Traction-Assisted Dermatogenesis by Serial Intermittent Skin Tape Application:

An Overview of Recent Developments in the Management of Burn Injuries

According to the World Health Organization (WHO), around 11 million people suffer from burns every year, and 180,000 die from them. A burn is a condition in which heat, chemical substances, an electrical current or other factors cause tissue damage. Burns mainly affect the skin, but can also affect deeper tissues such as bones or muscles. When burned, the skin loses its main functions, such as protection from the external environment, pathogens, evaporation and heat loss. Depending on the stage of the burn, the patient's condition and the cause of the burn, we need to choose the most appropriate treatment. Personalization and multidisciplinary collaboration are key to the successful management of burn patients. In this comprehensive review, we have collected and discussed the available treatment options, focusing on recent advances in topical treatments, wound cleansing, dressings, skin grafting, nutrition, pain and scar tissue management.

Noninvasive Soft Tissue Expansion Strips and Wound Complications After Total Ankle Arthroplasty

BACKGROUND

Total ankle arthroplasty through the anterior approach (TAR-AA) is an increasingly popular treatment for ankle arthritis, but it carries a known risk for wound complications. Several products have been investigated to mitigate this risk; however, most are either costly or invasive. Noninvasive skin expansion strips (NSESs) were designed to transfer tension away from the incision and induce new skin growth at the edges of the strips. We hypothesize that postoperative application of NSESs will decrease unplanned clinic visits and wound complications after TAR-AA.

METHODS

This is a prospective cohort study of 41 patients at a single institution (3 surgeons) treated with NSESs after undergoing TAR-AA. An additional 41 consecutive historical patients treated without NSESs were retrospectively included as a control group. Patients received application of NSESs in the operating room after routine wound closure and again 2 weeks postoperatively. No other changes were made to the surgeons' wound closure technique, immobilization, follow-up timing, or rehabilitation protocols. Primary outcomes included (1) additional clinic visit required for wound assessment or suture removal, (2) superficial wound complication, and (3) deep infection.

RESULTS

Baseline demographics did not differ significantly from our 41 consecutively treated historical controls. Additional clinic visits for suture removal or wound evaluation were significantly lower for patients treated with NSESs (15%, 6 of 41) compared to the control group (49%, 20 of 41) (P = .001). There was also a significant difference in the superficial wound complication rate in the treatment group vs control group, 2% and 12%, respectively (P = .04). There were no deep infections in either group.

CONCLUSION

Noninvasive skin expansion strips placed after TAR-AA with an anterior approach have the potential to decrease wound complications and unplanned clinic visits. Further high-volume or randomized studies are needed to clarify their cost effectiveness and effect on long-term outcomes.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Efficacy and safety of external tissue expansion technique in the treatment of soft tissue defects: a systematic review and meta-analysis of outcomes and complication rates

Background

Currently, various external tissue expansion devices are becoming widely used. Considering the scarcity of relevant application standards, this systematic review was performed to explore the effectiveness and safety of external tissue expansion techniques for the reconstruction of soft tissue defects.

Method

A systematic review and meta-analysis on the efficacy and safety of external tissue expansion technique was conducted. A comprehensive search was performed in the following electronic databases: PubMed/Medline, Embase, Cochrane Library (Wiley Online Library), and Web of Science. Studies reporting patients with soft tissue defects under the treatment of external tissue expansion technique were included.

Results

A total of 66 studies with 22 different types of external tissue expansion devices met the inclusion criteria. We performed a descriptive analysis of different kinds of devices. A single-arm meta-analysis was performed to evaluate the efficacy and safety of the external tissue expansion technique for different aetiologies. The pooled mean wound healing time among patients with defects after fasciotomy was 10.548 days [95% confidence interval (CI) = 5.796–15.299]. The pooled median wound healing times of patients with defects after excisional surgery, trauma, chronic ulcers and abdominal defects were 11.218 days (95% CI = 6.183-16.253), 11.561 days (95% CI = 7.062-16.060), 15.956 days (95% CI = 11.916-19.996) and 12.853 days (95% CI=9.444-16.227), respectively. The pooled wound healing rates of patients with defects after fasciotomy, excisional surgery, trauma, chronic ulcers and abdominal defects were 93.8% (95% CI=87.1-98.2%), 97.2% (95%CI=92.2-99.7%), 97.0% (95%CI=91.2-99.8%), 99.5% (95%CI=97.6-100%), and 96.8% (95%CI=79.2-100%), respectively. We performed a subgroup analysis in patients with diabetic ulcers and open abdominal wounds. The pooled median wound healing time of patients with diabetic ulcers was 11.730 days (95% CI = 10.334-13.125). The pooled median wound healing time of patients with open abdomen defects was 48.810 days (95% CI = 35.557–62.063) and the pooled successful healing rate was 68.8% (95% CI = 45.9-88.1%). A total of 1686 patients were included, 265 (15.7%) of whom experienced complications. The most common complication was dehiscence (n = 53, 3.14%).

