12 and 16 weeks ranged from 28% to 68%, while the average cost for treating one DFU varied from $2001 to $14,507 and $1207 to $8791 in the hospital outpatient department and physician's office setting, respectively. The estimated patient share of costs for treating a single DFU ranged from $400 to $2901 and $241 to $1758 in the hospital outpatient department and physician's office setting, respectively. Most importantly, the estimated number of wounds healed out of 100 DFUs per $1000 expenditure with each patient ranged from 3.9–26.5 DFUs in the hospital outpatient department, and 4.3–36.4 DFUs in the physicians' office setting.

Conclusions:

This study revealed that the costs of a skin substitute itself did not necessarily correlate with its healing efficacy. These results provide a comprehensive cost-effectiveness analysis to enable integrated health-care systems, health professionals and reimbursement payers to make informed value decisions when treating DFUs.

Role of Topical Biological Therapies and Dressings in Healing Ischemic Wounds

Ischemic wounds are the most severe expression of critical limb ischemia (CLI), and they have been defined clinically as an end stage of peripheral arterial disease. Urgent revascularization is a fundamental part for limb salvage in patients with CLI. However, the risk of revascularization should be weighed against the likelihood of success given a patient’s life-threatening comorbidities. Once the condition of arterial insufficiency is revascularized, wound care is an important aspect to promote the wound healing process and infection control. MOIST concept for wound care is a modern systematic treatment for enhanced wound healing process. Currently, advanced biological therapies are emerging in ischemic wound therapies to restore the wound healing process and involve active biological agents to support the wound healing process. We studied and summarized the different types of available topical biological therapies and their mechanisms on the healing process including platelet-derived growth factor, epidermal growth factor, fibroblast growth factor, and vascular endothelial growth factor, platelet-rich plasma, and honey for local wound care of patient with CLI. Our review suggests that topical platelet-derived growth factor, epidermal growth factor, platelet-rich plasma, and honey are available as well as considered in the ischemic wound healing process enhancement through the MOIST concept. In conclusion, biologic wound dressing or topical agent therapy may improve the wound healing process, increase limb salvage, is inexpensive, and provides potential safety with nontoxic low-risk therapy in patients with an ischemic wound. Thus, local wound care by biological dressing should be added in adjuvant treatment for ischemic wound patients. However, further randomized studies are needed to support efficacy and long-term outcomes of these biological dressing in patients with ischemic wound.

Delivery systems of current biologicals for the treatment of chronic cutaneous wounds and severe burns

While wound therapy remains a clinical challenge in current medical practice, much effort has focused on developing biological therapeutic approaches. This paper presents a comprehensive review of delivery systems for current biologicals for the treatment of chronic wounds and severe burns. The biologicals discussed here include proteins such as growth factors and gene modifying molecules, which may be delivered to wounds free, encapsulated, or released from living systems (cells, skin grafts or skin equivalents) or biomaterials. Advances in biomaterial science and technologies have enabled the synthesis of delivery systems such as scaffolds, hydrogels and nanoparticles, designed to not only allow spatially and temporally controlled release of biologicals, but to also emulate the natural extracellular matrix microenvironment. These technologies represent an attractive field for regenerative wound therapy, by offering more personalised and effective treatments.

Tissue Engineered Skin Substitutes

The fundamental skin role is to supply a supportive barrier to protect body against harmful agents and injuries. Three layers of skin including epidermis, dermis and hypodermis form a sophisticated tissue composed of extracellular matrix (ECM) mainly made of collagens and glycosaminoglycans (GAGs) as a scaffold, different cell types such as keratinocytes, fibroblasts and functional cells embedded in the ECM. When the skin is injured, depends on its severity, the majority of mentioned components are recruited to wound regeneration. Additionally, different growth factors like fibroblast growth factor (FGF), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) are needed to orchestrated wound healing process. In case of large surface area wounds, natural wound repair seems inefficient. Inspired by nature, scientists in tissue engineering field attempt to engineered constructs mimicking natural healing process to promote skin restoration in untreatable injuries. There are three main types of commercially available engineered skin substitutes including epidermal, dermal, and dermoepidermal. Each of them could be composed of scaffold, desired cell types or growth factors. These substitutes could have autologous, allogeneic, or xenogeneic origin. Moreover, they may be cellular or acellular. They are used to accelerate wound healing and recover normal skin functions with pain relief. Although there are a wide variety of commercially available skin substitutes, almost none of them considered as an ideal equivalents required for proper wound healing.

