Epidermal micrografts produced via an automated and minimally invasive tool form at the dermal/epidermal junction and contain proliferative cells that secrete wound healing growth factors

FastSkin® Concept: A Novel Treatment for Complex Acute and Chronic Wound Management

Successful treatments for acute and chronic skin wounds remain challenging. The goal of this proof-of-concept study was to assess the technical feasibility and safety of a novel wound treatment solution, FastSkin®, in a pig model. FastSkin® was prepared from skin micrografts patterned in blood using acoustic waves. Upon coagulation, the graft was transferred on a silicone sheet and placed on wounds. Six full-thickness wounds were created at the back of two pigs and treated with either FastSkin®, split-thickness skin graft (positive control), a gauze coverage (negative control, NC1), or blood patterned without micrografts (negative control, NC2). Silicone sheets were removed after 7, 14, and 21 days. Wound healing was monitored for six weeks and evaluated macroscopically for re-epithelialization and morphometrically for residual wound area and wound contraction. Tissue regeneration was assessed with histology after six weeks. Re-epithelialization was faster in wounds covered with FastSkin® treatments compared to NC2 and in NC2 compared to NC1. Importantly, an enhanced collagen organization was observed in FastSkin® in contrast to NC treatments. In summary, two clinically approved skin wound treatments, namely micrografting and blood clot graft, were successfully merged with sound-induced patterning of micrografts to produce an autologous, simple, and biologically active wound treatment concept.

Evaluating the Application Potential of a Recombinant Ganoderma Protein as Bioactive Ingredients in Cosmetics

The aim of this study was to evaluate the application potential of a recombinant fungal immunomodulatory protein from Ganoderma lucidum (rFIP-glu). First, a recombinant plasmid pPIC9K::FIP-glu-His was transferred into Pichia pastoris for the production of protein. The protein was then to assess its free radical scavenging abilities and the effect on the viability of both human immortalized keratinocytes (HaCaT cells) and mouse B16-F10 melanoma cells (B16 cells) in vitro, followed by the effect on the melanin synthesis of B16 cells. The results of SDS-PAGE and western blot showed that rFIP-glu was successfully expressed. Furtherly, a bioactivity assay in vitro indicated that the scavenging rate of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals reached 84.5% at 6.0 mg/mL (p ≤ 0.0001) of rFIP-glu, showing strong antioxidant activity. Subsequently, a safety evaluation demonstrated that rFIP-glu promoted the proliferation of HaCaT cells, with the cell viability reaching 124.3% at 48 μg/mL (p ≤ 0.01), regarding the cell viability of B16 cells after exposure to rFIP-glu (48 μg/mL) significantly inhibited, to 80.7% (p ≤ 0.01). Besides, rFIP-glu inhibited the melanin synthesis of B16 cells in a dose-dependent manner from 100–1000 μg/mL, and rFIP-glu at 500 μg/mL (p ≤ 0.01) exhibited the highest intracellular melanin amount reduction of 16.8%. Furthermore, a mechanism analysis showed that rFIP-glu inhibited tyrosinase (TYR) activity by up-regulating the expression of the microphthalmia-associated transcription factor (MITF) and down-regulating the gene expression of TYR and tyrosinase-related protein-1 (TYRP-1), thus inhibiting melanin synthesis. The data implied that rFIP-glu had significant antioxidant activity and whitening potency. It should be used as raw materials for cosmeceutical applications.

Comparative study of the efficacy and safety of two grafting procedures (an automated epidermal harvesting system and non-cultured epidermal cell suspension) in the treatment of stable vitiligo

Background

The non-cultured epidermal cell suspension method is a well-established but tedious grafting modality in the management of stable vitiligo. Recently a more user-friendly automated epidermal harvesting system has been introduced.

Aim

This was a pilot study to compare the efficacy and safety outcomes of the above two grafting procedures.

Study design

The study was a single-blinded split-body randomised controlled trial. After scientific and ethical clearance, the trial was registered with CTRI (CTRI/2018/05/014225). Thirty consenting patients of stable vitiligo with 60 near-symmetrical patches were recruited. Block randomisation was done using computer-generated randomisation software and each patch was allocated either of the two grafting modalities. Efficacy was assessed by the Physician Global Assessment Scale on serial images and pain by the Numerical Rating Pain Scale.

