Major Skin Loss Research Articles

Development of secretome-based strategies to improve cell culture protocols in tissue engineering

Advances in skin tissue engineering have promoted the development of artificial skin substitutes to treat large burns and other major skin loss conditions. However, one of the main drawbacks to bioengineered skin is the need to obtain a large amount of viable epithelial cells in short periods of time, making the skin biofabrication process challenging and slow. Enhancing skin epithelial cell cultures by using mesenchymal stem cells secretome can favor the scalability of manufacturing processes for bioengineered skin. The effects of three different types of secretome derived from human mesenchymal stem cells, e.g. hADSC-s (adipose cells), hDPSC-s (dental pulp) and hWJSC-s (umbilical cord), were evaluated on cultured skin epithelial cells during 24, 48, 72 and 120 h to determine the potential of this product to enhance cell proliferation and improve biofabrication strategies for tissue engineering. Then, secretomes were applied in vivo in preliminary analyses carried out on Wistar rats. Results showed that the use of secretomes derived from mesenchymal stem cells enhanced currently available cell culture protocols. Secretome was associated with increased viability, proliferation and migration of human skin epithelial cells, with hDPSC-s and hWJSC-s yielding greater inductive effects than hADSC-s. Animals treated with hWJSC-s and especially, hDPSC-s tended to show enhanced wound healing in vivo with no detectable side effects. Mesenchymal stem cells derived secretomes could be considered as a promising approach to cell-free therapy able to improve skin wound healing and regeneration.

Advances in Skin Tissue Bioengineering and the Challenges of Clinical Translation.

Skin tissue bioengineering is an emerging field that brings together interdisciplinary teams to promote successful translation to clinical care. Extensive deep tissue injuries, such as large burns and other major skin loss conditions, are medical indications where bioengineered skin substitutes (that restore both dermal and epidermal tissues) are being studied as alternatives. These may not only reduce mortality but also lessen morbidity to improve quality of life and functional outcome compared with the current standards of care. A common objective of dermal-epidermal therapies is to reduce the time required to accomplish stable closure of wounds with minimal scar in patients with insufficient donor sites for autologous split-thickness skin grafts. However, no commercially-available product has yet fully satisfied this objective. Tissue engineered skin may include cells, biopolymer scaffolds and drugs, and requires regulatory review to demonstrate safety and efficacy. They must be scalable for manufacturing and distribution. The advancement of technology and the introduction of bioreactors and bio-printing for skin tissue engineering may facilitate clinical products' availability. This mini-review elucidates the reasons for the few available commercial skin substitutes. In addition, it provides insights into the challenges faced by surgeons and scientists to develop new therapies and deliver the results of translational research to improve patient care.

Cultivation of 3D Dermal Tissue by Application of Autologous Matrix

Abstract The most common reasons for major skin loss are thermal trauma — burns and scalds that can result in rapid, extensive, deep wounds as well as chronic non-healing wounds. Treatment using common techniques is poor and depending on the trauma level can result in death. There is a substantial need for skin integrity restoration. The main goal of this study was to develop an autologous 3D skin model that could eventually be translated into clinical applications. The study examined a variety of factors — extracellular matrix components, cell count, culture medium modification and role of structurally and functionally high-quality 3D skin dermis layer tissue culture production. The results of this study are an essential prerequisite to standardise the use of both clinical, as well as in vitro test systems. Dermal cell lines applied in the study were isolated form patient biopsies obtained at Pauls Stradiņš Clinical University Hospital. Blood plasma type AB was used for fibrin matrix formation. As catalysts, CaCl2 or calcium gluconate, and tranexamic acid were applied. 3D tissue functionality was assessed by evaluation of gene expression and changes in growth factor secretion. Fibrin matrix formulations with 1% and 1.5% CaCl2 and 5 mg, 7 mg and 10 mg tranexamic acid concentration were tested. Better matrix properties were observed with higher concentration of CaCl2 and tranexamic acid. Differences in levels of collagen gene expression and growth factor secretion were observed. Changes in levels of fibroblast growth factor and gene expression were observed in fibrin matrix samples and the surface-cultivated cell culture monolayer, but structural protein synthesis was not detected.

