Partial-thickness Wounds Research Articles

Effect of TLC-NOSF Dressing on Epithelization of Diabetic Wounds: A Pilot Clinical Trial

Background: The positive effects of technology-lipid-colloid (TLC) dressings impregnated with nano-oligosaccharide factors (NOSF) have been well documented. However, there is insufficient study on the specific impact of TLC-NOSF dressings on epithelization in patients with diabetes who have partial-thickness wounds. This article presents the results of a pilot clinical trial conducted to address the aforementioned issue.Methods: Twenty patients with diabetes who underwent split-thickness skin grafting were enrolled in this study. Half of the donor site was covered with a TLC-NOSF dressing, whereas the other half was covered with a TLC dressing. The ratio of complete epithelialization within 14 days postoperatively was compared between the two groups. Furthermore, progress of epithelialization was assessed to determine whether the TLC or TLC-NOSF dressing promoted more rapid epithelialization.Results: Seventeen patients completed the study. The percentages of complete epithelialization in the TLC and TLC-NOSF dressing groups were 41% (7/17) and 53% (9/17), respectively (P = 0.49). Regarding the degree of epithelialization, the differences between the TLC-NOSF and TLC dressing were not statistically significant. The TLC-NOSF dressing was superior in nine patients, while the TLC dressing was superior in two patients. Six patients demonstrated “no significant difference” (P = 0.11).Conclusion: Based on the current results alone, it is difficult to definitively conclude that TLC-NOSF dressings are superior to TLC dressings. However, these findings suggest a potential positive effect of TLC-NOSF dressings. Further large-scale studies are required to validate these results.

Suprathel Versus Hypafix in the Management of Split-Thickness Donor Site Wounds in the Elderly: A Randomised Controlled Trial

(1) Background: Effective wound management aims for expedited healing, improved functional and scar outcomes, and reduced complications including infection. Delayed wound healing remains a prevalent problem in the elderly. Suprathel is a synthetic absorbable skin substitute and an attractive option in partial thickness wounds. The objective of this randomised controlled study was to assess the effect of skin substitute dressings on elderly split-skin graft (STSG) donor sites, evaluating time to heal, pain, itch and scar outcome. (2) Methods: 40 patients over 65 undergoing split-thickness skin grafting for non-melanoma skin cancer excision were randomised to STSG donor site dressings with either Suprathel or Hypafix. Patients were followed up weekly until healed and at 13 weeks post-procedure. (3) Results: There was no significant difference in time to healing, pain, itch, or scar outcome at 13 weeks between the two groups. The mean time to healing was 31.7 days for the skin substitute group and 27.3 days for the adhesive tape control group (p = 0.182). (4) Conclusions: Both dressings are appropriate for STSG donor sites. Hypafix remains a cost-effective dressing of choice for donor sites. Benefits demonstrated in other studies using skin substitutes have not translated into the elderly population. There remains scope in developing dressings that reduce elderly donor site morbidity.

Peculiarities of Early Surgical Treatment of Patients With Deep Burns Using Biological Dressings

Background: Early necrosectomy with immediate or delayed skin grafting is the gold standard in treatment of burn injuries. Despite all advances in active surgical treatment of burn patients, the optimal time of necrosectomy as well as methods and timing of skin grafting remain the subject of debate among burn surgeons. Reliability and practicality of methods to determine the viability of affected skin tissues act as a limiting factor to advances in surgical strategies for early treatment of burn injuries.Objective: To improve methods of early surgical treatment of patients with deep burns using biological dressings.Materials and methods: Our study analyzed treatment outcomes of 34 patients (age, 18 to 60 years) diagnosed with third-degree burn wounds of different localizations involving 5%-20% of body surface area (according to ICD-10). Group 1 included 18 (53%) patients who underwent skin grafting right after surgical removal of necroses; biological dressings (Chitopran) were applied. Group 2 comprised 16 (47%) patients who also underwent early surgical treatment (autografting), but autografts were covered with synthetic dressings (Voskopran).Results: We found that in group 1 the average time to engraftment after skin grafting followed by Chitopran application was 5.0 (5.0-6.0) days. In group 2, the average time to engraftment after skin grafting followed by Voskopran application was 6.0 (6.0-6.3) days. The statistical data demonstrated that biological dressings had an advantage over synthetic ones in terms of time to engraftment.Conclusions: We can conclude that biological dressings have an advantage over synthetic ones in surgical treatment of partial thickness and deep burn wounds.

