Duragen: A dermal substitute for the management of suboptimal wounds

Using a flap in a large wound with a very small area of exposed vital structures may be an excessive intrusion and cause unnecessary donor site morbidity. Dermal matrix (DuraGen) was applied onto critical areas where bone or tendons were exposed and a split skin graft was placed thereon. All patients had satisfactory wound closure without the need for a flap. DuraGen appears to be a safe, single-stage alternative, to a flap for the healing of complex wounds.

Upper Extremity Wounds Treated with Biodegradable Temporizing Matrix versus Collagen-Chondroitin Silicone Bilayer

Objective  This study aims to compare outcomes between Novosorb Biodegradable Temporizing Matrix (BTM) and Integra collagen-chondroitin silicone for upper-extremity wound reconstruction. Methods  This retrospective study analyzed adult patients who underwent wound reconstruction with either BTM or Integra at our institution between 2015 and 2020. Results  Forty-eight patients were included: 31 (64.6%) BTM and 17 (35.4%) Integra. Mean age was 44.0 (range: 18-68) years. Age, race, sex, smoking, comorbidities, and defect size were similar between groups. Wound etiologies included 12 (25.0%) burn, 22 (45.8%) trauma, and others. Median template size was 133 cm 2 for BTM and 104 cm 2 for Integra ( p  = 0.526). Skin grafting was performed after 14 (45.2%) and 14 (82.4%) wounds treated with BTM and Integra, respectively ( p  = 0.028). Template complications of infection and dehiscence were comparable. Skin-graft complications occurred in five (35.7%) and three (21.4%) wounds in BTM and Integra, respectively ( p  = 0.031). Skin-graft failure rates were comparable ( p  = 0.121). Mean number of secondary procedures required after template placement was higher in the Integra group (BTM, 1.0; Integra, 1.9; p  = 0.090). Final healing was achieved in 17 (54.8%) BTM and 11 (64.7%) Integra wounds ( p  = 0.694). Median time to healing was 4.1 months after BTM and 2.6 months after Integra placement ( p  = 0.014). Conclusion  Compared with Integra, BTM achieved comparable wound healing and complication rates. Fewer secondary procedures and skin grafts were observed in BTM wounds, likely as a result of the coronavirus disease 2019 pandemic. At our institution, 100 cm 2 of product costs $850 for BTM and $3,150 for Integra, suggesting BTM as an economical alternative to fulfill the high functional and aesthetic requirements of upper-extremity wounds.

Development of a Self-Assembled Dermal Substitute from Human Fibroblasts Using Long-term Three-Dimensional Culture

Skin substitutes have emerged as an alternative to autografts for the treatment of skin defects. Among them, scaffold-based dermal substitutes have been extensively studied; however, they have certain limitations, such as delayed vascularization, limited elasticity, and the inability to achieve permanent engraftment. Self-assembled, cell-based dermal substitutes are a promising alternative that may overcome these shortcomings but have not yet been developed. In this study, we successfully developed a cell-based dermal substitute (cultured dermis) through the long-term culture of human dermal fibroblasts using the net-mold method, which enables three-dimensional cell culture without the use of a scaffold. Spheroids prepared from human dermal fibroblasts were poured into a net-shaped mold and cultured for 2, 4, or 6 months. The dry weight, tensile strength, collagen and glycosaminoglycan levels, and cell proliferation capacity were assessed and compared among the 2-, 4-, and 6-month culture periods. We found that collagen and glycosaminoglycan levels decreased over time, while the dry weight remained unchanged. Tensile strength increased at 4 months, suggesting that remodeling had progressed. In addition, the cell proliferation capacity was maintained, even after a 6-month culture period. Unexpectedly, the internal part of the cultured dermis became fragile, resulting in the division of the cultured dermis into two collagen-rich tissues, each of which had a thickness of 400 μm and sufficient strength to be sutured during in vivo analysis. The divided 4-month cultured dermis was transplanted to skin defects of immunocompromised mice and its wound healing effects were compared to those of a clinically available collagen-based artificial dermis. The cultured dermis promoted epithelialization and angiogenesis more effectively than the collagen-based artificial dermis. Although further improvements are needed, such as the shortening of the culture period and increasing the size of the cultured dermis, we believe that the cultured dermis presented in this study has the potential to be an innovative material for permanent skin coverage.

Integra® Dermal Regeneration Template as an alternative technique to treat degloving injury of fingers

Soft tissue covering of degloving injuries of fingers remains a common challenge in trauma. In this case, we report the good long-term results after the use of Integra® Dermal Regeneration Template in combination with a split-thickness skin graft as an alternative treatment option for a patient with a traumatic degloving injury of multiple fingers.

Short- and Long-term Outcomes of an Acellular Dermal Substitute versus Standard of Care in Burns and Reconstructions: A Phase I/II Intrapatient Randomized Controlled Trial

OBJECTIVE

Dermal substitutes promote dermal regeneration and improve scar quality, but knowledge gaps remain regarding their efficacy and indications for use. The authors investigated the safety and short- and long-term efficacy of an acellular dermal substitute in patients with full-thickness wounds.

METHODS

This intrapatient randomized controlled, open-label, phase I (safety) and phase II (efficacy) study compared treatment with Novomaix (Matricel GmbH), a dermal collagen/elastin-based scaffold, with split-thickness skin graft (STSG) only. The primary safety outcome was graft take at 5 to 7 days postsurgery. Postsurgical scar quality was assessed by measuring elasticity, color, and scores on the Patient and Observer Scar Assessment Scale at 3 months, 12 months, and 6 years.

RESULTS

Twenty-five patients were included, of which 24 received treatment allocation. Graft take and wound healing were statistically significantly lower/delayed in the dermal matrix group compared with STSG alone (P < .004). Serious adverse events were delayed epithelialization in four dermal matrix and three STSG study areas. At 12 months postsurgery, skin extension (P = .034) and elasticity (P = .036) were better for the dermal matrix group compared with the group receiving STSG alone. Other scar quality parameters at 12 months and 6 years did not differ between treatment arms.

CONCLUSIONS

The dermal substitute was a safe treatment modality for full-thickness wounds. Compared with STSG alone, time to wound healing was slightly increased. Nevertheless, scar quality at 12 months seemed somewhat improved in the wounds treated with the dermal substitute, indicative of enhanced scar maturation. In the long term, final scar quality was similar for both treatment modalities.

Meshed dermal regeneration template for traumatic periocular tissue loss in the young population

The IntegraⓇ Dermal Regeneration Template (DRT) is a bioengineered dermal substitute that is becoming increasingly popular in the field of reconstruction. Its unique properties allow for immediate wound closure while providing a scaffold for tissue regeneration. Currently, it is commonly used to treat burns, ulcers, and complex wounds. In the setting of traumatic periocular tissue loss, only two prior reports have been published on its use for primary reconstruction. We present our institution's experience with a series of four young patients who received primary reconstruction with IntegraⓇ DRT as a full-thickness skin substitute for their large traumatic periorbital skin defects.