Evaluation of scrotal reconstruction with thigh flap

Background: Scrotal skin can be lost in many ways. Partial loss of scrotum is easy to manage but major scrotal skin loss represents a significant challenge to the reconstructive surgeon. Although many techniques have been established for the treatment of major scrotal defects, each technique has its own advantages and disadvantages in specific situations.Objective: The aim of this prospective study was to evaluate the outcome of thigh fascio-cutaneous flap for reconstruction of major scrotal loss with exposed testis.Methods: This prospective study was done for 5 years extending from January 2012 to December 2016. In this period we reconstructed major scrotal defects of eight patients with antero medial and pudendal thigh fascio-cutaneous flap in Burn and Plastic Surgery department, Khulna Medical College Hospital. Total eleven thigh fascio-cutaneous flaps were used for reconstruction of major scrotal defects.Results: The mean patient age was 41 years (range 24 to 62 years). The aetiology of scrotal loss was Fournier's gangrene in 4 cases and trauma in 4 cases. Three cases had bilateral and five cases had unilateral flap reconstruction. The flaps allowed sensate coverage and took well. Primary donor site closure obviated the need for skin grafts in most of the cases, Complications were flap tip necrosis (12.50%) and minor wound infection (12.50%) which were treated conservatively. Donor site scar was limited and acceptable. The flap had good aesthetic appearance except in one fatty patient where the flaps were bulky.Conclusion: The study concluded that thigh fascio-cutaneous flap is very reliable for coverage of major scrotal defects.Bang Med J (Khulna) 2017; 50 : 13-17

‘Medical skin loss’: Stevens–Johnson syndrome/toxic epidermal necrolysis and staphylococcal scalded skin syndrome

### Key points Several acute exfoliative skin conditions lead to major skin loss and require critical care treatment. Although rare, these conditions have high mortality rates, long critical care stays, and are associated with significant chronic morbidity. Included in this group are Stevens–Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) and staphylococcal scalded skin syndrome (SSSS). Widespread skin loss from these conditions leads to ‘acute skin failure’ which is comparable with any other major organ dysfunction. It is characterized by pain, loss of water, electrolytes and protein, altered thermoregulation and immune function, hypermetabolism, and increased cardiac output.1 Understanding the structure and function of skin improves our ability to care for these patients. Many of the challenges associated with managing these conditions are similar to those seen in patients with a major burn. Hence, these cases are most appropriately managed in specialized burns centres with access to multidisciplinary expertise including intensivists, plastic surgeons, dermatologists, ophthalmologists, dieticians, psychologists, and physiotherapists. Early input from other disciplines optimizes long-term outcomes.2 Current burns data suggest 60–80 cases of SJS/TEN and SSSS are admitted to burns critical care units in the UK per annum over the past 5 yr. In addition, intensive care …

Pixel Grafting

Split-thickness skin grafting is the gold standard for treatment of major skin loss. This technique is limited by donor-site availability in large burn injuries. With micrografting, a technique where split-thickness skin graft is minced into 0.8 × 0.8-mm pieces, the authors have demonstrated an expansion ratio of 1:100 and healing comparable to that achieved with split-thickness skin grafting. In this study, the authors explore the regenerative potential of a skin graft by cutting split-thickness skin grafts to pixel size (0.3 × 0.3 mm) grafts. Wound healing was studied in full-thickness wounds in a porcine model by creating an incubator-like microenvironment using polyurethane wound chambers. Multiple wound healing parameters were used to study the outcome of pixel grafting and compare it to micrografting and nontransplanted wounds. The authors' results show that 0.3 × 0.3-mm pixel grafts remain viable and contribute to skin regeneration. The pixel graft-transplanted wounds demonstrated a faster reepithelialization rate, decreased wound contraction, and increased mechanical stability compared with nontransplanted wounds. The reepithelialization rates of the wounds were significantly increased with pixel grafting at day 6 after wounding compared with micrografting. Among the other wound healing parameters, there were no significant differences between wounds transplanted with pixel grafts and micrografts. Pixel grafting technique would address the most commonly encountered limitations of the split-thickness skin graft with the possibility of an even larger expansion ratio than micrografting. This technique is simple and fast and can be conducted in the operating room or in the clinic.