Combination therapy of autologous adipose mesenchymal stem cell-enriched, high-density lipoaspirate and topical timolol for healing chronic wounds

Chronic venous leg ulcers are profoundly debilitating and result in billions in health care expenditure. Thus, there is a quest for engineered and innovative approaches. Herein we present a 63-year-old patient with a 30 year history of venous stasis and left lower extremity ulcers, which have been refractory to standard of care, anticoagulation and venous stripping. The medial ulcer was treated with transplantation of autologous adipose mesenchymal stem cell (AMSC)-enriched, high-density lipoaspirate (HDL) on OASIS wound matrix and compression therapy. The lateral ulcer was treated as a control with standard debridement and compression therapy. Four weeks later, both ulcers received daily topical timolol. Three months later, the test ulcer was completely epithelized and remains healed for over 15 months. However, the control showed minimal signs of improvement. In companion studies in our laboratory, human AMSC were cultured in Minimum Essential Medium Eagle Alpha Modifications (MEMα) with fetal bovine serum (FBS). Timolol was administered to AMSC prior to treatment with epinephrine and 104 bacteria/ml heat-killed Staphylococcus aureus. The MEMα with FBS devoid of AMSC served as a background control. After 24 h, cell culture supernatants and protein lysates were collected to determine cytokine production. There was a statistical significant decrease in pro-inflammatory interleukin-6 and -8 induced by the bacteria (to model the wound environment) in AMSC in the presence of timolol compared with control (p < 0.5). This is the first case of a successful combination of autologous AMSC-enriched, HDL with topical timolol for the healing of chronic venous leg ulcers. Copyright © 2016 John Wiley & Sons, Ltd.

Cost of diabetic eye, renal and foot complications: a methodological review

INTRODUCTION

Diabetic retinopathy (DR), diabetic kidney disease (DKD) and diabetic foot ulcer (DFU) represent a public health and economic concern that may be assessed with cost-of-illness (COI) studies.

OBJECTIVES

(1) To review COI studies published between 2000 and 2015, about DR, DKD and DFU; (2) to analyse methods used.

METHODS

Disease definition, epidemiological approach, perspective, type of costs, activity data sources, cost valuation, sensitivity analysis, cost discounting and presentation of costs may be described in COI studies. Each reviewed study was assessed with a methodological grid including these nine items.

RESULTS

The five following items have been detailed in the reviewed studies: epidemiological approach (59 % of studies described it), perspective (75 %), type of costs (98 %), activity data sources (91 %) and cost valuation (59 %). The disease definition and the presentation of results were detailed in fewer studies (respectively 50 and 46 %). In contrast, sensitivity analysis was only performed in 14 % of studies and cost discounting in 7 %. Considering the studies showing an average cost per patient and per year with a societal perspective, DR cost estimates were US $2297 (range 5-67,486), DKD cost ranged from US $1095 to US $16,384, and DFU cost was US $10,604 (range 1444-85,718).

DISCUSSION

This review reinforces the need to adequately describe the method to facilitate literature comparisons and projections. It also recalls that COI studies represent complementary tools to cost-effectiveness studies to help decision makers in the allocation of economic resources for the management of DR, DKD and DFU.

