Keloids and Hypertrophic Scars Can Now Be Cured Completely: Recent Progress in Our Understanding of the Pathogenesis of Keloids and Hypertrophic Scars and the Most Promising Current Therapeutic Strategy

Toward understanding scarless skin wound healing and pathological scarring

The efficient healing of skin wounds is crucial for securing the vital barrier function of the skin, but pathological wound healing and scar formation are major medical problems causing both physiological and psychological challenges for patients. A number of tightly coordinated regenerative responses, including haemostasis, the migration of various cell types into the wound, inflammation, angiogenesis, and the formation of the extracellular matrix, are involved in the healing process. In this article, we summarise the central mechanisms and processes in excessive scarring and acute wound healing, which can lead to the formation of keloids or hypertrophic scars, the two types of fibrotic scars caused by burns or other traumas resulting in significant functional or aesthetic disadvantages. In addition, we discuss recent developments related to the functions of activated fibroblasts, the extracellular matrix and mechanical forces in the wound environment as well as the mechanisms of scarless wound healing. Understanding the different mechanisms of wound healing is pivotal for developing new therapies to prevent the fibrotic scarring of large skin wounds.

Z-plasty and Postoperative Radiotherapy for Anterior Chest Wall Keloids: An Analysis of 141 Patients

Background

The therapies for anterior chest wall keloids include surgical excision, postoperative radiotherapy, silicone taping stabilization, and steroid plaster. However, to date, there is no universally accepted combination treatment strategy for anterior chest wall keloids.

Methods

All consecutive patients with single or multiple anterior chest wall keloids who underwent keloid excision, tension-reducing suturing, z-plasty, and postoperative radiotherapy in 2013-2016 in Nippon Medical School were included in this case series study. Only keloids that arose from small injuries such as folliculitis or acne were selected. The surgery was followed by tension-reducing self-management of the wounds with silicone tape and steroid plaster. The postsurgical radiotherapy modality was 18 Gy administered in 3 fractions over 3 days. The primary study outcome was keloid recurrence during the 24-month follow-up period. Recurrence was defined as the development of stiff and red lesions in even a small part of the scar that did not respond to 6 months of steroid plaster therapy.

Results

In total, 141 patients with 141 lesions were enrolled. Of the 141 lesions, 15 (10.6%) recurred. All recurrences were successfully treated by steroid plaster and steroid injection. The recurrence patients did not differ from the nonrecurrence patients in terms of the size of the original keloid or gender distribution.

Conclusions

Anterior chest wall keloids can be successfully treated by customized plans that involve appropriate surgical modalities (including z-plasty) followed by postoperative radiotherapy (18 Gy in 3 fractions over 3 days) and scar self-management with silicone tape and steroid plaster.

Surgery for scar revision and reduction: from primary closure to flap surgery

Scars are the final result of the four processes that constitute cutaneous wound healing, namely, coagulation, inflammation, proliferation, and remodeling. Permanent scars are produced if the wounds reach the reticular dermis. The nature of these scars depends on the four wound healing processes. If the remodeling process is excessive, collagen degradation exceeds collagen synthesis and atrophic scars are produced. If the inflammation phase is prolonged and/or more potent for some reason, inflammatory/pathological scars such as keloids or hypertrophic scars can arise. If these pathological scars are located on joints or mobile regions, scar contractures can develop. When used with the appropriate timing and when selected on the basis of individual factors, surgical techniques can improve mature scars. This review paper focuses on the surgical techniques that are used to improve mature scars, burn scars, and scar contractures. Those methods include z-plasties, w-plasties, split-thickness skin grafting, full-thickness skin grafting, local flaps (including the square flap method and the propeller flap), and expanded flaps, distant flaps, regional flaps, and free flaps.

Intralesional excision as a surgical strategy to manage keloid scars: what's the evidence?

INTRODUCTION

Keloid scars are a particularly challenging clinical entity and a variety of management approaches have been described in the literature including intralesional surgery. The current literature lacks a summative review to ascertain the evidence base behind this surgical approach.

METHODS

A comprehensive English literature database search was performed using PubMed Medline, EMBASE and Web of Science from their individual dates of inception to March 2018. We present the different rationales proposed for the use of this technique, the clinical outcomes reported in the literature as well as the scientific basis for intralesional excision of keloid scars.

DISCUSSION

A number of arguments have been proposed to support intralesional excision including avoiding injury to neighbouring non-keloidal skin and the deep layer of the dermis, removal of the most proliferative fibroblastic group as well as debulking to facilitate the administration of injectable steroid. The most current literature does not provide sufficient support for the adoption of intralesional excisions based on data emerging from basic science as well as clinical outcome studies.

