A Comparative Study of the ReCell® Device and Autologous Spit-Thickness Meshed Skin Graft in the Treatment of Acute Burn Injuries

Advancements in cell-based therapies for thermal burn wounds: a comprehensive systematic review of clinical trials outcomes

BACKGROUND

Burn trauma is one of the major causes of morbidity and mortality worldwide. The standard management of burn wounds consists of early debridement, dressing changes, surgical management, and split-thickness skin autografts (STSGs). However, there are limitations for the standard management that inclines us to find alternative treatment approaches, such as innovative cell-based therapies. We aimed to systematically review the different aspects of cell-based treatment approaches for burn wounds in clinical trials.

METHODS

A systematic search through PubMed, Medline, Embase, and Cochrane Library databases was carried out using a combination of keywords, including "Cell transplantation", "Fibroblast", "Keratinocyte", "Melanocyte", or "Stem Cell" with "Burn", "Burn wound", or "Burn injury". Firstly, titles and abstracts of the studies existing in these databases until "February 2024" were screened. Then, the selected studies were read thoroughly, and considering the inclusion and exclusion criteria, final articles were included in this systematic review. Moreover, a manual search was performed through the reference lists of the included studies to minimize the risk of missing reports.

RESULTS

Overall, 30 clinical trials with 970 patients were included in our study. Considering the type of cells, six studies used keratinocytes, nine used fibroblasts, eight used combined keratinocytes and fibroblasts, one study used combined keratinocytes and melanocytes, five used combined keratinocytes and fibroblasts and melanocytes, and one study used mesenchymal stem cells (MSCs). Evaluation of the preparation type in these studies showed that cultured method was used in 25 trials, and non-cultured method in 5 trials. Also, the graft type of 17 trials was allogeneic, and of 13 other trials was autologous.

CONCLUSIONS

Our study showed that employing cell-based therapies for the treatment of burn wounds have significant results in clinical studies and are promising approaches that can be considered as alternative treatments in many cases. However, choosing appropriate cell-based treatment for each burn wound is essential and depends on the situation of each patient.

Benefits of Aerosolized, Point-of-care, Autologous Skin Cell Suspension (ASCS) for the Closure of Full-thickness Wounds From Thermal and Nonthermal Causes: Learning Curves From the First 50 Consecutive Cases at an Urban, Level 1 Trauma Center

OBJECTIVE

To determine the utility of Autologous Skin Cell Suspension (ASCS) in closing full-thickness (FT) defects from injury and infection.

BACKGROUND

Although ASCS has documented success in closing partial-thickness burns, far less is known about the efficacy of ASCS in FT defects.

METHODS

Fifty consecutive patients with FT defects (burn 17, necrotizing infection 13, crush 7, degloving 5, and other 8) underwent closure with the bilayer technique of 3:1 widely meshed, thin, split-thickness skin graft and 80:1 expanded ASCS. End points were limb salvage rate, donor site reduction, operative and hospital throughput, incidence of complications, and re-epithelialization by 4, 8, and 12 weeks.

RESULTS

Definitive wound closure was achieved in 76%, 94%, and 98% of patients, at 4, 8, and 12 weeks, respectively. Limb salvage occurred in 42/43 patients (10 upper and 33 lower extremities). The mean area grafted was 435 cm 2 ; donor site size was 212 cm 2 , representing a potential reduction of 50%. The mean surgical time was 71 minutes; the total operating room time was 124 minutes. The mean length of stay was 26.4 days; the time from grafting to discharge was 11.2 days. Four out of 50 patients (8%) required 6 reoperations for bleeding (1), breakdown (4), and amputation (1). Four out of 50 patients (8%) developed hypertrophic scarring, which responded to silicone sheeting (2) and laser resurfacing (2). The mean follow-up was 92.7 days.

CONCLUSIONS

When used for the closure of FT wounds, point-of-care ASCS is effective and safe. Benefits include rapid re-epithelialization, high rate of limb salvage, reduction of donor site size and morbidity, and low incidence of hypertrophic scarring.

Combination of Cultured Epidermal Autograft and Meshed Skin Graft Enables Full-thickness Excision of Giant Congenital Nevus

Giant congenital melanocytic nevus (GCMN) is a skin condition characterized by an abnormally dark, noncancerous skin patch. Two main issues with GCMN are aesthetics and malignant transformation. Various methods of treatment are reported, but each method has its own disadvantages, such as risk of recurrence or restriction in the treatable area. We report three cases of GCMN treated with full-thickness excision and immediately covered with cultured epidermal autograft (CEA) combined with split-thickness skin graft (STSG). This is a single-center, single-arm, retrospective report of three cases. The nevus was excised at full skin thickness. Meshed STSG taken from scalp was grafted to the defect, and CEA was grafted over simultaneously. Two weeks later, CEA was applied again as a booster. The same procedures were performed until all nevi were excised. In all cases, nearly complete epithelialization was achieved at several weeks after operation. The reconstructed skin was elastic, and there was no persistent joint contracture. Vancouver Scar Scale score was 4-8. Mesh-like appearance was observed. A hypertrophic scar appeared in the area without meshed STSG. An intractable keloid was observed in one patient. No recurrence of the nevus was observed during the follow-up period. The donor site scar on the scalp was well hidden by the hair. Our method enables full-thickness resection and reconstruction of a wider area in a single operation while improving the take rate of CEA, with reasonable degree of scarring compared with conventional methods.

Management of Acute Wounds-Expert Panel Consensus Statement

Significance: The Wound Healing Foundation recognized the need for consensus-based unbiased recommendations for the treatment of wounds. As a first step, a consensus on the treatment of chronic wounds was developed and published in 2022. The current publication on acute wounds represents the second step in this process. Acute wounds may result from any number of conditions, including burns, military and combat operations, and trauma to specific areas of the body. The management of acute wounds requires timely and evidence-driven intervention to achieve optimal clinical outcomes. This consensus statement provides the clinician with the necessary foundational approaches to the causes, diagnosis, and therapeutic management of acute wounds. Presented in a structured format, this is a useful guide for clinicians and learners in all patient care settings. Recent Advances: Recent advances in the management of acute wounds have centered on stabilization and treatment in the military and combat environment. Specifically, advancements in hemostasis, resuscitation, and the mitigation of infection risk through timely initiation of antibiotics and avoidance of high-pressure irrigation in contaminated soft tissue injury. Critical Issues: Critical issues include infection control, pain management, and the unique considerations for the management of acute wounds in pediatric patients. Future Directions: Future directions include new approaches to preventing the progression and conversion of burns through the use of specific gel formulations. Additionally, the use of three-dimensional bioprinting and photo-modulation for reconstruction is a promising area for continued discovery.

Characterization of heterogeneous skin constructs for full thickness skin regeneration in murine wound models

An autologous heterogeneous skin construct (AHSC) has been developed and used clinically as an alternative to traditional skin grafting techniques for treatment of cutaneous defects. AHSC is manufactured from a small piece of healthy skin in a manner that preserves endogenous regenerative cellular populations. To date however, specific cellular and non-cellular contributions of AHSC to the epidermal and dermal layers of closed wounds have not been well characterized given limited clinical opportunity for graft biopsy following wound closure. To address this limitation, a three-part mouse full-thickness excisional wound model was developed for histologic and macroscopic graft tracing. First, fluorescent mouse-derived AHSC (mHSC) was allografted onto non-fluorescent recipient mice to enable macroscopic and histologic time course evaluation of wound closure. Next, mHSC-derived from haired pigmented mice was allografted onto gender- and major histocompatibility complex (MHC)-mismatched athymic nude mouse recipients. Resulting grafts were distinguished from recipient murine skin via immunohistochemistry. Finally, human-derived AHSC (hHSC) was xenografted onto athymic nude mice to evaluate engraftment and hHSC contribution to wound closure. Experiments demonstrated that mHSC and hHSC facilitated wound closure through production of viable, proliferative cellular material and promoted full-thickness skin regeneration, including hair follicles and glands in dermal compartments. This combined macroscopic and histologic approach to tracing AHSC-treated wounds from engraftment to closure enabled robust profiling of regenerated architecture and further understanding of processes underlying AHSC mechanism of action. These models may be applied to a variety of wound care investigations, including those requiring longitudinal assessments of healing and targeted identification of donor and recipient tissue contributions.

