Burn Scar Biomechanics after Pressure Garment Therapy

Amino Acid-Based Protein-Mimic Hydrogel Incorporating Pro-Regenerative Lipid Mediator and Microvascular Fragments Promotes the Healing of Deep Burn Wounds

Pro-regenerative lipid mediator 1 (PreM1) is a specialized pro-resolving lipid mediator that promotes wound healing and regenerative functions of mesenchymal stem cells (MSCs), endothelial cells, and macrophages. The healing of third-degree (3°) burns and regenerative functions of MSCs are enhanced by ACgel1, an arginine-and-chitosan-based protein-mimic hybrid hydrogel. Adipose-tissue derived microvascular fragments (MVFs) are native vascularization units and a rich source of MSCs, endothelial cells, and perivascular cells for tissue regeneration. Here we describe an innovative PreM1-MVFs-ACgel1 construct that incorporated PreM1 and MVFs into ACgel1 via optimal design and fabrication. This construct delivered PreM1 to 3°-burn wounds at least up to 7 days-post-burn (dpb), and scaffolded and delivered MVFs. PreM1-MVFs-ACgel1 promoted the healing of 3°-burns in mice, including vascularization and collagen formation. The re-epithelization and closure of 3° burn wounds were promoted by ACgel1, MVFs, PreM1, MVFs-ACgel1, PreM1-ACgel1, or PreM1-MVFs-ACgel1 at certain time-point(s), while PreM1-MVFs-ACgel1 was most effective with 97% closure and 4.69% relative epithelial gap at 13 dpb compared to saline control. The PreM1-ACgel1 and MVFs-ACgel1 also promoted blood vessel regeneration of 3°-burns although PreM1-MVFs-ACgel1 is significantly more effective. These PreM1- and/or MVF-functionalized ACgel1 have nonexistent or minimal graft-donor requirements and are promising adjuvant therapeutic candidates for treating deep burns.

Natural products for the treatment of hypertrophic scars: Preclinical and clinical studies

Hypertrophic scarring (HS) is a complication of wound healing that causes physiological and psychological distress in patients. However, the possible mechanism underlying HS is not fully understood, and there is no gold standard for its treatment. Natural products are more effective, economical, convenient, and safe than existing drugs, and they have a wide application prospect. However, there is a lack of literature on this topic, so we reviewed in vivo, in vitro, and clinical studies and screened natural products showing beneficial effects on HS that can become potential therapeutic agents for HS to fill in the gaps in the field. In addition, we discussed the drug delivery systems related to these natural products and their mechanisms in the treatment of HS. Generally speaking, natural products inhibit inflammation, myofibroblast activation, angiogenesis, and collagen accumulation by targeting interleukins, tumor necrosis factor-α, vascular endothelial growth factors, platelet-derived growth factors, and matrix metalloproteinases, so as to play an anti-HS effects of natural products are attributed to their anti-inflammatory, anti-proliferative, anti-angiogenesis, and pro-apoptotic (enhancing apoptosis and autophagy) roles, thus treating HS. We also screened the potential therapeutic targets of these natural compounds for HS through network pharmacology and constructed a protein-protein interaction (PPI) network, which may provide clues for the pharmacological mechanism of natural products in treating this disease and the development and application of drugs.

The emerging progress on wound dressings and their application in clinic wound management

BACKGROUND

In addition to its barrier function, the skin plays a crucial role in maintaining the stability of the body's internal environment and normal physiological functions. When the skin is damaged, it is important to select proper dressings as temporary barriers to cover the wound, which can exert significant effects on defence against microbial infection, maintaining normal tissue/cell functions, and coordinating the process of wound repair and regeneration. It now forms an important approach in clinic practice to facilitate wound repair.

SEARCH STRATEGIES

We conducted a comprehensive literature search using online databases including PubMed, Web of Science, MEDLINE, ScienceDirect, Wiley Online Library, CNKI, and Wanfang Data. In addition, information was obtained from local and foreign books on biomaterials science and traumatology.

RESULTS

This review focuses on the efficacy and principles of functional dressings for anti-bacteria, anti-infection, anti-inflammation, anti-oxidation, hemostasis, and wound healing facilitation; and analyses the research progress of dressings carrying living cells such as fibroblasts, keratinocytes, skin appendage cells, and stem cells from different origins. We also summarize the recent advances in intelligent wound dressings with respect to real-time monitoring, automatic drug delivery, and precise adjustment according to the actual wound microenvironment. In addition, this review explores and compares the characteristics, advantages and disadvantages, mechanisms of actions, and application scopes of dressings made from different materials.