Results and conclusion

The non-cultured epidermal cell suspension was found to be an overall statistically superior technique to the automated epidermal harvesting system in terms of efficacy (re-pigmentation). Both donor and recipient site complications were significantly less with the automated epidermal harvesting system grafting and this method had the distinct advantage of being a painless and easy technique with minimal recovery time. A novel observation was that a good colour match and near-complete re-pigmentation occurred in patients with a darker skin colour with both techniques.

Limitations

The main limitation of our study was the small sample size. Also, the size of the treated patches was limited such that they could be covered by the 5 × 5 cm size of the automated epidermal harvesting system blade. However, a larger area can be covered with multiple sessions.

Skin grafting treatment of adolescent lower limb avulsion injury

Background

Under the influence of various factors, the number of lower extremity avulsion injuries in adolescents is increasing year by year. The main modality of treatment is skin grafting. There are many types of skin grafting. Although many studies on skin grafting after avulsion injuries have been published in the past few decades, there are differences in the treatment options for adolescents with post avulsion injuries.

Main body

Thorough debridement and appropriate skin grafts are essential for the surgical management of avulsion injuries for optimal prognosis. In the acquisition of grafts, progress has been made in equipment for how to obtain different depths of skin. The severity of the avulsion injury varies among patients on admission, and therefore the manner and type of skin grafting will vary. Especially in adolescents, graft survival and functional recovery are of great concern to both patients and physicians. Therefore, many efforts have been made to improve survival rate and activity.

Conclusion

This review summarizes the principles of treatment of avulsion injuries, the historical development of skin grafts, and the selection of skin grafts, hoping to be helpful for future research.

Self-assembly of tessellated tissue sheets by expansion and collision

Tissues do not exist in isolation—they interact with other tissues within and across organs. While cell-cell interactions have been intensely investigated, less is known about tissue-tissue interactions. Here, we studied collisions between monolayer tissues with different geometries, cell densities, and cell types. First, we determine rules for tissue shape changes during binary collisions and describe complex cell migration at tri-tissue boundaries. Next, we propose that genetically identical tissues displace each other based on pressure gradients, which are directly linked to gradients in cell density. We present a physical model of tissue interactions that allows us to estimate the bulk modulus of the tissues from collision dynamics. Finally, we introduce TissEllate, a design tool for self-assembling complex tessellations from arrays of many tissues, and we use cell sheet engineering techniques to transfer these composite tissues like cellular films. Overall, our work provides insight into the mechanics of tissue collisions, harnessing them to engineer tissue composites as designable living materials.

Tissue boundaries in our body separate organs and enable healing, but boundary mechanics are not well known. Here, the authors define mechanical rules for colliding cell monolayers and use these rules to make complex, predictable tessellations.

The use of autologous epidermal grafts for diabetic foot ulcer emergencies: A clinical study

BACKGROUND

There are various surgical and invasive treatment systems such as conservative skin grafts and autologous epider-mal grafting (AEG) for diabetic foot ulcers. This study aims to evaluate the feasibility of using a novel epidermal graft harvesting system in diabetic foot ulcer emergencies.

METHODS

A retrospective clinical study was conducted with 15 diabetic foot ulcer patients, and after written and signed consent forms were taken, AEG system was applied to all patients. All of the clinical data of the patients such as their American Society of Anesthesiologists (ASA) Physical Status Classification System scores, size of pre-application wound area (cm2), time to complete re-epithelization of the wound, pain scores using the visual analog scale (VAS) for both donor and recipient sites, changes in size of wound, complete dermal response time, and patients' demographics, comorbidities were recorded. The age, gender, pre-post appli-cation wound area (cm2), time of healing, ASA, and VAS variables were compared each other and analyzed statistically. P<0.05 was considered as statistically significant.

RESULTS

The mean of time for complete wound healing was 5.9 (range 4-8) weeks. There was no statistically difference between recipient wound size and patient's age; size of both types of wounds (cm2) and time (weeks) for complete reduction for both types of wounds; and time to complete both types of wound healing and gender (p=0.509, 0.788, and 0.233, respectively). ASA scores did not impact the time required for complete healing of the wound (p=0.749).

CONCLUSION

The current study has tried to evaluate the efficacy of the AEG system in a homogenous population with diabetic foot ulcers. An epidermal harvesting system may be used effectively and safely in patients with diabetic foot ulcer emergencies.

