Ali Pirayesh

Burn scar assessment: A systematic review of objective scar assessment tools

PURPOSE All deep second and third degree burns are at risk to develop hypertrophic scars which can severely undermine the quality of survival. To assess the severity of scarring, several technical devices or tools have been introduced to evaluate one or more aspects of the scar, enabling comparison of different treatment protocols and allowing an objective follow-up. The objective of this study was to review which tools can be used in objective burn scar assessment. BASIC PROCEDURES The Systematic literature search involving PubMed, the Web of Science (incl. Science Citation Index). MAIN FINDINGS 51 articles with burn scar assessment as main topic were found. Several characteristics of the scar can be assessed, such as color, metric features and elasticity, but none of the available tools covers the whole aspect of the scar. Especially subjective factors such as pain and itching cannot be assessed with those tools, in spite of their great impact on the patients quality of life. CONCLUSIONS Scar tools enable objective and reproducible evaluation of scars, which is essential for scientific studies and medico-legal purposes, and in selected cases for the clinical follow-up of an individual patient. Further studies to evaluate these tools on scars are nevertheless required.

Skin replacement in burn wounds.

Historically, the main goal in burn management was increasing the survival of severely burned patients by rapid debridement and early closure of burn wounds, consequently reducing the infection risk.1–4 However, in the last decennia, surgical emphasis has shifted from survival to “quality of survival,” especially by improving the residual scars and preventing contractures. Traditionally, surgeons divide burns into deep burns requiring surgical therapy, and superficial burns which heal spontaneous by re-epithelialization with minimal scarring. Nevertheless, there is a gray zone between those two groups in which therapeutic decision making is difficult. The final decision for surgery generally remains case and surgeon dependent, and will mainly depend on the total burned surface area.5 Wound closure can be obtained by diverse therapeutic modalities depending on the depth and healing potential of the burn wound.5 In this article, the main focus is on the surgical treatment of deep dermal and full thickness burns. We endeavor to give a comprehensive overview of the developments in skin substitutes, which is impossible without mentioning some alternative treatments. The current golden standard for deep burns is surgical debridement and closure with autologous split thickness skin grafts or “STG” (epidermis plus a thin layer of dermis). Nevertheless, donor areas are limited in extended burns, and the residual scars remain unsatisfactory due to the lack of dermis. A more aesthetical reconstruction can be obtained with full thickness skin grafts (epidermis and whole dermis), which are limited in dimension and can only be harvested in a few areas (groin, lower abdomen, etc.). Deep defects with exposed bone or neurovascular structures are currently treated with flap surgery, which gives an optimal aesthetical and functional result. Nevertheless, the severe donor-site morbidity, the technical difficulty, and sometimes severe complications limit its use mostly to secondary reconstructions. Consequently, alternative conservative and surgical treatments were developed to improve the healing and the quality of the residual scars.6 Several mechanisms are supposed to enhance healing: (i) providing the ideal wound environment (wound dressings, etc.), (ii) by assisting the intrinsic healing capacities (growth factors, cytokines, etc.), or (iii) by surgically replacing the damaged skin (“skin substitutes”), which also should reduce scarring in full thickness defects. A permanent skin substitute is a surgically fixated “long lasting” skin replacement, consisting of naturally occurring skin elements which become incorporated in the normal skin. The main issue of this definition is the longevity of a skin substitute, which seems to be mostly of commercial importance, where terms such as biological dressings, and permanent and temporary skin substitutes are used without a clear distinction. This literature review showed that technically similar products are commercialized as “permanent” by one company and as biological dressing by another. Therefore, we chose to divide all these products in the following categories, depending on the skin layer which is (temporary) replaced: epidermal, dermal and combined skin substitutes (or composite grafts; Fig. 1). In the future, a fourth group might need to be added: the combined skin substitute with a subcutaneous adipose layer.7 However, the difference between skin replacements and some wound dressings can be small. Wound dressings are intended for coverage instead of replacement, to optimize wound healing. Wound dressings can roughly be divided in dressings containing natural elements (such as honey ointments), synthetic dressings (such as silver-impregnated dressings), and biological dressings containing mammalian cells or cell-derived substances like collagens and growth factors (human donor skin). Synthetically manufactured, naturally occurring elements, such as cellulose membranes, are also synthetic dressings. Wound dressings are not considered as (permanent) skin substitutes because they are not incorporated in the healing wound. Some authors previously named some of these products “skin substitutes” (without mentioning “permanent”) but this only lead to confusing terminology. The most important biological dressing, used since the 1940s, is human donor skin or “cadaver skin.”8 It contains several beneficial factors (growth factors, cytokines, etc.), and it provides the ideal environment for healing. Because of better preservation techniques (glycerol or cryopreserved), the risk of infection transmission is minimized, and its rejection will be delayed up to 3 weeks to 5 weeks.8,9 One of the Submitted for publication May 18, 2009. Accepted for publication November 6, 2009. Copyright