CONCLUSION

Emerging evidence supports the extralesional excision of keloid scars based on current mechanobiological, histological as well as clinical outcome data. Further trials comparing extralesional and intralesional surgical practices are eagerly awaited to ascertain the role of intralesional excisions in the keloid management arena.

Surgical excision and postoperative radiotherapy for keloids

Keloids can be treated in a number of ways, including by surgery. Multiple studies now show that while surgical monotherapy associates with extremely high rates of recurrence (50%-80%), postoperative radiotherapy can significantly reduce these recurrence rates. Ongoing improvements in radiation technology have further increased the safety and efficacy of this combination protocol. Of the various radiotherapies that have been used in this setting, electron beam (β-ray) irradiation is currently the best due to its excellent dose distribution and safety. The maximal biologically effective dose (BED) for keloids is 30 Gy (using an estimated α / β ratio of 10); increasing the dose has no further benefits and elevates side effects. Over the last two decades, we have modified and then fine-tuned our radiotherapy protocol for keloid excision wounds. Thus, our early protocol was used for all body sites and consisted of 15 Gy/3 fr/3 days. We then customised the radiotherapy protocol so that body sites that are highly prone to recurrence (e.g. the anterior chest) receive higher doses while low recurrence sites like the earlobe receive a much smaller dose. More recently, we tweaked this body site-customised protocol so that fewer fractions are employed. Therefore, we currently apply 18 Gy/3 fr/3 days to high-recurrence sites, 8 Gy/1 fr/1 day to earlobes and 15 Gy/2 fr/2 days to other body sites. These radiotherapy protocol changes were accompanied by the evolution of body site-customised surgical approaches. As a result of these developments, our overall keloid recurrence rate is now below 10%.

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.

Reconstruction of Anterior Neck Scar Contracture Using A Perforator-Supercharged Transposition Flap

Reconstruction of the anterior neck requires attention to both aesthetic and functional outcomes. In general, skin grafts are not suitable for anterior neck reconstruction in Asian patients, even when artificial dermis is used before skin grafting. Therefore, we have employed various types of thin flaps for anterior neck reconstruction, including the cervico-pectoral flap. However, we have realized that, to fully release neck contractures and therefore achieve the full range of neck extension, the skin pedicle must be sufficiently wide. Therefore, we have started reconstructing anterior neck scar contractures using wide, thin, and long flaps that are harvested from the anterior chest wall. In this article, we describe the case of a 71-year-old man who presented with a neck contracture and tracheal fistula after receiving extensive burns. A transposition flap bearing the internal mammary artery perforator was harvested from the anterior chest wall to repair the neck wounds that were left after removing the scar. At the same time, the tracheal fistula was covered by the flap. The aesthetic and functional results were acceptable. The effectiveness of supercharged transposition flaps from the anterior chest wall for reconstructing anterior neck scar contraction is discussed.

The tension biology of wound healing

Following skin wounding, the healing outcome can be: regeneration, repair with normal scar tissue, repair with hypertrophic scar tissue or the formation of keloids. The role of chemical factors in wound healing has been extensively explored, and while there is evidence suggesting the role of mechanical forces, its influence is much less well defined. Here, we provide a brief review on the recent progress of the role of mechanical force in skin wound healing by comparing laboratory mice, African spiny mice, fetal wound healing and adult scar keloid formation. A comparison across different species may provide insight into key regulators. Interestingly, some findings suggest tension can induce an immune response, and this provides a new link between mechanical and chemical forces. Clinically, manipulating skin tension has been demonstrated to be effective for scar prevention and treatment, but not for tissue regeneration. Utilising this knowledge, specialists may modulate regulatory factors and develop therapeutic strategies to reduce scar formation and promote regeneration.

Extension of flaps associated with burn scar reconstruction: A key difference between island and skin-pedicled flaps

OBJECTIVE

The choice between local flap designs for burn reconstruction is largely shaped by aesthetic, vascularity, procedural complexity, and wound-closure considerations. However, another key consideration is how well specific local flap designs release post-burn scar contractures. This is because constant tension on wound edges can generate pathological scarring. However, the ability of specific local flap to release post-burn scar contractures is poorly understood. This question was addressed by this study of patients who underwent local flap surgery to release post-burn scar contractures.

METHODS

The flap type, its original size, and the degree to which the flap extended 6 months after surgery were recorded.