The efficacy and safety of autologous epidermal cell suspensions for re-epithelialization of skin lesions: A systematic review and meta-analysis of randomized trials

BACKGROUND

Successful usage of autologous skin cell suspension (ASCS) has been demonstrated in some clinical trials. However, its efficacy and safety have not been verified. This latest systematic review and meta-analysis aim to examine the effects of autologous epidermal cell suspensions in re-epithelialization of skin lesions.

METHODS

Relevant articles were retrieved from PubMed, Embase, Cochrane Database, Web of Science, International Clinical Trials Registry Platform, China National Knowledge Infrastructureris, VIP Database for Chinese Technical Periodicals and Wanfang database. The primary output measure was the healing time, and the secondary outputs were effective rate, size of donor site for treatment, size of study treatment area, operation time, pain scores, repigmentation, complications, scar scale scores and satisfaction scores. Data were pooled and expressed as relative risk (RR), mean difference (MD) and standardized mean difference (SMD) with a 95% confidence interval (CI).

RESULTS

Thirty-one studies were included in this systematic review and meta-analysis, with 914 patients who received autologous epidermal cell suspensions (treatment group) and 883 patients who received standard care or placebo (control group). The pooled data from all included studies demonstrated that the treatment group has significantly reduced healing time (SMD = -0.86; 95% CI: -1.59-0.14; p = 0.02, I2 = 95%), size of donar site for treatment (MD = -115.41; 95% CI: -128.74-102.09; p<0.001, I2 = 89%), operation time (MD = 25.35; 95% CI: 23.42-27.29; p<0.001, I2 = 100%), pain scores (SMD = -1.88; 95% CI: -2.86-0.90; p = 0.0002, I2 = 89%) and complications (RR = 0.59; 95% CI: 0.36-0.96; p = 0.03, I2 = 66%), as well as significantly increased effective rate (RR = 1.20; 95% CI: 1.01-1.42; p = 0.04, I2 = 77%). There were no significant differences in the size of study treatment area, repigmentation, scar scale scores and satisfaction scores between the two groups.

CONCLUSION

Our meta-analysis showed that autologous epidermal cell suspensions is beneficial for re-epithelialization of skin lesions as they significantly reduce the healing time, size of donar site for treatment, operation time, pain scores and complications, as well as increased effective rate. However, this intervention has minimal impact on size of treatment area, repigmentation, scar scale scores and satisfaction scores.

Biological attributes required for epidermal regeneration: Evaluation of the next-generation autologous cell harvesting device

Early wound intervention and closure is critical for reducing infection and improving aesthetic and functional outcomes for patients with acute burn wounds and nonthermal full-thickness skin defects. Treatment of partial-thickness burns or full-thickness injuries with autologous skin cell suspension (ASCS) achieves robust wound closure while limiting the amount of donor skin compared with standard autografting. A Next Generation Autologous Cell Harvesting Device (NG-ACHD) was developed to standardize the preparation process for ASCS to ensure biological attributes are obtained known to correlate with well-established safety and performance data. This study compared ASCS prepared using the NG-ACHD and ACHD following the manufacturer's guidance, evaluating cellular yields, viability, apoptotic activity, aggregates, phenotypes and functional capacity. Non-inferiority was established for all biological attributes tested and comparable healing trajectories were demonstrated using an in vitro skin regeneration model. In addition to standardization, the NG-ACHD also provides workflow efficiencies with the potential to decrease training requirements and increase the ease of incorporation and utilization of ASCS in clinical practice.

Limited debridement combined with ReCell® Techniques for deep second-degree burns

BACKGROUND

The purpose of this article is to introduce a method that combines limited debridement and ReCell® autologous cell regeneration techniques for the treatment of deep second-degree burn wounds.

METHOD

A total of 20 patients suffered with deep second-degree burns less than 10% of total body surface area (TBSA) who were admitted to our department, from June 2019 to June 2021, participated in this study. These patients first underwent limited debridement with an electric/pneumatic dermatome, followed by the ReCell® technique for secondary wounds. Routine treatment was applied to prevent scarring after the wound healed. Clinical outcomes were scored using the Vancouver Scar Scale (VSS).

RESULTS

All wounds of the patients healed completely. One patient developed an infection in the skin graft area and finally recovered by routine dressing changes. The average healing time was 12 days (range: 10-15 days). The new skin in the treated area was soft and matched the colour of the surrounding normal skin and the VSS score ranged from 3~5 for each patient. Of the 20 patients, 19 were very satisfied and 1 was satisfied.

CONCLUSIONS

This article reports a useful treatment method that combines electric dermatome-dependent limited debridement and the ReCell® technique for the treatment of deep second-degree burn wounds. It is a feasible and effective strategy that is easy to implement and minimally invasive, and it is associated with a short healing time, mild scar formation and little damage to the donor skin area.

A novel method for the establishment of autologous skin cell suspensions: characterisation of cellular sub-populations, epidermal stem cell content and wound response-enhancing biological properties

Introduction: Autologous cell suspension (ACS)-based therapy represents a highly promising approach for burns and chronic wounds. However, existing technologies have not achieved the desired clinical success due to several limitations. To overcome practical and cost-associated obstacles of existing ACS methods, we have established a novel methodology for rapid, enzymatic disaggregation of human skin cells and their isolation using a procedure that requires no specialist laboratory instrumentation and is performed at room temperature. Methods: Cells were isolated using enzymatic disaggregation of split-thickness human skin followed by several filtration steps for isolation of cell populations, and cell viability was determined. Individual population recovery was confirmed in appropriate culture medium types, and the presence of epidermal stem cells (EpSCs) within keratinocyte sub-populations was defined by flow cytometry via detection of CD49 and CD71. Positive mediators of wound healing secreted by ACS-derived cultures established on a collagen-based wound-bed mimic were detected by proteome arrays and quantified by ELISA, and the role of such mediators was determined by cell proliferation assays. The effect of ACS-derived conditioned-medium on myofibroblasts was investigated using an in-vitro model of myofibroblast differentiation via detection of α-SMA using immunoblotting and immunofluorescence microscopy. Results: Our methodology permitted efficient recovery of keratinocytes, fibroblasts and melanocytes, which remained viable upon long-term culture. ACS-derivatives comprised sub-populations with the CD49-high/CD71-low expression profile known to demarcate EpSCs. Via secretion of mitogenic factors and wound healing-enhancing mediators, the ACS secretome accelerated keratinocyte proliferation and markedly curtailed cytodifferentiation of myofibroblasts, the latter being key mediators of fibrosis and scarring. Discussion: The systematic characterisation of the cell types within our ACS isolates provided evidence for their superior cell viability and the presence of EpSCs that are critical drivers of wound healing. We defined the biological properties of ACS-derived keratinocytes, which include ability to secrete positive mediators of wound healing as well as suppression of myofibroblast cytodifferentiation. Thus, our study provides several lines of evidence that the established ACS isolates comprise highly-viable cell populations which can physically support wound healing and possess biological properties that have the potential to enhance not only the speed but also the quality of wound healing.

Skin Substitutes and Autograft Techniques: Temporary and Permanent Coverage Solutions

Coverage of burn wounds is crucial to prevent sequalae including dehydration, wound infection, sepsis, shock, scarring, and contracture. To this end, numerous temporary and permanent options for coverage of burn wounds have been described. Temporary options for burn coverage include synthetic dressings, allografts, and xenografts. Permanent burn coverage can be achieved through skin substitutes, cultured epithelial autograft, ReCell, amnion, and autografting. Here, we aim to summarize the available options for burn coverage, as well as important considerations that must be made when choosing the best reconstructive option for a particular patient.