A Standardized Porcine Model for Partial-Thickness Wound Healing Studies: Design, Characterization, Model Validation, and Histological Insights.

Wound healing is a complex process that is still not fully understood despite extensive research. To address this, we aimed to design and characterize a standardized porcine model for the evaluation of wound healing, dressings, cell therapies, and pharmaceutical agents. Using a standardized approach, we examined the wound healing process in 1.2 mm-deep dermatome wounds at defined positions in 11 female pigs. Unlike previous studies that have only described/analyzed selected punch biopsies, we performed and described histological analyses along the complete wound length using quantitative morphometric methods. All animals remained fully healthy following surgery and showed no signs of infection. Our histopathological evaluation using a predetermined grading score and quantitative manual morphometry demonstrated the impact of different tissue sampling methods, sampling sites, and residual dermis thickness on wound healing. Our study presents a reproducible model for wound healing evaluation and demonstrates the usefulness of porcine models for assessing dermal and epidermal wound healing. The use of histological analyses over the complete wound length provides advantages over previous studies, leading to the possibility of a deeper understanding of the wound healing process. This model could potentially facilitate future research on novel wound dressings and local wound healing therapies.

A ropivacaine-eluting poly(lactide-co-caprolactone) wound dressing provided enhanced analgesia in partial-thickness porcine injuries.

Partial-thickness skin wounds are some of the most painful injuries due to large areas of exposed nerve endings. These injuries often require systemic opioid treatments to manage pain adequately. However, in 2021 alone, the CDC reported nearly 17,000 prescription opioid-related deaths in the USA, highlighting the ongoing need for non-opioid treatment strategies. In this manuscript, we developed a novel single-application ropivacaine-eluting primary wound dressing that could provide sustained ropivacaine delivery to partial-thickness wounds and assessed its in vivo feasibility for prolonged non-opioid analgesia. Sustained release of ropivacaine from a poly(lactide-co-e-caprolactone) matrix was first optimized in vitro using dissolution testing and a Box Behnken design of experiments. The optimized dressing was then tested against a clinical control silicone dressing in a porcine partial-thickness wound study to assess analgesic effect, pharmacokinetics, and wound healing. The ropivacaine-eluting dressing showed a moderate analgesic effect in vivo, where normalized single pinprick scores significantly improved pain over the testing period (4-168h) (control vs treatment: 232±25% vs 145±16%, p<0.0003). Ropivacaine blood plasma levels peaked at 8 hours post-treatment, with a maximum concentration of 246 ± 74 ng/mL. No significant differences in wound healing were found when compared to control. The ropivacaine-loaded poly(lactide-co-e-caprolactone)-based wound dressing provided sustained delivery of ropivacaine to partial-thickness skin wounds and enhanced analgesic effect compared to a clinical standard control dressing.

805 A Simple Technique to Create Partial-Thickness Wounds and Harvest Split-Thickness Skin Grafts in Rat Models

805 A Simple Technique to Create Partial-Thickness Wounds and Harvest Split-Thickness Skin Grafts in Rat Models

Comparison of the Effectiveness of Lyophilized Amniotic Membranes in the Partial Thickness Wound Healing Process in Mus musculus

