Engineered Skin Substitutes in Dermatologic Surgery: A Systematic Review

BACKGROUND

Artificial skin substitutes are a flexible alternative to autografting in Mohs micrographic surgery (MMS), but the characteristics and clinical outcomes of skin substitutes are not well defined.

OBJECTIVE

Summarize clinical data of skin substitutes in MMS for cutaneous malignancy.

METHODS

A MEDLINE/Embase/Web of Science search was conducted. Articles with original data on outcomes after skin substitute use in MMS for cutaneous malignancy were included. Articles not in English or without original data were excluded. Bias was assessed using the Oxford CEBM Levels of Evidence Table. Outcomes were synthesized using weighted averages. This study was prospectively registered in PROSPERO.

RESULTS

Of 1,007 articles, 40 met eligibility for inclusion. In total, 898 patients who underwent MMS and received a skin substitute were included. Xenografts were most commonly used ( n = 613). Semi-synthetic grafts (∼$<1/cm 2 ) and xenografts (∼$10/cm 2 ) are most affordable. Overall, outcomes were excellent for all skin substitutes, with a small proportion of patients experiencing correctable complications.

CONCLUSION

Skin substitutes are highly effective in MMS, with enormous potential. While the data demonstrate positive outcomes, they predominately draw from small, retrospective studies or case reports. There is also a scarcity of data comparing skin substitutes with each other or controls. Prospective studies are recommended.

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

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

Integra® Dermal Regeneration Template in Complex Scalp Reconstruction

Background/Objectives: The need for surgical reconstruction of scalp defects following the excision of cutaneous skin cancers is an increasingly common procedure. Particular challenges arise when considering options for reconstruction of large defects not amenable to local skin flap coverage. The use of skin grafts poses the risk of donor site morbidity. This paper investigates the emerging use of Integra®, a synthetic acellular dermal regeneration template, as an alternative or adjunct to skin grafting in scalp reconstruction. Methods: The study presents a retrospective analysis of 101 patients who underwent Integra®-based reconstruction of scalp defects. Demographics, procedure details, complications, need for further surgery, and time to healing were evaluated. Results: The overall success rate of the one-stage Integra®-only procedure was 95%, with a minor complication rate of 30.7%. Anticoagulation medication was identified as an independent risk factor for post-operative infection, while previous head and neck radiotherapy and increased defect depth were associated with the requirement for a second-stage skin graft. Conclusions: These findings support the consideration of Integra® as a safe and viable alternative for both partial and full thickness scalp defects in a select cohort of complex highly co-morbid patients, reducing complications and the need for additional procedures.

One-stage reconstruction of extensive exposed tibia on malnourished patient using single-layer Integra and amino acid supplements: A case report and literature review

RATIONALE

Extremity injuries resulting from motor vehicle collisions, especially those leading to bone-exposed wounds, present challenges for achieving effective wound coverage. Such injuries are susceptible to complications including infections, osteomyelitis, and unexpected amputations due to inadequate blood supply. Severe traumatic degloving injuries often entail damage to the surrounding blood vessels, making local or free flaps impractical choices in many cases. Consequently, treatment options may vary based on distinct clinical scenarios, with no standardized guidelines available. Our study introduces an integrated approach utilizing dermal substitutes and skin grafts as a safer treatment modality for managing large-area tibial exposure resulting from traffic accidents.

PATIENT CONCERNS

A 66-year-old male with a compromised nutritional status was struck by a car while riding a motorcycle. Previous attempts using double-layer Integra and negative pressure wound therapy (NPWT) for two-stage reconstruction have been unsuccessful.

DIAGNOSES

Computed tomography imaging studies revealed multiple comminuted and displaced fractures involving the left femoral shaft, left proximal tibia, left patella, and proximal fibula, as well as a fracture of the right fibular shaft and an avulsion fracture of the right distal medial femur. The patient's condition corresponded to Type 3B in the Gustilo classification for open fractures, and the patient had an Injury Severity Score of 25.