CONCLUSION

The real-time and dynamic acquisition and analysis of wound conditions are crucial for wound management and prognostic evaluation. Therefore, the development of modern dressings that integrate multiple functions, have high similarity to the skin, and are highly intelligent will be the focus of future research, which could drive efficient wound management and personalized medicine, and ultimately facilitate the translation of health monitoring into clinical practice.

Hypertrophic Scar

Hypertrophic scars frequently develop post-burn, and are characterized by their pruritic, painful, raised, erythematous, dyschromic, and contractile qualities. This article aims to synthesize knowledge on the clinical and molecular development, evolution, management, and measurement of hypertrophic burn scar for both patient and clinician knowledge.

NRP1 transduces mechanical stress inhibition via LATS1/YAP in hypertrophic scars

Hypertrophic scar (HS) is an abnormal fibrous hyperplasia of the skin caused by excessive tissue repair in response to skin burns and trauma, which restricts physical function and impairs patients' quality of life. Numerous studies have shown that pressure garment therapy (PGT) is an effective treatment for preventing hypertrophic scars. Herein, we found that mechanical stress stimulates the neuropilin 1 (NRP1) expression through screening GSE165027, GSE137210, and GSE120194 from Gene Expression Omnibus (GEO) database and bioinformatics analysis. We verified this stimulation in the human hypertrophic scar, pressure culture cell model, and rat tail-scar model. Mechanical compression increased LATS1 and pYAP enrichment, thus repressing the expression of YAP. Functionally, the knockdown of NRP1 promoted the expression of LATS1, thus decreasing the expression of YAP and inhibiting endothelial cell proliferation. Furthermore, co-immunoprecipitation analysis confirmed that NRP1 binds to YAP, and mechanical compression disrupted this binding, which resulted in the promotion of YAP relocation to nuclear. In conclusion, our results indicated that NRP1 transduces mechanical force inhibition by inhibiting YAP expression. Mechanical pressure can release YAP bound to NRP1, which explains the phenomenon that mechanical stress increases YAP in the nucleus. Strategies targeting NRP1 may promote compression therapy with optimal and comfortable pressures.

Use of sensory modulation approaches to improve compression garment adherence in adults after burn: An e-Delphi study

BACKGROUND

Sensory over-responsiveness, identified through self-report and quantitative sensory testing, has been associated with compression garment non-adherence in a burn-injured cohort. This study sought expert consensus on the usefulness of, and recommendations for, sensory modulation strategies to improve compression garment adherence in sensory over-responsive adults after burn.

METHOD

Experts in the field of sensory modulation were invited to participate in a mixed-methods, three-round electronic Delphi study.

RESULTS

Experts (N = 18) agreed that sensory modulation therapy may be a useful clinical tool to improve compression garment adherence. Twenty-two items reached consensus as essential to assessment, treatment, or therapist training.

CONCLUSION

With adequate therapist training and individualized assessment and treatment, sensory modulation strategies may be a useful clinical approach to improving compression garment adherence in those who are sensory over-responsive after burn. Further research is needed to gather perceptions from burns therapists, and to implement and evaluate the effectiveness in clinical practice.

Proceedings of the 2021 American Burn Association State and Future of Burn Science Meeting

Periodically, the American Burn Association (ABA) has convened a State of the Science meeting on various topics representing multiple disciplines within burn care and research. In 2021 at the request of the ABA President, meeting development was guided by the ABA's Burn Science Advisory Panel (BSAP) and a subgroup of meeting chairs. The goal of the meeting was to produce both an evaluation of the current literature and ongoing studies, and to produce a research agenda and/or define subject matter-relevant next steps to advance the field(s). Members of the BSAP defined the topics to be addressed and subsequently solicited for nominations of expert speakers and topic leaders from the ABA's Research Committee. Current background literature for each topic was compiled by the meeting chairs and the library then enhanced by the invited topic and breakout discussion leaders. The meeting was held in New Orleans, LA on November 2nd and 3rd and was formatted to allow for 12 different topics, each with two subtopics, to be addressed. Topic leaders provided a brief overview of each topic to approximately 100 attendees, followed by expert-lead breakout sessions for each topic that allowed for focused discussion among subject matter experts and interested participants. The breakout and topic group leaders worked with the participants to determine research needs and associated next steps including white papers, reviews and in some cases collaborative grant proposals. Here, summaries from each topic area will be presented to highlight the main foci of discussion and associated conclusions.