RESULTS

Of the 40 patients enrolled, 20 received an island flap and 20 received a skin-pedicled flap. The scars were most commonly located on the anterior chest, axilla, and cubital fossa, followed by the lateral chest, abdomen, thigh, and popliteal fossa. Six months after surgery, the skin-pedicled and island flaps had extended on average by 1.53- and 1.28-fold, respectively.

CONCLUSIONS

While it was technically easier to transfer island flaps to the recipient site, they released contractures less effectively than skin-pedicled flaps. The postoperative extensibility of flaps should be considered when determining which flap design is optimal for the individual patient.

A Case of Keloids Complicated by Castleman's Disease: Interleukin-6 as a Keloid Risk Factor

Keloids are a manifestation of a fibroproliferative scarring disorder of the skin and develop in response to dermal injury in patients with a susceptible background. Local, systemic, and genetic factors contribute to keloid susceptibility. These factors include tension on the edges of the wound, hormonal influences, and ethnicity, respectively. Castleman's disease is a rare lymphoproliferative disorder that is characterized by the unregulated overproduction of interleukin-6, which leads to systemic lymphadenopathy and constitutional inflammatory symptoms. This case report shows that the bilateral auricular keloids of an adult woman were greatly exacerbated by the onset of Castleman's disease. We present our multimodal management algorithm for auricular keloids, which involves core excision and radiation therapy and achieves excellent aesthetic outcomes. The current treatment pathway for auricular keloids and the possible relationship between interleukin-6 and keloid progression will be discussed.

Autologous fat grafting in keloids and hypertrophic scars: a review

Keloid and hypertrophic scars are unique human dermal fibroproliferative disorders of the injured skin and are associated with pain, itch and can cause functional limitations. A number of genetic, systemic and local factors have been identified in the formation of keloids and hypertrophic scars. Studies have shown that adipose-derived stem cells have angiogenic and antiapoptotic properties which has effects on wound healing, soft-tissue restoration and scar remodelling, and thus may have a role in managing keloid scaring. However, this role is not well described in the literature. A systemic review of available literature was thus undertaken, regarding the use of fat grafting in treatment of keloids and hypertrophic scarring. In total, 858 articles were identified, with ten studies ultimately fulfilling inclusion criteria. There were no studies specifically isolating the keloids and hypertrophic group of patients, and thus quantitative data were completely lacking from the literature. There were, however, individual cases described, and qualitatively encouraging clinical results were reported for the use of fat grafting on keloids and hypertrophic scars. Combined with the current theoretical and immunohistochemical understanding through other laboratory and animal studies, fat grafting may play a role in the treatment of keloids and hypertrophic scaring; however, specific evidence is currently lacking. The role for further research is clear.

Keloid and hypertrophic scars are difficult to treat conditions. Some studies have suggested that fat cells may have a role in managing these scars although this role is not well described in the literature. We perform a systematic review of available literature, examining the evidence for this.

Keloid and Hypertrophic Scars Are the Result of Chronic Inflammation in the Reticular Dermis

Keloids and hypertrophic scars are caused by cutaneous injury and irritation, including trauma, insect bite, burn, surgery, vaccination, skin piercing, acne, folliculitis, chicken pox, and herpes zoster infection. Notably, superficial injuries that do not reach the reticular dermis never cause keloidal and hypertrophic scarring. This suggests that these pathological scars are due to injury to this skin layer and the subsequent aberrant wound healing therein. The latter is characterized by continuous and histologically localized inflammation. As a result, the reticular layer of keloids and hypertrophic scars contains inflammatory cells, increased numbers of fibroblasts, newly formed blood vessels, and collagen deposits. Moreover, proinflammatory factors, such as interleukin (IL)-1α, IL-1β, IL-6, and tumor necrosis factor-α are upregulated in keloid tissues, which suggests that, in patients with keloids, proinflammatory genes in the skin are sensitive to trauma. This may promote chronic inflammation, which in turn may cause the invasive growth of keloids. In addition, the upregulation of proinflammatory factors in pathological scars suggests that, rather than being skin tumors, keloids and hypertrophic scars are inflammatory disorders of skin, specifically inflammatory disorders of the reticular dermis. Various external and internal post-wounding stimuli may promote reticular inflammation. The nature of these stimuli most likely shapes the characteristics, quantity, and course of keloids and hypertrophic scars. Specifically, it is likely that the intensity, frequency, and duration of these stimuli determine how quickly the scars appear, the direction and speed of growth, and the intensity of symptoms. These proinflammatory stimuli include a variety of local, systemic, and genetic factors. These observations together suggest that the clinical differences between keloids and hypertrophic scars merely reflect differences in the intensity, frequency, and duration of the inflammation of the reticular dermis. At present, physicians cannot (or at least find it very difficult to) control systemic and genetic risk factors of keloids and hypertrophic scars. However, they can use a number of treatment modalities that all, interestingly, act by reducing inflammation. They include corticosteroid injection/tape/ointment, radiotherapy, cryotherapy, compression therapy, stabilization therapy, 5-fluorouracil (5-FU) therapy, and surgical methods that reduce skin tension.