Background: Currently, tulle or gentamicin ointment is generally used to prevent wound infections in wound care. Human amniotic membrane has been used in medical fields such as wound care. So far, there is no comparative evidence of the effectiveness of each ingredient. This study aimed to compare the effectiveness of lyophilized amniotic membrane, tulle, and 0.1% gentamicin ointment in the wound healing process. partial thickness on Mus musculus clinically and histologically.&#x0D; Methods: This type of research is experimental with a post-test-only control group design. There were 24 rats divided into each group. This research was conducted at the anatomical pathology laboratory, Faculty of Medicine, Universitas Andalas, and INA lab in July - September 2023 using rats (Mus musculus), which were divided into 3 treatment groups and one control group.&#x0D; Results: Clinically, lyophilized amniotic membrane, 0.1% gentamicin ointment, and tulle provided better results than controls regarding erythema variables. Histologically, the results showed that the lyophilized amniotic membrane group had the thinnest epidermis and dermis, as well as better histological scores for granulation, fibroblasts, and collagen than the 0.1% gentamicin ointment, tulle, and control groups. In this study, significant differences in effectiveness were found in terms of erythema, skin thickness, granulation, fibroblast, and collagen histological scores, with better results in the lyophilized amniotic membrane group.&#x0D; Conclusion: Clinically, lyophilized amniotic membrane, tulle, and 0.1% gentamicin ointment were more effective than controls for wound treatment due to faster reduction in erythema. However, histologically, the lyophilized amniotic membrane was proven to be more effective than tulle, 0.1% gentamicin ointment, and control in terms of epidermis and dermis thickness, granulation level, fibroblasts, and collagen.

Human amniotic membranes as an allogenic biological dressing for the treatment of burn wounds: Protocol for a randomized-controlled study

BackgroundBurn wounds pose significant challenges in medical treatment due to their devastating nature and resource-intensive requirements. Temporary coverage of burn wounds using synthetic or biological dressings allows for reepithelization before definitive skin grafting. Allogenic skin grafts have been widely used but come with drawbacks such as rejection and disease transmission. The use of amniotic membranes (AMs) offers a promising alternative for temporary coverage, as they possess biological properties that promote faster healing and improved scar quality. The various components of the amniotic membrane, including pluripotent stem cells, extracellular matrix proteins, and regenerative factors, contribute to cell growth, migration, and differentiation, as well as preservation of the original epithelial phenotype. ObjectiveReliable information on the treatment of burn wounds with AM is needed. The knowledge gained in this project may help to include this advantageous modern concept of biological dressings in clinical practice. The purpose of this study is to use human amniotic membranes from our in hospital laboratory, as an allogenic biological dressing after enzymatic debridement in superficial partial thickness, deep partial thickness or full thickness burn wounds. MethodsWe will include 30 patients in a randomized-controlled trial with each patient receiving the study intervention and the control intervention. Two 7 × 7 cm burn wound areas will be compared regarding percentage of skin graft take, healing time, healing percentage value and total healing time. Human amniotic membranes will be compared to allogenic skin grafts.

Birch Bark Extract: A Review in Epidermolysis Bullosa.

Birch bark extract (Filsuvez®; also known as the developmental name Oleogel-S10), a topical gel consisting of 10% dry birch bark extract and 90% sunflower oil, is the first therapy approved in the EU and UK for the treatment of partial thickness wounds associated with dystrophic and junctional epidermolysis bullosa (EB) in patients aged ≥ 6 months old. In the pivotal double-blind, randomized, vehicle-controlled, phase III EASE trial in patients with EB, the primary endpoint was met, in which birch bark extract relative to control gel significantly increased the proportion of patients with first complete target wound closure within 45 days. Moreover, patients treated with birch bark extract demonstrated several other positive findings in improving wound burden and wound-associated symptoms. The clinical benefits of birch bark extract were maintained in the 24-month open-label extension period of the EASE trial. Birch bark extract was generally well tolerated in patients with EB, with the tolerability profile being similar to that of control gel. Current evidence indicates that birch bark extract is an effective, emerging treatment option for patients with dystrophic and junctional EB.