INTERVENTIONS

We applied a one-stage reconstruction involving single-layer Integra, split-thickness skin grafts, NPWT, and nutritional supplements containing various amino acids.

OUTCOMES

By implementing an integrated treatment approach and providing diligent wound care over a total of 2 months, the patient achieved successful healing and expressed satisfaction with the postoperative results.

LESSONS

This study offers insights into the effectiveness of employing one-stage reconstruction for traumatic injuries with extensive exposed tibias. In addition, it underscores the impact of a patient's nutritional status on wound healing and introduces a potential solution for similar challenging cases.

Basic fibroblast growth factor-impregnated collagen gelatin sponge completes formation of dermis-like tissue within 2 weeks: A prospective cohort study

Introduction

Methods

Results

Conclusion

•

This study examined the usefulness of bFGF-CGS for skin defects.

•

bFGF-CGS completes dermis-like tissue within 2 weeks.

•

bFGF-CGS rapidly achieved wound closure of acute full-thickness skin defects.

Comparison of Skin Substitutes for Acute and Chronic Wound Management

Chronic and acute wounds, such as diabetic foot ulcers and burns, respectively, can be difficult to treat, especially when autologous skin transplantations are unavailable. Skin substitutes can be used as a treatment alternative by providing the structural elements and growth factors necessary for reepithelialization and revascularization from a nonautologous source. As of 2020, there are 76 commercially available skin substitute products; this article provides a review of the relevant literature related to the major categories of skin substitutes available.

Dermal Regeneration Templates in Maxillo-Facial District: A Multipurpose Aid

ABSTRACT

Since 1980s, the use of dermal regeneration templates (DRT) for reconstructive purposes has been described in Literature.1 The authors present their experience of 13 patients treated with integra dermal regeneration template and a single-stage surgery for different indications like oncologic reconstruction, trauma injuries, and preprosthetic surgery in the maxillo-facial district.The authors retrospectively reviewed a total of 13 patients treated with DRT at Maxillo-Facial Department of S. Maria Hospital in Terni.Inclusion criteria included the presence of a defect nonapproachable primarily or by secondary intention with an easy locoregional flap reconstruction, a complete clinical record, and a minimum 6 months follow-up.A total of 12 patients underwent surgical reconstruction with DRT at the S. Maria Hospital from June 2018 to February 2020.During follow-up, all patients in which intraoral reconstruction was performed showed first signs of re-mucosization and neovascularization after 10 days.Only in 1 patient (8%) a seroma underneath the silicon sheet was observed. Afterward, the patient healed correctly with no other complications.Dermal regeneration template represents an option that should be considered in the head and neck district reconstruction, especially for intraoral defects where, thanks to its long-term functional results and limited alternatives, should represent a relevant choice.

Impact of dermal matrix thickness on split-thickness skin graft survival and wound contraction in a single-stage procedure

Optimal treatment of full‐thickness skin injuries requires dermal and epidermal replacement. To spare donor dermis, dermal substitutes can be used ahead of split‐thickness skin graft (STSG) application. However, this two‐stage procedure requires an additional general anaesthetic, often prolongs hospitalisation, and increases outpatient services. Although a few case series have described successful single‐stage reconstructions, with application of both STSG and dermal substitute at the index operation, we have little understanding of how the physical characteristics of dermal substitutes affects the success of a single‐stage procedure. Here, we evaluated several dermal substitutes to optimise single‐stage skin replacement in a preclinical porcine model. A porcine full‐thickness excisional wound model was used to evaluate the following dermal substitutes: autologous dermal graft (ADG; thicknesses 0.15‐0.60 mm), Integra (0.4‐0.8 mm), Alloderm (0.9‐1.6 mm), and chitosan‐based hydrogel (0.1‐0.2 mm). After excision, each wound was treated with either a dermal substitute followed by STSG or STSG alone (control). Endpoints included graft take at postoperative days (PODs) 7 and 14, wound closure at POD 28, and wound contracture from POD 28‐120. Graft take was highest in the STSG alone and hydrogel groups at POD 14 (86.9% ± 19.5% and 81.3% ± 12.3%, respectively; P < .001). There were no differences in graft take at POD 7 or in wound closure at POD 28, though highest rates of wound closure were seen in the STSG alone and hydrogel groups (93.6% ± 9.1% and 99.8% ± 0.5%, respectively). ADG‐treated wounds demonstrated the least amount of wound contracture at each time point. Increase dermal substitute thickness was associated with worse percent graft take at PODs 14 and 28 (Spearman ρ of −0.50 and −0.45, respectively; P < .001). In this preclinical single‐stage skin reconstruction model, thinner ADG and hydrogel dermal substitutes outperformed thicker dermal substitutes. Both substitute thickness and composition affect treatment success. Further preclinical and clinical studies to optimise this treatment modality are warranted.