Current Approaches to Wound Repair in Burns: How far Have we Come From Cover to Close? A Narrative Review

Burn injuries are a significant global health concern, with more than 11 million people requiring medical intervention each year and approximately 180,000 deaths annually. Despite progress in health and social care, burn injuries continue to result in socioeconomic burdens for victims and their families. The management of severe burn injuries involves preventing and treating burn shock and promoting skin repair through a two-step procedure of covering and closing the wound. Currently, split-thickness/full-thickness skin autografts are the gold standard for permanent skin substitution. However, deep burns treated with split-thickness skin autografts may contract, leading to functional and appearance issues. Conversely, defects treated with full-thickness skin autografts often result in more satisfactory function and appearance. The development of tissue-engineered dermal templates has further expanded the scope of wound repair, providing scar reductive and regenerative properties that have extended their use to reconstructive surgical interventions. Although their interactions with the wound microenvironment are not fully understood, these templates have shown potential in local infection control. This narrative review discusses the current state of wound repair in burn injuries, focusing on the progress made from wound cover to wound closure and local infection control. Advancements in technology and therapies hold promise for improving the outcomes for burn injury patients. Understanding the underlying mechanisms of wound repair and tissue regeneration may provide new insights for developing more effective treatments in the future.

Autologous Skin Cell Suspension for Full-Thickness Skin Defect Reconstruction: Current Evidence and Health Economic Expectations

Despite differing etiologies, acute thermal burn injuries and full-thickness (FT) skin defects are associated with similar therapeutic challenges. When not amenable to primary or secondary closure, the conventional standard of care (SoC) treatment for these wound types is split-thickness skin grafting (STSG). This invasive procedure requires adequate availability of donor skin and is associated with donor site morbidity, high healthcare resource use (HCRU), and costs related to prolonged hospitalization. As such, treatment options that can facilitate effective healing and donor skin sparing have been highly anticipated. The RECELL® Autologous Cell Harvesting Device facilitates preparation of an autologous skin cell suspension (ASCS) for the treatment of acute thermal burns and FT skin defects. In initial clinical trials, the approach showed superior donor skin-sparing benefits and comparable wound healing to SoC STSG among patients with acute thermal burn injuries. These findings led to approval of RECELL for this indication by the US Food and Drug Administration (FDA) in 2018. Subsequent clinical evaluation in non-thermal FT skin wounds showed that RECELL, when used in combination with widely meshed STSG, provides donor skin-sparing advantages and comparable healing outcomes compared with SoC STSG. As a result, the device received FDA approval in June of 2023 for treatment of FT skin defects caused by traumatic avulsion or surgical excision or resection. Given that health economic advantages have been demonstrated for RECELL ± STSG versus STSG alone when used for burn therapy, it is prudent to examine similarities in the burn and FT skin defect treatment pathways to forecast the potential health economic advantages for RECELL when used in FT skin defects. This article discusses the parallels between the two indications, the clinical outcomes reported for RECELL, and the HCRU and cost benefits that may be anticipated with use of the device for non-thermal FT skin defects.

Effectiveness of a Regenerative Epithelial Suspension (RES), on the pigmentation of split-thickness skin graft donor sites in children: the dRESsing pilot randomised controlled trial protocol

BACKGROUND

Paediatric donor site wounds are often complicated by dyspigmentation following a split-thickness skin graft. These easily identifiable scars can potentially never return to normal pigmentation. A Regenerative Epidermal Suspension (RES) has been shown to improve pigmentation in patients with vitiligo, and in adult patients following a burn injury. Very little is known regarding the efficacy of RES for the management of donor site scars in children.

METHODS AND ANALYSIS

A pilot randomised controlled trial of 40 children allocated to two groups (RES or no RES) standard dressing applied to donor site wounds will be conducted. All children aged 16 years or younger requiring a split thickness skin graft will be screened for eligibility. The primary outcome is donor site scar pigmentation 12 months after skin grafting. Secondary outcomes include re-epithelialisation time, pain, itch, dressing application ease, treatment satisfaction, scar thickness and health-related quality of life. Commencing 7 days after the skin graft, the dressing will be changed every 3-5 days until the donor site is ≥ 95% re-epithelialised. Data will be collected at each dressing change and 3, 6 and 12 months post skin graft.

ETHICS AND DISSEMINATION

Ethics approval was confirmed on 11 February 2019 by the study site Human Research Ethics Committee (HREC) (HREC/18/QCHQ/45807). Study findings will be published in peer-reviewed journals and presented at national and international conferences. This study was prospectively registered on the Australian New Zealand Clinical Trials Registry (available at https://anzctr.org.au/ACTRN12620000227998.aspx).

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry [Available at https://anzctr.org.au/ACTRN12620000227998.aspx].

First do no harm: A patient-reported survey of split skin graft donor site morbidities following thin and super-thin graft harvest

The split-thickness skin graft (STSG) donor site is the commonest used during burn surgery which has its own complications and as such the focus should be on minimizing it. Modifications to practice in our unit which we believe aid this include limiting the amount of STSG taken and the harvest of super-thin STSGs, with 0.003-0.005 in. (0.08-0.13 mm) being the commonest dermatome settings used. A patient-reported survey via a mobile phone link to a questionnaire was sent to 250 patients who had a STSG for an acute burn between 1st August 2020 and 31st July 2021. Patient demographics were collected from electronic records including the thickness of the FTSG taken when recorded. Patient responses were statistically analyzed and logistic regression with backwards elimination was performed to explore which contributing factors led to an improved experience of the donor site. Questionnaire responses were obtained from 107 patients (43%). These were between one and two and a half years after the injury. Concerning early donor site issues, itch was a problem for 52% of patients, pain was a problem for 48% of patients. Less common problems (fewer than 25% of patients) were leaking donor sites, wound breakdown, and over-granulation. Regarding long-term outcomes, increased, decreased or mixed pigmentation at the donor site was reported by 32% patients at the time of the survey. Hyper-vascular donor sites were reported by 24% patients. Raised or uneven feeling donor sites were reported by 19% patients, firm or stiff donor sites by 13% patients, and altered sensation by 10% patients. At the time of the survey, 70% responders reported their donor site looked "the same or about the same as my normal skin". Of these, 62 reported how long it took for this to happen, and it equates to a third looking normal at 6 months and half looking normal at a year. For the 32 patients who reported their donor site looking abnormal, 72% were "not bothered" by it. Patients with super-thin grafts (0.003-0.005 in.) were significantly more likely to have normal sensation, normal stiffness, and be less raised at their donor sites than those who had thin grafts (0.006-0.008 in.). This survey gives important information on patients' experiences of donor site morbidity that may form part of an informed consent process and allow tailored advice. Furthermore, it suggests that super-thin grafts may provide a superior donor site experience for patients.

Maximizing wound coverage in full-thickness skin defects: A randomized-controlled trial of autologous skin cell suspension and widely meshed autograft versus standard autografting

BACKGROUND

Traumatic insults, infection, and surgical procedures can leave skin defects that are not amenable to primary closure. Split-thickness skin grafting (STSG) is frequently used to achieve closure of these wounds. Although effective, STSG can be associated with donor site morbidity, compounding the burden of illness in patients undergoing soft tissue reconstruction procedures. With an expansion ratio of 1:80, autologous skin cell suspension (ASCS) has been demonstrated to significantly decrease donor skin requirements compared with traditional STSG in burn injuries. We hypothesized that the clinical performance of ASCS would be similar for soft tissue reconstruction of nonburn wounds.

METHODS

A multicenter, within-patient, evaluator-blinded, randomized-controlled trial was conducted of 65 patients with acute, nonthermal, full-thickness skin defects requiring autografting. For each patient, two treatment areas were randomly assigned to concurrently receive a predefined standard-of-care meshed STSG (control) or ASCS + more widely meshed STSG (ASCS+STSG). Coprimary endpoints were noninferiority of ASCS+STSG for complete treatment area closure by Week 8, and superiority for relative reduction in donor skin area.