Profile of Closed Globe Injury in a Secondary Eye Hospital

INTRODUCTION Closed globe injury of the eye is the type of injury in which the eyewall (sclera and cornea) is intact or only partial thickness wound is present. Studies focused only on closed globe injury of eye are limited. So the aim of the study was to analyse the demographic pattern, modes of trauma, place of trauma, agent of trauma and impact of trauma in different ocular structures and in vision. MATERIAL AND METHODS It was a retrospective, descriptive, cross-sectional study. Details of 167 patients with closed globe injury attending Dr.Binod Neeta Kandel Eye Hospital, Nawalparasi from Aug 2017 to July 2018 were reviewed. Demographic profile, detailed history and examination findings were analysed. RESULTS Closed globe injury was more common in males (61.7%) than females (38.3%). The mean age was 30.76 ± 16.58 yrs, youngest being 3 years old whereas oldest 90 years old. Left eye was more involved. Domestic accident (38.92%) was the commonest. Conjunctival laceration (21.55%) and traumatic uveitis (21.55%) were the commonest sequelae of closed globe injury. Good vision (Visual acuity (VA) 6/6 -6/18) was seen in 79.64% cases whereas 7.78% cases were blind (VA less than 3/60). CONCLUSION Closed globe injury can occur from different modes of trauma. Anterior segment of eye was more involved than the posterior segment. Even a trivial ocular trauma can have a sight threatening impact.

A Single Institution's Recent Experience With Pediatric Hand Burns.

Children are at risk for sustaining hand burns due to their innate curiosity, slow withdrawal reflexes, and thin palmar epidermis. We sought to summarize our recent experience managing pediatric hand burns, focusing on injuries that required surgical management. This was a retrospective review of children with burn-injured hands managed at a quaternary referral children's hospital between 2016 and 2020. Demographics and mechanisms of injury were collected for all patients. Initial management of all wounds included pain control, deflation of blisters, and mechanical debridement. Wounds were then dressed, and a plaster-backed soft cast was applied for positioning if the swelling was controlled. Wounds were reassessed in 4-7 days, at which time a nonadherent dressing with antifungal ointment or a bismuth dressing was applied to partial-thickness wounds, vs an active silver dressing for deep partial-thickness burns. For patients who underwent split-thickness or full-thickness skin grafting, additional wound care, operative, and short-term outcomes data were collected. A total of 3715 children were seen for burn injuries during the study period, of which 2100 (56.5%) were seen for hand burns. In total, 123 (5.8%) required a skin graft an average of 11.7 days from the date of their burn injury. Surgical complications were minimal with 5 (4.1%) incomplete graft takes, though none required reoperation, and 1 (0.8%) experiencing a postoperative wound infection. Pediatric hand burns are common. A multidisciplinary treatment approach, including standardized wound care and adept therapeutic interventions, will lead to spontaneous healing in approximately 95% of patients.

Bandaging products and topical therapeutics: a summary review

One of the most important aspects of wildlife rehabilitation is successful wound management. Wounds come in a vast diversity of types, including abrasions, lacerations, partial and full thickness wounds, punctures, abscesses, chronicwounds and burns, to name just a few. To properly treat a wound, it is imperative to understand not only the type of wound being treated and the mechanics of how the wound occurred and will hopefully heal, but also the products andsupplies available to facilitate healing.