Selection of Artificial Dermis for Shortening Treatment Period: Integra versus Pelnac

Skin reconstruction of full-thickness skin defect wounds using artificial dermis is performed using secondary split-thickness skin grafting. For the selection of artificial dermis to shorten the treatment period, the waiting time until secondary skin grafting was investigated when the dermis-like tissue was constructed with Pelnac or Integra.

Historical Evolution of Skin Grafting-A Journey through Time

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

The Combined Use of Negative-Pressure Wound Therapy and Dermal Substitutes for Tissue Repair and Regeneration

In clinical practice, skin defects occur frequently due to various kinds of acute and chronic diseases. The standard treatment for these wounds is autografting, which usually results in complications such as scar formation and new wounds at donor sites. The advent of dermal substitutes has provided a novel method for wound repair, and rapid angiogenesis of the dermal substitutes is crucial for the graft to take. At present, many strategies have been developed to improve the process of vascularisation, some of which have shown promising potentials, but they could be very far from clinical applications. Most recently, negative-pressure wound therapy (NPWT) has been used extensively in clinical practice for wound care and management. It has been reported that NPWT reduces the time required for vascular ingrowth into the dermal substitute and improves graft take, indicating great potentials for wound repair. This article presents a comprehensive overview of the combined use of NPWT and dermal substitutes for tissue repair and regeneration. Relative concerns and prospects are also discussed.

Reconstruction of Full-thickness Soft Tissue Defects with Integra: Risk Factors and Treatment Algorithm

Background:

Despite the fact that dermal substitutes are widely used in reconstructive surgery, there have been no studies focused on predictors of complications or delayed matrix take. We propose an algorithm for management of soft tissue reconstruction with Integra dermal matrix, based on our 5-year-long clinical experience.

Methods:

An estimated 111 patients who underwent Integra reconstruction of full-thickness soft tissue defects of different anatomical sites and etiology were enrolled, and dichotomized in two groups according to complications. Participants were further studied according to the wound healing strategy: healing by secondary intention, skin graft (STSG), and flap surgery. A regression analysis was conducted in the whole sample to identify possible predictors of complications.

Results:

No significant differences according to complications were observed. The between-group statistical analysis showed significant differences in age, comorbidities, defect area, diagnosis, and defect site. The regression analysis revealed that the timing of split-thickness skin graft (STSG) was not influenced by age, comorbidities, body mass index (BMI), defect area, site, wound etiology, and risk factors in the subjects who underwent a two-step reconstruction. Healing by secondary intention is recommended for small post-oncological defects of the head, especially in elderly and multimorbid patients. Variables that may interfere with dermal substitutes’ incorporation are independent of the timing of STSG placement; therefore, no predictors of complications or delayed matrix take were identified.

Conclusions:

Our findings showed that Integra can be used in a wide range of patients regardless of their general features, thus acting as a useful alternative to conventional reconstructive techniques in selected cases.

Biologics in Acute Burn Injury

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

Single-stage Composite Skin Reconstruction Using a Dermal Regeneration Template

Background:

Composite reconstruction with a dermal substitute followed by skin graft is sometimes used for reconstructing high-quality skin while preserving donor sites. This often necessitates 2 separate procedures, additional general anesthetic, and longer hospitalization. Concurrent use of dermal substitutes and skin graft in a single stage has been previously reported in small series. Here, we report our experience with single-stage skin reconstruction with Integra and split-thickness skin graft for coverage of wounds post burn eschar excision and post burn scar contracture release.