Conclusions

Our systematic review is the first to demonstrate the efficacy and safety of external tissue expansion in the management of soft tissue defects. However, we must interpret the meta-analysis results with caution considering the limitations of this review. Large-scale randomized controlled trials and long-term follow-up studies are still needed to confirm the effectiveness and evaluate the quality of healing.

Mechanotransduction in Wound Healing: From the Cellular and Molecular Level to the Clinic

GENERAL PURPOSE

To review the various mechanical forces that affect fibroblasts, keratinocytes, endothelial cells, and adipocytes at the cellular and molecular level as well as scar-reducing mechanical devices currently in clinical use.

TARGET AUDIENCE

This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.

LEARNING OBJECTIVES/OUTCOMES

After participating in this educational activity, the participant will:1. Compare and contrast the responses of various types of cells to mechanical forces.2. Identify the mechanical devices and techniques that can help restore skin integrity.

Clinical efficacy of intermittent magnetic pressure therapy for ear keloid treatment after excision

BACKGROUND

Keloids are benign fibro-proliferative lesion, related to excessive inflammatory reactions in certain anatomical areas, including the auricles. Their specific etiology remains unclear; nonetheless they exhibit tumor-like characteristics of significant recurrence and cause emotional distress, even with various treatment strategies. We applied intermittent magnetic pressure therapy on ear keloids in combination with surgical excision, and present its effectiveness herein.

METHODS

Ear keloid patients were treated with surgical excision followed by magnetic pressure therapy. The keloid tissues underwent excision and keloid marginal flaps were utilized for wound closure. Intermittent magnetic pressure therapy was applied 2 weeks after the surgical procedure. The pressure therapy consisted of a 3-hour application and 2-hour resting protocol (9 hr/day), and lasted for 6 months. The results were analyzed 6 months after the therapeutic procedures, using the scar assessment scale.

RESULTS

Twenty-two ear keloids from 20 patients were finally reviewed. Among the keloids that completed the therapeutic course, 20 ear keloids out of 22 in total (90.9%) were successfully eradicated. Two patients (2 keloids) exhibited slight under-correction. Postoperative complications such as wound dehiscence or surgical site infection were not noted. The scar assessment scale demonstrated a significant improvement in each index. The intermittent pressure therapy led to patient compliance, and avoided pressure-related pain and discomfort.

CONCLUSION

Excision followed by intermittent pressure application using a magnet successfully reduced the burden of fibro-proliferative keloids, and had good patient compliance. The role of intermittent pressure application and resting should be studied with regard to keloid tissue remodeling.

The use of a skin-stretching device combined with vacuum sealing drainage for closure of a large skin defect: a case report

Background

This case report presents the treatment of a large infected skin defect, which was caused by an accidental explosion, through a skin-stretching device combined with vacuum sealing drainage. To the best of our knowledge, the area of the wound that we treated may currently be the largest.

Case presentation

A 41-year-old Asian man was transferred to the Center of Trauma Surgery of our hospital for the closure of an open infected wound with a large skin defect in his right lower limb caused by an accidental explosion of 100 pieces of blasting cap. The wounds located in his right gluteal were approximately 40 cm × 35 cm. On admission, the wounds had hemorrhaged, exhibiting a darkened appearance, and included scattered metallic foreign bodies. Debridement of his right gluteal area was conducted 6 hours after injury. Subsequently, a skin-stretching device combined with vacuum sealing drainage was applied to reduce the skin defect. This treatment proved to be valuable for the closure of the skin defect and to attain successful functional rehabilitation without sciatic nerve entrapment or amputation in this case.

Conclusions

It is difficult to close large skin defects, especially when they are infected. The application of a skin-stretching device combined with vacuum sealing drainage should be commonly applied to treat infected wounds because it is a safe and easy operative technique.

Recent Understandings of Biology, Prophylaxis and Treatment Strategies for Hypertrophic Scars and Keloids

Hypertrophic scars and keloids are fibroproliferative disorders that may arise after any deep cutaneous injury caused by trauma, burns, surgery, etc. Hypertrophic scars and keloids are cosmetically problematic, and in combination with functional problems such as contractures and subjective symptoms including pruritus, these significantly affect patients’ quality of life. There have been many studies on hypertrophic scars and keloids; but the mechanisms underlying scar formation have not yet been well established, and prophylactic and treatment strategies remain unsatisfactory. In this review, the authors introduce and summarize classical concepts surrounding wound healing and review recent understandings of the biology, prevention and treatment strategies for hypertrophic scars and keloids.