Urinary bladder matrix for lower extremity split-thickness skin graft donor site

Split-thickness skin grafts (STSG) are commonly used to treat soft-tissue defects. Harvesting a STSG creates an additional partial thickness wound at the donor site which must be managed. Many dressings are commercially available for the management of STSG donor sites; however, there is no evidence-based consensus on optimal dressing for site management. Urinary bladder matrix (UBM) is an extracellular matrix that acts as a structural support for tissue remodeling and provides molecular components for repair. Common clinical applications of UBM include coverage of deep wounds, burns, and irradiated skin. Skin grafting from the lower extremities poses a challenge due to the increased dermal tension. UBM-based reconstruction is an alternative method of managing lower extremity skin graft donor sites. This case study demonstrates the use of UBM in the reconstruction of a STSG donor site of the anterolateral thigh, which resulted in satisfactory healing, no pain, and excellent cosmetic and functional outcomes.

Meek Micro-Skin Grafting and Acellular Dermal Matrix in Pediatric Patients: A Novel Approach to Massive Extravasation Injury

(1) Background: Extravasation injuries in pediatric patients can lead to significant harm if they are not promptly diagnosed and treated. However, evidence-based standardization on extravasation management remains limited, particularly for extensive wound necrosis. This case report presents the management of an 8-week-old premature patient with an extensive extravasation injury involving the right forearm and dorsum of the hand. (2) Methods: The patient was evaluated by a multidisciplinary team in our Neonatal Intensive Care Unit. Surgical intervention involved the debridement of necrotic tissues, followed by temporary coverage with an acellular dermal matrix. Definitive coverage was achieved through Meek micrografting after three weeks. Physical therapy was provided with pre- and post-rehabilitation range of motion assessed using goniometric measurements. Scar quality was evaluated using the Vancouver Scar Scale. (3) Results: The engraftment rate of the Meek micrografts was 93%, with 16 out of 226 micrografts lost. The patient achieved a Vancouver Scar Scale score of 6, indicating a moderate degree of scarring. Significant improvements in elbow, wrist, and finger joint range of motion were observed at a 1-year follow-up. (4) Conclusions: Close observation and heightened awareness of extravasation risks by trained personnel are crucial. Meek micrografting combined with dermal substitute coverage represents an innovative approach to managing extravasation wounds in pediatric patients.

The optimization of PLGA knitted mesh reinforced-collagen/chitosan scaffold for the healing of full-thickness skin defects

Collagen-based scaffolds reveals promising to repair severe skin defects. The mechanical strength of collagen-based scaffold (CCS) limited its clinical application. Embedding poly(lactic-co-glycolic) acid (PLGA) knitted mesh into CCS improves the mechanical strength of the scaffold. This study was conducted to optimize the configuration of PLGA knitted mesh-collagen-chitosan scaffold (PCCS), and explore possible mechanisms. PLGA knitted mesh was embedded in CCS through freeze-drying method. With the PLGA knitted mesh located at the bottom, middle, or both bottom and top layers of the CCS, three kinds of PCCS were developed. A full-thickness skin wound model was established in Sprague Dawley rats to evaluate the therapeutic effects of different PCCS against CCS. The properties and healing effect of the scaffolds were investigated. Several growth factors and chemotactic factors, that is, VEGF, PDGF, CD31, α-SMA, TGF-β1, and TGF-β3 were analyzed and evaluated. Re-epithelialization and angiogenesis were observed in all animal groups with the treatment of three kinds of PCCS scaffolds and the CCS scaffold (control). The protein and gene expression of VEGF, PDGF, CD31, α-SMA, TGF-β1, and TGF-β3 showed different dynamics at different time points. Based on the healing effects and the expression of growth factors and chemotactic factors, scaffold with the PLGA knitted mesh located at the bottom layer of the CCS demonstrated the best healing effect and accelerated re-epithelialization and angiogenesis among all the scaffolds evaluated. PCCS with the PLGA mesh located in the bottom layer of the scaffold accelerated wound healing by creating a more supportive environment for re-epithelialization and angiogenesis.

Wound Healing after Acellular Dermal Substitute Positioning in Dermato-Oncological Surgery: A Prospective Comparative Study

BACKGROUND

MatriDerm and Integra are both widely used collagenic acellular dermal matrices (ADMs) in the surgical setting, with similar characteristics in terms of healing time and clinical indication. The aim of the present study is to compare the two ADMs in terms of clinical and histological results in the setting of dermato-oncological surgery.

METHODS

Ten consecutive patients with medical indications to undergo surgical excision of skin cancers were treated with a 2-step procedure at our Dermatologic Surgery Unit. Immediately after tumor removal, both ADMs were positioned on the wound bed, one adjacent to the other. Closure through split-thickness skin grafting was performed after approximately 3 weeks. Conventional histology, immunostaining and ELISA assay were performed on cutaneous samples at different timepoints.

RESULTS

No significant differences were detected in terms of either final clinical outcomes or in extracellular matrix content of the neoformed dermis. However, Matriderm was observed to induce scar retraction more frequently. In contrast, Integra was shown to carry higher infectious risk and to be more slowly reabsorbed into the wound bed. Sometimes foreign body-like granulomatous reactions were also observed, especially in Integra samples.

CONCLUSIONS

Even in the presence of subtle differences between the ADMs, comparable global outcomes were demonstrated after dermato-oncological surgery.

Head and Neck Wound Reconstruction Using Biodegradable Temporizing Matrix Versus Collagen-Chondroitin Silicone Bilayer

BACKGROUND

Head and neck reconstruction is challenging because of the functional requirements of movement, sensation, and cosmesis of this highly visible region. This study is the first to compare Novosorb biodegradable temporizing matrix (BTM) and Integra collagen-chondroitin silicone (CCS) skin substitutes for reconstruction of soft tissue head and neck wounds.

METHODS

This retrospective review included adults who underwent wound reconstruction of the head/neck with either BTM or CCS between 2015 and 2020. Patient-level data, complications, and closure rates were compared.

RESULTS

The review identified 15 patients: 5 who received BTM and 10 who received CCS. Mean age at dermal template placement was 55 (range, 28-79) years. Race, sex, smoking status, medical comorbidities, defect size, radiation history, prior surgeries, and follow-up time were not significantly different between groups. Wound etiologies for BTM and CCS included burn (40% vs 60%), trauma (20% vs 20%), surgical wounds (20% vs 20%), and skin cancer (20% vs 0%), respectively (P = .026). Skin grafts were placed in 8 (80%) wounds after CCS placement, compared with 3 (60%) after BTM (P = .670). Template reapplication was required in 2 (40%) BTM wounds and 3 (30%) CCS wounds (P = 1.0). Infection, hematoma, and seroma were comparable between groups, although skin graft failure was higher in the CCS group at 3 (37.5%) compared with 0 for BTM (P = .506). More secondary procedures were required after CCS placement (CCS, 1.9 ± 2.2; BTM, 0.9 ± 0.8; P = .090). Definitive closure in patients not lost to follow-up occurred in 4 (100%) BTM and 6 (75%) CCS cases (P = 1.0).