RESULTS

At 8 weeks, complete closure was observed for 58% of control areas compared with 65% of ASCS+STSG areas (p = 0.005), establishing noninferiority of ASCS+STSG. On average, 27.4% less donor skin was required with ASCS+ STSG, establishing superiority over control (p < 0.001). Clinical healing (≥95% reepithelialization) was achieved in 87% and 85% of Control and ASCS+STSG areas, respectively, at 8 weeks. The treatment approaches had similar long-term scarring outcomes and safety profiles, with no unanticipated events and no serious ASCS device-related events.

CONCLUSION

ASCS+STSG represents a clinically effective and safe solution to reduce the amount of skin required to achieve definitive closure of full-thickness defects without compromising healing, scarring, or safety outcomes. This can lead to reduced donor site morbidity and potentially decreased cost associated with patient care.Clincaltrials.gov identifier: NCT04091672.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level I.

Telomerase mRNA Enhances Human Skin Engraftment for Wound Healing

Deep skin wounds represent a serious condition and frequently require split-thickness skin grafts (STSG) to heal. The application of autologous human-skin-cell-suspension (hSCS) requires less donor skin than STSG without compromising the healing capacity. Impaired function and replicative ability of senescent cutaneous cells in the aging skin affects healing with autologous hSCS. Major determinants of senescence are telomere erosion and DNA damage. Human telomerase reverse transcriptase (hTERT) adds telomeric repeats to the DNA and can protect against DNA damage. Herein, hTERT mRNA lipid nanoparticles (LNP) are proposed and evaluated for enhancing cellular engraftment and proliferation of hSCS. Transfection with optimized hTERT mRNA LNP system enables delivery and expression of mRNA in vitro in keratinocytes, fibroblasts, and in hSCS prepared from donors' skin. Telomerase activity in hSCS is significantly increased. hTERT mRNA LNP enhance the generation of a partial-thickness human skin equivalent in the mouse model, increasing hSCS engraftment (Lamin) and proliferation (Ki67), while reducing cellular senescence (p21) and DNA damage (53BP1).

"Minimally Invasive" Skin Grafting With Enzymatic Debridement and Autologous Skin Cell Spray: A Retrospective Case Series

Minimally invasive surgery is becoming the standard of care across surgical subspecialties. Several new "minimally invasive" options for burn debridement and autografting exist. Enzymatic bromelain-based debridement (BBD) and autologous skin cell spray (ASCS) have independently proven to reduce the rate of split-thickness skin grafting (STSG) and decrease donor site size when grafting is performed. There is a paucity in the literature regarding the combination of these two therapies. The purpose of this study is to characterize a cohort of patients treated with both BBD and ASCS and qualitatively compare data to expected outcomes without these therapies. This retrospective study of a single academic burn center's experience using BBD and ASCS together included 13 patients with a total burn surface area (TBSA) from 1-30% and all had >50% deep partial thickness. All patients received BBD and ASCS. Deeper burns additionally received STSG with ASCS overspray. Median burn size was 14% TBSA (IQR:5.45,20), donor site size was 225 sq cm (IQR:28.5,556.5), and ratio of donor site area to total treatment area of 0.082 (IQR: 0.039, 0.241) was observed. Median observed length of stay (LOS) was 19 days (IQR:10,27), expected LOS was 15.4 days, and O/E ratio 1.06. Donor sites in both groups of patients were much smaller than expected versus treatment with conventional meshed STSG alone and length of stay is lower than expected based on burn size. An emphasis on expenses and scar development will guide future studies into the patient subset and wound features that are best for this combination treatment.

Assessment and Management of Acute Burn Injuries

Burn injuries can affect patients from all walks of life and represent a significant healthcare problem globally. The skin is the largest organ of the body and consequences of injury range of minor pain to severe end-organ dysfunction and even death. The acute assessment and management of burn-injured patients is a critical part of their short-term and long-term outcomes and often benefit from specialty, multidisciplinary care. Local wound care and appropriate excision and grafting are important parts of managing the functional, cosmetic, and physiologic derangements caused by burn injuries. Large burns also require judicious fluid resuscitation. Electrical, chemical, and inhalational injuries are less common than thermal burns but require additional care and are often associated with increased morbidity.

Personalised burn treatment: bedside electrospun nanofibre scaffold with cultured autologous keratinocytes: a case study

Nearly four decades after cultured epidermal autografts (CEA) were first used for the treatment of extensive burn wounds, the current gold standard treatment remains grafting healthy autologous skin from a donor site to the damaged areas, with current skin substitutes limited in their clinical use. We propose a novel treatment approach, using an electrospun polymer nanofibrous matrix (EPNM) applied on-site directly on the CEA-grafted areas. In addition, we propose a personalised treatment on hard-to-heal areas, in which we spray suspended autologous keratinocytes integrated with 3D EPNM applied on-site, directly onto the wound bed. This method enables the coverage of larger wound areas than possible with CEA. We present the case of a 26-year-old male patient with full-thickness burns covering 98% of his total body surface area (TBSA). We were able to show that this treatment approach resulted in good re-epithelialisation, seen as early as seven days post CEA grafting, with complete wound closure within three weeks, and to a lesser extent in areas treated with cell spraying. Moreover, in vitro experiments confirmed the feasibility of using keratinocytes embedded within the EPNM: cell and culture viability, identity, purity and potency were determined. These experiments show that the skin cells are viable and can proliferate within the EPNM. The results presented are of a promising novel strategy for the development of personalised wound treatment, integrating on-the-spot 'printed' EPNM with autologous skin cells, which will be applied at the bedside, over deep dermal wounds, to accelerate healing time and wound closure.

Burn Scar Management and Reconstructive Surgery

This chapter highlights the importance of a comprehensive burn scar treatment plan in approaching a burn survivor. General concepts of burn scar physiology and a practical system to describe burn scars based on cause, biology, and symptoms are presented. Common scar management modalities including nonsurgical, surgical, and adjuvant therapies are further discussed.

A single institution case series of ReCell® use in treating pediatric burns

BACKGROUND

Thermal injury has a significant impact on disability and morbidity in pediatric patients. Challenges in caring for pediatric burn patients include limited donor sites for large total body surface area (TBSA) burn as well as optimization of wound management for long term growth and cosmesis. ReCell^® technology produces autologous skin cell suspensions from minimal donor split-thickness skin samples, allowing for expanded coverage using minimal donor skin. Most literature on outcomes reports on adult patients.

OBJECTIVE

We present the largest to-date retrospective review of ReCell^® technology use in pediatric patients at a single pediatric burn center.

METHOD

Patients were treated at a quaternary care, free-standing, American Burn Association verified Pediatric Burn Center. A retrospective chart review was performed from September 2019 to March 2022, during which time twenty-one pediatric burn patients had been treated with ReCell^® technology. Patient information was collected, including demographics, hospital course, burn wound characteristics, number of ReCell^® applications, adjunct procedures, complications, healing time, Vancouver scar scale measurements, and follow-up. A descriptive analysis was performed, and medians were reported.

RESULTS

Median TBSA burn on initial presentation was 31% (ranging 4%-86%). The majority of patients (95.2%) had placement of a dermal substrate prior to ReCell^® application. Four patients did not receive split thickness skin grafting with their ReCell^® treatment. The median time between date of burn injury and first ReCell^® application was 18 days (ranging 5-43 days). The number of ReCell^® applications ranged from 1-4 per patient. Median time until wound was classified as healed was 81 days (ranging 39-573 days). The median maximum Vancouver scar scale measurement per patient at time healed was 8, ranging from 3-14. Five patients who received skin grafts had graft loss and three of these patients had graft loss from areas with ReCell^®.

CONCLUSION

ReCell^® technology provides an additional method for wound coverage, either on its own or in conjunction with split thickness skin grafting, and is safe and effective in pediatric patients.