Challenging the Conventional Therapy: Emerging Skin Graft Techniques for Wound Healing.

Split-thickness skin grafting is the current gold standard for treatment of major traumatic skin loss. However, split-thickness skin grafting is limited by donor-skin availability, especially in large burns. In addition, the donor-site wound is associated with pain and scarring. Multiple techniques have been developed in the past to overcome these limitations but have been unable to achieve clinical relevance. In this study, the authors examine the novel emerging skin grafting techniques, aiming to improve the utility of split-thickness skin grafting. An extensive literature review was conducted on PubMed, MEDLINE, and Google Scholar to look for new skin grafting techniques. Special focus was given to techniques with potential for large expansion ratio and decreased donor-site pain. The new modalities of modified skin grafting technique, discussed in this article, include (1) Xpansion Micrografting System, (2) fractional skin harvesting, (3) epidermal suction blister grafting, and (4) ReCell technology. These techniques are able to achieve significantly increased expansion ratios compared with conventional split-thickness skin grafting and also have decreased donor-site morbidity. These techniques can be used separately or in conjunction with split-thickness skin grafting to overcome the associated pitfalls. Further studies and clinical trials are needed to define the utility of these procedures and where they fit into routine clinical practice.

Utilities of Split-Thickness Skin Grafting for Male Genital Reconstruction

To report our successful outcomes of genital split-thickness skin graft (STSG) in covering major skin loss and providing good functional and cosmetic outcomes. A retrospective chart review was performed for all adult urology patients who underwent STSG at our institution from 1998 to 2014. Patients had a wide range of disease etiologies, including tissue loss (eg post-Fournier's gangrene), lymphedema, buried penis, foreign body injection, and tumors. A total of 54 patients were identified with the following breakdown of etiology: 13 patients with tissue loss (eg post-Fournier's gangrene), 13 with lymphedema, 12 with buried penis, 8 with foreign body injection, 4 with hidradenitis suppurativa, and 4 with tumors. Fifty-two out of 54 patients had more than 90% graft take, with maintained or improved erection, normal voiding, good cosmetic outcome as judged by the patient and the examining surgeon, and normal mobility. One patient died at 3 months due to cardiovascular cause, and 1 patient had a poor take of the graft. We show the wide variety of indications for STSG use, the ease of the technique, and its successful outcomes. We believe this procedure should be offered to patients as a first-line treatment and also as a last resort when other more conservative approaches fail.

OP019: A review of the indications and outcomes of 100 patients managed with a pectoralis major flap in a UK maxillofacial unit