Traditional Chinese medicine for hypertrophic scars—A review of the therapeutic methods and potential effects

Hypertrophic scar (HS) is a typical pathological response during skin injury, which can lead to pain, itching, and contracture in patients and even affect their physical and mental health. The complexity of the wound healing process leads to the formation of HS affected by many factors. Several treatments are available for HS, whereas some have more adverse reactions and can even cause new injuries with exacerbated scarring. Traditional Chinese Medicine (TCM) has a rich source, and most botanical drugs have few side effects, providing new ideas and methods for treating HS. This paper reviews the formation process of HS, the therapeutic strategy for HS, the research progress of TCM with its relevant mechanisms in the treatment of HS, and the related new drug delivery system of TCM, aiming to provide ideas for further research of botanical compounds in the treatment of HS, to promote the discovery of more efficient botanical candidates for the clinical treatment of HS, to accelerate the development of the new drug delivery system and the final clinical application, and at the same time, to promote the research on the anti-HS mechanism of multiherbal preparations (Fufang), to continuously improve the quality control and safety and effectiveness of anti-HS botanical drugs in clinical application.

Advantages and Disadvantages of Using Small and Large Animals in Burn Research: Proceedings of the 2021 Research Special Interest Group

Multiple animal species and approaches have been used for modeling different aspects of burn care, with some strategies considered more appropriate or translatable than others. On April 15, 2021, the Research Special Interest Group of the American Burn Association held a virtual session as part of the agenda for the annual meeting. The session was set up as a pro/con debate on the use of small versus large animals for application to four important aspects of burn pathophysiology: burn healing/conversion; scarring; inhalation injury; and sepsis. For each of these topics, 2 experienced investigators (one each for small and large animal models) described the advantages and disadvantages of using these preclinical models. The use of swine as a large animal model was a common theme due to anatomic similarities with human skin. The exception to this was a well-defined ovine model of inhalation injury; both of these species have larger airways which allow for incorporation of clinical tools such as bronchoscopes. However, these models are expensive and demanding from labor and resource standpoints. Various strategies have been implemented to make the more inexpensive rodent models appropriate for answering specific questions of interest in burns. Moreover, modelling burn-sepsis in large animals has proven difficult. It was agreed that the use of both small and large animal models have merit for answering basic questions about the responses to burn injury. Expert opinion and the ensuing lively conversations are summarized herein, which we hope will help inform experimental design of future research.

Mechanomodulation of Burn Scarring Via Pressure Therapy

Significance: The physical and psychological sequalae of burn injuries account for 10 million disability-adjusted life years lost annually. Hypertrophic scarring (HSc) after burn injury results in reduced mobility, contracture, pain, itching, and aesthetic changes for burn survivors. Despite the prevalence of scarring and the number of scar therapies available, none are highly effective at preventing HSc after burn injury. Recent Advances: Recent studies modulating the mechanical environment surrounding incisional and excisional wounds have shown off-loading of tension to be a powerful strategy to prevent scar formation. Preclinical studies applying force perpendicular to the surface of the skin or using a combination of pressure both circumferentially and perpendicularly have shown substantial reductions in scar thickness and contraction after burn injury. Critical Issues: Though pressure therapy is highly effective in preclinical studies, outcomes in clinical studies have been variable and may be a result of differing therapy protocols and garment material fatigue. A recent adult clinical study reported a significant reduction in pressure after 1 month of use and significant reduction between 1 and 2 months of use, resulting in below therapeutic doses of pressure applied after only 1 month of use. Future Directions: To enhance efficacy of pressure garments, new low-fatigue materials must be developed for use in standard garments or garments must be redesigned to allow for adjustment to compensate for the loss of pressure with time. Additionally, measurements of applied pressure should be performed routinely during clinic visits to ensure that therapeutic doses of pressure are being delivered.