Methods:

This is a retrospective review of consecutive operations from 2013 to 2017 in which single-stage bilayer reconstruction (SSBR) was performed. Data were obtained from electronic medical records and perioperative photographs.

Results:

In this 5-year period, 13 surgical sites were identified in which SSBR was used in 8 subjects. Average and median graft take was 86.2% and 95%, respectively. Graft take was over 90% in 10 out of 13 cases. One case required regrafting after initial graft failure.

Conclusions:

In the appropriate setting, SSBR is a practical technique in covering wounds post burn eschar excision and post burn scar contracture release resulting in reasonable graft take. Use of noncontaminated wound beds is crucial. Although there is risk of regrafting, it is not clear whether this risk is any higher than in split-thickness skin grafting alone. This study was unable to evaluate contribution of dermal substitute to contraction, function, and mobility, nor how hypothesized improvement of skin quality compares to the original thick dermal substitute. We recommend further investigation.

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.

Improved Dermal Regeneration Using a Combination of Dermal Substitutes and Dermal Fibroblast Optimization: A Hypothesis

In human adults, the repair of cutaneous wounds usually leads to scar formation rather than regeneration. Dermal substitutes have been used as a regenerative template for reducing scar formation and improving the extent of dermal regeneration. However, achievement of complete regeneration is still a long way off. Dermal substitutes are characterized by unusual regenerative activity, appearing to function by acting as temporary configurational guides for cell infiltration and synthesis of new stroma. Fibroblasts are important cells with many vital functions in wound-healing processes. They are heterogeneous with distinct characteristics according to their source location, such as subcutaneous tissue, superficial-layer dermis, and deep-layer dermis. Many studies have shown that superficial dermal fibroblasts possess the potential to form dermis-like tissue. Fibroblasts in deep-layer dermis and subcutaneous tissue may play a critical role in the formation of hypertrophic scars. Fibroblast phenotype affects the newly formed dermal architecture and influences the dermal regeneration effect induced by dermal substitutes. It is hypothesized that better regeneration of the dermis can be achieved using dermal substitutes along with dermal fibroblast optimization.

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.

Stem cells, niches and scaffolds: Applications to burns and wound care

The importance of skin to survival, and the devastating physical and psychological consequences of scarring following reparative healing of extensive or difficult to heal human wounds, cannot be disputed. We discuss the significant challenges faced by patients and healthcare providers alike in treating these wounds. New state of the art technologies have provided remarkable insights into the role of skin stem and progenitor cells and their niches in maintaining skin homeostasis and in reparative wound healing. Based on this knowledge, we examine different approaches to repair extensive burn injury and chronic wounds, including full and split thickness skin grafts, temporising matrices and scaffolds, and composite cultured skin products. Notable developments include next generation skin substitutes to replace split thickness skin autografts and next generation gene editing coupled with cell therapies to treat genodermatoses. Further refinements are predicted with the advent of bioprinting technologies, and newly defined biomaterials and autologous cell sources that can be engineered to more accurately replicate human skin architecture, function and cosmesis. These advances will undoubtedly improve quality of life for patients with extensive burns and difficult to heal wounds.

The caudolaterally inserted transposition flap and its variations for reconstruction of defects of the nasal ala

Closure of non-full-thickness defects of the nasal ala can be a surgical challenge. While there is a plethora of various reconstructive techniques, not all of them are easy to learn and carry out. Recently, the dermatosurgeon Andreas Lösler from the Department of Dermatology at the Hornheide Medical Center, Germany, developed and published the caudolaterally inserted transposition flap for the reconstruction of alar defects. Given its relative novelty, this technique, which is characterized by a very low complication rate, is still unknown to most dermatosurgeons and has not yet found its way into standard dermatosurgery textbooks. The present review describes the caudolaterally inserted transposition flap and two modifications thereof, which allow for the closure of large alar defects as well as defects of the alar crease. Comparisons are made to the two flaps most commonly employed for alar reconstruction, the bilobed flap and the cranially inserted nasolabial transposition flap (melolabial flap).