CONCLUSIONS

Head and neck wounds treated with BTM had comparable closure and complication rates as CCS bilayer and required fewer secondary procedures and skin grafts. These findings suggest that BTM is safe and efficacious for application in head and neck wounds and may be considered as an economical alternative.

Technical Refinements with the Use of Biologic Healing Agents

Soft tissue defects resulting from trauma, vascular disease, burns, and postoncologic resections require reconstructive surgery for appropriate wound coverage and support. Dermal substitutes have been applied to a vast array of reconstructive settings across nearly all anatomical areas with demonstrable success. However, they require meticulous handling and operative technical expertise to optimize management of these soft tissue defects. In this review, we will address three dermal substitutes, their operative techniques, and their surgical applications.

Comparison of Efficacy among Three Dermal Substitutes in the Management of Critical Lower-Limb Wounds: The Largest Biases-Reduced Single-Center Retrospective Cohort Study in Literature

Background and objectives: The skin recently became the main focus of regenerative medicine and, in this context, skin substitutes are fully entering into the plastic surgeon’s armamentarium. Among the various types of skin substitutes, dermal substitutes (DSs) are the most used. Our study aims to retrospectively compare three renowned and extremely similar DS in the management of critical lower limb wounds in the largest cohort analysis currently present in literature. Materials and Methods: We followed a strict protocol of application and evaluation of the DS for each patient and wound and, after a meticulous bias reduction process, we compared final outcomes in terms of efficacy and speed in achieving the defect coverage. Results: Among patients who did not receive a skin graft after the DS, we registered a wound healed surface of 50% for Pelnac, 52% for Integra, and 19% for Nevelia, after 30 days from the external silicon layer removal; among those who received a skin graft after the DS, we observed a significantly lower mean percentage of graft take after 7 days with Pelnac (53%) compared to Integra and Nevelia (92% and 80%, respectively). The overall percentage of wound healed surface obtained after 30 days from the external silicon sheet removal, either with or without skin graft, was 71% for Pelnac, 63% for Integra and 63% for Nevelia. We also ran a sub-group analysis only including grafted wounds with a negative microbiological test and the mean percentage of graft take was similar this time. Eventually, we assessed the influence of the wound’s “chronicity” on its healing, comparing the mean graft take only in “acute” wounds who received a skin graft and it resulted 63% for Pelnac, 91% for Integra and 75% for Nevelia. Conclusions: Integra demonstrates the highest rate of skin graft viability and the highest rate of skin graft takes after 7 days. Pelnac shows the quickest induction of secondary healing in acute wounds. Nevelia is not different from Integra and shows a superior graft take compared to Pelnac, but features the lowest secondary healing induction rate. No differences exist between the three DSs in terms of wound healing after 30 days from the skin graft or from the removal of the external silicon layer.

Adipose Tissue-Derived Microvascular Fragments From Male and Female Fat Donors Exhibit a Comparable Vascularization Capacity

Adipose tissue-derived microvascular fragments (MVF) represent effective vascularization units for tissue engineering. Most experimental studies exclusively use epididymal fat tissue of male donor mice as a source for MVF isolation. However, in future clinical practice, MVF-based approaches may be applied in both male and female patients. Therefore, we herein compared the vascularization capacity of MVF isolated from the epididymal and peri-ovarian fat tissue of male and female donor mice. Freshly isolated MVF from male and female donors did not differ in their number, length distribution, viability and cellular composition. After their assembly into spheroids, they also exhibited a comparable in vitro sprouting activity. Moreover, they could be seeded onto collagen-glycosaminoglycan matrices, which were implanted into full-thickness skin defects within mouse dorsal skinfold chambers. Repetitive intravital fluorescence microscopy as well as histological and immunohistochemical analyses revealed a comparable vascularization and incorporation of implants seeded with MVF of male and female origin. Taken together, these findings demonstrate that the vascularization capacity of MVF is not gender-specific.

A New Dermal Substitute Containing Polyvinyl Alcohol with Silver Nanoparticles and Collagen with Hyaluronic Acid: In Vitro and In Vivo Approaches

The experimental use of poly (alcohol-vinyl) (PVA) as a skin curative is increasing widely. However, the use of this hydrogel is challenging due to its favorable properties for microbiota growth. The association with silver nanoparticles (AgNPs) as an antimicrobial agent turns the match for PVA as a dressing, as it focuses on creating a physical barrier to avoid wound dehydration. When associated with extracellular components, such as the collagen matrix, the device obtained can create the desired biological conditions to act as a skin substitute. This study aimed to analyze the anti-microbiological activity and the in vitro and in vivo responses of a bilaminar device of PVA containing AgNPs associated with a membrane of collagen-hyaluronic acid (col-HA). Additionally, mesenchymal stem cells were cultured in the device to evaluate in vitro responses and in vivo immunomodulatory and healing behavior. The device morphology revealed a porous pattern that favored water retention and in vitro cell adhesion. Controlled wounds in the dorsal back of rat skins revealed a striking skin remodeling with new epidermis fulfilling all previously injured areas after 14 and 28 days. No infections or significant inflammations were observed, despite increased angiogenesis, and no fibrosis-markers were identified as compared to controls. Although few antibacterial activities were obtained, the addition of AgNPs prevented fungal growth. All results demonstrated that the combination of the components used here as a dermal device, chosen according to previous miscellany studies of low/mid-cost biomaterials, can promote skin protection avoiding infections and dehydration, minimize the typical wound inflammatory responses, and favor the cellular healing responses, features that give rise to further clinical trials of the device here developed.

Trichoderma longibrachiatum and Aspergillus fischeri Infection as a Cause of Skin Graft Failure in a Patient with Critical Burns after Liver Transplantation

Infectious complications are responsible for the majority of mortalities and morbidities of patients with critical burns. Although bacteria are the predominant etiological agents in such patients, yeasts and fungi have become relatively common causes of infections over the last decade. Here, we report a case of a young man with critical burns on 88% TBSA (total body surface area) arising as a part of polytrauma. The patient's history of orthotopic liver transplantation associated with the patient's need to use combined immunosuppressant therapy was an additional complication. Due to deep burns in the forearm region, we have (after a suitable wound bed preparation) applied a new bi-layered dermal substitute. The patient, however, developed a combined fungal infection in the region of this dermal substitute caused by Trichoderma longibrachiatum and Aspergillus fischeri (the first case ever reported). The infection caused the loss of the split-thickness skin grafts (STSGs); we had to perform repeated hydrosurgical and mechanical debridement and a systemic antifungal treatment prior to re-application of the STSGs. The subsequent skin transplant was successful.

