Negative pressure wound therapy is a generally accepted method of treating septic or secreting wounds. In contrast to that, postoperative application of negative pressure wound therapy to primarily closed surgical wounds is referred to as closed-incision negative-pressure wound therapy (Ci-NPWT). According to available sources, wounds after prophylactic application of Ci-NPWT show lower complication rates, especially wound infections, and dehiscence. The literature confirms that the Ci-NPWT technique improves healing of all surgical wounds, both septic and aseptic.

BACKGROUND: Custom-made transparent facial orthoses (TFOs) (face masks) are used to improve facial burn scars. We conducted a systematic literature review on TFO manufacture and use.
METHODS: Pubmed and Cochrane databases were searched without restrictions for relevant articles. TFO manufacture details and use according to international recommendations (20-32 mmHg pressure, TFO worn 20-23 h/day for ≥2 months) were extracted.
RESULTS: Of 279 retrieved articles, 11 published over the last 41 years (four in the last 5 years) discussed TFO manufacture/use. There were five technical notes, five case reports, and a patient-cohort study (total patients in the studies=21). TFO-manufacture methods could be categorized as classical, digital, or mixed classical-digital. Relative clinical efficacies and cost advantages were unclear. The plastics used, harness materials, harness-point number, and silicone-interface use differed from study to study. Target pressure, actual pressure, expected daily wearing time, and treatment duration ranged widely and often did not meet current guidelines. Actual wearing time and treatment duration were never measured.
CONCLUSIONS: Although TFOs play an important global role in burn care, there is a grave paucity of research. Further research is needed to promote the standardization of TFO-related practices and thereby improve the outcomes of facial-burn patients.

At present, there are many kinds of hypertrophic scar treatment methods, among which pressure therapy and silicone therapy are very common and standard therapies, but whether they are used alone or in combination is still controversial. Therefore, the purpose of this systematic review was to compare the efficacy and safety of the combination of pressure therapy and silicone therapy (PTS) with pressure therapy alone (PT) in the treatment of hypertrophic scars to provide clinicians with information so that they can make better decisions.
Relevant randomized controlled trials (RCTs) were collected by searching PubMed, Ovid MEDLINE, Embase, ScienceDirect, Web of Science, The Cochrane Library, Scopus, and Google Scholar databases to assess scar scores (The Vancouver Scar Scale, VSS; Visual Analog Scale, VAS) and adverse effects.
We screened 1270 articles and included 6 RCTs including 228 patients. We found that height (MD = 0.15, 95%CI 0.10-0.21, p < 0.01) and pliability (MD = 0.35, 95%CI 0.25-0.46, p <0.01) had a significant difference, these two measures showed that the PTS group was superior to the PT group. Results in other aspects, such as VSS, vascularity, pigmentation, VAS, and adverse effects were similar between the two groups.
There was no significant difference between PTS and PT in the overall treatment efficacy of hypertrophic scars with similar VSS and adverse effects, but PTS might have potential benefits for height and pliability. Additional studies with larger sample size and sound methodological quality are needed to confirm our conclusions. Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Pressure garment therapy is frequently used to prevent pathologic scarring, especially in burns. Less common is its use for the treatment of facial wounds. Pathologic scarring can create functional and aesthetic problems, which can have psychological implications. The aim of this study is to report our experience in the treatment of traumatic facial wounds using an elastic custom facial mask.

Pressure therapy (PT) is an effective intervention for reducing scarring, but its underlying mechanism remains largely unclear. Here, we demonstrate that human scar-derived myofibroblasts dedifferentiate into normal fibroblasts in response to PT, and we identify how SMYD3/ITGBL1 contributes to the nuclear relay of mechanical signals. In clinical specimens, reductions in SMYD3 and ITGBL1 expression levels are strongly associated with the anti-scarring effects of PT. The integrin β1/ILK pathway is inhibited in scar-derived myofibroblasts upon PT, leading to decreased TCF-4 and subsequently to reductions in SMYD3 expression, which reduces the levels of H3K4 trimethylation (H3K4me3) and further suppresses ITGBL1 expression, resulting the dedifferentiation of myofibroblasts into fibroblasts. In animal models, blocking SMYD3 expression results in reductions of scarring, mimicking the positive effects of PT. Our results show that SMYD3 and ITGBL1 act as sensors and mediators of mechanical pressure to inhibit the progression of fibrogenesis and provide therapeutic targets for fibrotic diseases.