Introduction The pedicled pectoralis major (PPM) flap retains a vital role in the developing world but is less commonly used in the United Kingdom (UK) now that free tissue transfer is well established. The aim of this study was to review the indications and outcomes for the flap, and identify factors associated with complications in a cohort of patients in a UK Maxillofacial unit. Materials and methods A retrospective review based on a contemporaneous database. Data included demographics, indications, ASA grade, medical co-morbidity, previous treatment, resection, TNM staging, MRSA status and length of hospital admission. Complications were classified as described by Ord in 1996. Statistical analyses were performed using SPSS 14.0®. Results In the period December 1996 and June 2012 one hundred and two PPM flaps were performed on 100 consecutive patients. The majority of disease was squamous cell carcinoma ( n = 90, 88.2%), a high proportion was stage four primary disease ( n = 68, 75.6%) or recurrent/metastatic disease ( n = 13, 14.4%). There was substantial comorbidity (46.1% ASA grade 3 or 4). The majority were salvage operations (57%) following surgery and/or chemo-radiotherapy, or free flap failure. The incidence of complete flap loss was 2% ( n = 2), major skin loss 6.9% ( n = 7) and minor loss 12.7% ( n = 13). Flap loss (any degree) was associated with ischaemic heart disease ( P = 0.028), diabetes mellitus ( P = 0.040) and acquisition of MRSA ( P = 0.013). Major or total flap loss was associated with previous free flap failure ( P = 0.044). During the second part of the study there was a significant increase in flap use ( P P = 0.008), MRSA acquisition ( P P = 0.014) and a trend towards reduced flap loss ( P = 0.083). Conclusions These outcomes support the continued use of aggressive surgery combined with PPM flap reconstruction when appropriate.

Interval Inset of TRAM Flaps in Immediate Breast Reconstruction

Healthy, viable mastectomy skin is a critical factor in the outcome of immediate breast reconstruction. Unfortunately, mastectomy skin viability can be problematic and intraoperative assessment is unreliable. For this reason, we have modified our approach to immediate transverse rectus abdominus myocutaneous flap (TRAM) reconstruction. Instead of completing the reconstruction with a definitive inset at the time of the mastectomy, the TRAM flap is left intact and buried beneath the mastectomy skin for 3 to 5 days. This falls within the normal period of postoperative hospitalization, and at this point, the viability of the mastectomy skin is clear. Ischemic skin is debrided and replaced with healthy TRAM skin, and nipple reconstruction can be performed at the time of this interval inset. The purpose of this study was to review a large case series of patients who underwent an interval inset of their TRAM flap in the setting of immediate skin-sparing mastectomy. Retrospective chart data were obtained for all TRAM patients who underwent immediate postmastectomy breast reconstruction by a single surgeon during a 5-year period. Data were collected on procedures, complications, margin status, and number of immediate versus delayed nipple reconstructions. There were 63 patients who underwent immediate TRAM reconstruction with interval inset of the flap. This included 25 bilateral cases, for a total of 89 flaps. Interval insets were performed an average of 3.9 days after the TRAM. Twenty-seven percent (17/63) required replacement of nonviable mastectomy skin with TRAM skin and had no nipple reconstruction; 4.8% (3/63) had additional skin taken because of residual tumor close to or at the mastectomy margins. Seventy-three percent of patients (46/63) had a nipple reconstruction with minimal or no mastectomy skin loss. We present the interval inset of TRAM flaps during the normal period of postoperative hospitalization as a technical refinement to optimize cosmetic outcomes. Mastectomy skin viability can be more easily assessed and necrotic or ischemic skin replaced with TRAM skin as needed. This avoids the need for prolonged dressing changes or a compromised aesthetic result from skin loss. When there is no major skin loss, the nipple reconstruction can be performed concurrently with the inset. These refinements optimize the appearance of the reconstructed breast and reduce the need for future surgeries. In addition, the surgical oncologist has the opportunity to excise close or positive margins as indicated by pathologic findings. Thus, the benefits of the interval inset of TRAM flaps are shared by the reconstructive surgeon, the surgical oncologist, and most importantly, the patient.

A review of tissue-engineered skin bioconstructs available for skin reconstruction

Situations where normal autografts cannot be used to replace damaged skin often lead to a greater risk of mortality, prolonged hospital stay and increased expenditure for the National Health Service. There is a substantial need for tissue-engineered skin bioconstructs and research is active in this field. Significant progress has been made over the years in the development and clinical use of bioengineered components of the various skin layers. Off-the-shelf availability of such constructs, or production of sufficient quantities of biological materials to aid rapid wound closure, are often the only means to help patients with major skin loss. The aim of this review is to describe those materials already commercially available for clinical use as well as to give a short insight to those under development. It seeks to provide skin scientists/tissue engineers with the information required to not only develop in vitro models of skin, but to move closer to achieving the ultimate goal of an off-the-shelf, complete full-thickness skin replacement.