The Use of Dalbavancin with a Dermal Substitute Application - a Case Report

Skin and soft tissue infections (SSTIs) are a large group of diseases with a wide range of clinically different conditions, some of which can be immediately life-threatening. A number of bacteria play an important role in the etiology of SSTIs, especially gram-positive cocci Staphylococcus aureus and Streptococcus pyogenes. In this case report, a young woman with skin defects after a fasciotomy was treated using a dermal substitute application. Multiple infectious complications in the skin and soft tissues with a high risk of development of phlebitis and with significant intolerance to a variety of antimicrobials were observed. The dramatic SSTI was treated using intravenous administration of dalbavancin, a very potent bactericidal antibiotic representing a rational option in the treatment of SSTIs caused by gram-positive bacteria.

Malignant Skin Cancer Excision in Combined Therapy with Electro-Chemotherapy and Dermal Substitute

Squamous cell carcinoma (SCC) is the second most common malignancy skin cancer. It is characterized by abnormal, accelerated growth of squamous cells (SCs). SCC occurs when DNA damage from exposure to ultraviolet radiation or other damaging agents trigger abnormal changes in the SCs, presenting as painless lesions on areas of high sun exposure, such as the dorsum of the hand and upper extremity. For most skin SCC, the surgical excision alone is standard practice. However, recent efforts in new treatment strategies have involved around adjuvant or concomitant electrochemotherapy (ECT). ECT is a non-thermal tumor ablation modality, safe and effective on any type of solid tumor. An 87-year-old patient affected by hand SCC with invasion of deep structures including tendons was treated with neoadjuvant intra-tumoral ECT sessions followed by a selective surgical removal and reconstruction of the substance loss with collagen dermal template (CDT). Two neoadjuvant intra-tumoral ECT procedures, at distance of 3 months, with the aim to reduce the tumor size before a selective surgery, were performed. This study shows that combined surgical selective excision with ECT and CDT is a valid technique for the extended-deep dorsal hand tumor lesions reconstruction.

Matriderm dermal substitute in the treatment of post traumatic hand's fingertip tissue loss

INTRODUCTION

Treatment of fingers tissue loss is particularly challenging as it often necessitates advanced reconstructive techniques such as flaps or grafts, with esthetic and functional results that are not always as good as hoped for, with long healing times. Recently, along with tissue engineering development, numerous types of dermal substitute have been commercialized, with promising possibilities of treatment in finger tissue loss. In the author's unit, Matriderm^® is the most commonly used dermal substitute. As described by the manufacturer, this scaffold is designed to be covered with a split-thickness skin graft. In using a two-step procedure, the authors realized that in most cases of fingertips injuries, at three weeks follow-up, the wound appeared in an advanced state of healing, which permitted to avoid grafting.

MATERIAL AND METHODS

Between October 2017 and October 2018, 27 fingers have been included in this study. Patients have been divided in two groups: those treated with Matriderm^® alone (15 fingers) and those who had a skin graft three weeks after the first surgery (12 fingers). At the 6-month follow-up, authors evaluated the esthetic results with the Vancouver Scar Scale (VSS), the functional results with Quick Disability of the Arm, Shoulder and Hand (qDASH) score, and sensibility by the mean of two-point discrimination test (2-PD).

RESULTS

All outcomes were overlapping in patients treated with or without skin graft: mean VSS was 2.3, mean qDASH was 13.3, and mean 2-PD was 7.7 mm.

CONCLUSIONS

The results obtained allow to consider Matriderm^® , used also without skin graft coverage, as a valid solution for treatment of fingertip tissue loss.

Outcomes of Pediatric Syndactyly Repair Using Synthetic Dermal Substitute

PURPOSE

Full-thickness skin grafts are classically used for areas of skin deficit in syndactyly reconstruction surgery. However, skin grafting requires additional time under anesthesia and includes donor site morbidity. Synthetic dermal substitute has produced favorable web creep and scar appearance outcomes in syndactyly reconstruction. We sought to validate these results using objective outcome measures.

METHODS

All patients who had undergone syndactyly reconstruction with synthetic dermal substitute with 1-year follow-up were identified. We included 23 webs in 16 patients; 2 were lost to follow-up. Median age at surgery was 27 months; 7 patients were female. Five webs were revision surgeries. Two patients had a diagnosis of amniotic constriction band, and 3 had symbrachydactyly. All webs were assessed from blinded clinical photos. Outcome measures included web creep assessment (range, 0-5) and Vancouver Scar Scale.

RESULTS

Of 21 webs, 2 had minimal creep and 16 had none; 3 had clinically relevant creep (grade 2). Vancouver Scar Scale scores for all webs averaged 1.19 (0 is normal). There was normal vascularity in 20 webs, pigmentation was normal in 17 webs, skin pliability was normal in 13 webs, and scar height was flat in 15 webs. On the visual analog scale assessment, surgeons rated the appearance of the 21 webs as an average of 8.8 (range, 5-10). There were no postoperative complications.

CONCLUSIONS

Synthetic dermal substitute is an effective, efficient, and visually satisfactory option for coverage of skin deficits in syndactyly reconstruction. The current heterogeneous sample revealed that this approach can provide satisfactory outcomes for patients, families, and surgeons. Although no surgical complications were noted, the rate of integration and healing has yet to be determined.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Distal Digital Nerve Repair Using Nerve Allograft With a Dermal Substitute: A Case Report

Background: Distal digital nerve repairs can present unique challenges for hand surgeons due to their sensitive location and ongoing difficulty obtaining soft tissue coverage in this region. Although autografts and nerve conduits have been shown to be of benefit with nerve gaps, they can have morbidities associated with their use. Nerve allografts have become a viable option over the past decade as their use has increased and data are now showing similar outcomes, particularly in short gap segments. Flaps and skin grafts are traditional coverage options for full thickness wounds but can pose challenges with multiple digit involvement, depth of wound, and critical structures exposed. Methods: We present a case where nerve allograft was used for distal digital nerve repair. Due to the distal nature of the nerve repair in the index digit distal to the trifurcation, the distal end of the nerve graft was connected to multiple small nerve ends. Dermal substitute was placed to achieve distal coverage of the affected digits. Results: At 6-month follow-up, the patient demonstrated improved strength, normal sensation, and full return of digital function. Conclusion: Nerve allograft can be used in combination with dermal skin substitute to achieve normal sensation and return of digital function following distal digital nerve injuries.

Use of a multilayered acellular dermal substitute with simultaneous full-thickness skin graft for the one-stage coverage of nasal skin defects

BACKGROUND

Nasal skin defect closures are challenging because the nose is a complex anatomic structure with several subunits, and the nasal tip and ala represent particularly difficult subunits to reconstruct. The traditional full-thickness skin graft (FTSG) is an easy and well-established method, but often results in undesirable outcomes in terms of the nasal contour caused by a lack of dermal tissue.