23 Chlorhexidine Delays Wound Healing in Human Skin

IntroductionChlorhexidine (CHG) is ubiquitous in surgical perioperative care. In vivo studies of CHG cytotoxicity on human skin are lacking. Given the use of CHG for daily wound cares and as a presurgical scrub, including donor site preparation, we sought to identify if CHG cytotoxicity would persist in a clinically relevant in vivo human skin xenograft model.MethodsHuman skin tissues were obtained from elective surgeries. Partial thickness wounds were created ex vivo in human skin using a 4 mm punch biopsy. 2% CHG (treatment) or PBS (control) was applied to the wounds for 30 minutes followed by rinsing the tissue +/- mechanical disruptive irrigation. Tissues were cultured at the air-liquid interface for 24 hours in culture media after treatment and tissue viability was performed using an MTT assay. For in vivo studies, athymic mice (n=4) were grafted on bilateral flanks with human skin. Eight weeks after engraftment and normalization of skin architecture, 4 mm partial thickness wounds were created on each xenograft (2 per mouse – treatment and control). 2% CHG was applied daily for 2 minutes followed by irrigation with PBS in the treatment wound. The control wound received PBS application and irrigation. The xenografts received treatment daily for 14 days to mimic daily wound cares, and digital images were obtained to document presence of infection and gross wound healing. On day 14, the xenografts were harvested and stained for lactate dehydrogenase and H&E to assess cell viability and wound re-epithelization, respectively.ResultsAn MTT assay on ex vivo human skin wounds showed that CHG treated groups (irrigation or non-irrigation) had lower cell viability compared to the PBS treated group, however irrigation mitigates the cytotoxicity of CHG on human skin. In the in vivo xenograft study, no signs of infection were identified in either PBS or CHG treated wounds throughout the study. The wound size appeared larger on gross inspection in the CHG treated group compared to the PBS group as early as day 2.Microscopically, the PBS treated wounds were fully re-epithelialized (n=2) or had significantly more re-epithelialization (n=2) than the CHG treated wounds (n=4) after 14 days of treatment. The PBS-treated wounds were viable throughout the tissue, indicating the irrigation procedure was not harmful to the cells. In the CHG-treated wounds, nonviable cells were observed in the dermis beneath the wound that was directly in contact with CHG suggesting penetration of CHG contributes to cytotoxicity in acute wounds.ConclusionsDaily CHG use is cytotoxic to human skin and impedes wound healing.

52 Refinement of a Histologic Algorithm for Burn Depth Categorization Using 1142 Consecutive Burn Wound Biopsies

IntroductionOur group previously reported a theoretical burn biopsy algorithm (BBA-V1) for the categorization of burn wound depth based on histologic analysis, and informed it with the largest series of burn wound biopsies in the literature. That iteration of the BBA resulted in clinical misclassification rates consistent with past literature. Since our last report of that process, we have refined the algorithm with new criteria and a larger repository of burn wound biopsies. Here, we sought to promulgate this newer, simpler version of the BBA (BBA-V2).MethodsThis was an IRB-approved, prospective, multicenter study. Patients with burn wounds assessed by burn experts as requiring excision and autograft underwent 4mm biopsies procured every 25cm2. Serial still photos were obtained at enrollment and at excision intraoperatively.Using H&E with whole slide scanning, a board-certified dermatopathologist assessed each burn biopsy. The criteria used for categorization of burn wound depth in BBA-V1 were: 1) proportion of necrotic adnexal structures, and 2) presence/absence of each of epidermis, papillary dermis, and reticular dermis. The criteria used for BBA-V2 were: 1) magnitude of reticular dermal degeneration, 2) proportion of necrotic adnexal structures, and 3) magnitude of vessel thrombosis.Biopsy pathology results were correlated with still photos by 3 burn experts for consensus of final burn depth diagnosis. Superficial partial thickness (SPT) wounds were considered to be burn wounds likely to have healed without surgery, while deep partial thickness (DPT) and full thickness (FT) were considered unlikely to heal by 21 days.ResultsThe development of BBA V-1 was previously informed by 66 subjects with 117 wounds and 816 biopsies, and resulted in wound categorizations as follows: SPT (20%), DPT (43%), and FT (37%). Therefore, according to BBA-V1, 20% of burn wounds were incorrectly judged as needing excision and grafting by the clinical team. The overall cohort was enlarged to 162 subjects with 294 wounds and 1142 biopsies. The most recent 838 burn wound biopsies were then re-reviewed and re-categorized according to the new BBA-V2 criteria and algorithm. Under BBA-V2, 3% of all burn wound biopsies were categorized as superficial partial thickness, 69% were categorized as deep partial thickness, and 29% were categorized as full thickness.ConclusionsOur study demonstrates that by adding dermal degeneration severity and vessel thrombosis to our previous criterion of adnexal structure necrosis, BBA-V2 had a much higher rate of concordance with visual clinical assessment for burn wounds clinically judged as needing surgical excision. This study serves as the largest analysis of burn biopsies by modern day burn experts.