Hypertrophic scarring is a deviate occurrence after wound closure and is a common burn sequela. The mainstay of scar treatment consists of a trifold approach: hydration, UV-protection and the use of pressure garments with or without extra paddings or inlays to provide additional pressure. Pressure therapy has been reported to induce a state of hypoxia and to reduce the expression pattern of transforming growth factor-β1 (TGF-β1), therefore limiting the activity of fibroblasts. However, pressure therapy is said to be largely based on empirical evidence and a lot of controversy concerning the effectiveness still prevails. Many variables influencing its effectivity, such as adherence to treatment, wear time, wash frequency, number of available pressure garment sets and amount of pressure remain only partially understood. This systematic review aims to give a complete and comprehensive overview of the currently available clinical evidence of pressure therapy.
A systematic search for articles concerning the use of pressure therapy in the treatment and prevention of scars was performed in 3 different databases (Pubmed, Embase, and Cochrane library) according to the PRISMA statement. Only case series, case-control studies, cohort studies, and RCTs were included. The qualitative assessment was done by 2 separate reviewers with the appropriate quality assessment tools.
The search yielded 1458 articles. After deduplication and removal of ineligible records, 1280 records were screened on title and abstract. Full text screening was done for 23 articles and ultimately 17 articles were included. Comparisons between pressure or no pressure, low vs high pressure, short vs long duration and early vs late start of treatment were investigated.
There is sufficient evidence that indicates the value of prophylactic and curative use of pressure therapy for scar management. The evidence suggests that pressure therapy is capable of improving scar color, thickness, pain, and scar quality in general. Evidence also recommends commencing pressure therapy prior to 2 months after injury, and using a minimal pressure of 20-25 mmHg. To be effective, treatment duration should be at least 12 months and even preferably up to 18-24 months. These findings were in line with the best evidence statement by Sharp et al. (2016).

Pressure therapy has been used for the prevention and treatment of hypertrophic scars for decades. However, the cellular and molecular mechanisms of this treatment modality have not been fully elaborated, leading to long-lasting controversies regarding its clinical effectiveness. In this current study, we adopted an in vitro 3D culture and compression model to explore the effect of pressure force on fibroblasts, in order to further explain the working mechanism of compression force during pressure treatment. Human dermal fibroblasts were cultured in the 3D culture hydrogel and treated with 1.5 atm of external compression force through a syringe tube device, for 4, 8, and 20 h respectively. RNA-seq identified 437 differentially regulated genes after an 8-h compression intervention compared with control cells, among which 256 genes were up-regulated and 181 genes were down-regulated. Further q-PCR analysis confirmed that early growth response 1(EGR1) and c-fos were down-regulated after an 8-h compression intervention. However, the down-regulation of EGR1 and c-fos at the mRNA level does not lead to altered protein synthesis through western blot, for both 8 and 20-h time points after pressure intervention. Genes closely related to the fibrotic function of fibroblasts including type I collagen (COL1), type III collagen (COL3), transforming growth factor β1(TGF-β1), matrix metallopeptidase 1 (MMP1), matrix metallopeptidase 1 (TIMP1), connective tissue growth factor (CTGF), α smooth muscle actin (α-SMA), and fibronectin 1 (FN1), were also unaffected after pressure treatment for 8 h. The current study indicated that in our 3D hydrogel culture model, pressure does not directly affect the fibrotic function of dermal fibroblast in vitro. Indirect regulation including reducing oedema, blood perfusion, and tension could be a more possible mechanism of pressure therapy.