AIMS

The purpose of the study is to report the outcomes of the simultaneous application of the acellular dermal substitute (Matriderm^® ) with FTSG in the treatment of nasal skin defects.

PATIENTS/METHODS

Five patients with various nasal skin defects were treated with multilayered Matriderm grafts followed by FTSGs harvested from the pre- or postauricular region. Graft survival, scar quality, and patient satisfaction were evaluated and compared with 10 patients treated with conventional FTSGs.

RESULTS

One-stage Matriderm-aided FTSGs were well-taken in all cases. Scar quality in the Matriderm group (8.0 ± 1.9) was statistically superior to that in the FTSG only group (10.8 ± 1.7). The Matriderm-aided graft was also superior in patient satisfaction.

CONCLUSIONS

The multilayered application of Matriderm in combination with FTSG is a reliable method for covering nasal skin defects, especially in the thick skin zone of the tip and ala.

A comparison of the wound healing process after the application of three dermal substitutes with or without basic fibroblast growth factor impregnation in diabetic mice

Pelnac Gplus^Ⓡ, Integra^Ⓡ, and Terudermis^Ⓡ are approved artificial dermis products in Japan. Previously, we proved that Pelnac Gplus^Ⓡ was able to sustain basic fibroblast growth factor (bFGF) and accelerated wound healing by releasing impregnated bFGF. In this study, we impregnated Pelnac Gplus^Ⓡ, Integra^Ⓡ, and Terudermis^Ⓡ with bFGF and compared the binding activity and wound-healing process. We applied bFGF to each material and compared the bFGF concentrations in the surrounding area after 24-h incubation. For the in vivo study, dermal substitutes were impregnated with bFGF and implanted into full-thickness wounds of BKS.Cg-+Leprdb/+Leprdb/Jcl mice. Wounds were evaluated at days 7, 14, and 21 after implantation. The in vitro study showed that bFGF is strongly bound to Integra^Ⓡ, followed by Pelnac Gplus^Ⓡ and Terudermis^Ⓡ. The in vivo study showed that fibroblasts and capillaries had infiltrated into the Pelnac Gplus^Ⓡ but not the Integra^Ⓡ or Terudermis^Ⓡ. Furthermore, long epithelium and wide granulation tissue were formed in the Pelnac Gplus^Ⓡ with bFGF group. The Terudermis^Ⓡ with bFGF group had more capillaries than other groups, but only at the base of the wound. The combination of Pelnac Gplus^Ⓡ with bFGF may be a novel approach for treating full-thickness skin defects or chronic skin ulcers.

Promotion of dermal regeneration using pullulan/gelatin porous skin substitute

Tissue-engineered dermal substitutes represent a promising approach to improve wound healing and provide more sufficient regeneration, compared with current clinical standards on care of large wounds, early excision, and grafting of autografts. However, inadequate regenerative capacity, impaired regeneration/degradation profile, and high cost of current commercial tissue-engineered dermal regeneration templates hinder their utilization, and the development of an efficient and cost-effective tissue-engineered dermal substitute remains a challenge. Inspired from our previously reported data on a pullulan/gelatin scaffold, here we present a new generation of a porous pullulan/gelatin scaffold (PG2) served as a dermal substitute with enhanced chemical and structural characteristics. PG2 shows excellent biocompatibility (viability, migration, and proliferation), assessed by in vitro incorporation of human dermal fibroblasts in comparison with the Integra® dermal regeneration template (Control). When applied on a mouse full-thickness excisional wound, PG2 shows rapid scaffold degradation, more granulation tissue, more collagen deposition, and more cellularity in comparison with Control at 20 days post surgery. The faster degradation is likely due to the enhanced recruitment of inflammatory macrophages to the scaffold from the wound bed, and that leads to earlier maturation of granulation tissue with less myofibroblastic cells. Collectively, our data reveal PG2's characteristics as an applicable dermal substitute with excellent dermal regeneration, which may attenuate scar formation.

Benefits of cryopreserved human amniotic membranes in association with conventional treatments in the management of full-thickness burns

The use of split-thickness skin autografts (STSA) with dermal substitutes is the gold standard treatment for third-degree burn patients. In this article, we tested whether cryopreserved amniotic membranes could be beneficial to the current treatments for full-thickness burns. Swines were subjected to standardised full-thickness burn injuries, and then were randomly assigned to treatments: (a) STSA alone; (b) STSA associated with the dermal substitute, Matriderm; (c) STSA plus human amniotic membrane (HAM); and (d) STSA associated with Matriderm plus HAM. Clinical and histological assessments were performed over time. We also reported the clinical use of HAM in one patient. The addition of HAM to classic treatments reduced scar contraction. In the presence of HAM, skin wound healing displayed high elasticity and histological examination showed a dense network of long elastic fibres. The presence of HAM increased dermal neovascularization, but no effect was observed on the recruitment of inflammatory cells to the wound. Moreover, the use of HAM with classical treatments in one human patient revealed a clear benefit in terms of elasticity. These results give initial evidence to consider the clinical application of HAM to avoid post-burn contractures and therefore facilitate functional recovery after deep burn injury.

Vasculogenic Chronic Ulcer: Tissue Regeneration with an Innovative Dermal Substitute

The healing of venous and arterial ulcers is slow, and in some cases, they may not heal at all. This study aims to demonstrate the clinical advantage of Nevelia^®, an innovative collagen dermal template substitute (DS) in venous and arterial chronic ulcers treatment. 35 patients affected by chronic vascular ulcers with a mean area of 35.1 ± 31.8 cm² were treated with DS followed by autologous dermal epidermal graft (DEG). Follow-up was performed at 7-14-21 and 28 days after DS implant and 7-14-21 and 28 days after DEG. At 28 days after DEG, the mean values of Manchester Scar Scale was of 1.8 ± 0.7 for skin color, 1.6 ± 0.7 for skin contour, 1.7 ± 0.7 for distortion, and 1.7 ± 0.7 for skin texture, whereas skin was matte in 27 patients (77%) and shiny in the remaining eight cases (23%). Histological findings correlate with the clinical result showing a regenerated skin with reactive epidermal hyperplasia and dermal granulation tissue after two weeks (T1), and after three weeks (T2) a re-epithelialization and a formed new tissue architecture analogue to normal skin physiology. These data suggest that Nevelia^® could be useful to treat chronic venous and arterial ulcers.

Skin graft using MatriDerm® for plantar defects after excision of skin cancer

Skin cancer should be excised with sufficient margin to reduce recurrence rate. However, the surgeon always has to worry about the reconstruction method of skin defects after excision. In particular, defects in the plantar surface of the foot are difficult to reconstruct due to their position and structure, and various methods are applied by each surgeon. Surgeons think which methods are easier to apply to patients and less morbidity. To alleviate these concerns, we applied artificial dermal substitute to skin defects after skin cancer. Bowen’s disease (squamous cell carcinoma in situ) and melanoma in situ on the plantar surface of the foot were subjected to wide excision with sufficient margin. After excision, a skin defect with exposed plantar fascia was applied with a matrix defect and vacuum. A granulation tissue (dermal matrix) was formed and a split-thickness skin graft was performed. Both patients had good functional results and no problems with skin donor sites. Thus, we report a skin graft method that is relatively easy to apply after skin cancer excision on the plantar surface of the foot.