Smart Scar Care-Industry 4.0 in Individualized Compression Garments: A Randomized Controlled Crossover Feasibility Study

Background:

We tested the workflow and comparability of compression garments (CG) automatically knitted from 3D-body-scan data (3DBSD) versus manually measured data for scar treatment. Industry 4.0 has found its way into surgery, enhancing the trend toward personalized medicine, which plays an increasingly important role in CG scar therapy. Therefore, we conducted a study to evaluate the workflow from 3DBSD to fast and precisely knitted CG and compared it with standard of care.

Methods:

A randomized controlled crossover feasibility study was conducted as part of the individual medical technology research project “Smart Scar Care.” Objective and patient-reported outcome measures were documented for 10 patients with hypertrophic burn scars at baseline and after wearing CG automatically knitted from 3DBSD versus CG from manually measured data for one month.

Results:

The “scan-to-knit” workflow and the study design were feasible in 10 of 10 patients. No adverse effects were found. 3DBSD showed a bias of half a centimeter compared with manually measured data and wider limits of agreement. With respect to fit, comfort, suitability, Vancouver Scar Scale, Patient and Observer Scar Assessment Scale, stiffness and microcirculation, this was a promising pilot study. Stiffness and blood flow were increased in scars compared with normal skin. The highest rank correlations were found between pain and itch, stiffness and Patient and Observer Scar Assessment Scale, Vancouver Scar Scale, and pain.

Conclusions:

These results indicate that automatically knitted CG using 3DBSD could become an alternative to the standard of care, especially with regard to economical and faster patient care. The produced scan data opens the door for objective scar science.

A method for precise local pressurization in scar-repairing surgery

BACKGROUND

Pressure Garment Treatment (PGT) is currently recognized as an effective method to prevent scar formation or treat scar hyperplasia. Research on PGT remains controversial. These controversies indicate that PGT lacks reliable evidence of evidence-based medicine. Different studies on PGT need to be conducted under the same 'gold standard' so that different studies can be compared. We consider this 'gold standard' to be that the pressure remains stable within a confidence interval during treatment.

METHODS

We calibrated and verified the reference value of the sensor using a cuff of sphygmanometer.A pressure adjustable pressure system was obtained by installing a soft tissue expander on the pressure garment.Local pressure was adjusted by charging and releasing air.Subsequently, the flexible pressure sensor was placed on the upper arm of the healthy volunteers. We validated the compression system on healthy volunteers' forearms and AO standard prostheses (forearms).

RESULTS

Reference value of the sensor was calibrated on No.1 volunteer. Measuring repeated on No.2 and No. 3. The measurement was very reproducible. The test results in the experimental group showed that the local pressure gradually increased with the increase of the inflation of the airbag. However, the pressure at the opposite position of the forearm changed little.

CONCLUSIONS

Real-time pressure monitoring and pressure adjustment enable the pressure to be maintained at a certain value. Our study provides a new idea for the production of elastic clothing with the function of pressure measurement and pressure regulation, which may promote the accuracy and reliability of PGT.

Management of Thermal Injuries in Donkeys: A Case Report

Simple Summary

Reports or descriptions of medical management of thermal injuries in donkeys is lacking. Four donkeys sustained burn injuries during the wildland–urban interface fire in Valparaiso, Chile, in 2014. The donkeys received first aid care at the scene of the fire, and then were hospitalized and treated for three months for thermal injuries, of various degrees of severity, in several body parts. The clinical findings and treatment of four of the donkeys are described in this paper. All donkeys recovered and were retired to an animal shelter.

Abstract

Burn injuries are uncommon in large animals and there are no reports of these injuries in donkeys. Burns cause local and systemic effects. Extensive thermal injuries can be challenging to manage and the extent of the burn surface affected will directly impact the severity of the illness and the prognosis. Burns are classified according to the depth of injury into four categories, from first-degree burns, and the least affect to fourth-degree burns, which are the more severely affected patients. This case report describes the medical management of four donkeys that sustained various degrees of external burn injuries during the wildland–urban interface fire in Valparaiso, Chile. The donkeys were treated topically for several weeks and closely monitor for inadequate nutritional intake. Water based topical medications are preferred in burn cases because they can be easily applied and removed without interfering with wound healing. Of note, the caloric demands of these cases can be achieved by increasing the amount of grain, adding fat (i.e., vegetable oil), and free-choice alfalfa hay. All donkeys recovered and were retired to an animal shelter.