Pathological scarring imposes a major clinical and social burden worldwide. Human cutaneous wounds are responsive to mechanical forces and convert mechanical cues to biochemical signals that eventually promote scarring. To understand the mechanotransduction pathways in cutaneous scarring and develop new mechanotherapy approaches to achieve optimal scarring, the current study highlights the mechanical behavior of unwounded and scarred skin as well as intra- and extracellular mechanisms behind keloid and hypertrophic scars. Additionally, the therapeutic interventions that promote optimal scar healing by mechanical means at the molecular, cellular or tissue level are extensively reviewed. The current literature highlights the significant role of fibroblasts in wound contraction and scar formation via differentiation into myofibroblasts. Thus, understanding myofibroblasts and their responses to mechanical loading allows the development of new scar therapeutics. A review of the current clinical and preclinical studies suggests that existing treatment strategies only reduce scarring on a small scale after wound closure and result in poor functional and aesthetic outcomes. Therefore, the perspective of mechanotherapies needs to consider the application of both mechanical forces and biochemical cues to achieve optimal scarring. Moreover, early intervention is critical in wound management; thus, mechanoregulation should be conducted during the healing process to avoid scar maturation. Future studies should either consider combining mechanical loading (pressure) therapies with tension offloading approaches for scar management or developing more effective early therapies based on contraction-blocking biomaterials for the prevention of pathological scarring.

Transparent facemask has been widely used for the prevention and treatment of facial hypertrophic scars all over the world. 3D printing has improved the fabrication accuracy of the traditional transparent facemasks. However, the pressure distribution pattern generated by the 3D-printed transparent facemasks has not been thoroughly investigated. The aim of this study is to develop a biomechanical model to simulate the pressure distribution of the 3D-printed transparent facemask, and to form the biomechanical basis to guide facemask design.
A finite element model comprised of the head bones, the soft tissues of the face and the transparent facemask was established in ABAQUS CAE package. The contact pressure between the facemask and the face was simulated under 7 loading conditions. The calculated results from the model were validated through comparing with the experimental pressure measurements.
The calculated results from the model well correlated with the experimental pressure measurements (P < 0.05). The biomechanical model is acceptable for the prediction of interface pressure between the facemask and the face.
The pressure distribution pattern showed the facial areas with thin soft tissues and bony prominence experienced concentrated pressure while areas with thick soft tissues received less or no pressure. Suggestions for future facemask design based on the biomechanical model is releasing the areas with concentrated pressure and indenting areas with insufficient pressure.

OBJECTIVE: To compared with the modified Robert Jones bandage of 3M elastic bandage, to evaluate the fitness, convenience, safety and comfort of the modular combination lower limb elastic compression device.
METHODS: Forty healthy adult college students, including 28 males and 12 females, aged 16 to 25 (20.3±2.2) years old and weighing 40 to 81 (60.4±20.2) kg, were randomly divided into two groups with 40 samples in each group. According to the body surface parameters of Chinese lower limbs and guided by the concept of modularization, a group of modular combined lower limb elastic compression device was designed. Each module was combined to evaluate the fitness of the modular combined compression device in thelength and circumference of the lower limbs. The left and right lower limbs were randomly paired and divided into groups, with 40 samples in each group. The convenience of the operation time, adjustment times and required time were compared between two groups. The safety of the two groups after 24 hours of application of pressure injury was compared. The subjective pain feeling changes within 24 hours were recorded by visual analogue scale (VAS) to evaluate the comfort.
RESULTS: The device was composed of several elastic compression outer lining modules with different length and width of 15 cm, an inner lining module for buffering, positioning and attaching the main body, and an elastic ankle compression module. The length of the elastic compression outer lining module covers the circumference of the human lower limbs. The length of a single outer lining module increased from 15 cm to 80 cm every 5 cm interval, and the length of a single inner lining module increased from 62 cm to 83 cm every 3 cm interval. After the modules were selected and combined, the length and circumference of the lower limbs can reach 100% fitness. The operation time of the first placement(118.23±7.33) s and re operation(60.08±5.88) s of experimental group were significantly shorter than those of control group (164.68±8.93) s and re operation (131.23±7.91) s. The adjustment times (3) and operation time (3.50±0.71) s of experimental group were significantly shorter than those of control group(11)and operation time(139.00±5.66) s (P<0.05), but there was no significant difference between two groups (P>0.05). The VAS score of experimental group was significantly lower than that of control group at each time point (P<0.01).
CONCLUSIONS: The modular combined elastic compression device has good fitness, better placement and flexible adjustment, convenience and safety, and better comfort than modified Robert Jones bandage of 3M elastic bandage.