Chronic Wound Healing: A Review of Current Management and Treatments

Wound healing is a complex, highly regulated process that is critical in maintaining the barrier function of skin. With numerous disease processes, the cascade of events involved in wound healing can be affected, resulting in chronic, non-healing wounds that subject the patient to significant discomfort and distress while draining the medical system of an enormous amount of resources. The healing of a superficial wound requires many factors to work in concert, and wound dressings and treatments have evolved considerably to address possible barriers to wound healing, ranging from infection to hypoxia. Even optimally, wound tissue never reaches its pre-injured strength and multiple aberrant healing states can result in chronic non-healing wounds. This article will review wound healing physiology and discuss current approaches for treating a wound.

An update and review of cell-based wound dressings and their integration into clinical practice

Chronic wounds affect over 4 million individuals and pose a significant burden to the US healthcare system. Diabetes, venous stasis, radiation or paralysis are common risk factors for chronic wounds. Unfortunately, the current standard of care (SOC) has a high relapse rate and these wounds continue to adversely affect patients' quality of life. Fortunately, advances in tissue engineering have allowed for the development of cell-based wound dressings that promote wound healing by improving cell migration and differentiation. As the available options continue to increase in quantity and quality, physicians should have a user-friendly guide to reference when deciding which dressing to use. The objective of this review is to identify the currently available biologic dressings, describe their indications, and provide a framework for integration into clinical practice. This review included 53 studies consisting of prospective and retrospective cohorts as well as several randomized control trials. Three general categories of cell-based biologic dressings were identified and nine brands were included. Cell-based biologic dressings have shown efficacy in a broad range of scenarios, and studies examining their efficacy have improved our understanding of the pathophysiology of chronic wounds. Amniotic and placental membranes have the widest scope and can be used to treat all subtypes of chronic wounds. Human skin allografts and bioengineered skin substitutes can be used for chronic ulcers but generally require a vascularized wound bed. Autologous platelet rich plasma (PRP) has shown promise in venous stasis ulcers and decubitus ulcers that have failed conventional treatment. Overall, more research is necessary to determine if these novel therapeutic options will change the current SOC, but current studies demonstrate encouraging results in the treatment of chronic wounds.

Current Status and Future of Skin Substitutes for Chronic Wound Healing

Chronic wounds, including diabetic ulcers, pressure ulcers, venous ulcers, and arterial insufficiency ulcers, are both difficult and expensive to treat. Conventional wound care may sometimes lead to suboptimal wound healing and significant morbidity and mortality for patients. The use of skin substitutes provides an alternative therapy showing superior efficacy and, in some cases, similar cost-effectiveness compared to traditional treatments. This review discusses the different types of currently available commercial skin substitutes for use in chronic wounds as well as the paucity of strong evidence supporting their use. It then delves into the limitations of these skin substitutes and examines the most recent research targeting these limitations.

Treatment of chronic diabetic lower extremity ulcers with advanced therapies: a prospective, randomised, controlled, multi-centre comparative study examining clinical efficacy and cost