Enhanced Cycling Time-Trial Performance During Multiday Exercise With Higher-Pressure Compression Garment Wear

PURPOSE

Compression garments are widely used as a tool to accelerate recovery from intense exercise and have also gained traction as a performance aid, particularly during periods of limited recovery. This study tested the hypothesis that increased pressure levels applied via high-pressure compression garments would enhance "multiday" exercise performance.

METHODS

A single-blind crossover design, incorporating 3 experimental conditions-loose-fitting gym attire (CON), low-compression (LC), and high-compression (HC) garments-was adopted. A total of 10 trained male cyclists reported to the laboratory on 6 occasions, collated into 3 blocks of 2 consecutive visits. Each "block" consisted of 3 parts, an initial high-intensity protocol, a 24-hour period of controlled rest while wearing the applied condition/garment (CON, LC, and HC), and a subsequent 8-km cycling time trial, while wearing the respective garment. Subjective discomfort questionnaires and blood pressure were assessed prior to each exercise bout. Power output, oxygen consumption, and heart rate were continuously measured throughout exercise, with plasma lactate, creatine kinase, and myoglobin concentrations assessed at baseline and the end of exercise, as well as 30 and 60 minutes postexercise.

RESULTS

Time-trial performance was significantly improved during HC compared with both CON and LC (HC = 277 [83], CON = 266 [89], and LC = 265 [77] W; P < .05). In addition, plasma lactate was significantly lower at 30 and 60 minutes postexercise on day 1 in HC compared with CON. No significant differences were observed for oxygen consumption, heart rate, creatine kinase, or subjective markers of discomfort.

CONCLUSION

The pressure levels exerted via lower-limb compression garments influence their effectiveness for cycling performance, particularly in the face of limited recovery.

Improved Scar Outcomes with Increased Daily Duration of Pressure Garment Therapy

Objective: Despite the development of a number of treatment modalities, scarring remains common postburn injury. To reduce burn scarring, pressure garment therapy has been widely utilized but is complicated by low patient adherence. To improve adherence, reduced hours of daily garment wear has been proposed. Approach: To examine the efficacy of pressure garment therapy at reduced durations of daily wear, a porcine burn-excise-autograft model was utilized. Grafted burns were treated with pressure garments (20 mmHg) for 8, 16, or 24 h of daily wear with untreated burns serving as controls. Scar area, thickness, biomechanical properties, and tissue structure were assessed over time. Results: All treatment groups reduced scar thickness and contraction versus controls and improved scar pliability and elasticity. Pressure garments worn 24 h per day significantly reduced contraction versus the 8- and 16-h groups and prevented alignment of collagen within the dermis. Innovation: Though pressure garment therapy is prescribed for use 23 h per day, the need for almost continuous use has not been previously examined. Adjustable, low-fatigue pressure garments were developed for this porcine study to examine the role of daily duration of wear without confounding factors such as garment fatigue and patient adherence. Conclusion: For maximum efficacy, pressure garments should be worn 23 to 24 h per day; however, garments worn as little as 8 h per day significantly improve scar outcomes versus no treatment.

Efficacy of Silicone Gel versus Silicone Gel Sheet in Hypertrophic Scar Prevention of Deep Hand Burn Patients with Skin Graft: A Prospective Randomized Controlled Trial and Systematic Review

Burn injuries are burdensome to the public health system. Hypertrophic scars are the most common undesirable sequelae associated with burn scar contracture, resulting in reduced hand function. This study compared 2 different forms of silicone combined with pressure garment (PG) to determine the efficacy in hypertrophic scar prevention in hand burns.

[Severe burns, a long journey of care and rehabilitation]

At the patient's bedside 24 hours a day, the nurse is at the heart of the rehabilitation management of the severely burnt patient: installation, technical dressings, supervision of postures and placement of compressors, to limit the functional consequences to the type of retractable and hypertrophic scars. The nurse takes care of the patient in this long journey leading to social reintegration; from accompaniment to autonomy and acceptance of self-image.