To compare the efficacy and safety of autologous non-cultured non-trypsinized keratinocyte and melanocyte grafting (Jodhpur technique) with autologous platelet-rich fibrin matrix (PRFM) in the treatment of chronic non-healing ulcer

Background:

Aims:

Materials and Methods:

Statistical Analysis:

Results:

Conclusion:

Efficacy and safety of automated epidermal micrograft in patients with stable segmental and nonsegmental vitiligo

Vitiligo is a common, psychologically devastating pigmentary disorder. Surgical graftings are used to treat stable vitiligo when medical treatment fails. An automated epidermal micrograft harvesting (AEMH) system was first designated to treat wounds, and very few studies investigated the application of AEMH in vitiligo. In this study, we investigated the efficacy and safety of the AEMH system in patients with stable segmental and nonsegmental vitiligo. The rate of repigmentation and adverse events was recorded bimonthly for at least 12 months. We analyzed the efficacy based on patient characteristics, vitiligo subtypes, and different anatomical locations. A total of 56 depigmented lesions from 34 patients were included. 95.50% of the automated epidermal micrografts were successfully grafted at the recipient sites. There was a significant improvement in Vitiligo Area Scoring Index (VASI) and Dermatologic Life Quality Index (DLQI) in patients treated with AEMH (p < 0.001). The rate of repigmentation by VASI score improves from 96.25 ± 8.59 to 48.30 ± 28.16 after the treatment (p < 0.001). Treatment outcomes were comparable between the patients of segmental and stable nonsegmental vitiligo. The face and neck region achieved a better outcome, followed by the trunk (chest, abdomen, back, and axilla), limbs, and the worse outcome was found in the acral region (p < 0.014). Conclusively, AEMH is an effective treatment procedure with limited adverse events in patients with stable vitiligo. This harvesting method may be a feasible option for vitiligo surgical treatment.

The Importance of Mimicking Dermal-Epidermal Junction for Skin Tissue Engineering: A Review

There is a distinct boundary between the dermis and epidermis in the human skin called the basement membrane, a dense collagen network that creates undulations of the dermal-epidermal junction (DEJ). The DEJ plays multiple roles in skin homeostasis and function, namely, enhancing the adhesion and physical interlock of the layers, creating niches for epidermal stem cells, regulating the cellular microenvironment, and providing a physical boundary layer between fibroblasts and keratinocytes. However, the primary role of the DEJ has been determined as skin integrity; there are still aspects of it that are poorly investigated. Tissue engineering (TE) has evolved promising skin regeneration strategies and already developed TE scaffolds for clinical use. However, the currently available skin TE equivalents neglect to replicate the DEJ anatomical structures. The emergent ability to produce increasingly complex scaffolds for skin TE will enable the development of closer physical and physiological mimics to natural skin; it also allows researchers to study the DEJ effect on cell function. Few studies have created patterned substrates that could mimic the human DEJ to explore their significance. Here, we first review the DEJ roles and then critically discuss the TE strategies to create the DEJ undulating structure and their effects. New approaches in this field could be instrumental for improving bioengineered skin substitutes, creating 3D engineered skin, identifying pathological mechanisms, and producing and screening drugs.

Quantitative Outcome Assessment of Color Match and the Extent of Repigmentation after Pixel Array Epidermal Grafting for Head and Neck Stable Vitiligo: A Prospective Cohort Study

BACKGROUND

Epidermal grafting with an automatic harvesting system has been reported as a simple and efficacious procedure for stable vitiligo. However, no prospective cohort study has quantitatively evaluated the color matching and extent of repigmentation in the head and neck area by this method.

OBJECTIVE

To evaluate the color matching and extent of repigmentation after pixel array epidermal grafting by image analysis software and physicians' naked eye.

METHODS

Ten Asian patients with head and neck vitiligo lesions stable for at least 6 months were treated with pixel array epidermal grafting with an automatic harvesting system and post-grafting phototherapy. The patients were evaluated 1, 3, and 6 months post grafting for the percentage of repigmentation by blinded physicians' assessment and image analysis software. The color matching index of repigmentation was evaluated by measuring the melanin index in the grafted area and the juxta non-vitiliginous area.

RESULTS

The average blister harvest time was 46.3 ± 9.7 min. The area percentile of repigmentation by the image analysis software were 32.3 ± 26.8, 64.6 ± 29.4, and 76.5 ± 25.9 at 1, 3, and 6 months post grafting, respectively. There were no significant differences between the physicians' assessments and the results from the image analysis software. The change in the area percentile of repigmentation between 3 and 6 months post grafting was only statistically significant using image analysis software. The grafted area achieved a color match of 83.1 ± 13.4% that of the juxta non-vitiliginous area 6 months after grafting. Three patients had repigmentation of leukotrichia.