The Use of Dermal Skin Substitutes for the Treatment of the Burned Hand

The hand is commonly affected in burn injuries. Joints and extensor tendons are vulnerable given their superficial location. Durable coverage that permits relative frictionless tendon gliding and minimizes scar contracture is required to optimize functional outcomes. When soft tissue donor sites are limited, the use of dermal skin substitutes provides stable coverage with minimal scarring, good mobility, and acceptable appearance. A comprehensive review of dermal skin substitutes and their use with burn reconstruction of the hand is provided.

Retrospektive Analyse von56 Weichteildefekten nach einzeitiger Rekonstruktion unter Verwendung von Dermisersatzpräparaten

HINTERGRUND

Der Verschluss von Wunden mit ausgeprägtem Weichteilschaden stellt eine chirurgische Herausforderung dar und erfordert häufig umfangreiche plastische Operationen sowie freie Lappenplastiken. Die Kombination von Dermisersatzpräparaten und Spalthauttransplantationen ist eine innovative Methode die zur Versorgung von komplexen Verletzungen der Extremitäten angewandt werden kann. Wir haben diese Technik in das Standard-Handwerkszeug bei komplexen Verletzungen der Extremitäten aufgenommen. Die klinischen Ergebnisse von 56 behandelten Patienten werden vorgestellt.

PATIENTEN UND METHODEN

In 44 Fällen (78,6 %) wurde die beschriebene Methode an Defekten der unteren Extremitäten verwendet, einschließlich sieben Personen (12,5 %), die sich einer Stumpfdeckung nach Amputation unterzogen. Zwölf Defekte (21,4 %) befanden sich an den oberen Extremitäten. In zwei Fällen (3,6 %) wurde die Matriderm(®) -Matrix verwendet, um Nerven von unmittelbar angrenzenden chirurgischen Implantaten zu schützen.

ERGEBNISSE

Bei 41 Patienten (73,2 %) kam es zur Einheilung des Transplantats ohne Komplikationen. Fünfzehn Patienten (26,8 %) zeigten eine gestörte Wundheilung nach Defektverschluss, die unter konservativer Therapie zur Ausheilung gebracht werden konnte. Ein Patient (1,8 %) zeigte ein Transplantatversagen, was eine Revisionsoperation erforderlich machte. Umfangreiche plastische Rekonstruktionen mussten bei keinem Patienten angewandt werden.

SCHLUSSFOLGERUNGEN

Bei Fällen, in denen ausgedehnte plastische Operationen nicht möglich oder nicht erwünscht sind, ist die Verwendung von Dermisersatzpräparaten in Kombination mit Spalthauttransplantationen eine vielversprechende Alternative zum Wundverschluss bei ausgedehnten Weichteilschäden.

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.

Scarring, stem cells, scaffolds and skin repair

The treatment of full thickness skin loss, which can be extensive in the case of large burns, continues to represent a challenging clinical entity. This is due to an on-going inability to produce a suitable tissue engineered substrate that can satisfactorily replicate the epidermal and dermal in vivo niches to fulfil both aesthetic and functional demands. The current gold standard treatment of autologous skin grafting is inadequate because of poor textural durability, scarring and associated contracture, and because of a paucity of donor sites in larger burns. Tissue engineering has seen exponential growth in recent years with a number of 'off-the-shelf' dermal and epidermal substitutes now available. Each has its own limitations. In this review, we examine normal wound repair in relation to stem/progenitor cells that are intimately involved in this process within the dermal niche. Endothelial precursors, in particular, are examined closely and their phenotype, morphology and enrichment from multiple sources are described in an attempt to provide some clarity regarding the controversy surrounding their classification and role in vasculogenesis. We also review the role of the next generation of cellularized scaffolds and smart biomaterials that attempt to improve the revascularisation of artificial grafts, the rate of wound healing and the final cosmetic and functional outcome.