Evaluation of a Novel Biodegradable Polymer for the Generation of a Dermal Matrix

Dermal skin substitutes can be used to overcome the immediate problem of donor site shortage in the treatment of major skin loss conditions, such as burn injury. In this study, the biocompatibility, safety, and potential of three variants of NovoSorb (a family of novel biodegradable polyurethanes) as dermal scaffolds were determined in a series of in vitro and in vivo systems. All three polymers exhibited minimal cytotoxic effects on human skin cells, allowing keratinocytes, dermal fibroblasts, and microvascular endothelial cells to grow normally in coculture. Subcutaneous implantation of the polymers in rats demonstrated no systemic toxic effects of the materials or their degradation products. The anticipated local foreign body reaction compared favorably with commercially available medical sutures. Assessment of a three-dimensional polymer matrix followed. The success of sequential culturing of dermal fibroblasts and keratinocytes within the matrix indicated that the generation of a cultured skin substitute is achievable. The polymeric matrix also provided a scaffold for the guided formation of a cultured microvasculature. When engrafted onto a surgically created full-thickness sheep wound, the noncellular matrix integrated, healed with an epidermis supported by a basement membrane, and was capable of withstanding wound contraction. The resistance to contraction compared favorably with a commercially available collagen-based dermal matrix (Integra). These results suggest that the NovoSorb matrix could form the basis of an elegant two-stage burn treatment strategy, with an initial noncellular biodegradable temporizing matrix to stabilize the wound bed followed by the application of cultured skin substitute.

Inhaled insulin treatment for type 1 diabetes, following major skin loss from necrotising fasciitis

AbstractA 21‐year‐old female with poorly controlled type 1 diabetes was admitted with diabetic ketoacidosis and a groin abscess which was incised and drained. She developed necrotising fasciitis affecting the lower abdomen and upper thighs, which required extensive debridement. Subsequent skin grafts were successful; however, injection sites were now limited. She was commenced on inhaled insulin with meals and glargine insulin once daily.This is an unusual indication for inhaled insulin. This case demonstrates the importance of alternative routes of administration of insulin when intensive subcutaneous therapy is not possible. Copyright © 2008 John Wiley & Sons.

Malignant tumors requiring maxillectomy.

Seventy cases with malignant tumors requiring maxillary resection in the past 10 years were reviewed, retrospectively. The primary site of tumor was adjacent skin in 53%, maxillary sinus or maxilla in 20%, palate and alveolar arch in 13%, lip and buccal mucosa in 13%, and mandible in 1% of the cases. The most common histopathological diagnoses was squamous cell carcinoma (54%), followed by basal cell carcinoma (20%). Most of the patients had advanced tumors, either neglected or recurred. Orbital exenteration was performed in 28 cases, mandibulectomy in six cases, combined craniofacial resection in seven cases, and radical neck dissection in 18 cases. Major skin loss was present in majority of the patients. Postsurgical defects were reconstructed with pedicled flaps in 37 cases and free flaps in 12 cases. Lining of the maxillary sinus defects was provided with split-thickness skin grafts. Patients with palatal defects were encouraged to use prosthetic obturators. Postoperative radiotherapy was performed in 32 patients and combined radiotherapy and chemotherapy in 12 patients. Communication could be established with only 52 patients. Sixty-three percent of them have survived without recurrence and distant metastasis. Resection of the tumor with free surgical margins and appropriate evaluation of the surgical defect for the most suitable reconstruction are the mainstays of treatment of the midfacial tumors.