Advanced therapies such as bioengineered skin substitutes (BSS) and dehydrated human amnion/chorion membrane (dHACM) have been shown to promote healing of chronic diabetic ulcers. An interim analysis of data from 60 patients enrolled in a prospective, randomised, controlled, parallel group, multi-centre clinical trial showed that dHACM (EpiFix, MiMedx Group Inc., Marietta, GA) is superior to standard wound care (SWC) and BSS (Apligraf, Organogenesis, Inc., Canton, MA) in achieving complete wound closure within 4-6 weeks. Rates and time to closure at a longer time interval and factors influencing outcomes remained unassessed; therefore, the study was continued in order to achieve at least 100 patients. With the larger cohort, we compare clinical outcomes at 12 weeks in 100 patients with chronic lower extremity diabetic ulcers treated with weekly applications of Apligraf (n = 33), EpiFix (n = 32) or SWC (n = 35) with collagen-alginate dressing as controls. A Cox regression was performed to analyse the time to heal within 12 weeks, adjusting for all significant covariates. A Kaplan-Meier analysis was conducted to compare time-to-heal within 12 weeks for the three treatment groups. Clinical characteristics were well matched across study groups. The proportion of wounds achieving complete closure within the 12-week study period were 73% (24/33), 97% (31/32), and 51% (18/35) for Apligraf, EpiFix and SWC, respectively (adjusted P = 0·00019). Subjects treated with EpiFix had a very significant higher probability of their wounds healing [hazard ratio (HR: 5·66; adjusted P: 1·3 x 10(-7) ] compared to SWC alone. No difference in probability of healing was observed for the Apligraf and SWC groups. Patients treated with Apligraf were less likely to heal than those treated with EpiFix [HR: 0·30; 95% confidence interval (CI): 0·17-0·54; unadjusted P: 5·8 x 10(-5) ]. Increased wound size and presence of hypertension were significant factors that influenced healing. Mean time-to-heal within 12 weeks was 47·9 days (95% CI: 38·2-57·7) with Apligraf, 23·6 days (95% CI: 17·0-30·2) with EpiFix group and 57·4 days (95%CI: 48·2-66·6) with the SWC alone group (adjusted P = 3·2 x 10(-7) ). Median number of grafts used per healed wound were six (range 1-13) and 2·5 (range 1-12) for the Apligraf and EpiFix groups, respectively. Median graft cost was $8918 (range $1,486-19,323) per healed wound for the Apligraf group and $1,517 (range $434-25,710) per healed wound in the EpiFix group (P < 0·0001). These results provide further evidence of the clinical and resource utilisation superiority of EpiFix compared to Apligraf for the treatment of lower extremity diabetic wounds.

Skin grafting and tissue replacement for treating foot ulcers in people with diabetes

BACKGROUND

Foot ulceration is a major problem in people with diabetes and is the leading cause of hospitalisation and limb amputations. Skin grafts and tissue replacements can be used to reconstruct skin defects for people with diabetic foot ulcers in addition to providing them with standard care. Skin substitutes can consist of bioengineered or artificial skin, autografts (taken from the patient), allografts (taken from another person) or xenografts (taken from animals).

OBJECTIVES

To determine the benefits and harms of skin grafting and tissue replacement for treating foot ulcers in people with diabetes.

SEARCH METHODS

In April 2015 we searched: The Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE and EBSCO CINAHL. We also searched clinical trial registries to identify ongoing studies. We did not apply restrictions to language, date of publication or study setting.

SELECTION CRITERIA

Randomised clinical trials (RCTs) of skin grafts or tissue replacements for treating foot ulcers in people with diabetes.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the quality of the included studies.

MAIN RESULTS

We included seventeen studies with a total of 1655 randomised participants in this review. Risk of bias was variable among studies. Blinding of participants, personnel and outcome assessment was not possible in most trials because of obvious differences between the treatments. The lack of a blinded outcome assessor may have caused detection bias when ulcer healing was assessed. However, possible detection bias is hard to prevent due to the nature of the skin replacement products we assessed, and the fact that they are easily recognisable. Strikingly, nearly all studies (15/17) reported industry involvement; at least one of the authors was connected to a commercial organisation or the study was funded by a commercial organisation. In addition, the funnel plot for assessing risk of bias appeared to be asymmetrical; suggesting that small studies with 'negative' results are less likely to be published.Thirteen of the studies included in this review compared a skin graft or tissue replacement with standard care. Four studies compared two grafts or tissue replacements with each other. When we pooled the results of all the individual studies, the skin grafts and tissue replacement products that were used in the trials increased the healing rate of foot ulcers in patients with diabetes compared to standard care (risk ratio (RR) 1.55, 95% confidence interval (CI) 1.30 to 1.85, low quality of evidence). However, the strength of effect was variable depending on the specific product that was used (e.g. EpiFix® RR 11.08, 95% CI 1.69 to 72.82 and OrCel® RR 1.75, 95% CI 0.61 to 5.05). Based on the four included studies that directly compared two products, no specific type of skin graft or tissue replacement showed a superior effect on ulcer healing over another type of skin graft or tissue replacement.Sixteen of the included studies reported on adverse events in various ways. No study reported a statistically significant difference in the occurrence of adverse events between the intervention and the control group.Only two of the included studies reported on total incidence of lower limb amputations. We found fewer amputations in the experimental group compared with the standard care group when we pooled the results of these two studies, although the absolute risk reduction for amputation was small (RR 0.43, 95% CI 0.23 to 0.81; risk difference (RD) -0.06, 95% CI -0.10 to -0.01, very low quality of evidence).