Regenerative medicine and nasal surgery

Nasal surgery is a constellation of operations that are intended to restore form and function to the nose. The amount of augmentation required for a given case is a delicate interplay between patient aesthetic desires and corrective measures taken for optimal nasal airflow. Traditional surgical techniques make use of autologous donor tissue or implanted alloplastic materials to restore nasal deficits. Limited availability of donor tissue and associated harvest site morbidity have pushed surgeons and researchers to investigate methods to bioengineer nasal tissues. For this article, we conducted a review of the literature on regenerative medicine as it pertains to nasal surgery. PubMed was searched for articles dating from January 1, 1994, through August 1, 2014. Journal articles with a focus on regenerative medicine and nasal tissue engineering are included in this review. Our search found that the greatest advancements have been in the fields of mucosal and cartilage regeneration, with a growing body of literature to attest to its promise. With recent advances in bioscaffold fabrication, bioengineered cartilage quality, and mucosal regeneration, the transition from comparative animal models to more expansive human studies is imminent. Each of these advancements has exciting implications for treating patients with increased efficacy, safety, and satisfaction.

Complete skin resection of the dorsum of the hand: a prophylactic approach using a dermal regeneration template

BACKGROUND

Surgical treatment of multiple and recurring invasive carcinomas on the dorsum of the hand often results in a reconstructive challenge. Reconstruction is limited due to reduced adjacent tissue. Preserving the functionality of the hand is pivotal and needs to be respected while planning reconstruction.

OBJECTIVE

We present a case of extensive, multiple, and recurring invasive squamous cell carcinoma on the dorsum of the hand and describe a prophylactic surgical approach.

METHODS

We performed a radical excision of the skin on the dorsum of the hand and surgical reconstruction using a bilayer dermal skin substitute and split-thickness skin grafting.

RESULTS

After a 1-year follow-up, we observed an excellent cosmetic and functional result with no signs of recurrence.

CONCLUSIONS

In case of extensive invasive squamous cell carcinoma on the dorsum of the hand, prophylactic resection and surgical reconstruction using a dermal regeneration template should be considered.

Reconstruction of skin avulsion injuries of the upper extremity with integra(®) dermal regeneration template and skin grafts in a single-stage procedure

INTRODUCTION

Management of skin avulsion injuries of the upper extremity may require coverage with large flaps or skin autografts. Cutaneous grafting is frequently combined with artificial skin to optimize the final functional and cosmetic result. The conventional use of bilaminated dermal substitutes consists of a two-stage procedure and requires long immobilization of the operated area. The purpose of this retrospective study is to evaluate the impact of a dermal regeneration template immediately covered by skin grafts in a one-step procedure for reconstructing skin avulsion injuries of the hand and forearm.

MATERIALS AND METHODS

We performed this technique in eight patients who presented with extended skin defects of the hand and forearm following skin avulsion injuries. Dimensions of the defects ranged from 160 to 1,250 cm(2). After debridement, Integra(®) Single Layer was applied and covered with unmeshed thin skin autografts; compressive dressings were used for 1 week and mobilization started by the second postoperative week. Histological examination of the grafted areas was performed 2 weeks after surgery. Functional and cosmetic outcome was assessed 12 months postoperatively.

RESULTS

The overall take rate of the dermal substitute and skin graft was 95-98 %. Histological results showed complete incorporation and vascular proliferation of the template, which allowed the neo-vascularization of the overlying autograft. The mean grip strength of the operated hands was at the 83 % of the normal contralateral hands. Pliability and overall appearance of the reconstructed areas was satisfactory (mean Vancouver Scar Scale Score 1.875).

CONCLUSIONS

The use of Integra(®) Single Layer dermal substitute and immediate skin overgrafting consists an alternative reconstructive option for managing extended skin avulsion injuries of the upper extremity; it reduces postoperative immobilization, minimizes donor site morbidity and provides good functional and esthetic results in a single surgical procedure.