IMMEDIATE DE-SYNDACTYLIZATION OF THE REVERSE RADIAL FOREARM FLAP

The reverse radial forearm flap was used to cover soft tissue defects on the dorsal aspect of the hand and fingers with immediate de-syndactylization of the distal part of the flap in four cases. A total of 14 fingers were covered with de-syndactylized segments and these were divided into two groups. In group A (nine fingers) the defect extended to or just distal to the proximal interphalangeal (PIP) joint. The defect in group B (five fingers) was proximal to the PIP joint. Primary wound healing was observed in the proximal and lateral edges of the flap in all cases. However, delayed wound healing was observed in the distal edge of five of the 14 segments. All five segments that suffered from edge necrosis were from group A, indicating that longer segments are more likely to develop distal edge ischaemia. The fact that there was no major skin loss in any of the patients despite immediate de-syndactylization indicates that the reverse radial forearm flap has a reliable blood supply and can support a portion with a random blood supply without significant necrosis.

Experience with severe extensive blistering skin disease in a paediatric burns unit

Vesiculobullous disorders are thankfully uncommon. A brief overview of the literature is presented together with our experience of managing these cases on a paediatric burns unit in the six years 1992–1998. The advantages of management on such a unit are outlined and include a facility for major dressings and frequent changes and a familiarity with fluid resuscitation in the child with major skin loss. The financial cost of treatment and rehabilitation of these children is high.

Engineering a Skin Replacement

Major skin loss from trauma or burns cannot always be replaced with the patient's own skin. An engineered skin replacement would restore the barrier function of the skin, remain permanently on the wound, and minimize late functional complications of wound contraction. Cultured epithelial autograft (CEA) sheets reproduce the epidermis' function and have been used in burn patients to close large wounds. There are several promising avenues for dermal replacement, but none has yet had wide clinical application.

Meningococcemia: recognizing and reducing complications in pediatric patients.

Meningococcemia is a true infectious emergency that requires tremendous skill and collaboration among health-care professionals to reduce the high morbidity and mortality associated with this disease. Complications and sequelae may effect virtually every body system with meningococcal disease. The critical care nurse plays a crucial role in preventing and recognizing complications to reduce serious consequences, including respiratory distress syndrome, myocarditis, cardiovascular collapse, coagulopathies, major skin loss, and limb amputations.

A National Survey of Complications Associated with Suction Lipectomy

In March of 1988, a survey form was sent to all 2695 U.S. and Canadian members of the American Society of Plastic and Reconstructive Surgeons. Nine-hundred and thirty-five members responded, for a response rate of 34.7 percent. The purpose of the survey was to ascertain the total number of major liposuction, dermatolipectomy, and abdominoplasty procedures performed from January of 1984 to January of 1988 and to compare nine specific complications that are associated with these three procedures. The 935 surgeons reported a total of 112,756 procedures performed: major liposuction (75,591), dermatolipectomy (10,603), and abdominoplasty (26,562). Nine major complications were surveyed: mortality, myocardial infarction, cerebrovascular accident or transient ischemic attack, pulmonary thromboembolism, fat embolism, major skin loss, anesthesia complication, transfusion complications, and deep venous thrombosis. The findings in this survey showed, when comparing these three procedures and the nine types of complications, that the complication rate for major suction lipectomy was 0.1 percent, for dermatolipectomy 0.9 percent, and for abdominoplasty 2.0 percent. Fat emboli did not prove to be a significant factor associated with any of the three procedures. However, of the 15 reported deaths (major liposuction 2, dermatolipectomy 2, and abdominoplasty 11), pulmonary thromboembolism was the causative factor in 9 deaths (60 percent). Based on these analyzed data, we feel that major suction lipectomy has a low complication rate and is a reasonably safe procedure.

The degloved hand: immediate complete restoration of skin cover with a contralateral forearm free flap

This paper describes a method of repair of a serious injury with major skin loss on both the volar and dorsal aspects of the hand and wrist using a free “forearm flap” from the opposite limb. The technique is a one-stage procedure, provides a completely variable amount of skin, the freedom to elevate the repaired hand and the opportunity to revascularise the most distal structures using the vessels incorporated in the flap.