Evidence-Based Abdominoplasty Review With Body Contouring Algorithm

Abdominal contour deformities are an aesthetic challenge to the plastic surgeon. Patients present with diverse clinical histories, multiple comorbidities, and unique aesthetic demands. Weight loss, previous pregnancy, and aging are 3 principal indications for abdominoplasty. Bariatric surgery has increased demand for body contouring procedures. This heterogeneous patient cohort means a "one-size-fits-all" abdominoplasty is not appropriate. Precise evaluation, evidence-based decision-making, and artistic acumen are required while balancing patient goals with safe, realistic, and long-lasting aesthetic outcomes. This article reviews surgical options for abdominal body contouring, providing an evidence-based treatment algorithm for selecting the appropriate procedure for each patient to maximize clinical and patient reported outcomes.

Role of Early Application of Pressure Garments following Burn Injury and Autografting

BACKGROUND

Pressure garment therapy, used for reduction of postburn scarring, is commonly initiated after complete healing of the wound or autograft. Although some clinicians have suggested that earlier treatment may improve outcomes, the effect of early initiation of therapy has not been studied in a controlled environment.

METHODS

Full-thickness burns were created on red Duroc pigs, burn eschar was excised, and the wound bed was grafted with split-thickness autografts. Grafts were treated with pressure garments immediately, 1 week (early), or 5 weeks (delayed) after grafting with nontreated grafts as controls. Scar morphology, biomechanics, and gene expression were measured at multiple time points up to 17 weeks after grafting.

RESULTS

Grafts that received pressure within 1 week after grafting exhibited no reduction in engraftment rates. Immediate and early application of pressure resulted in scars with decreased contraction, reduced scar thickness, and improved biomechanics compared with controls. Pressure garment therapy did not alter expression of collagen I, collagen III, or transforming growth factor β1 at the time points investigated; however, expression of matrix metalloproteinase 1 was significantly elevated in the immediate pressure garment therapy group at week 3, whereas the delayed pressure garment therapy and control groups approached baseline levels at this time point.

CONCLUSIONS

Early application of pressure garments is safe and effective for reducing scar thickness and contraction and improving biomechanics. This preclinical study suggests that garments should be applied as soon as possible after grafting to achieve greatest benefit, although clinical studies are needed to validate the findings in humans.

Non-invasive in vivo quantification of human skin tension lines

Human skin is a composite tissue that exhibits anisotropic mechanical properties. This anisotropy arises primarily from the alignment of collagen and elastin fibers in the dermis, which causes the skin to exhibit greater tension in one direction, making it appear stiffer. A diverse number of skin tension guidelines have been developed to assist surgeons in making incisions that produce the least conspicuous scars. However, skin anisotropy is believed to vary from subject to subject, and no single guideline is universally recognized as the best to implement for surgical applications. To date, no system exists that can rapidly and non-invasively measure lines of skin tension in vivo. In this article, we evaluate the ability of a new aspiration system to measure the anisotropy of human skin. The device painlessly applies a radial stress of 17 kPa to a region of skin, and captures radially asymmetric skin deformations via a dermal camera. These deformations are used to quantify orientations of strain extrema and the direction of greatest skin stiffness. The ratio of these asymmetric strains varies between 1 and -0.75. A simple 2D transverse isotropic model captures this behavior for multiple anatomical sites. Clinical trials reveal that skin tension line orientations are comparable with existing skin tension maps and generally agree across subjects, however orientations statistically differ between individuals. As such, existing guidelines appear to provide only approximate estimates of skin tension orientation. STATEMENT OF SIGNIFICANCE: Skin tension lines (STL) in human skin arise primarily from collagen fiber alignment in the dermis. These lines are used by surgeons to guide incisions that produce the least conspicuous scars. While numerous anatomical STL maps exist, no single guideline is universally recognized as the most reliable. Moreover, manual methods of quantifying STL are imprecise. For the first time, we have developed a device capable of rapidly and non-invasively measuring STL orientations in vivo, using a single test. Our results are used to establish a simple constitutive model of mechanical skin anisotropy. Clinical trials further reveal STL orientations are comparable with existing maps, but statistically differ between individuals. Existing guidelines therefore appear to provide only approximate estimates of STL orientation.

Survey of national and local practice of compression therapy timing for burn patients in the United States

OBJECTIVE

Compression therapy (CT) has been an important, but debated, treatment for burn scars. To better understand one source of variation in observed outcomes after CT, an evaluation of CT timing of application is needed.