CONCLUSION

By quantitative measurement, uniform pixel array micrografts provide a very good extent of repigmentation and color match in the head and neck area. Image analysis software revealed a steady increase in repigmentation after POM3 until POM6, which was not detected by subjective assessment.

Immune tolerance of allogeneic haematopoietic cell transplantation supports donor epidermal grafting of recessive dystrophic epidermolysis bullosa chronic wounds

BACKGROUND

Chronic wounds, a common morbidity in recessive dystrophic epidermolysis bullosa (RDEB), lack definitive therapies.

OBJECTIVES

To assess allogeneic epidermal skin grafts in terms of wound healing and durability over time.

METHODS

In a prospective, open-label clinical trial for postallogeneic haematopoietic cell transplantation (post-alloHCT) patients with RDEB, up to nine chronic wounds per patient were grafted over 1 year. Epidermal grafts measuring 5 cm² were obtained from related alloHCT donors in the outpatient setting using the CELLUTOME^TM Epidermal Harvesting System. Wounds were photographed and symptom inventories completed at baseline and 6, 12 and 52 weeks after grafting. The trial was registered at ClinicalTrials.gov (NCT02670837).

RESULTS

Between August 2016 and January 2019, eight patients with RDEB received a total of 35 epidermal allografts at a median of 1157 days (range 548-2884) post-alloHCT. The median (interquartile range) percentage reductions in wound surface area were 75% (52-94), 95% (72-100) and 100% (97-100) at 6, 12 and 52 weeks postgraft, respectively, each significantly reduced from baseline (P < 0·001). Donor harvest sites healed quickly without scarring. Biopsy evaluation at 1 year of an epidermal allograft site revealed wildtype type VII collagen (immunofluorescence), anchoring fibrils (electron microscopy), and full-thickness skin whole-DNA donor chimerism of 42% (compared with 16% in concurrently biopsied native skin). This strategy subsequently supported release of RDEB pseudosyndactyly.

CONCLUSIONS

The immune tolerance established by alloHCT supports successful adoptive transfer of donor epidermal grafts. Persistence of donor grafts in a single patient beyond 1 year and observed migration of donor-grafted cells into adjacent wound suggest that epidermal allografts include nonterminally differentiated cells and/or trigger recruitment of donor bone-marrow-derived cells to mediate wound healing.

Clinical observation on therapeutic effect of filiform fire needle for vitiligo: A retrospective study

Vitiligo is a common and refractory disease worldwide. The limited efficiency and side effects of the conventional treatment options create demands towards the development of strategies. Excellent repigmentation is demonstrated after several filiform fire needle sessions in the vitiligo lesions. In this observational study, we aimed to observe the response to filiform fire needle therapy in patients with vitiligo, and determine whether there was a difference of efficiency with respect to the type, affected site, and disease duration of vitiligo. Patients received filiform fire needle therapy once every 2 weeks for 12 consecutive weeks. The results of the 77 vitiligo patients were: 34 (44.15%) with an excellent repigmentation rate, 15 (19.48%) with a marked improvement, 15 (19.48%) with a moderate response, 6 (7.79%) with a slight improvement, and 7 (9.09%) with an absent response. Among the vitiligo patients with different affected sites, the most effective location of therapy was the face. Shorter course leads to better therapeutic effect. Two patients developed hypertrophic scars on the lesion site. In conclusion, this study shows filiform fire needle therapy is an effective and relatively safe therapeutic option for vitiligo.

Comparative study on the donor site aesthetic outcome between epidermal graft and split-thickness skin graft

Donor site aesthetic outcomes of epidermal graft (EG) vs split-thickness skin graft (SSG) have yet to be objectively compared. Here, we evaluate donor site healing using a validated scar assessment tool and digital colorimetric technique, which compares colour in a consistent and objective manner. Ten patients (SSG (n = 5) and EG (n = 5)) were included. Donor site scarring was evaluated using the Vancouver Scar Scale (VSS) at Week 6 and Month 3. Colorimetric measurement was performed at Weeks 3 and 6 and Month 3. The mean donor site healing time for EG was significantly shorter (EG: 4.6 days (95% c.i. 3.8-5.3), SSG: 16.8 days (95% c.i. 13.3-20.1) (P = 0.003)). The VSS scores of the EG donor site were lower at Week 6 and Month 3(P < 0.001). The colour match between the donor site and surrounding skin for EG was better compared with SSG at all time points and was almost identical to their surrounding healthy skin at Month 3. This study is the first to objectively measure the clinical appearance of the EG donor site against SSG. EG donor site has faster healing with excellent scarring and good colour match with its surrounding normal skin at all time points compared with SSG.