Burn Scar Assessment: A Systematic Review of Different Scar Scales

BACKGROUND Scars can be devastating and disfiguring, because they are clearly visible, stigmatizing, and permanent reminders of the initial accident or surgical event. Yet, there is still no consensus about the optimal scale or tool to assess the characteristics and evolution. Our aim was to evaluate the clinical importance of scar scales specifically developed for burn scars. MATERIALS AND METHODS The systematic literature search involved PubMed and the Web of Science (including Science Citation Index). RESULTS The search resulted in 29 articles (including seven reviews) dealing with a new, modified, or validated scale. Scar scales assess several characteristics, of which color, pliability, and thickness were considered the most important. Physical limitation, pain, and pruritus are often more disturbing than the appearance of the scar, and are therefore also introduced in scar evaluation, as well as the interference with daily life activities (e.g., psychologic impact). CONCLUSION In contrast to the more objective scar assessment tools, scar scales usually cover more aspects of the scars and are less time-consuming in clinical practice. However, no strong conclusions can be made about their efficacy and validity. In addition to digital photography, scar scales are a valuable instrument in the clinical evaluation and follow-up of scars.

Scar management by means of occlusion and hydration: A comparative study of silicones versus a hydrating gel-cream

Despite the worldwide use of silicones in scar management, its exact working mechanism based on a balanced occlusion and hydration, is still not completely elucidated. Moreover, it seems peculiar that silicones with completely different occlusive and hydrating properties still could provide a similar therapeutic effect. The objective of the first part of this study was to compare the occlusive and hydrating properties of three fluid silicone gels and a hydrating gel-cream. In a second part of the study these results were compared with those of silicone gel sheets. Tape stripped skin was used as a standardized scar like model on both forearms of 40 healthy volunteers. At specific times, trans epidermal water loss (TEWL) and the hydration state of the stratum corneum were measured and compared with intact skin and a scar-like control over a 3-4h period. Our study clearly demonstrated that fluid silicone gels and a hydrating gel-cream have comparable occlusive and hydrating properties while silicone gel sheets are much more occlusive, reducing TEWL values far below those of normal skin. A well-balanced, hydrating gel-cream can provide the same occlusive and hydrating properties as fluid silicone gels, suggesting that it could eventually replace silicones in scar treatment.

Glyaderm® dermal substitute: Clinical application and long-term results in 55 patients

INTRODUCTION Glycerol preserved acellular dermis (Glyaderm(®)) consists of collagen and elastin fibers and is the first non-profit dermal substitute derived from glycerol-preserved, human allogeneic skin. It is indicated for bi-layered skin reconstruction of full thickness wounds. METHODS A protocol for clinical application and optimal interval before autografting with split thickness skin graft (STSG) was developed in a pilot study. A phase III randomized, controlled, paired, intra-individual study compared full thickness defects engrafted with Glyaderm(®) and STSG versus STSG alone. Outcome measures included percentage of Glyaderm(®) take, STSG take, and scar quality assessment. RESULTS Pilot study (27 patients): Mean take rates equaled 91.55% for Glyaderm(®) and 96.67% for STSG. The optimal autografting interval was 6 days (±1 day). Randomized trial (28 patients): Mean Glyaderm(®) take rate was 88.17%. STSG take rates were comparable for both research groups (p=0.588). One year after wound closure, Glyaderm(®)+STSG was significantly more elastic (p=0.003) than STSG alone. Blinded observers scored Glyaderm(®) treated wounds better in terms of scar quality. DISCUSSION The efficacy of Glyaderm(®) as a suitable dermal substitute for full thickness wounds is attested. Currently a procedure for simultaneous application of Glyaderm(®) and STSG is adopted, allowing for further widespread use of Glyaderm(®).

The role of silver sulphadiazine in the conservative treatment of partial thickness burn wounds: A systematic review

BACKGROUND For more than 40 years, silver sulphadiazine 1% (SSD) is considered as standard therapy for the conservative treatment of burn wounds. However, in the last 10 years, substantial disadvantages of SSD have been reported in the literature and probably as a result of this, several new dressings for burn wounds have been developed and put on the market. The objective of this systematic review is to evaluate the available evidence on SSD in the conservative treatment of burns, specifically in comparison with the newer burn dressings that are increasingly being used nowadays. MATERIALS AND METHODS A search filter was composed to select randomized controlled trials (RCTs) from the MEDLINE database. Only RCTs studying the effect of conservative treatment on burns were selected. At least one of the two comparative groups was treated with SSD. Each included article was analysed and relevant data (baseline parameters, interventions, outcomes and methodological parameters) were registered using Microsoft Office Excel 2007. RESULTS Many dressings showed superior healing properties compared to SSD, but no dressing was able to show a clear benefit over SSD regarding infection. The number of dressing changes, pain and patients satisfaction are more favourable in the newer dressings, especially with solid and biological dressings. CONCLUSIONS The results of this systematic review clearly demonstrate that a faster wound healing is obtained with the newly developed burn dressings. Additionally, these new dressings tend to be more comfortable for the patients and easier to use for care givers. The minor differences in antibacterial activity between SSD and the new products did not seem to have any influence on the rate of wound healing. Since rapid wound closure is essential to obtain an optimal functional and aesthetic outcome, it can be concluded from the results of this systemic review that the standard use of SSD in the conservative treatment of burn wounds can no longer be supported.