Experimentally Induced Burns in Rats Treated with Innovative Polymeric Films Type Therapies

Considering that microbial resistance to antibiotics is becoming an increasingly widespread problem, burn management, which usually includes the use of topical antimicrobial dressings, is still facing difficulties regarding their efficiency to ensure rapid healing. In this context, the main objective of this research is to include new oxytetracycline derivatives in polymeric-film-type dressings for the treatment of wounds caused by experimentally induced burns in rats. The structural and physico-chemical properties of synthesized oxytetracycline derivatives and the corresponding membranes were analyzed by FT-IR and MS spectroscopy, swelling ability and biodegradation capacity. In vitro antimicrobial activity using Gram-positive and Gram-negative bacterial strains and pathogenic yeasts, along with an in vivo study of a burn wound model induced in Wistar rats, was also analyzed. The newly obtained polymeric films, namely chitosan-oxytetracycline derivative membranes, showed good antimicrobial activity noticed in the tested strains, a membrane swelling ratio (MSR) of up to 1578% in acidic conditions and a biodegradation rate of up to 15.7% on day 7 of testing, which are important required characteristics for the tissue regeneration process, after the production of a burn. The in vivo study proved that chitosan-derived oxytetracycline membranes showed also improved healing effects which contributes to supporting the idea of using them for the treatment of wounds caused by burns.

A Brief History of RECELL® and Its Current Indications

A concise history of the development of the RECELL® device and the seminal work of Dr. Fiona Wood will be provided, as well as the current indications and potential future prospects for the use of RECELL® in the United States.

Analysis of real-world length of stay data and costs associated with use of autologous skin cell suspension for the treatment of small burns in U.S. centers

BACKGROUND

Autologous skin cell suspension (ASCS) is a treatment for acute thermal burn injuries associated with significantly lower donor skin requirements than conventional split-thickness skin grafts (STSG). Projections using the BEACON model suggest that among patients with small burns (total body surface area [TBSA]<20 %), use of ASCS± STSG leads to a shorter length of stay (LOS) in hospital and cost savings compared with use of STSG alone. This study evaluated whether data from real-world clinical practice corroborate these findings.

MATERIALS AND METHODS

Electronic medical record data were collected from January 2019 through August 2020 from 500 healthcare facilities in the United States. Adult patients receiving inpatient treatment with ASCS± STSG for small burns were identified and matched to patients receiving STSG using baseline characteristics. LOS was assumed to cost $7554/day and to account for 70 % of overall costs. Mean LOS and costs were calculated for the ASCS± STSG and STSG cohorts.

RESULTS

A total of 151 ASCS± STSG and 2243 STSG cases were identified; 63.0 % of patients were male and the average age was 44.2 years. Sixty-three matches were made between cohorts. LOS was 18.5 days with ASCS± STSG and 20.6 days with STSG (difference: 2.1 days [10.2 %]). This difference led to bed cost savings of $15,587.62 per ASCS± STSG patient. Overall cost savings with ASCS± STSG were $22,268.03 per patient.

CONCLUSIONS

Analysis of real-world data shows that treatment of small burn injuries with ASCS± STSG provides reduced LOS and substantial cost savings compared with STSG, supporting the validity of the BEACON model projections.

Synergistic Use of Novel Technological Advances in Burn Care Significantly Reduces Hospital Length of Stay Below Predicted: A Case Series

Length of stay is an important metric in healthcare systems, primarily because it reflects the cost of care provided. In the US, as in many countries, inpatient hospital stays are significantly more expensive than outpatient care across all healthcare conditions [1], so earlier discharge and transition to outpatient care is crucial to help control the ever-increasing cost of healthcare. In burn patients, length of stay has traditionally been estimated at 1 day per 1% total body surface area of burn. This estimation was first described in a round table discussion in 1986.[2] However, since that time there has been significant evolution in the quality of care available to burn patients, in both the operating room and ICU. The use of new harvesting techniques, synthetic dermal substitution, and autologous epidermal skin cell suspension are allowing large, deep burns to be excised and covered in much quicker time frames than historically were possible. Examples include the skin harvesting and wound debridement device for grafting and excision, biodegradable temporizing matrix as a fully synthetic dermal template, and regenerative epidermal suspension concerning cell harvesting. Although these modalities can all be used separately, we believe that using them in conjunction has allowed us to shorten the length of stay in patients with severe partial and full-thickness burns. We present an initial case series of 3 patients with anticipated hospital lengths of stay of 54.5, 55, and 51 days, who were ready for discharge in 37, 35, and 43 days, respectively.

The Role of Skin Substitutes in Acute Burn and Reconstructive Burn Surgery: An Updated Comprehensive Review

Burns disrupt the protective skin barrier with consequent loss of cutaneous temperature regulation, infection prevention, evaporative losses, and other vital functions. Chronically, burns lead to scarring, contractures, pain, and impaired psychosocial well-being. Several skin substitutes are available and replace the skin and partially restore functional outcomes and improve cosmesis. We performed a literature review to update readers on biologic and synthetic skin substitutes to date applied in acute and reconstructive burn surgery. Improvement has been rapid in the development of skin substitutes in the last decade; however, no available skin substitute fulfills criteria as a perfect replacement for damaged skin.

Reversibly immortalized keratinocytes (iKera) facilitate re-epithelization and skin wound healing: Potential applications in cell-based skin tissue engineering

Skin injury is repaired through a multi-phase wound healing process of tissue granulation and re-epithelialization. Any failure in the healing process may lead to chronic non-healing wounds or abnormal scar formation. Although significant progress has been made in developing novel scaffolds and/or cell-based therapeutic strategies to promote wound healing, effective management of large chronic skin wounds remains a clinical challenge. Keratinocytes are critical to re-epithelialization and wound healing. Here, we investigated whether exogenous keratinocytes, in combination with a citrate-based scaffold, enhanced skin wound healing. We first established reversibly immortalized mouse keratinocytes (iKera), and confirmed that the iKera cells expressed keratinocyte markers, and were responsive to UVB treatment, and were non-tumorigenic. In a proof-of-principle experiment, we demonstrated that iKera cells embedded in citrate-based scaffold PPCN provided more effective re-epithelialization and cutaneous wound healing than that of either PPCN or iKera cells alone, in a mouse skin wound model. Thus, these results demonstrate that iKera cells may serve as a valuable skin epithelial source when, combining with appropriate biocompatible scaffolds, to investigate cutaneous wound healing and skin regeneration.

Surgical procedures and innovative approaches for vitiligo regenerative treatment and melanocytorrhagy

Surgical treatments for vitiligo are a safe and effective treatment modality for select patients with vitiligo. Many techniques of vitiligo surgery exist, each with unique advantages and disadvantages. We reviewed the various surgical therapies and innovative approaches for vitiligo regenerative treatment reported in the literature. Surgical therapies can be subdivided into tissue grafting methods and cellular grafting methods. Tissue grafting methods mainly include mini punch grafts, suction blister roof grafts, and hair follicle grafts. Cellular grafting methods include cultured and non-cultured treatments. The efficacy needs to be improved largely due to the poor proliferation and quality of the autologous melanocytes. Rho-associated protein kinase inhibitor enhances primary melanocyte culture proliferation from vitiligo patients to prevent apoptosis. Innovative approaches using stem cell methods could prove invaluable in developing a novel cell therapy for patients suffering from vitiligo. We succeeded in inducing melanin pigmentation in mice skin in vivo using our human induced pluripotent stem cell-derived melanocytes. In addition, we reviewed melanocytorrhagy, detachment and transepidermal loss of melanocytes, and melanocyte-related adhesion molecules. These adhesion molecules include epithelial cadherin, discoidin domain receptor tyrosine kinase 1, glycoprotein non-metastatic melanoma protein B, macrophage migration inhibiting factor, 17β-hydroxysteroid dehydrogenase 1, and E26 transformation-specific 1.

The Direct to Consumer Stem Cell Market and the Role of Primary Care Providers in Correcting Misinformation

INTRODUCTION

Direct to consumer stem cell and regenerative interventions (SCRIs) for various medical conditions have increased in popularity due to unmet medical needs and the promise of SCRIs to meet those needs. These interventions may have varying levels of safety and efficacy data and many lack sufficient scientific data to be marketed. The direct to consumer SCRI industry has received significant attention due to potential physical, economic, and emotional harms to patients. Patients may seek the counsel of their primary care providers when considering stem cell therapy for their condition.