Use of Cellutome for the healing of venous or mixed ulcers

Venous or mixed ulcers are common and invalidating. Cutaneous transplants may be necessary if conventional treatment is ineffective. We evaluated the performance of Cellutome in promoting the healing of venous or mixed ulcers 2 months after grafting. This was a retrospective, multi-centric, descriptive study of patients who had a venous or mixed ulcer for at least several months and who received an autologous skin graft using the Cellutome system at least 2 months before. The principle evaluation criterion was the state of the wound after 2 months (completely healed vs not healed). The secondary evaluation criterion was the percentage of wound healing after 2 months. A total of 47 patients were included in the study. The ulcers had evolved over an average of 18 months. The average surface area was 13.37 cm² . After 2 months, the grafts of 26 of 47 patients (55.3%) were completely healed. The grafts of 21 patients (44.6%) were not completely healed but showed an average rate of healing of 51%. Use of the Cellutome system for epidermal transplants promoted complete or improved healing after 2 months for 55.3% of patients with chronic venous or mixed ulcers. The limited data on the rate of healing of conventional transplants in the literature report rates of approximately 50%. The Cellutome system may therefore be of interest as the healing rate is similar to that of conventional techniques, but using a much simpler, painless procedure on an outpatient basis.

Use of epidermal skin grafts in chronic wounds: a case series

In stalled, chronic wounds, more aggressive and proactive wound closure efforts are needed. We describe adjunctive use of epidermal grafting in patients with chronic wounds. Wound bed preparation consisted of surgical necrotectomy or sharp debridement, hyperbaric oxygen therapy, negative pressure wound therapy, compression therapy, platelet-rich plasma therapy and/or heparan sulphate agents. Epidermal grafts were harvested from the patient's thigh and applied to the wound. Wound and donor site healing was monitored. A total of 78 patients (average age = 64·1 ± 15·6 years) were included in the study. Common comorbidities included hypertension (47·4%), venous insufficiency (37·2%) and obesity (28·2%). Average wound duration was 13·2 months (range: 0·3-180 months). The most common wound types were dehiscence (29·5%), radiation ulcer (24·4%) and venous ulcer (17·9%). Total time from epidermal grafting to wound closure was 10·0 ± 7·3 weeks. Of the 78 wounds, 66 (84·6%) reached full wound closure (49 < 3 months, 16 > 3 months, 1 without time data). Of 78 wounds, 10 (12·8%) underwent partial wound healing, while 2 wounds (2/78; 2·6%) remained unhealed. These results suggest that wound surface reduction can be achieved by proactive early application of biological therapies and epidermal skin grafts, which may help decrease time to wound healing.

Treatment of standardised wounds with pure epidermal micrografts generated with an automated device

In this study, we analysed the effects of pure epidermal micrografts generated with an automated device in a standardised human wound model. Epidermal micrografts were harvested using an automated device. Micrografts were then transplanted onto split-skin donor sites. The target area was only partially covered with transplants to create an intra-individual control area. Wounds were evaluated by subjective assessment as well as measurements with combined laser and white light spectroscopy and cutometry. The epidermal graft sites remained completely stable, whereas control sites offered partially unstable and blistering areas. Statistically, no measurable difference in the speed of initial reepithelialisation could be shown. However, there was an increased pliability and softness of the treated areas that correlated with the subjective impression of both investigators and patients. There was a significantly higher relative haemoglobin concentration, measurable in treated and untreated areas at 4 weeks and 6 months. Cutometry showed no differences in skin properties between treated and untreated areas. This study shows an effect of epidermal micrografts in a standardised human wound model and supports the positive impact of keratinocytes on early wound healing as described in literature. Long-term effects of epidermal grafting deserve further studies.

An Automated and Minimally Invasive Tool for Generating Autologous Viable Epidermal Micrografts

OBJECTIVE:

A new epidermal harvesting tool (CelluTome; Kinetic Concepts, Inc, San Antonio, Texas) created epidermal micrografts with minimal donor site damage, increased expansion ratios, and did not require the use of an operating room. The tool, which applies both heat and suction concurrently to normal skin, was used to produce epidermal micrografts that were assessed for uniform viability, donor-site healing, and discomfort during and after the epidermal harvesting procedure.