Closure of large wounds using rubber bands in rabbits

OBJECTIVE

to verify the effectiveness of the rubber elastic band in the treatment of large wounds of the body wall of rabbits by means of traction of its edges.

METHODS

we studied 30 New Zealand rabbits, divided into three groups (n=10): Group 1- healing by secondary intention; Group 2- removal and eutopic repositioning of skin as full thickness skin graft; Group 3- Approximation of wound edges with elastic rubber band. In all animals, we removed a segment of the back skin and subcutaneous tissue down to the fascia, in accordance with an acrylic mold of 8 cm long by 12 cm wide. All animals were observed for 21 days.

RESULTS

two animals of groups 1 and 2 had wound abscess. In Group 2, there was partial or total graft loss in 90% of animals. The complete closure of the wounds was observed in four animals of Group 1, six of Group 2 and eight of Group 3. There was no difference between the scar resistance values of groups 2 and 3, which were higher than those in Group 1. The scars of the three groups were characterized by the presence of mature connective tissue mixed with blood vessels and inflammatory infiltration, predominantly polymorphonuclear.

CONCLUSION

the tensile strength of the wound edges with rubber elastic band is as efficient as the skin graft to treat rabbits' large body wounds.

Reverse tissue expansion by liposuction deflation for revision of post-surgical thigh scars

Scars hypertrophy and widen when stretching mechanical forces are applied to resilient newly formed collagen before it reaches final maturity marring the final result of many surgical procedures and resulting in a clinical problem for many patients. Scar revision by surgical excision remains the traditional treatment for hypertrophic or widespread scars. It relies upon recruitment of local tissues for closure of the ensuing defect. Providing tension-free skin closure is the best option to avoid recurrence. Although tissue expansion procedure is a valuable and reliable technique for scar revision, it has its own disadvantages and potential complications. We describe an alternative method for scar revision that may be applicable in certain situations. Instead of expanding the soft tissues to make available additional skin, deflation by liposuction may be affected to relax the skin envelope thus indirectly providing additional skin for scar revision. We call this method 'reverse tissue expansion'.

Controlled induction of distributed microdeformation in wounded tissue via a microchamber array dressing

Mechanical stimuli are known to play an important role in determining the structure and function of living cells and tissues. Recent studies have highlighted the role of mechanical signals in mammalian dermal wound healing. However, the biological link between mechanical stimulation of wounded tissue and the subsequent cellular response has not been fully determined. The capacity for researchers to study this link is partially limited by the lack of instrumentation capable of applying controlled mechanical stimuli to wounded tissue. The studies outlined here tested the hypothesis that it was possible to control the magnitude of induced wound tissue deformation using a microfabricated dressing composed of an array of open-faced, hexagonally shaped microchambers rendered in a patch of silicone rubber. By connecting the dressing to a single vacuum source, the underlying wounded tissue was drawn up into each of the microchambers, thereby inducing tissue deformation. For these studies, the dressings were applied to full-thickness murine dermal wounds with 200 mmHg vacuum for 12 h. These studies demonstrated that the dressing was capable of inducing wound tissue deformation with values ranging from 11 to 29%. Through statistical analysis, the magnitude of the induced deformation was shown to be a function of both microchamber height and width. These results demonstrated that the dressing was capable of controlling the amount of deformation imparted in the underlying tissue. By allowing the application of mechanical stimulation with varying intensities, such a dressing will enable the performance of sophisticated mechanobiology studies in dermal wound healing.

In vivo acceleration of skin growth using a servo-controlled stretching device

Tension is a principal force experienced by skin and serves a critical role in growth and development. Optimal tension application regimens may be an important component for skin tissue engineering and dermatogenesis. In this study, we designed and tested a novel servo-controlled skin-stretching device to apply predetermined tension and waveforms in mice. The effects of static and cyclical stretching forces were compared in 48 mice by measuring epidermal proliferation, angiogenesis, cutaneous perfusion, and principal growth factors using immunohistochemistry, real-time reverse transcriptase-polymerase chain reaction, and hyperspectral imaging. All stretched samples had upregulated epidermal proliferation and angiogenesis. Real-time reverse transcriptase-polymerase chain reaction of epidermal growth factor, transforming growth factor beta1, and nerve growth factor demonstrated greater expression in cyclically stretched skin when compared to static stretch. Hypoxia-induced factor 1alpha was significantly upregulated in cyclically stretched skin, but poststretch analysis demonstrated well-oxygenated tissue, collectively suggesting the presence of transient hypoxia. Waveform-specific mechanical loads may accelerate tissue growth by mechanotransduction and as a result of repeated cycles of temporary hypoxia. Further analysis of mechanotransduction signaling pathways may provide additional insight to improve skin tissue engineering methods and optimize our device.