Advances in addressing full-thickness skin defects: a review of dermal and epidermal substitutes

full-thickness skin defects remain a reconstructive challenge. Novel regenerative modalities can aid in addressing these defects. A literature review of currently available dermal and epidermal regenerates was performed. The mechanism and application for each skin substitute was analyzed to provide a guide for these modalities. Available epidermal substitutes include autografts and allografts and may be cultured or noncultured. Dermal regenerate templates exist in biologic and synthetic varieties that differ in the source animal and processing. Epidermal and dermal skin substitutes are promising adjunctive tools for addressing certain soft tissue defects and have improved outcomes in reconstructive procedures. The following article provides a comprehensive review of the biologic materials available and the types of complex wounds amenable to their use.

Skin cancers and dermal substitutes: Is it safe? Review of the literature and presentation of a 2-stage surgical protocol for the treatment of non-melanoma skin cancers of the head in fragile patients

Non-melanoma skin cancers (NMSC) represent the most common skin tumours of the head region. We describe the use of dermal substitute in a 2-stage surgery protocol for selected fragile patients to remove NMSC of the head region. A review of the literature focusing on dermal substitutes' safety after skin tumours excision is provided. A total of 45 fragile patients with NMSC in the head region were selected and scheduled for the 2-stage surgical protocol. The first stage consisted of traditional surgical excision and immediate coverage with Hyalomatrix (Fidia Advanced Biopolymers, Abano Terme, Italy). After histology confirmed diagnosis and clearance of the margins, full-thickness skin autografts were performed. All of the patients reached complete tumour excision and wound healing. No local recurrences were registered during 24 months follow up. The 2-stage surgical therapeutic-diagnostic-reconstructive approach represents a less stressful and oncologically safe surgical protocol in selected fragile patients. When patients cannot tolerate invasive and long surgical procedures, general anaesthesia, and long hospitalisation, skin grafting following temporary skin substitute coverage can achieve oncological clearance and provide good functional and aesthetic results. The use of dermal substitutes represents a valid alternative surgical option in cases of ASA III, fragile patients non-eligible for complex reconstructive surgery. To our knowledge, this is the first paper reviewing literature focusing on dermal substitutes' applications and safety after skin tumour excision.

Plantar Reconstruction Using a Dermal Substitute: Description of 2 Cases

Acral lentiginous melanoma is the most common subtype among melanomas on the foot. Reconstruction of a wide surgical defect once it is excised may result in a challenge that requires replacing the lost tissue with another tissue having similarly unique physical characteristics. Although reconstructive options such as skin grafts and either local or distant flaps offer adequate coverage, they often are subject of contraction, muscle atrophy, and contour abnormalities. Dermal substitutes provide support and structure and recreates the dermal layer to ensure a durable reconstruction. We report 2 cases of plantar melanoma in which adequate reconstruction was achieved using a dermal substitute.

Bioresorbable scaffold as a dermal substitute

INTRODUCTION

Bioresorbable polymers are often used in medical procedures. Since they are biocompatible, this class of materials is a viable alternative for cases in which tissue regeneration is strongly compromised. Bioresorbable synthetic polymers may be used as membranes to support and guide cell growth through the process of tissue repair.

OBJECTIVE

To assess the efficiency of a porous bioresorbable membrane Poly (L-co-DL lactic acid)-co-trimethylene carbonate, PL-co-DLA-co-TMC, as a dermal substitute associated with partial skin graft in rats.

METHODS

A 1.5×1.5 cm defect was created on the backs of 40 Wistar rats. The rats were divided into a control group, in which the defects were filled with partial skin graft, and a treated group, in which a membrane associated with the graft was implemented. The animals were sacrificed 7 days or 60 days after the procedure and the results were evaluated by macroscopic and microscopic analysis.

RESULTS

The polymer was biocompatible and allowed better regeneration of the dermis with less shrinkage, unlike what occurs in second intention healing. Compared to the control group, the treated group showed a thicker and wider dermis with the presence of skin appendages, suggesting partial graft integration and better healing. The skin graft acted as a biological protection of the wound.

CONCLUSION

The study material was shown to act as a biocompatible dermal substitute and promoted less scarring of the dermis. Further studies should be conducted to improve the methodology of the surgical procedure.

Use of a Dermal Regeneration Template Wound Dressing in the Treatment of Combat-Related Upper Extremity Soft Tissue Injuries

PURPOSE

To assess the outcomes of treatment with a dermal regeneration template (DRT) in a cohort of combat casualties with severe upper extremity injuries.

METHODS

Records of all active duty military patients treated with DRT at our institution between November 2009 and July 2013 were screened. Inclusion criteria were upper extremity open wounds sustained during combat, requiring split-thickness or full-thickness skin grafting for closure. The primary outcome measure was wound healing after the first attempt at definitive treatment (defined as the first application of split-thickness or full-thickness skin graft). Independent variables collected included time from injury to arrival at our facility, mechanism of injury, wound infection, tobacco use, location of wound, number of operative debridements, and patient demographics.

RESULTS

A total of 60 patients with 69 wounds met the inclusion criteria. Most wounds were to the wrist or forearm (54%) or fingers (19%). All wounds were heavily contaminated, requiring a mean of 2.5 operative debridements before DRT placement. All wounds treated with full-thickness skin grafting after DRT healed completely without further complication. Split-thickness skin grafting was successful in 96% of patients.

CONCLUSIONS

DRT wound dressings are a helpful adjunct in the treatment of contaminated war wounds to the upper extremity.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

The application of Integra in a challenging context

Integra dermal regeneration template is commonly used in the developed world. This case history documents the application of Integra for the first time in Gaza, Palestine. This single case history illustrates how a tried and tested technique can be imported to a more challenging environment. The emphasis in this case history is not to recount a well-known technique of Integra application but to outline how the environment has to be prepared and the surgeon adapt to minimise risk and maximise the chances of success. This first application of Integra in Gaza illustrates the importance of starting with simple cases when a technique is being piloted in an austere environment. Patient selection, local theatre set up, staff and surgical technique, as well as patient follow-up facilities, all need consideration before doing the first trial of even this most established of products in a new environment.

Integra dermal regeneration template is a material that can be applied to resurface areas of scarring and burns contracture. The template consists of two layers: the upper layer is a Silone sheet that acts to protect the deeper layer that consists of a protein matrix. Once an area of troublesome scar has been surgically removed, it leaves a gap, or defect. The Integra can be applied to the defect and, providing the areas has a good blood supply, is free of bacteria and immobilised, a new blood supply enters the protein matrix. This allows the migration of cells, called fibroblasts, into the matrix. The fibroblasts will use the matrix as scaffolding to lay down new protein and eventually replace the matrix.