AUTHORS' CONCLUSIONS

Based on the studies included in this review, the overall therapeutic effect of skin grafts and tissue replacements used in conjunction with standard care shows an increase in the healing rate of foot ulcers and slightly fewer amputations in people with diabetes compared with standard care alone. However, the data available to us was insufficient for us to draw conclusions on the effectiveness of different types of skin grafts or tissue replacement therapies. In addition, evidence of long term effectiveness is lacking and cost-effectiveness is uncertain.

Development of cell-laden 3D scaffolds for efficient engineered skin substitutes by collagen gelation

Cell-laden layered scaffolds containing keratinocytes and fibroblasts were fabricated using a 3D cell-printing technique. The scaffolds effectively promoted proliferation and migration, and can be efficiently used as engineered skin substitutes.

Effectiveness of wound healing using the novel collagen dermal substitute INSUREGRAF®

The pore structure of INSUREGRAF® built up from parallel collagen layers connected by single fivers and sizes are very uniform. Therefore, this is more suitable with respect to cell penetration, distribution, and acceleration of skin regeneration.

A mathematical model for lymphangiogenesis in normal and diabetic wounds

Several studies suggest that one possible cause of impaired wound healing is failed or insufficient lymphangiogenesis, that is the formation of new lymphatic capillaries. Although many mathematical models have been developed to describe the formation of blood capillaries (angiogenesis) very few have been proposed for the regeneration of the lymphatic network. Moreover, lymphangiogenesis is markedly distinct from angiogenesis, occurring at different times and in a different manner. Here a model of five ordinary differential equations is presented to describe the formation of lymphatic capillaries following a skin wound. The variables represent different cell densities and growth factor concentrations, and where possible the parameters are estimated from experimental and clinical data. The system is then solved numerically and the results are compared with the available biological literature. Finally, a parameter sensitivity analysis of the model is taken as a starting point for suggesting new therapeutic approaches targeting the enhancement of lymphangiogenesis in diabetic wounds. The work provides a deeper understanding of the phenomenon in question, clarifying the main factors involved. In particular, the balance between TGF-β and VEGF levels, rather than their absolute values, is identified as crucial to effective lymphangiogenesis. In addition, the results indicate lowering the macrophage-mediated activation of TGF-β and increasing the basal lymphatic endothelial cell growth rate, inter alia, as potential treatments. It is hoped the findings of this paper may be considered in the development of future experiments investigating novel lymphangiogenic therapies.

Cost-effectiveness of becaplermin gel on wound healing of diabetic foot ulcers

We sought to determine the long-term cost effectiveness (payer's perspective) of becaplermin gel plus good wound care (BGWC) vs. good wound care (GWC) alone in terms of wound healing and risk of amputation in patients with diabetic foot ulcers (DFUs). Outcomes data were derived from a propensity score-matched cohort from the Curative Health Services database between 1998 and 2004, which was followed for 20 weeks. A four-state Markov model was used to predict costs and outcomes of wound healing and risk of amputation for BGWC vs. GWC alone over 1 year in patients with DFU. The primary outcome was closed-wound weeks. Transition probabilities for healing and amputation were derived from the aforementioned propensity score-matched cohorts. Ulcer recurrence was estimated from the medical literature. Utilization for becaplermin was calculated using the dosing algorithm in the product labeling. Of 24,898 eligible patients, 9.6% received BGWC. Based on the model, patients treated with BGWC had substantially more closed-wound weeks compared with GWC (16.1 vs. 12.5 weeks, respectively). More patients receiving BGWC had healed wounds at 1 year compared with those receiving GWC (48.1% vs. 38.3%). Risk of amputation was lower in the BGWC cohort (6.8% vs. 9.8%). Expected annual direct costs for DFU were $21,920 for BGWC and $24,640 for GWC. BGWC was economically dominant over GWC, providing better outcomes at a lower cost in patients with DFU. Compared with GWC alone, BGWC is more effective in healing wounds and lowering amputation risk, thereby decreasing long-term costs for DFU.