DESIGN:

This study was a prospective, noncomparative institutional review board–approved healthy human study to assess epidermal graft viability, donor-site morbidity, and patient experience.

SETTING:

These studies were conducted at the multispecialty research facility, Clinical Trials of Texas, Inc, San Antonio.

PATIENTS:

The participants were 15 healthy human volunteers.

RESULTS:

The average viability of epidermal micrografts was 99.5%. Skin assessment determined that 76% to 100% of the area of all donor sites was the same in appearance as the surrounding skin within 14 days after epidermal harvest. A mean pain of 1.3 (on a scale of 1 to 5) was reported throughout the harvesting process.

CONCLUSIONS:

Use of this automated, minimally invasive harvesting system provided a simple, low-cost method of producing uniformly viable autologous epidermal micrografts with minimal patient discomfort and superficial donor-site wound healing within 2 weeks.

Epidermal grafting for wound healing: a review on the harvesting systems, the ultrastructure of the graft and the mechanism of wound healing

Epidermal grafting for wound healing involves the transfer of the epidermis from a healthy location to cover a wound. The structural difference of the epidermal graft in comparison to the split-thickness skin graft and full-thickness skin graft contributes to the mechanism of effect. While skin grafting is an epidermal transfer, little is known about the precise mechanism of wound healing by epidermal graft. This paper aims to explore the evolution of the epidermal graft harvesting system over the last five decades, the structural advantages of epidermal graft for wound healing and the current hypotheses on the mechanism of wound healing by epidermal graft. Three mechanisms are proposed: keratinocyte activation, growth factor secretion and reepithelialisation from the wound edge. We evaluate and explain how these processes work and integrate to promote wound healing based on the current in vivo and in vitro evidence. We also review the ongoing clinical trials evaluating the efficacy of epidermal graft for wound healing. The epidermal graft is a promising alternative to the more invasive conventional surgical techniques as it is simple, less expensive and reduces the surgical burden for patients in need of wound coverage.

Clinical and Economic Benefits of Autologous Epidermal Grafting

Chronic wounds are an increasingly prevalent disease with a significant healthcare burden. These wounds often do not respond to standard of care therapy alone, requiring the use of adjuvant therapies. Epidermal grafting, previously utilized primarily for correction of leukoderma, is increasingly being recognized as a beneficial therapy for wounds, both acute and chronic. Epidermal grafting has been shown to be effective in the management of chronic wounds, with successful healing in refractory patients. It has not only been shown to be effective, but it is also associated with lower cost and morbidity than traditional skin grafting techniques as well as improved donor site healing. Through the use of a novel epidermal harvesting system, the CelluTome™ Epidermal Harvesting System (KCI, an Acelity company, San Antonio, TX), this treatment modality has become more standardized, reproducible, and easy to use as well as less time consuming, making its use in the clinical setting more convenient and beneficial. Epidermal grafting, therefore, represents a promising, efficacious, and cost-effective option for treatment of refractory non-healing wounds.

A Case Series of Complex Recalcitrant Wounds Treated with Epidermal Grafts Harvested from an Automated Device

Introduction: Epidermal grafting has several advantages over full-thickness or split-thickness grafts in the treatment of complex non-healing wounds. These include the low risk of donor site complications, minimal patient discomfort, and abstention from the operating room. Traditionally, the lack of reliable epidermal harvesting techniques has limited its clinical utilization. The development of an automated suction blister epidermal graft (SBEG) harvesting device may facilitate clinical utilization of this technique. The authors present a case series of multimorbid patients who were poor surgical candidates and were treated with this technique.

Methods: A retrospective review of all patients treated with CelluTome™​ Epidermal Harvesting System (KCI, an Acelity company, San Antonio, TX) prior to May 2016 at our institution was conducted.