725 Case Series: New Porcine Placental ECM for Burn Injuries

IntroductionHuman amniotic membrane (HAM) has been used as a biologic dressing for burn wounds since 1955 but limited due to availability, size, and processing costs. In 2021 a new porcine placental product was FDA-approved overcoming challenges with human-sourced products. Our study is the first case series to report outcomes using porcine placental extracellular matrix (PPECM) in the use of adult burn patients.MethodsAdults with thermal burns resulting in partial-thickness burn wounds (PTBW) were consented and included in the study from 03/2021 to 09/2021. Patients with full-thickness injures, concomitant trauma, or adverse beliefs to porcine products were not included in the study. Serial still images and initial wound measurements were obtained intraoperatively and post-operatively. PPECM trial product processed with a proprietary decellularization method to produce single sheets up to 15x20cm was approved by the facility value assessment committee. Adverse events were defined a priori as infection, increased pain or itching relative to adjacent autografts, or failure to heal. Infection was defined as a PPECM treatment site requiring any change from standard of care or initiation of local or systemic antibiotics. Pain was assessed using a visual analogue scale. Itching was assessed at discharge and follow-up. Healing was assessed using the FDA guidance for wound closure with 2 consecutive visits 2 weeks apart demonstrating 100% epithelialization without drainage or dressing requirements.ResultsFour patients were treated during the study period with wounds involving the torso and major joints such as the hands/wrists and knees. None of the PPECM wounds demonstrated failure to heal or required revision excision, or autograft. None of the PPECM wounds had evidence of infection. PPECM wounds had decreased pain/itching relative to adjacent burn wounds which were treated with split-thickness autograft, autologous skin cell suspension, or allogeneic cultured skin substitute (VAS mean 1 vs 3.1). Healing was noted in all wounds at 1-week primary dressing removal with confirmation at 2-week interval follow-up.ConclusionsPPECM treatment of PTBW was not associated with adverse events and resulted in favorable outcomes clinically. The large size, ease of use, and lower costs relative to HAM is an intriguing alternative for PTBW. Comparative studies are needed in the field to determine best practices and overall value.

534 Allogeneic Cellularized Living Tissue in Pediatric Deep Partial Thickness Burns Reduces Need for Donor Sites

IntroductionHealing potential of deep partial thickness burns is not easily determined early after injury. Prolonged and continued inflammation can contribute to burn wound conversion. Early excision compared to a wait and see approach to wound healing decreases inflammation, shortens length of stay, and decreases painful wound procedures. However, early excision is at the expense of removing tissue that may otherwise heal without autografting. Use of a cryopreserved, allogeneic cellularized scaffold living tissue product (CTP) in pediatric deep partial thickness wounds with dermal elements remaining after excision is an alternative approach to wound closure. CTP may allow early excision without compromising healing potential, thereby minimize donor site morbidity, infectious complications and decrease length of stay. This case series describes the expanded access experience of a CTP on pediatric patients with thermal injury.MethodsExpanded use approval of a CTP was obtained through the FDA for pediatric patients with burns at three burn centers. Patients were taken to the operating room for excision and grafting of burns at the discretion of the attending surgeon. In wounds with dermal elements present after excision, CTP was grafted to the wound bed (Table 1). Postoperative wound care and follow up was per institutional standards of care.ResultsSix pediatric patients (9 weeks – 13 years old) with mixed depth burns having dermal elements remaining after excision were treated successfully with a CTP. Donor site surface area was reduced in all patients. No serious adverse events related to the CTP were noted in any of the cases. Average time to heal wounds treated with the CTP was approximately 2-3 weeks. In wounds ultimately deemed to be full thickness, CTP was not detrimental to subsequent autograft take. See Table 1.ConclusionsThis case series demonstrates that use of a CTP in pediatric patients is donor site sparing without any serious adverse events. Furthermore, use in full thickness burns is not detrimental to subsequent autograft take. The degree of dermal elements necessary to support wound healing is unknown and requires further study. This case series supports the application for a clinical trial investigating the safety and efficacy of CTP as an adjunct to wound healing in pediatric deep partial thickness burns.