Efficacy of intralesional recombinant human epidermal growth factor in diabetic foot ulcers in Mexican patients: a randomized double-blinded controlled trial

The healing process in diabetic foot ulcer (DFU) is hindered by factors such as chronic inflammation, defects in fibroblast function, poor angiogenesis, and lack of cell migration. Recombinant human epidermal growth factor (rhEGF) has been shown to enhance extracellular matrix formation, cellular proliferation, and angiogenesis. Therefore, intralesional application of rhEGF in DFU could accelerate wound healing. Our objective was to determine the efficacy and safety of rhEGF in patients with DFU. A randomized, double-blinded, placebo-controlled study was conducted comparing a thrice-per-week intralesional application of rhEGF (75 μg) or placebo in patients with DFU for 8 weeks. The number of completely healed ulcers, size, and wound bed characteristics were evaluated to determine the efficacy of rhEGF. Adverse events were recorded and analyzed to establish its safety. A total of 34 patients were recruited for the study. After three dropouts, we were able to follow and analyze 16 patients in the placebo group and 15 patients in the rhEGF study to the end of the trial. Baseline testing showed that both groups were similar. Compared to the placebo group, more ulcers achieved complete healing in the rhEGF group (rhEGF, n = 4; placebo, n = 0; p = 0.033); ulcers in the rhEGF group decreased in area size (12.5 cm2 [rhEGF] vs. 5.2 cm2 [placebo]; p = 0.049); and more epithelial islands in the wound bed were present (28% vs. 3%; p = 0.025). Mild transitory dizziness was the only side effect that was more frequently noted in the rhEGF group. Our results showed that in patients with DFU who received standard care, intralesional rhEGF application resulted in complete healing in more patients, promoted the epithelialization of the wound bed, and significantly reduced the area of the DFU treated. Therefore, rhEGF resulted in better outcomes for patients suffering from DFU.

Exploratory clinical trial of combination wound therapy with a gelatin sheet and platelet-rich plasma in patients with chronic skin ulcers: study protocol

INTRODUCTION

Chronic skin ulcers, such as diabetic ulcers, venous leg ulcers and pressure ulcers, are intractable and increasing in prevalence, representing a costly problem in healthcare. We developed a combination therapy with a gelatin sheet, capable of providing sustained release of platelet-rich plasma (PRP). The objective of this study is to investigate the safety and efficacy of autologous PRP covered with a hydrocolloid dressing and PRP covered with a gelatin sheet in the treatment of chronic skin ulcers.

METHODS AND ANALYSIS

Thirty patients with chronic skin ulcers who have not healed with conventional therapy for at least 1 month are being recruited. The patients will receive PRP after debridement, and the wounds will be covered with a hydrocolloid dressing or gelatin sheet. The efficacy will be evaluated according to the time from the beginning of PRP application to secondary healing or the day on which wound closure is achieved with a relatively simple surgical procedure, such as skin grafting or suturing. All patients will be followed up until 6 weeks after application to observe adverse events related to the application of PRP and the dressings. This study was designed to address and compare the safety and efficacy of PRP covered with a hydrocolloid dressing versus a gelatin sheet. If successful, this combination therapy may be an alternative to bioengineered skin substitutes containing living cells and lead to substantial progress in the management of chronic skin ulcers.

ETHICS AND DISSEMINATION

The study protocol was approved by the Institutional Review Board of Kansai Medical University (KMU Number 0649-1, 4 August 2014: V.1.0). The findings of this trial will be disseminated through peer-reviewed journals, and national and international scientific meetings as well as to the patients.