Results: A total of 12 patients underwent 14 epidermal grafting procedures. Multiple comorbidities were identified, including smoking (33%), immunosuppression by immunotherapy or steroids (25%), chronic venous insufficiency (25%), diabetes mellitus (25%), malignancy (25%), polysubstance abuse (17%), HIV/AIDS (17%), and peripheral artery disease (8%). Among the two acute wounds (≤ 3 months) and 10 chronic wounds, the average wound size was 49.1 cm² (± 77.6 cm²) and the median wound duration was 5.7 months (interquartile range: 4.1 - 15.8 months) before SBEG was attempted. These complex wounds had failed prior therapies, such as local wound care (100%), incision and drainage (58%), vacuum-assisted closure (33%), split-thickness skin graft (16%), and hyperbaric oxygen (8%). Following the procedure, all donor sites healed within one week. Three patients were lost to follow-up. Of the remaining nine patients, four patients had complete resolution of their wounds at a median follow-up of 13.1 weeks (interquartile range: 6.8-17.3 weeks). Among those with partial resolutions, the average wound size was 4.2 cm² (± 2.1 cm²) with an average wound reduction of 79% (± 23%). No donor or recipient site complications were observed.

Conclusions: The automated SBEG harvesting device is an effective and safe option for treating complex non-healing wounds in multimorbid patients who may be poor surgical candidates. This procedure demonstrates minimal contraindications to its use and donor or recipient site complications.

Epidermal skin grafting

Autologous skin grafts, such as full- and split-thickness, have long been part of the reconstructive ladder as an option to close skin defects. Although they are effective in providing coverage, they require the need for a trained surgeon, use of anaesthesia and operating room and creation of a wound at the donor site. These drawbacks can be overcome with the use of epidermal skin grafts (ESGs), which can be harvested without the use of anaesthesia in an office setting and with minimal to no scarring at the donor site. ESGs consist only of the epidermal layer and have emerged as an appealing alternative to other autologous grafts for the treatment of acute and chronic wounds. In this article, we provide an overview of epidermal grafting and its role in wound management.

Epidermal skin grafting in vitiligo: a pilot study

Vitiligo is a multifactorial acquired dermatosis characterised by achromic or hypochromic macules and by the absence of functioning melanocytes. Treatment depends on the extent of the affected areas and on disease activity. Surgical techniques have proven to be effective in stable cases but can be time-consuming and, in some cases, aesthetically unsatisfying or painful for the patients. The aim of the study was to assess the clinical safety and effectiveness of a new automatic epidermal skin harvesting device in patients with stable localised vitiligo over a minimum 12-month period. This new system (CELLUTOME™ Epidermal Harvesting System, KCI, an ACELITY Company, San Antonio, TX) is a commercially available epidermal skin harvesting system that can be used without local anaesthesia or other pre-treatments and has been shown to have low rates of donor site morbidity. Epidermal skin grafts can used in patients with acute and hard to heal chronic wounds, burns and stable vitiligo. The use of advanced therapies may improve the quality of life, have cost benefits and accelerate re-pigmentation of patients with vitiligo. In our preliminary study, this system was seen to be a safe and efficacious means of harvesting epidermal micrografts containing melanocytes for use in patients with stable vitiligo unresponsive to standard therapies.

Epidermal skin grafting in patients with complex wounds: a case series

OBJECTIVE

Complex wounds are often difficult to close and sometimes require a split-thickness skin graft (STSG). However, epidermal skin grafts, which contain only an epidermal layer of skin, are a viable option for wound coverage in these challenging wounds. We report our experience using an automated epidermal harvesting tool to harvest epidermal skin grafts for the treatment of complex wounds.

METHOD

Epidermal skin grafts were harvested from the patient's thigh, which was first washed with isopropyl alcohol. After harvesting, they were transferred to the recipient site using a film dressing. A bolster dressing using gauze and a self-adherent wrap held the grafts in place.

RESULTS

We selected 34 patients with wounds that had been present from several weeks to over a year. Prior treatments, included skin substitutes, alginate dressings, Unna Boot, and collagen dressings. There were 17 female and 17 male patients with a mean age of 67.1 years (range: 37-103). Wound types were: traumatic wounds, diabetic foot ulcers, venous stasis ulcers, pressure ulcers, and surgical wounds. Patient comorbidities included hypertension, diabetes, congestive heart failure, and osteoarthritis. Mean epithelialisation rate at the recipient site was 7.0 weeks (range: 1-35 weeks). Wound complications included drainage, hypergranulation, and oedema. At follow-up 82.4% (28/34) of wounds were healed, 2.9% (1/34) wounds showed improved healing, 11.8% (4/34) of wounds did not heal, and 2.9% (1/34) were lost to follow-up. All donor sites healed without complications.

CONCLUSION

In our cohort, use of epidermal skin grafts in conjunction with bolster dressings resulted in full closure or wound improvement of a majority of patients. Epidermal grafting provides another treatment option to physicians when only the epidermal layer is needed.