811 Statistical Analyses of Multiple Burn Wounds within an Animal

IntroductionPorcine animal models are frequently used to study the effects of various burn wound treatments and conditions. In these studies, multiple wounds are created on the dorsum of an anesthetized pig. Wounds within an animal are correlated, and the analysis of such a design should account for this dependence. Two recent studies are used as examples to illustrate the use of random effects for animal to account for the dependence of wound measurements within each pig.MethodsIn both studies, treatments were randomized to wound location, and neither contained repeated measurements within a wound.Study #1 investigated the effectiveness of enzymatic debridement. Forty 3-cm diameter partial-thickness burn wounds were created on the dorsum of 5 anesthetized pigs, arranged in 4 rows and 10 columns. Dorsal quadrants with 10 wounds each were created by combinations of two conditions: wounds that were wet or dry and wounds that were treated for either 72 or 96 hours. Debridement Efficiency Scores were calculated for each wound and evaluated for differences by inferential statistical comparisons between experimental treatments and conditions. The multilevel statistical model contained Treatment Group (5 levels), Treatment Time (2 levels: 72 hour and 96 hour), and Wet/Dry Condition (2 levels) as fixed effects, which were crossed to create a 3-way block, resulting in 2 wounds per animal for each Treatment, Wet/Dry, and Time combination. Random effects of animal and treatment block within animal were included in the model.Study #2 investigated the effectiveness of an experimental treatment applied at 3 different post-burn injury time points versus a standard of care (SOC). Up to 12 5-cm2 deep partial thickness wounds were created in 2 rows and 6 columns on each dorsum of 6 anesthetized pigs. Each treated wound was compared with a SOC wound located along the same cranio-caudal axis. Paired differences for wound closure % were calculated and analyzed with time as a fixed effect with a random effect for animal.ResultsFor Study #1, there were 200 total wounds, and for Study #2 there were 72 total wounds. These experimental units are not independent, as required by statistical testing. For both studies, there was graphical evidence that the burn wound measurements differed both within and between pigs. The statistical tests accounted for this variability by incorporating the effects due to pigs.ConclusionsMatching the statistical model to the experimental design is critical for correct interpretation of the results. Failure to use the correct model by assuming wounds within a pig are independent (and thereby ignoring any effect due to the pig) will result in erroneous statistical test results and less powerful tests of treatment differences.

49 Bromelain Based Enzymatic Debridement of Pediatric Deep Burns: Top Line Results of a Multicenter RCT

IntroductionBromelain based debridement (BBD) of deep burns with a concentrate of proteolytic enzymes enriched in Bromelain is approved for use in adults in several regions worldwide. Children are a large part of the patient population in many burn centers around the world. Clinical trial experience and off label reports point to BBD safety and efficacy in children as well. The aim of this study was to further assess the safety and efficacy of BBD in children, in efforts to support regulatory approval for the use of BBD in children.MethodsOne hundred and forty five children aged 0-18 years old suffering from deep thermal burns between 1-30% TBSA were enrolled in a multicenter, multinational, open label, randomized, controlled phase III study. Seventy two children were randomized to eschar removal with BBD and 73 children to standard of care (SOC) surgical and/or non-surgical eschar removal methods, at the investigators' discretion. Patients who did not achieve complete eschar removal after BBD application were rescued with SOC eschar removal methods. Wound care after achieving complete eschar removal was according to routine methods, at the investigators' discretion. Patients are currently in stages of long term follow-up, planned for a duration of >2 years. This abstract reports the top line results of the study including the first year of follow-up.ResultsBaseline characteristics were similar between the arms. The median age was 3.4 years in the BBD arm and 3.9 years in the SOC arm. The average burn area was 7.0±4.9 %TBSA in the BBD arm and 6.2±4.8 %TBSA in the SOC arm. The study met all 3 primary endpoints: Median time to complete eschar removal was 1 day for BBD and 6 days for SOC (p< 0.001), the percent wound area excised in order to complete eschar removal was 1.5% for BBD and 48% for SOC (p< 0.0001), and the MVSS scores at 12 months were 3.83 for BBD and 4.86 for SOC (non-inferiority endpoint). Secondary endpoints demonstrated 8.3% incidence of surgical excision to complete eschar removal for BBD and 64.4% for SOC (p< 0.0001), mean eschar removal associated blood loss of 32±284ml for BBD and 202±409 for SOC (NS), a 25.9% incidence of autografting in deep partial thickness wounds for BBD and 37.7% for SOC (p=0.054), and a mean percent area of deep partial thickness wound autografting of 15.9±38.6 for BBD and 22.8±43.7 for SOC (NS). Safety endpoints demonstrated a non-inferior time to complete wound closure (median 32 days for BBD, 34 days for SOC) and no significant safety issues were demonstrated during the study.ConclusionsBBD was shown to be a safe and effective debridement agent in pediatric burns.