TRIAL REGISTRATION NUMBER

UMIN000015689.

The rapid inactivation of porcine skin by applying high hydrostatic pressure without damaging the extracellular matrix

We previously reported that high hydrostatic pressure (HHP) of 200 MPa for 10 minutes could induce cell killing. In this study, we explored whether HHP at 200 MPa or HHP at lower pressure, in combination with hyposmotic distilled water (DW), could inactivate the skin, as well as cultured cells. We investigated the inactivation of porcine skin samples 4 mm in diameter. They were immersed in either a normal saline solution (NSS) or DW, and then were pressurized at 100 and 200 MPa for 5, 10, 30, or 60 min. Next, we explored the inactivation of specimens punched out from the pressurized skin 10×2 cm in size. The viability was evaluated using a WST-8 assay and an outgrowth culture. The histology of specimens was analyzed histologically. The mitochondrial activity was inactivated after the pressurization at 200 MPa in both experiments, and no outgrowth was observed after the pressurization at 200 MPa. The arrangement and proportion of the dermal collagen fibers or the elastin fibers were not adversely affected after the pressurization at 200 MPa for up to 60 minutes. This study showed that a HHP at 200 MPa for 10 min could inactivate the skin without damaging the dermal matrix.

Cost-effectiveness of clostridial collagenase ointment on wound closure in patients with diabetic foot ulcers: economic analysis of results from a multicenter, randomized, open-label trial

BACKGROUND

Approximately 10%-15% of people with diabetes develop at least one foot ulcer during their lifetime. Treatment of diabetic foot ulcers (DFUs) represents a significant economic burden. Enzymatic debridement with clostridial collagenase ointment (CCO) can be used to remove necrotic tissue from wounds. This study examined the impact of CCO as an effective adjunct therapy to serial sharp debridement (SSD) and assessed the cost-effectiveness of CCO compared with standard DFU treatments over 1 year.

METHODS

Adults 18 years or older with a diagnosis of type 1 or type 2 diabetes who had a neuropathic DFU were enrolled in a 12-week, randomized, open-label trial. Patients were randomly assigned to either treatment with CCO + SSD or to investigator-selected supportive care + SSD (Control). A 3-state Markov model with a 1-week cycle length was developed using wound-closure rates from the trial to estimate the number of healed-wound weeks and the expected DFU cost per patient. The 3 states included unhealed, healed, and death. Results were extrapolated to 1 year to estimate the number of healed-wound weeks per treatment and the average cost to achieve epithelialization. The perspective of the analysis was that of the payer, specifically, the third party payer.

RESULTS

The study sample included 55 patients (28 in CCO group; 27 Control). The majority were men (74.5%) with a mean age of 57.9 years. Projected healing rates were greater for the CCO + SSD group compared to Control (89% vs. 80%, respectively). The expected number of epithelialized weeks accumulated over 1 year was 25% greater in the CCO + SSD group than for Control (35 vs. 28 weeks, respectively). Over a 1-year time horizon, the expected cost per DFU was greater in the Control group than the CCO group ($2,376 vs. $2,099, respectively). The estimated cost per ulcer-free week was 40% higher for Control ($85/closed-wound week) than for CCO + SSD ($61/closed-wound week).

CONCLUSIONS

CCO + SSD therapy is a cost-effective method of debridement in the management of patients with DFUs, providing better outcomes at a lower cost. Further high quality trials are needed to confirm this finding.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov as NCT01408277.

Acellular dermal matrix-based gene therapy augments graft incorporation

BACKGROUND

Acellular dermal matrix (ADM) is widely used for structural or dermal replacement purposes. Given its innate biocompatibility and its potential to vascularize, we explored the possibility of ADM to function as a small interfering RNA (siRNA) delivery system. Specifically, we sought to improve ADM vascularization by siRNA-mediated inhibition of prolyl hydroxylase domain-2 (PHD2), a cytoplasmic protein that regulates hypoxia inducible factor-1α, and improve neovascularization.