DECLARATION OF INTEREST

Dr. Bhatia is a consultant for KCI, an Acelity company.

Epidermal grafting versus split-thickness skin grafting for wound healing (EPIGRAAFT): study protocol for a randomised controlled trial

Background

Split-thickness skin grafting (SSG) is an important modality for wound closure. However, the donor site becomes a second, often painful wound, which may take more time to heal than the graft site itself and holds the risk of infection and scarring. Epidermal grafting (EG) is an alternative method of autologous skin grafting that harvests only the epidermal layer of the skin by applying continuous negative pressure on the normal skin to raise blisters. This procedure has minimal donor site morbidity and is relatively pain-free, allowing autologous skin grafting in an outpatient setting. We plan to compare EG to SSG and to further investigate the cellular mechanism by which each technique achieves wound healing.

Methods/design

EPIGRAAFT is a multicentre, randomised, controlled trial that compares the efficacy and wound-healing mechanism of EG with SSG for wound healing. The primary outcome measures are the proportion of wounds healed in 6 weeks and the donor site healing time. The secondary outcome measures include the mean time for complete wound healing, pain score, patient satisfaction, health care utilisation, cost analysis, and incidence of adverse events.

Discussion

This study is expected to define the efficacy of EG and promote further understanding of the mechanism of wound healing by EG compared to SSG. The results of this study can be used to inform the current best practise for wound care.

Trial registration

Clinicaltrials.gov identifier, NCT02535481. Registered on 11 August 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1352-y) contains supplementary material, which is available to authorized users.

Epidermal Grafting for Chronic Complex Wounds in India: A Case Series

BACKGROUND : In India, the high cost of medical treatments and limited resources can deter patients from receiving available care, leading to the development of chronic wounds. We evaluated the use of epidermal grafting in patients with complex, long-term chronic wounds.

METHODS

Eighteen patients with complex wounds were treated with epidermal micrografts between September 2014 and March 2015 at a state-run, community health center in Mahe, Puducherry, India. Wound re-epithelialization was monitored for up to 14 weeks. RESULTS : Comorbidities in the patient group (nine females and nine males; mean age 54.1 ± 10.8 years, range 32-70 years) included diabetes mellitus, hypertension, obesity (body mass index (BMI) >30 kg/m(2)), and peripheral vascular disease. The wound types included diabetic and nondiabetic foot, pressure, and venous leg ulcers. The average wound age prior to treatment was 36.8 ± 48.5 months (range 2-180 months) in the majority of patients. All wounds measured less than 7 cm × 7 cm. The mean time to wound epithelialization was 3.7 ± 1.8 weeks (range 2-9 weeks). The majority of wounds healed following epidermal grafting (n=16, 88.9%). One patient developed infection following removal of the dressing under non-sterile conditions against the advice of the healthcare providers. Another patient developed wound hypergranulation after grafting. Both wounds healed completely after treatment with antibiotic therapy and tissue resection, respectively. All donor sites healed without complications. CONCLUSION : In patients with small- to medium-sized chronic wounds, epidermal grafting offered a viable wound closure option for wounds requiring only the epidermal layer. Additionally, epidermal grafting was performed in the clinic without anesthesia or a surgeon, making the procedure more accessible in resource-challenged regions.

Plastic chronic wound management with Cellutome

Chronic wounds continue to present a significant challenge to health-care providers around the globe. Unlike acute wounds, chronic wounds do not proceed through an orderly process of repair. In recent years many new modalities of modern wound treatment systems have been promoted. However, until recently there were few modalities designed to promote epithelialisation of a fully granulated wound. Mesh graft procedures have long been the gold standard for the management of acute wounds and chronic wounds but have also many disadvantages like discomfort associated with the donor site and the creation of a second painful wound (donor site).

The increase of chronical wounds in Germany due to the average age of patients, the aggressiveness of medical treatment and increase of numbers of patients with diabetes and severe polymorbidity requires specialized wound treatment and plastic surgery. Since 2014 there was a new innovative system introduced in the market called Cellutome epidermal harvesting system. The Cellutome system is a epidermal harvesting system for skin grafting and can replace in many cases the traditional meshgraft procedure with a classic dermatoma. The skin donor section on the patient`s thigh heals within days without scarring. The system offers a precise, simplified and minimal invasive option for skin grafting in the treatment of especially chronic wounds.