Exposed tibial bone after burns: Flap reconstruction versus dermal substitute

A 44 years old male patient had suffered extensive 3rd degree burns on both legs, undergoing thorough surgical debridement, resulting in both tibias being exposed. Approximately 5 months after the incident he was referred to the Department of Plastic and Reconstructive Surgery of the University Hospital Gent, Belgium, to undergo flap reconstruction. Free flap surgery was performed twice on both lower legs but failed on all four occasions. In between flap surgery, a dermal substitute (Integra(®)) was applied, attempting to cover the exposed tibias with a layer of soft tissue, but also without success. In order to promote the development of granulation tissue over the exposed bone, small holes were drilled in both tibias with removal of the outer layer of the anterior cortex causing the bone to bleed and subsequently negative pressure wound therapy (NPWT) was applied. The limited granulation tissue resulting from this procedure was then covered with a dermal substitute (Glyaderm(®)), consisting of acellular human dermis with an average thickness of 0.25mm. This dermal substitute was combined with a NPWT-dressing, and then served as an extracellular matrix (ECM), guiding the distribution of granulation tissue over the remaining areas of exposed tibial bone. Four days after initial application of Glyaderm(®) combined with NPWT both tibias were almost completely covered with a thin coating of soft tissue. In order to increase the thickness of this soft tissue cover two additional layers of Glyaderm(®) were applied at intervals of approximately 1 week. One week after the last Glyaderm(®) application both wounds were autografted. The combination of an acellular dermal substitute (Glyaderm(®)) with negative pressure wound therapy and skin grafting proved to be an efficient technique to cover a wider area of exposed tibial bone in a patient who was not a candidate for free flap surgery. An overview is also provided of newer and simpler techniques for coverage of exposed bone that could question the universal plastic surgery paradigm that flap surgery is the only way to cover these defects.

Evaluation of Acellular Dermis for Closure of Abdominal Wall Defects in a Rat Model

Background: Abdominal wall repair can be performed with synthetic or biological materials. Biological materials may reduce the risk of infections and fibrosis. The aim of this study was to evaluate two acellular human dermis products. Materials and Methods: A rat model was used to compare the two materials. One was prepared using low concentrations of NaOH; the other material was SureDerm™, which is commercially available. Full thickness defects were prepared in the abdominal wall and closed with the materials. Rats were sacrificed at 1 or 4 months after operation and the numbers of adhesions to the bowels were scored. Samples were tak- en for histological analysis and to measure the breaking strength. Results: In both groups a good functional integration of the implants with the abdominal wall was observed. There was no adhesion formation with the bowels in the group with the NaOH prototype. In the SureDerm group, 4 out of 7 rats showed only small adhesions at 4 months after operation. Breaking strength of the healed tissue was significantly higher in the NaOH prototype group at 4 months after operation (p < 0.0026). Conclusions: The results indicate that both human acellular dermis products may be used in clinical trials for closure of abdominal wall defects.

Microneedling: Where do we stand now? A systematic review of the literature

BACKGROUND Patients who suffer from scars or wrinkles have several therapeutic options to improve the appearance of their skin. The available treatment modalities that provide desirable results are often overtly invasive and entail a risk of undesirable adverse effects. Microneedling has recently emerged as a non-ablative alternative for treating patients who are concerned with the aesthetic changes that result from injury, disease or ageing. OBJECTIVE This review aims to evaluate the current evidence in the literature on microneedling. METHODS A systematic literature review was performed by searching the electronic databases PubMed and Google Scholar. The reviewed articles were analysed and compared on study design, treatment protocol, outcome parameters, efficacy measurement and results to evaluate the strength of the current evidence. RESULTS Microneedling was investigated in experimental settings for its effects on atrophic acne scars, skin rejuvenation, hypertrophic scars, keloids, striae distensae, androgenetic alopecia, melasma and acne vulgaris. Several clinical trials used randomisation and single-blindation to strengthen the validity of the study outcome. Microneedling showed noteworthy results when used on its own and when combined with topical products or radiofrequency. When compared with other treatments, it showed similar results but was preferred due to minimal side effects and shorter downtime. CONCLUSION This systematic review positions microneedling as a safe and effective therapeutic option for the treatment of scars and wrinkles. The current literature does show some methodological shortcomings, and further research is required to truly establish microneedling as an evidence-based therapeutic option for treating scars, wrinkles and other skin conditions.