A novel dressing with silver to treat meticillin-resistant Staphylococcus aureus biofilm infection in a pig model.

The purpose of this study was to use an in vivo biofilm porcine model to examine a new polyvinyl alcohol-based gelling fibre dressing with silver and compare it to other commercial dressings containing: polyvinyl alcohol-based gelling fibre without silver; carboxymethyl cellulose-based fibre with silver, benzethonium chloride and ethylenediaminetetraacetic acid; and untreated control. A total of 52 deep partial-thickness wounds (10x7x0.5mm) were created on each of three animals and inoculated with 25µl of meticillin-resistant Staphylococcus aureus (MRSA) (106 colony forming units (CFU)/ml). Wounds were covered for 24 hours to allow biofilm formation and were randomly designated to one of the four treatments. Samples were recovered for microbiological and histological analysis on days 3, 5 and 7 post-treatment. Polyvinyl alcohol-based gelling fibre dressing with silver was able to significantly reduce biofilm more effectively than the other treatment groups. By day 7, wounds treated with the dressing had a 2.72±0.01 log CFU/g reduction in MRSA count versus untreated control wounds and a 2.59±0.01 log CFU/g reduction versus baseline counts. For histology analysis, all wounds reached 100% re-epithelialisation by day 5. The results of this study indicated that polyvinyl alcohol-based gelling fibre dressing with silver was effective against biofilm of antibiotic-resistant staphylococcal strains without inhibiting the wound healing process, and may have important clinical implications when treating acute and/or hard-to-heal wounds.

Evaluation of healing outcomes combining a novel polymer formulation with autologous skin cell suspension to treat deep partial and full thickness wounds in a porcine model: a pilot study

Autologous skin cell suspensions (ASCS) can treat burns of varying depths with the advantage of reduced donor site wound burden. The current standard primary dressing for ASCS is a nonabsorbant, non-adherent, perforated film (control) which has limited conformability over heterogeneous wound beds and allows for run-off of the ASCS. To address these concerns, a novel spray-on polymer formulation was tested as a potential primary dressing in porcine deep partial thickness (DPT) and full thickness (FT) wounds. It was hypothesized that the polymer would perform as well as control dressing when evaluating wound healing and scarring.DPT or FT wounds were treated with either a spray-on poly(lactic-co-glycolic acid) (PLGA) and poly(lactide-co-caprolactone) (PLCL) formulation or control ASCS dressings. Throughout the experimental time course (to day 50), we found no significant differences between polymer and control wounds in % re-epithelialization, graft-loss, epidermal or dermal thickness, or % dermal cellularity in either model. Pigmentation, erythema, elasticity, and trans-epidermal water loss (TEWL), were not significantly altered between the treatment groups, but differences between healing wounds/scars and un-injured skin were observed. No cytotoxic effect was observed in ASCS incubated with the PLGA and PLCL polymers.These data suggest that the novel spray-on polymer is a viable option as a primary dressing, with improved ease of application and conformation to irregular wounds. Polymer formulation and application technique should be a subject of future research.