METHODS

Here we describe strategies primary care providers can utilize when counseling patients.

RESULTS

Although we recommend constructing these discussions around individual patients' needs, one can utilize a general approach consisting of 4 parts. First, providers should recognize what information the patient is seeking and what is their understanding of stem cell and regenerative medicine. Next, providers should convey evidence-based information at the level of patients understanding so that they are aware of the risks, benefits, and descriptions of possible procedures. Throughout the conversations, attempts should be made to guide patients to a trusted resource that can provide additional information. Finally, providers should make an effort to address misinformation in a way that is nonjudgmental and patient-centered to make the patient feel safe and comfortable.

CONCLUSION

Effectively communicating risk information by primary care providers to patients is important given the harms reported from direct-to-consumer SCRIs. Correcting misinformation remains a priority when discussing SCRI's. Providers should strive to offer patients with additional resources such as the opportunity for consultation with a specialist or a consultation service dedicated to informing patients about regenerative medicine.

Length of Stay and Costs with Autologous Skin Cell Suspension Versus Split-Thickness Skin Grafts: Burn Care Data from US Centers

INTRODUCTION

Autologous skin cell suspension (ASCS) significantly reduces donor skin requirements versus conventional split-thickness skin grafts (STSG) for thermal burn treatment. In analyses using the Burn-medical counter measure Effectiveness Assessment Cost Outcomes Nexus (BEACON) model, ASCS was associated with shorter hospital length of stay (LOS) and cost savings versus STSG. This study hypothesized that daily practice data from the USA would support these findings.

METHODS

Electronic medical record data from 500 healthcare facilities (January 2019-August 2020) were used to match adult patients who received inpatient burn treatment with ASCS (± STSG) to patients treated with STSG alone on the basis of sex, age, percent total body surface area (TBSA), and comorbidities. Based on BEACON analyses, LOS was assumed to represent 70% of total costs and used as a proxy to assess the data. Mean LOS, costs, and the incremental revenue associated with inpatient capacity changes were calculated.

RESULTS

A total of 151 ASCS and 2443 STSG patients were identified: 63.0% were male and average age was 44.5 years. Eight-one matches were made between cohorts. LOS was 21.7 days with ASCS and 25.0 days with STSG alone (difference 3.3 days [13.2%]). LOS was lower with ASCS than STSG in four of five TBSA intervals. The LOS difference led to hospital bed cost savings of $25,864 per ASCS patient; overall cost savings were $36,949 per patient. Similar cost savings were observed in TBSA groupings < 20% and ≥ 20%. The reduced LOS with ASCS translated into an increased capacity of 2.2 inpatients/bed annually, which increased hospital revenue by $92,283/burn unit bed annually.

CONCLUSIONS

Real-world data show that ASCS (± STSG) is associated with reduced LOS and cost savings versus STSG alone across all burn sizes, supporting the validity of the BEACON analyses. ASCS use may also increase patient capacity and throughput, leading to increased hospital revenue.

Wound healing in animals: a review of physiology and clinical evaluation

Wound healing is a complicated process consisting of overlapping phases directed and regulated by many mediators of healing produced locally at the wound. The end goal of wound healing is the production of tissue at the site of injury which has a similar structure and provides protection to the body. Any alterations in the normal healing process can lead to delayed healing or additional tissue damage. Factors that contribute to aberrant wound healing can be species-specific and include both intrinsic (systemic) factors and extrinsic (environmental) factors. Management of wounds and recognition of alterations can be optimised by adoption of a structured framework for wound assessment, such as the TIME principle (acronym referring to the following categories: tissue, inflammation or infection, moisture, and edge of wound or epithelial advancement). This review article provides an overview of the phases of wound healing, variation of healing among different species, factors reported to delay healing, and an introduction to the TIME principle as a structured approach to clinical evaluation of wounds.

The Current Challenges on Spray-Based Cell Delivery to the Skin Wounds

Cell delivery through spray instruments is a promising and effective method in tissue engineering and regenerative medicine. It is used for treating different acute and chronic wounds, including burns with different etiologies, chronic diabetic or venous wounds, postcancer surgery, and hypopigmentation disorders. Cell spray can decrease the needed donor site area compared with conventional autologous skin grafting. Keratinocytes, fibroblasts, melanocytes, and mesenchymal stem cells are promising cell sources for cell spray procedures. Different spray instruments are designed and utilized to deliver the cells to the intended skin area. In an efficient spray instrument, cell viability and wound coverage are two determining parameters influenced by various physical and biological factors such as air pressure, spraying distance, viscosity of suspension, stiffness of the wound surface, and velocity of impact. Besides, to improve cell delivery by spray instruments, some matrices and growth factors can be added to cell suspensions. This review focuses on the different types of cells and spray instruments used in cell delivery procedures. It also discusses physical and biological parameters associated with cell viability and wound coverage in spray instruments. Moreover, the recent advances in codelivery of cells with biological glues and growth factors, as well as clinical translation of cell spraying, have been reviewed. Impact statement Skin wounds are a group of prevalent injuries that can lead to life-threatening complexities. As a focus of interest, stem cell therapy and spray-based cell delivery have effectively decreased associated morbidity and mortality. This review summarizes a broad scope of recent evidence related to spray-based cell therapy, instruments, and approaches adopted to make the process more efficient in treating skin wounds. An overview including utilized cell types, clinical cases, and current challenges is also provided.

A systematic review and meta-analysis of randomized trials evaluating the efficacy of autologous skin cell suspensions for re-epithelialization of acute partial thickness burn injuries and split-thickness skin graft donor sites

BACKGROUND

This systematic review evaluated the efficacy of autologous skin cell suspensions (ASCS) on the re-epithelialization of partial thickness burn injuries and skin graft donor site wounds.

METHODS

Four databases (EMBASE, Google Scholar, MEDLINE, Web of Science), grey literature and select journal hand-searching identified studies from 1975 - 2020. Randomized trials evaluating partial thickness burn management with non-cultured ASCS compared to any other intervention were included. Time to re-epithelialization (TTRE) was the primary outcome. Three independent researchers completed screening, data extraction and certainty of evidence assessment using Cochrane Risk of Bias Tool and Grading of Recommendations Assessment, Development and Evaluation.

RESULTS

Five trials (n = 347) reported on adults (2 trials) and children (1 trial) with burn wounds, and adults with donor site wounds (2 trials). The effect of ASCS compared to control on TTRE in adult burn wounds was not estimable. TTRE was shorter in pediatric burn wounds (SMD -1.75 [95% CI: -3.45 to -0.05]) and adult donor site wounds (SMD-5.71 [95% CI: -10.61 to-0.81]) treated with ASCS. The certainty of evidence was very low.

CONCLUSION

Compared to standard care, ACSC may reduce pediatric partial thickness burn wound and adult split-thickness skin graft donor site TTRE.

REGISTRATION

PROSPERO CRD42019133171.

Repigmentation of nipple-areola complex after ReCell® treatment on breast vitiligo

BACKGROUND

Nipple-areola complex is a naturally hyperpigmented skin area which can be involved in vitiligo. But limited study focused on the treatment of nipple-areola complex vitiligo, and few methods were proven to be effective. In this study, we aimed to explore the feasibility and efficacy of ReCell® on vitiligo in the nipple-areola complex area.

METHODS

Medical records of patients with vitiligo involving nipple-areola complex and underwent ReCell® treatment from October 2016 to April 2020 were retrospectively reviewed. The repigmentation rate of the nipple-areola complex and other breast area were calculated under the Wood's light at each follow-up. The grade of repigmentation and patient-reported satisfaction rate were also evaluated to prove the effect of ReCell® on vitiligo of breast and especially in the nipple-areola complex area.