MATERIALS AND METHODS

Fluorescently labeled siRNA was used to rehydrate thin implantable ADM. Pharmacokinetic release of siRNA was determined. Twelve millimeter sections of ADM reconstituted with PHD2 siRNA (nonsense siRNA as control) and applied to dorsal wounds of 40 FVB mice. Grafts were sewn in, bolstered, and covered with occlusive dressings. Photographs were taken at 0, 7, and 14 d. Wounds were harvested at 7 and 14 d and analyzed (messenger RNA, protein, histology, and immunohistochemistry).

RESULTS

Release kinetics was first-order with 80% release by 12 h. By day 14, PHD2-containing ADM appeared viable and adherent, whereas controls appeared nonviable and nonadherent. Real-time reverse transcription-polymerase chain reaction demonstrated near-complete knockdown of PHD2, whereas vascular endothelial growth factor and FGF-2 were increased 2.3- and 4.7-fold. On enzyme-linked immunosorbent assay, vascular endothelial growth factor was increased more than fourfold and stromal cell-derived factor doubled. Histology demonstrated improved graft incorporation in treated groups. Immunohistochemical demonstrated increased vascularity measured by CD31 staining and increased new cell proliferation by denser proliferating cell nuclear antigen staining in treated versus controls.

CONCLUSIONS

We concluded that ADM is an effective matrix for local delivery of siRNA. Strategies to improve the matrix and/or genetically alter the local tissue environment can be envisioned.

Current wound healing procedures and potential care

In this review, we describe current and future potential wound healing treatments for acute and chronic wounds. The current wound healing approaches are based on autografts, allografts, and cultured epithelial autografts, and wound dressings based on biocompatible and biodegradable polymers. The Food and Drug Administration approved wound healing dressings based on several polymers including collagen, silicon, chitosan, and hyaluronic acid. The new potential therapeutic intervention for wound healing includes sustained delivery of growth factors, and siRNA delivery, targeting microRNA, and stem cell therapy. In addition, environment sensors can also potentially utilize to monitor and manage microenvironment at wound site. Sensors use optical, odor, pH, and hydration sensors to detect such characteristics as uric acid level, pH, protease level, and infection - all in the hopes of early detection of complications.

A prospective, randomised, controlled, multi-centre comparative effectiveness study of healing using dehydrated human amnion/chorion membrane allograft, bioengineered skin substitute or standard of care for treatment of chronic lower extremity diabetic ulcers

A prospective, randomised, controlled, parallel group, multi-centre clinical trial was conducted at three sites to compare the healing effectiveness of treatment of chronic lower extremity diabetic ulcers with either weekly applications of Apligraf(®) (Organogenesis, Inc., Canton, MA), EpiFix(®) (MiMedx Group, Inc., Marietta, GA), or standard wound care with collagen-alginate dressing. The primary study outcome was the percent change in complete wound healing after 4 and 6 weeks of treatment. Secondary outcomes included percent change in wound area per week, velocity of wound closure and a calculation of the amount and cost of Apligraf or EpiFix used. A total of 65 subjects entered the 2-week run-in period and 60 were randomised (20 per group). The proportion of patients in the EpiFix group achieving complete wound closure within 4 and 6 weeks was 85% and 95%, significantly higher (all adjusted P-values ≤ 0·003) than for patients receiving Apligraf (35% and 45%), or standard care (30% and 35%). After 1 week, wounds treated with EpiFix had reduced in area by 83·5% compared with 53·1% for wounds treated with Apligraf. Median time to healing was significantly faster (all adjusted P-values ≤0·001) with EpiFix (13 days) compared to Apligraf (49 days) or standard care (49 days). The mean number of grafts used and the graft cost per patient were lower in the EpiFix group campared to the Apligraf group, at 2·15 grafts at a cost of $1669 versus 6·2 grafts at a cost of $9216, respectively. The results of this study demonstrate the clinical and resource utilisation superiority of EpiFix compared to Apligraf or standard of care, for the treatment of diabetic ulcers of the lower extremities.