The resultant structure is called a ‘neodermis’. The protective silicone sheet can then be removed and replaced by a conventional, very thin skin graft. The advantage to applying this Integra two-stage reconstruction technique to a scarred area is that the reconstruction will be elastic and expand. In children, this allows for growth without recurrence of contractures across joints.

The application of Integra is a tried and tested technique. This case explains how, and with due care, it can be used for severe scarred cases in a challenging environment provided careful technique and follow-up are respected.

Current and emerging vascularization strategies in skin tissue engineering

Vascularization is a key process in skin tissue engineering, determining the biological function of artificial skin implants. Hence, efficient vascularization strategies are a major prerequisite for the safe application of these implants in clinical practice. Current approaches include (i) modification of structural and physicochemical properties of dermal scaffolds, (ii) biological scaffold activation with growth factor-releasing systems or gene vectors, and (iii) generation of prevascularized skin substitutes by seeding scaffolds with vessel-forming cells. These conventional approaches may be further supplemented by emerging strategies, such as transplantation of adipose tissue-derived microvascular fragments, 3D bioprinting and microfluidics, miRNA modulation, cell sheet engineering, and fabrication of photosynthetic scaffolds. The successful translation of these vascularization strategies from bench to bedside may pave the way for a broad clinical implementation of skin tissue engineering.

Use of bioartificial dermal regeneration template for skin restoration in combat casualty injuries

A letter in response to: Seavey JG, Masters ZA, Balazs GC, Tintle SM, Sabino J, Fleming ME & Valerio IL. Use of bioartificial dermal regeneration template for skin restoration in combat casualty injuries. Regen. Med. 11(1), 81-90 (2016).

Report on immediate irradiation of a rapidly growing sarcoma of the scalp prior to wound closure

Cutaneous sarcomas are primarily treated with extensive surgery, and occasionally require adjuvant radiation therapy following complete wound healing. Thus, sarcoma surgery leads to large and deep wounds, and the initiation of adjuvant radiation therapy depends on the time required for defect closure. We present the case of a male patient with pleomorphic sarcoma of the temporal skin, which was treated with multiple wide and deep excisions, instant application of an Integra(®) bilayer, and immediate radiation therapy prior to wound closure. The objective was to investigate the usefulness of a dermal substitute (Integra(®) ) in accelerating the effect of adjuvant radiation therapy on scalp defects after tumor surgery. A ring-shaped skin area - at risk for recurrence - around the Integra(®) bilayer was irradiated with a total of 59.4 Gy. No necrosis, infection, or major radiotoxicity was observed, and a subsequent split skin graft following radiation therapy remained fully vital until complete healing. In conclusion, a combined procedure consisting of sequential tumor surgery and subsequent application of a dermal substitute in conjunction with immediate initiation of adjuvant radiation therapy is, in principle, possible, and may permit innovative therapeutic options in dermatooncology and dermatosurgery.

Acceleration of diabetic wound healing by a cryopreserved living dermal substitute created by micronized amnion seeded with fibroblasts

Bioengineered dermal substitutes have been used for the treatment of diabetic ulcers in clinics and achieved satisfactory results. However, constructing traditional tissue engineered dermal substitutes with two-step method is high-cost, time-consuming and greatly decreases fibroblast proliferative activity because of repeated trypsinization. Inthisstudy, we created a 3D micronized amniotic membrane (mAM) and used it as a natural microcarrier for ex vivo culture and amplification of human dermal fibroblasts (HDF) combined with the rotary cell culture system (RCCS). This one-step mAM-RCCS method couldamplify HDF quickly and construct a dermal substitute HDF-mAM simultaneously. To facilitate the clinical application of mAM-RCCS, anoptimized storage method was used.Post-thawing HDF-mAM retained high cell viability, intact cell morphology and active peptide secretion. When transplanted to the wounds of db/db mice, cryopreserved HDF-mAM promoted vascularization and diabetic wound healing significantly. These results demonstrate the potential application of cryopreserved HDF-mAM as a living dermal substitutefor treating diabetic ulcers and other chronic wounds in clinics.

Tropoelastin incorporation into a dermal regeneration template promotes wound angiogenesis

Severe burn injury results in substantial skin loss and cannot be treated by autografts. The Integra Dermal Regeneration Template (IDRT) is the leading synthetic skin substitute because it allows for wound bed regeneration and wound healing. However, all substitutes suffer from slow blood vessel ingrowth and would benefit considerably from enhanced vascularization to nurture tissue repair. It is shown here that by incorporating the human elastic protein tropoelastin into a dermal regeneration template (TDRT) we can promote angiogenesis in wound healing. In small and large animal models comprising mice and pigs, the hybrid TDRT biomaterial and IDRT show similar contraction to autografts and decrease wound contraction compared to open wounds. In mice, TDRT accelerates early stage angiogenesis by 2 weeks, as evidenced by increased angiogenesis fluorescent radiant efficiency in live animal imaging and the expression of endothelial cell adhesion marker CD146. In the pig, a full thickness wound repair model confirms increased numbers of blood vessels in the regenerating areas of the dermis closest to the hypodermis and immediately below the epidermis at 2 weeks post-surgery. It is concluded that including tropoelastin in a dermal regeneration template has the potential to promote wound repair through enhanced vascularization.

Contribution of fibroblasts to the mechanical stability of in vitro engineered dermal-like tissue through extracellular matrix deposition

Tissue-engineered skin with mechanical and biological properties that match the native tissue could be a valuable graft to treat non-healing chronic wounds. Fibroblasts grown on a suitable biodegradable scaffold are a feasible strategy for the development of a dermal substitute above which epithelialization may occur naturally. Cell growth and phenotype maintenance are crucial to ensure the functional status of engineered tissue. In this study, an electrospun biodegradable polymer scaffold composed of a terpolymer PLGC [poly(lactide-glycolide-caprolactone)] with appropriate mechanical strength was used as a scaffold so that undesirable contraction of the wound could be prevented when it was implanted. To enhance cell growth, synthetic PLGC was incorporated with a fibrin-based biomimetic composite. The efficacy of the hybrid scaffold was evaluated by comparing it with bare PLGC in terms of fibroblast growth potential, extracellular matrix (ECM) deposition, polymer degradation, and mechanical strength. A significant increase was observed in fibroblast attachment, proliferation, and deposition of ECM proteins such as collagen and elastin in the hybrid scaffold. After growing fibroblasts for 20 d and 40 d, immunochemical staining of the decellularized scaffolds showed deposition of insoluble collagen and elastin on the hybrid scaffold but not on the bare scaffold. The loss of mechanical strength consequent to in vitro polymer degradation seemed to be balanced owing to the ECM deposition. Thus, tensile strength and elongation were better when cells were grown on the hybrid scaffold rather than the bare samples immersed in culture medium. Similar patterns of in vivo and in vitro degradation were observed during subcutaneous implantation and fibroblast culture, respectively. We therefore postulate that a hybrid scaffold comprising PLGC and fibrin is a potential candidate for the engineering of dermal tissue to be used in the regeneration of chronic wounds.