RESULTS

A total of 18 patients were included in this study. No surgical complications were reported. The mean postoperative repigmentation rate in the nipple-areola complex area (3rd-month, 78.7 ± 5.8%; 6th-month, 87.6 ± 5.1%; and 12th-month, 96.1 ± 3.5%) was significantly higher than that in the other breast treatment area (3rd-month, 70.4 ± 6.9%; 6th-month, 84.2 ± 5.7%, and 12th-month, 93.2 ± 3.6%). All patients showed good or excellent grades at the last follow-up, and 94.4% of them considered the overall treatment results satisfactory.

CONCLUSIONS

ReCell® is a feasible and efficient treatment strategy in the nipple-areola complex vitiligo.

Initial Experience Combining Negative Pressure Wound Therapy With Autologous Skin Cell Suspension and Meshed Autografts

The success of autologous split-thickness skin grafts (STSGs) in the treatment of full-thickness burns is often dependent on the dressing used to secure it. Tie-over bolsters have been used traditionally; however, they can be uncomfortable for patients and preclude grafting large areas in one definitive operation. Negative pressure wound therapy (NPWT) is used as an alternative to bolster dressings and may afford additional wound healing benefits. In our center, NPWT has become the dressing of choice for securing STSGs. While the RECELL® system is being used in conjunction with STSGs, it is currently unknown whether autologous skin cell suspensions (ASCS) can be used with NPWT. This report is a retrospective chart review of nine patients treated in this manner. All wounds were almost completely re-epithelialized within 14 days, and their healing was as expected. Wound healing trajectories are shown. There were no significant complications in these patients. This dressing technique can be considered as an option when using ASCS and widely meshed STSG.

A Pilot Study of Negative Pressure Therapy with Autologous Skin Cell Suspensions in a Porcine Model

BACKGROUND

Negative pressure wound therapy (NPWT) is an option for securing meshed split thickness skin grafts (mSTSGs) after burn excision to optimize skin graft adherence. Recently, the use of autologous skin cell suspension (ASCS) has been approved for use in the treatment of burn injuries in conjunction with mSTSGs.To date, limited data exists regarding the impact of NPWT on healing outcomes when the cellular suspension is utilized. It was hypothesized that NPWT would not negatively impact wound healing of ASCS+mSTSG.

MATERIALS AND METHODS

A burn, excision, mSTSG, ASCS ± NPWT model was used. Two Duroc pigs were utilized in this experiment, each with 2 sets of paired burns. Four wounds received mSTSG+ASCS+NPWT through post-operative day 3, and 4 wounds received mSTSG+ACSC+ traditional ASCS dressings. Cellular viability was characterized prior to spraying. Percent re-epithelialization, graft-adherence, pigmentation, elasticity, and blood perfusion and blood vessel density were assessed at multiple time points through 2 weeks.

RESULTS

All wounds healed within 14 days with minimal scar pathology and no significant differences in percent re-epithelialization between NPWT, and non-NPWT wounds were observed. Additionally, no differences were detected for pigmentation, perfusion, or blood vessel density. NPWT treated wounds had less graft loss and improved elasticity, with elasticity being statistically different.

CONCLUSIONS

These data suggest the positive attributes of the cellular suspension delivered are retained following the application of negative pressure. Re-epithelialization, revascularization, and repigmentation are not adversely impacted. The use of NPWT may be considered as an option when using ASCS with mSTSGs for the treatment of full-thickness burns.

Outcomes For Hand Burns Treated With Autologous Skin Cell Suspension In 20% Tbsa And Smaller Injuries

HYPOTHESIS

In order to address the confounder of TBSA on burn outcomes, we sought to analyze our experience with the use of autologous skin cell suspensions (ASCS) in a cohort of subjects with hand burns whose TBSA totaled 20% or less. We hypothesized that the use of ASCS in conjunction with 2:1 meshed autograft for the treatment of hand burn injuries would provide comparable outcomes to hand burns treated with sheet or minimally meshed autograft alone.

METHODS

A retrospective review was conducted for all deep partial and full thickness hand burns treated with split thickness autograft (STAG) at our urban verified burn center between April, 2018 to September, 2020. Exclusion criterion was a TBSA greater than 20%. The cohorts were those subjects treated with ASCS in combination with STAG (ASCS(+)) versus those treated with STAG alone (ASCS(-)). All ASCS(+) subjects were treated with 2:1 meshed STAG and ASCS overspray while all ASCS(-) subjects had 1:1, piecrust, or unmeshed sheet graft alone. Outcomes measured included demographics, time to wound closure, proportion returning to work (RTW), and length of time to RTW. Mann-Whitney U test was used for comparisons of continuous variables, and Fishers Exact test for categorical variables. Values are reported as medians and 25 th and 75 th interquartile ranges.

RESULTS

Fifty-one subjects fit the study criteria (ASCS(+) n=31, ASCS(-) n=20). The ASCS(+) group was significantly older than the ASCS(-) cohort (44 yrs [32, 54] vs 32 [27.5, 37], p=0.009) with larger %TBSA burns (15% [9.5, 17] vs 2% [1, 4], p <0.0001), and larger size hand burns (190 cm2 [120, 349.5] vs 126 cm2 [73.5, 182], p=0.015). Comparable results were seen between ASCS(+) and ASCS(-), respectively, for time to wound closure (9 days [7, 13] vs 11.5 [6.75, 14], p=0.63), proportion RTW (61% vs 70%, p=0.56), and days for RTW among those returning (35 [28.5, 57] vs 33 [20.25, 59], p=0.52). The ASCS(+) group had two graft infections with no reoperations, while ASCS(-) had one infection with one reoperation. No subjects in either group had a dermal substitute placed.

CONCLUSION

Despite being significantly older, having larger hand wounds, and larger overall wounds within the parameters of the study criteria, patients with 20% TBSA burns or smaller whose hand burns were treated with 2:1 mesh and ASCS overspray had comparable time to wound closure, proportion of returning to work, and time to return to work as subjects treated with 1:1 or pie-crust meshed STAG. Our group plans to follow this work with scar assessments for a more granular picture of pliability and reconstructive needs.

ASCs derived from burn patients are more prone to increased oxidative metabolism and reactive oxygen species upon passaging

Background

Patients with severe burn injury (over 20% of the total body surface area) experience profound hypermetabolism which significantly prolongs wound healing. Adipose-derived stem cells (ASCs) have been proposed as an attractive solution for treating burn wounds, including the potential for autologous ASC expansion. While subcutaneous adipocytes display an altered metabolic profile post-burn, it is not known if this is the case with the stem cells associated with the adipose tissue.

Methods

ASCs were isolated from discarded burn skin of severely injured human subjects (BH, n = 6) and unburned subcutaneous adipose tissue of patients undergoing elective abdominoplasty (UH, n = 6) and were analyzed at passages 2, 4, and 6. Flow cytometry was used to quantify ASC cell surface markers CD90, CD105, and CD73. Mitochondrial abundance and reactive oxygen species (ROS) production were determined with MitoTracker Green and MitoSOX Red, respectively, while JC-10 Mitochondrial Membrane Potential Assays were also performed. Mitochondrial respiration and glycolysis were analyzed with a high-resolution respirometer (Seahorse XFe24 Analyzer).

Results

There was no difference in age between BH and UH (34 ± 6 and 41 ± 4 years, respectively, P = 0.49). While passage 2 ASCs had lower ASC marker expression than subsequent passages, there were no significant differences in the expression between BH and UH ASCs. Similarly, no differences in mitochondrial abundance or membrane potential were found amongst passages or groups. Two-way ANOVA showed a significant effect (P < 0.01) of passaging on mitochondrial ROS production, with increased ROS in BH ASCs at later passages. Oxidative phosphorylation capacities (leak and maximal respiration) increased significantly in BH ASCs (P = 0.035) but not UH ASCs. On the contrary, basal glycolysis significantly decreased in BH ASCs (P = 0.011) with subsequent passaging, but not UH ASCs.

Conclusions

In conclusion, ASCs from burned individuals become increasingly oxidative and less glycolytic upon passaging when compared to ASCs from unburned patients. This increase in oxidative capacities was associated with ROS production in later passages. While the autologous expansion of ASCs holds great promise for treating burned patients with limited donor sites, the potential negative consequences of using them require further investigation.