The effect of collagen-chitosan porous scaffold thickness on dermal regeneration in a one-stage grafting procedure

Dermal substitutes are used as dermal regeneration templates to reduce scar formation and improve wound healing. Unlike autografts, dermal substitutes lack normal vascular networks. The increased distance required for diffusion of oxygen and nutrients to the autograft following interpositioning of the substitute dramatically affects graft survival. To evaluate the effect of collagen-chitosan scaffold thickness on dermal regeneration, single-layer collagen-chitosan porous scaffolds of 0.5-, 1- and 2-mm thicknesses were fabricated and used to treat full-thickness wounds in a one-stage grafting procedure in a rat model. Skin-graft viability, wound contraction, histological changes, and wound tensile strength were evaluated. The results indicated that the distance for the diffusion of oxygen and nutrients to the autograft in the 2-mm-thick scaffold provided less support for graft take, which resulted in graft necrosis, extensive inflammatory reaction, marked foreign-body reaction (FBR), rapid scaffold degradation, and abnormal collagen deposition and remodeling. In contrast, the thinner scaffolds, especially of that 0.5-mm thickness, promoted earlier angiogenesis, ensuring skin-graft viability with a mild FBR, and ordered fibroblast infiltration and better collagen remodeling. It can be concluded that collagen-chitosan porous scaffolds with a thickness of <1mm are more suitable for dermal regeneration and can be used as dermal templates for treatment of dermal defects using a one-stage grafting procedure.

One-stage Reconstruction of Soft Tissue Defects with the Sandwich Technique: Collagen-elastin Dermal Template and Skin Grafts

Background:

A full-thickness soft tissue defect closure often needs complex procedures. The use of dermal templates can be helpful in improving the outcome.

Objective:

The objective was to evaluate a sandwich technique combining the dermal collagen–elastin matrix with skin grafts in a one-stage procedure.

Materials and Methods:

Twenty-three patients with 27 wounds were enrolled in this prospective single-centre observational study. The mean age was 74.8 ± 17.2 years. Included were full-thickness defects with exposed bone, cartilage and/ or tendons. The dermal collagen–elastin matrix was applied onto the wound bed accomplished by skin transplants, i.e. ‘sandwich’ transplantation. In six wounds, the transplants were treated with intermittent negative pressure therapy.

Results:

The size of defects was ≤875 cm². The use of the dermal template resulted in a complete and stable granulation in 100% of wounds. Seventeen defects showed a complete closure and 19 achieved a complete granulation with an incomplete closure. There was a marked pain relief. No adverse events were noted due to the dermal template usage.

Conclusions:

Sandwich transplantation with the collagen–elastin matrix is a useful tool when dealing with full-thickness soft tissue defects with exposed bone, cartilage or tendons.

Matriderm® 1 mm versus Integra® Single Layer 1.3 mm for one-step closure of full thickness skin defects: a comparative experimental study in rats

PURPOSE

Dermal templates, such as Matriderm® and Integra®, are widely used in plastic and reconstructive surgery, often as two-step procedures. A recent development is the application of thin dermal templates covered with split thickness skin grafts in one-step procedures. In this experimental study, we compare the two thin matrices Matriderm® 1 mm and Integra® Single Layer in a one-step procedure with particular focus on neodermis formation.

METHODS

Matriderm® 1 mm and Integra® Dermal Regeneration Template-Single Layer (1.3 mm) were compared in a rat model. In three groups of five animals each, a full thickness wound was covered with (a) Matriderm® 1 mm and neonatal rat epidermis, (b) Integra® Single Layer and neonatal rat epidermis, or, (c) neonatal rat epidermis only (control). Histological sections 2 weeks post transplantation were analyzed with regard to take of template and epidermis, neodermal thickness, collagen deposition, vascularization, and inflammatory response.

RESULTS

Take of both templates was complete in all animals. The Matriderm®-based neodermis was thinner but showed a higher cell density than the Integra®-based neodermis. The other parameters were similar in both matrices.

CONCLUSION

The two templates demonstrate a comparable biological behavior early after transplantation. The only difference was found regarding neodermal thickness, probably resulting from faster degradation of Matriderm®. These preliminary data suggest that both dermal templates appear similarly suitable for transplantation in a one-step procedure.