Long-term in vivo assessment of bioengineered skin substitutes: a clinical study

The aim of the study was an objective in vivo assessment of skin properties after reconstruction with two artificial dermal substitutes, Integra® and Hyalomatrix®. Twenty-seven patients underwent reconstruction of 36 skin-loss sites with full-thickness skin graft, split-thickness skin graft, Hyalomatrix® bioengineered skin substitute and sequential split-thickness skin graft and Integra® bioengineered skin substitute and sequential split-thickness skin graft. Objective assessments were carried out using three instrumental devices: Multi Probe Adapter System MPA; 22 MHz ultrasound skin scan; and Primos Pico for a three-dimensional (3D) skin scan. The skin parameters under study in our sample were: corneometry, transepidermal water loss, elastometry, colorimetry, skin thickness and 3D skin surface pattern. A skin reconstruction with Hyalomatrix seemed to most closely approach the hydration, transepidermal water loss and skin surface 3D pattern of normal skin. A skin reconstruction with Integra seemed to demonstrate the best skin colour feature and elastic properties. Although no statistically significant differences were observed, the descriptive analysis of the outcomes might suggest a better cell regulation, regenerated extracellular matrix and neoangiogenesis with the use of Hyalomatrix, and the formation of a more elastic regenerated dermis, with overall better physical, mechanical and optical properties, with the use of Integra.

Integra™ in burns reconstruction: Our experience and report of an unusual immunological reaction

Limited availability of autologous donor sites poses significant challenges for soft-tissue reconstruction in severe and complex burns. Integra™ is a bi-layered dermal regeneration template (DRT) which has played a significant role in soft tissue reconstruction since its initial use for full-thickness burn defects. The purpose of this study is to report our institutional experience of Integra™ in burns management over a 4-year period and highlight an unusual reaction to its second application. Twenty-four cases underwent Integra™ resurfacing for burn management from September 2007 to August 2011. Data on patient demographics, including co-morbidities, indications, operative data, complications, secondary reconstruction and outcomes were recorded. Integra™ was used in 24 patients on 37 anatomical sites. One patient died 3 weeks after injury and first stage of Integra™ application, and was therefore excluded from the study. Split-thickness skin grafting was performed within an average of 23 days (with a range of 7-55 days) and mean graft take was 87% (with a range of 75-100%). Five cases of local infection at the graft site were recorded. The average length of hospital stay was 47 days (with a range of 1-162 days). The mean follow-up time was 17 months (with a range of 9-34 months). Overall, our experience with DRT was mixed, that is to say we found it satisfactory with acute burns resurfacing but very good with secondary reconstruction. The main advantage of Integra™ is its immediate availability in unlimited quantities for soft-tissue reconstruction in major and complex burns. The main drawbacks are financial implications, twostage procedure, complex wound care and risk of infection. We believe that Integra™ can be considered as a promising modality in burns management.

Nonmicrosurgical options for soft tissue reconstruction of the hand

There are many options for nonmicrosurgical soft tissue coverage of hand wounds, ranging from split thickness skin grafting to pedicled soft tissue transfer, depending on the size, location, blood supply, and depth of the wound. Although many of these techniques have been available for decades, recent advancements in wound management include synthetic dermal substitution, new dressing materials, and variations on previously described or novel pedicled flaps.The goals of coverage include maximizing healing, function, aesthetic appearance, and patient satisfaction, while minimizing donor site morbidity. Optimal management often relies on an individual surgeon's assessment and judgment, as hand wounds can vary greatly and pose unique challenges, and multiple coverage options often exist for each wound. Here, we aim to present useful and up-to-date information on nonmicrosurgical soft tissue coverage for hand reconstruction focusing on recent findings of interest to provide an update on areas with evolving evidence.

Uniaxial cyclic strain stimulates cell proliferation and secretion of interleukin-6 and vascular endothelial growth factor of human dermal fibroblasts seeded on chitosan scaffolds

Human dermal fibroblasts were inoculated into chitosan sponge scaffolds coated with type I collagen and it might be developed as a dermal substitute and/or dressing material. The application of 14% uniaxial cyclic strain to the cellular scaffolds affected the characteristics of the seeded human dermal fibroblasts. Cyclic strain enhanced cellular proliferation, the activity of metalloproteinase-2, and the expression of extracellular matrix proteins such as fibronectin. Moreover, cyclic strain increased the expression of vascular endothelial growth factor (VEGF) and interleukin (IL)-6, which are critical to wound healing. Even under static culture (strain, 0%) following 14% cyclic strain, the expression of VEGF and IL-6, which had increased under 14% strain, was amplified or maintained for at least 3 days. Uniaxial cyclic strain may enhance the wound-healing potential of human dermal fibroblasts seeded on chitosan scaffolds through the changes in the cellular characteristics of the fibroblasts when the cellular scaffold is transplanted into skin wounds, especially chronic wounds such as diabetic wounds.

The use of a dermal substitute to preserve maximal foot length in diabetic foot wounds with tendon and bone exposure following urgent surgical debridement for acute infection

In this study, we evaluated the utility of a dermal substitute for preserving maximal foot length after urgent surgical debridement. Patients referred to our Diabetic Foot Center with foot lesions were assessed for sensory-motor neuropathy, infection and critical limb ischaemia. The presence of acute foot infection indicated the need for immediate surgical debridement. The degree of amputation, if necessary, was based on the amount of apparently non infected vital tissue. When vital tendon/bone tissue remained exposed, the lesion was covered with a dermal substitute. From January to December 2008, 393 patients underwent surgical treatment for diabetic foot syndrome; 30 patients underwent immediate surgical debridement resulting in exposed tendon and/or bone tissues. An average of 4.4 +/- 2.1 days following surgical debridement, all 30 patients underwent dermal regeneration template grafting to cover-exposed healthy tendon and bone tissues, instead of achieving primary wound closure with a proximal amputation. After 21 days, a skin graft was performed. Complete wound healing occurred in 26 patients (86.7%). In these patients, the amputation level was significantly more distal (P < 0.003) with respect to that potentially required for immediate wound closure. The average healing time was 74.1 +/- 28.9 days. Four patients underwent a more proximal amputation. No patients underwent major amputation. The use of the dermal substitute for treating exposed tendon and bone tissues allowed timely wound healing and preserved maximal foot length. Continued follow-up will allow assessment of long-term relapse and complication rates. Such treatment could constitute part of the comprehensive management of diabetic wounds.