Use of Autologous Skin Cell Suspension for the Treatment of Hand Burns: A Pilot Study

Purpose

Autologous skin cell suspension (ASCS) is a valid alternative and adjunct to split-thickness skin grafting (STSG) for treating burns. Limited data exists regarding the use of ASCS for hand burns. We hypothesized that using ASCS in hand burns shortens healing time with no difference in complications and less donor site morbidity.

Methods

This was a retrospective chart review of second- and third-degree hand burns treated at a level 1 Trauma and Burn Center from 2017 to 2019. Study groups included patients with hand burns treated with ASCS in combination with STSG and those treated with STSG alone. Outcomes included time to re-epithelialization, return to work, length of hospital stay, and complications including reoperation, graft failure, and infection.

Results

Fifty-nine patients aged 14 to 85 years (mean age 39 ± 15 years) met inclusion criteria. The ASCS treatment group comprised 37 patients; STSG comprised 22 patients. Mean follow-up time was 14 ± 7 months. The ASCS treatment group had a larger mean percent total body surface area (TBSA) (22% ± 14% vs 6% ± 8%; P < .05). There was no difference in time to wound re-epithelialization between both groups (ASCS, 11 ± 4 days vs STSG, 11 ± 5 days). Mean length-of-stay was 23 ± 13 days compared to 10 ± 13 days (P < .05) between the ASCS and STSG groups, respectively. No patients in the ASCS group required reoperation, whereas 2 patients in the STSG group required such for an infection-related graft loss and a web space contracture release. On multivariable analysis adjusting for TBSA, ASCS was associated with an earlier return to work (P < .05).

Conclusions

ASCS is safe and effective in treating hand burns. ASCS was associated with similar rates of re-epithelialization, earlier return to work, and no difference in complications compared with STSG.

Type of study/level of evidence: Therapeutic IV.

A Narrative Review of the History of Skin Grafting in Burn Care

Thermal injuries have been a phenomenon intertwined with the human condition since the dawn of our species. Autologous skin translocation, also known as skin grafting, has played an important role in burn wound management and has a rich history of its own. In fact, some of the oldest known medical texts describe ancient methods of skin translocation. In this article, we examine how skin grafting has evolved from its origins of necessity in the ancient world to the well-calibrated tool utilized in modern medicine. The popularity of skin grafting has ebbed and flowed multiple times throughout history, often suppressed for cultural, religious, pseudo-scientific, or anecdotal reasons. It was not until the 1800s, that skin grafting was widely accepted as a safe and effective treatment for wound management, and shortly thereafter for burn injuries. In the nineteenth and twentieth centuries skin grafting advanced considerably, accelerated by exponential medical progress and the occurrence of man-made disasters and global warfare. The introduction of surgical instruments specifically designed for skin grafting gave surgeons more control over the depth and consistency of harvested tissues, vastly improving outcomes. The invention of powered surgical instruments, such as the electric dermatome, reduced technical barriers for many surgeons, allowing the practice of skin grafting to be extended ubiquitously from a small group of technically gifted reconstructive surgeons to nearly all interested sub-specialists. The subsequent development of biologic and synthetic skin substitutes have been spurred onward by the clinical challenges unique to burn care: recurrent graft failure, microbial wound colonization, and limited donor site availability. These improvements have laid the framework for more advanced forms of tissue engineering including micrografts, cultured skin grafts, aerosolized skin cell application, and stem-cell impregnated dermal matrices. In this article, we will explore the convoluted journey that modern skin grafting has taken and potential future directions the procedure may yet go.

Historical Evolution of Skin Grafting-A Journey through Time

Autologous skin grafting was developed more than 3500 years ago. Several approaches and techniques have been discovered and established in burn care since then. Great achievements were made during the 19th and 20th century. Many of these techniques are still part of the surgical burn care. Today, autologous skin grafting is still considered to be the gold standard for burn wound coverage. The present paper gives an overview about the evolution of skin grafting and its usage in burn care nowadays.

Split-thickness skin graft donor-site morbidity: A systematic literature review

The purpose of this systematic literature review is to critically evaluate split-thickness skin graft (STSG) donor-site morbidities. The search of peer-reviewed articles in three databases from January 2009 to July 2019 identified 4271 English-language publications reporting STSG donor-site clinical outcomes, complications, or quality of life. Of these studies, 77 met inclusion criteria for analysis. Mean time to donor-site epithelialization ranged from 4.7 to 35.0 days. Mean pain scores (0-10 scale) ranged from 1.24 to 6.38 on postoperative Day 3. Mean scar scores (0-13 scale) ranged from 0 to 10.9 at Year 1. One study reported 28% of patients had donor-site scar hypertrophy at 8 years. Infection rates were generally low but ranged from 0 to 56%. Less frequently reported outcomes included pruritus, wound exudation, and esthetic dissatisfaction. Donor-site wounds underwent days of wound care and were frequently associated with pain and scarring. Widespread variations were noted in STSG donor-site outcomes likely due to inconsistencies in the definition of outcomes and utilization of various assessment tools. Understanding the true burden of donor sites may drive innovative treatments that would reduce the use of STSGs and address the associated morbidities.

Biologics in Acute Burn Injury

There have been significant advances in the care of burns over the past decade. As a result of the improved survival of burn patients, attention has shifted to the optimized management of their wounds. Traditionally, autografts have been described as the gold standard treatment in cases of deep second- and third-degree burn wounds; however, they are limited especially in large surface area burns. As such, advancements have been made in the development of biologic dressings, which attempt to mimic the function of the lost epidermis and/or dermis. The ideal biologic dressing is nontoxic, lacks antigenicity, is immunologically compatible, and is sterile. Additionally, easy storage conditions, long shelf lives, and reasonable costs are key determinants of whether biologic dressings may truly be widely used in the clinical setting. Biologic dressings serve an important role as skin substitutes in the setting of acute burn injury. This review aims to summarize the multitude of available biologic dressings and their applications. METHODS: The PubMed and Google Scholar databases were searched for the following terms either alone or in combination: "burn injury," "biologic membrane," "skin substitutes," "biosynthetic dressings," and "acellular membrane."

The Pediatric Burn: Current Trends and Future Directions

Management of the pediatric burn patient presents a variety of clinical challenges for the pediatric anesthesiologist. Despite the high incidence of burn injuries, standard management strategies are far from universal. The complex physiologic changes presented by burn injuries present airway management and resuscitation challenges and mandate careful consideration of adequate nutritional support. Long hospital stays with frequent operations and dressing changes necessitate creative approaches to anxiolysis and pain control. Underutilized modalities warranting further research include regional anesthesia and nonpharmacologic approaches, such as virtual reality. Further research and collaboration between burn centers are needed to standardize care for this population.

Pediatric burn resuscitation, management, and recovery for the pediatric anesthesiologist

PURPOSE OF REVIEW

The purpose of this article is to summarize literature in pediatric burn resuscitation and management that is relevant to the pediatric anesthesiologist. The scope of the literature is expanding as long-term survival in even the most critically ill, burn-injured children has increased.

RECENT FINDINGS

Longstanding variations in the care of burn-injured children exist despite decades of experience in burn care management. There seems to be a discomfort outside major burn centers in the triage, evaluation, and assessment of burned children. This is evidenced by the prevalence of 'unnecessary intubations', continued overestimation of total body surface area injured, and subsequent fluid administration disproportionate to injury leading to over-resuscitation. Techniques, such as virtual reality and regional anesthesia are increasingly available and serve adjuncts to pharmacologic therapies for anxiolysis and analgesia. Such techniques reduce opioid utilization while maintaining patient comfort and satisfaction particularly during wound dressing changes. Questions about transfusion threshold and ratio of blood products remain topics of ongoing research.

SUMMARY

Literature review continues to reveal underpowered or retrospective analyses of these very important questions. Public health burden caused by burns warrants rigorous, prospective studies to take the best care of these patients and portend the best long-term outcomes. Collaboration amongst pediatric anesthesiologists who care for these children is necessary to develop and execute powered studies to answer important questions.