MATERIALS AND METHODS

Following IRB approval, 126 burn centers were contacted to complete a 17-question survey regarding the center's practice pattern for compression garment therapy. Locally, study subjects were identified between March 1, 2014 and December 31, 2015 and medical records examined for timing of garment ordering, delivery and fitting.

RESULTS

The majority believed that compression therapy is beneficial. Most centers reported using custom-fit and pre-fabricated garments, and a goal time of application between 2-4 weeks (42%) and 4-6 weeks (36%). After the garments are ordered, 61% of centers estimate that it takes 2-4 weeks for them to arrive. No significant differences in practices were found among centers treating pediatric patients only, adults only or both. Locally, the mean number of weeks between the date of original injury and garment order placement was 9.1 weeks with an additional 8.7 weeks between the date of order and date of delivery.

CONCLUSIONS

The current study identified that although the national reporting of time to garment application is estimated to be between 2-6 weeks at the majority of burn centers including our own, we found our center to be well in excess of 17 weeks. The findings offer an opportunity for local improvement, and raise the possibility of similar incongruity between goals and practice at other centers.

Effect of skin graft thickness on scar development in a porcine burn model

Animal models provide a way to investigate scar therapies in a controlled environment. It is necessary to produce uniform, reproducible scars with high anatomic and biologic similarity to human scars to better evaluate the efficacy of treatment strategies and to develop new treatments. In this study, scar development and maturation were assessed in a porcine full-thickness burn model with immediate excision and split-thickness autograft coverage. Red Duroc pigs were treated with split-thickness autografts of varying thickness: 0.026in. ("thin") or 0.058in. ("thick"). Additionally, the thin skin grafts were meshed and expanded at 1:1.5 or 1:4 to evaluate the role of skin expansion in scar formation. Overall, the burn-excise-autograft model resulted in thick, raised scars. Treatment with thick split-thickness skin grafts resulted in less contraction and reduced scarring as well as improved biomechanics. Thin skin autograft expansion at a 1:4 ratio tended to result in scars that contracted more with increased scar height compared to the 1:1.5 expansion ratio. All treatment groups showed Matrix Metalloproteinase 2 (MMP2) and Transforming Growth Factor β1 (TGF-β1) expression that increased over time and peaked 4 weeks after grafting. Burns treated with thick split-thickness grafts showed decreased expression of pro-inflammatory genes 1 week after grafting, including insulin-like growth factor 1 (IGF-1) and TGF-β1, compared to wounds treated with thin split-thickness grafts. Overall, the burn-excise-autograft model using split-thickness autograft meshed and expanded to 1:1.5 or 1:4, resulted in thick, raised scars similar in appearance and structure to human hypertrophic scars. This model can be used in future studies to study burn treatment outcomes and new therapies.

Effects of Autologous Fat and ASCs on Swine Hypertrophic Burn Scars: A Multimodal Quantitative Analysis

Background:

Hypertrophic scar formation is unpredictable and poorly understood, afflicting both the pediatric and adult populations. Treatment methods with conservative and invasive approaches have low rates of compliance and high rates of morbidity. The purpose of this study was to test a reproducible scar model and investigate a new technique of scar modification through the use of adipose- derived progenitor stromal cells (ASCs).

Methods:

Twenty thermal deep-partial thickness contact burns were created on the dorsum of three 8-week-old domestic swine and allowed to mature for 10 weeks. Scars were then injected with 2 cc saline, expanded autologous ASCs, or 2 cc fresh lipoaspirate and sampled at 2 week intervals up to 10 weeks postinjection. Volumetric analysis with a 3-D scanner, mechanical elasticity testing through negative pressure transduction, and standardized photography evaluation with Image J was performed. RNA sequencing was performed on scar tissue samples, cultured cells, and fresh lipoaspirate to determine relevant gene transcription regulation. Immunohistochemistry was used to verify expression level changes within the scars.

Results:

Volumetric analysis demonstrates a reduction in average scar thickness at 6 weeks when injected with ASCs (−1.6 cc³) and autologous fat (−1.95 cc³) relative to controls (−0.121 cc³; P < 0.05). A decrease in overall tissue compliance is observed with fat or ASC injection when compared with unburned skin at 8 weeks (35.99/37.94 versus 49.36 mm Hg × mm; P < 0.01). RNA sequencing demonstrates altered regulation of fibroblast gene expression and a decreased inflammatory profile when scars are injected with autologous fat/ASCs over controls.

Conclusion:

Early results suggest that autologous fat and/or ASCs may improve healing of hypertrophic scarring by altering the cellular and structural components during wound remodeling up to 20 weeks after injury. This may have beneficial applications in early treatment of large or cosmetically sensitive immature burn scars.

Scar formation following excisional and burn injuries in a red Duroc pig model

Scar research is challenging because rodents do not naturally form excessive scars, and burn depth, size, and location cannot be controlled in human longitudinal studies. The female, red Duroc pig model has been shown to form robust scars with biological and anatomical similarities to human hypertrophic scars. To more closely mimic the mode of injury, recreate the complex chemical milieu of the burn wound environment and enhance scar development, an animal model of excessive burn-induced scarring was developed and compared with the more commonly used model, which involves excisional wounds created via dermatome. Standardized, full-thickness thermal wounds were created on the dorsum of female, red Duroc pigs. Wounds for the dermatome model were created using two different total dermatome settings: ∼1.5 mm and ≥ 1.9 mm. Results from analysis over 150 days showed that burn wounds healed at much slower rate and contracted more significantly than dermatome wounds of both settings. The burn scars were hairless, had mixed pigmentation, and displayed fourfold and twofold greater excess erythema values, respectively, compared with ∼1.5 mm and ≥ 1.9 mm deep dermatome injuries. Burn scars were less elastic, less pliable, and weaker than scars resulting from excisional injuries. Decorin and versican gene expression levels were elevated in the burn group at day 150 compared with both dermatome groups. In addition, transforming growth factor-beta 1 was significantly up-regulated in the burn group vs. the ∼1.5 mm deep dermatome group at all time points, and expression remained significantly elevated vs. both dermatome groups at day 150. Compared with scars from dermatome wounds, the burn scar model described here demonstrates greater similarity to human hypertrophic scar. Thus, this burn scar model may provide an improved platform for studying the pathophysiology of burn-related hypertrophic scarring, investigating current anti-scar therapies, and development of new strategies with greater clinical benefit.

The effectiveness of pressure therapy (15-25 mmHg) for hypertrophic burn scars: A systematic review and meta-analysis

Although pressure therapy (PT) represents the standard care for prevention and treatment of hypertrophic scar (HS) from burns, its practice is largely based on empirical evidence and its effectiveness remains controversial. To clarify the effect of PT (15-25 mmHg) for HS, we performed the systematic review and meta-analysis. Several electronic databases were screened to identify related randomized controlled trials (RCTs). 12 RCTs involving 710 patients with 761 HS resulting from burn injuries were included. Compared with non/low-PT, cases treated with PT (15-25 mmHg) showed significant differences in Vancouver Scar Scale score (MD = -0.58, 95% CI = -0.78--0.37), thickness (SMD = -0.25, 95% CI = -0.40--0.11), brightness (MD = 2.00, 95% CI = 0.59-3.42), redness (MD = -0.79, 95% CI = -1.52--0.07), pigmentation (MD = -0.16, 95% CI = -0.32--0.00) and hardness (SMD = -0.65, 95% CI = -1.07--0.23). However, there was no difference in vascularity (MD = 0.03, 95% CI = -0.43-0.48). Our analysis indicated that patients with HS who were managed with PT (15-25 mmHg) showed significant improvements. Due to limitations, more large and well-designed studies are needed to confirm our findings and the side-effects of the PT may also need to be evaluated.

Hypertrophic scarring: the greatest unmet challenge after burn injury

Improvements in acute burn care have enabled patients to survive massive burns that would have once been fatal. Now up to 70% of patients develop hypertrophic scars after burns. The functional and psychosocial sequelae remain a major rehabilitative challenge, decreasing quality of life and delaying reintegration into society. Approaches to optimise healing potential of burn wounds use targeted wound care and surgery to minimise the development of hypertrophic scarring. Such approaches often fail, and modulation of the established scar is continued although the optimal indication, timing, and combination of therapies have yet to be established. The need for novel treatments is paramount, and future efforts to improve outcomes and quality of life should include optimisation of wound healing to attenuate or prevent hypertrophic scarring, well-designed trials to confirm treatment efficacy, and further elucidation of molecular mechanisms to allow development of new preventive and therapeutic strategies.