Steroid tape: A promising adjunct to scar management

Introduction:

Intralesional steroid administration is a popular adjunct to scar management with numerous reports in the literature appraising this modality in hypertrophic and keloid scars. The percutaneous delivery of steroids using adhesive tape is an alternative modality, which was first described in the dermatological literature in the 1960s. It is infrequently used in most countries apart from the Orient, where it represents one of the mainstays of specialist scar management protocols.

Methods:

An English and Japanese literature review was performed and reports were stratified using the Joanna Briggs Institute Levels of Evidence. Data were extracted relating to the maximum dose of steroid that can be delivered safely, the reported therapeutic efficacy, as well as the side effects associated with the percutaneous delivery of steroids.

Discussion:

Steroid tape has the potential to be a safe and patient-friendly adjunct to scar management for carefully selected cases of keloid and hypertrophic scars. The main limitation for its widespread adoption is the lack of data to enable the determination of safe exposure thresholds in adult and paediatric patients.

Conclusion:

Despite the existing encouraging reports regarding the potential to be a useful adjunct in scar management, steroid tape is not widely used apart from a limited number of scar services worldwide. Further research is warranted to delineate the role of this modality in specialist scar management protocols.

Steroid medications are frequently used to relieve symptoms as well as improve the appearance of bulky and unsightly scars. In most cases, this treatment involves injections; nevertheless, there is a more patient-friendly way to deliver this type of medicine to scars, which involves a sticky tape. Steroid tape is very popular in the East but is not commonly used in the rest of the world. We undertook this study to find out what has been written about this method of treatment in the skin disease literature and we focused our search on the treatment of scars in particular. We concluded that at present there some studies to support the safe use of steroid tape to treat carefully selected troublesome scars. Nevertheless, further research is needed to determine the maximum size of scar as well as duration of treatment that the steroid tape can be used for.

Keloid progression: a stiffness gap hypothesis

Keloids are fibroproliferative skin disorders characterised clinically by continuous horizontal progression and post-surgical recurrence and histologically by the accumulation of collagen and fibroblast ingredients. Till now, their aetiology remains clear, which may cover genetic, environmental and metabolic factors. Evidence in the involvement of local mechanics (e.g. predilection site and typical shape) and the progress in mechanobiology have incubated our stiffness gap hypotheses in illustrating the chronic but constant development in keloid. We put forward that the enlarged gap between extracellular matrix (ECM) stiffness and cellular stiffness potentiates keloid progression. Matrix stiffness itself provides organisational guidance cues to regulate the mechanosensitive resident cells (e.g. proliferation, migration and apoptosis). During this dynamic process, the ECM stiffness and cell stiffness are not well balanced, and the continuously enlarged stiffness gap between them potentiates keloid progression. The cushion factors, such as prestress for cell stiffness and topology for ECM stiffness, serve as compensations, the decompensation of which aggravates keloid development. It can well explain the typical shape of keloids, their progression in a horizontal but not vertical direction and the post-surgical recurrence, which were evidenced by our clinical cases. Such a stiffness gap hypothesis might be bridged to mechanotherapeutic approaches for keloid progression.

Reconstruction after Anterior Chest Wall Keloid Resection Using Internal Mammary Artery Perforator Propeller Flaps

It is difficult to completely resect huge anterior chest wall keloids and then close the wound directly. We report here our retrospective analysis of our case series of patients with such keloids who underwent reconstruction with internal mammary artery perforator (IMAP) pedicled propeller flaps and then received postoperative high-dose-rate superficial brachytherapy.

Negative Pressure Wound Therapy in Maxillofacial Applications

Negative pressure wound therapy has greatly advanced the field of wound healing for nearly two decades, by providing a robust surgical adjunct technique for accelerating wound closure in acute and chronic wounds. However, the application of negative pressure wound therapy in maxillofacial applications has been relatively under utilized as a result of the physical articulations and contours of the head and neck that make it challenging to obtain an airtight seal for different negative pressure wound therapy systems. Adapting negative pressure wound therapies for maxillofacial applications could yield significant enhancement of wound closure in maxillofacial applications. The current review summarizes the basic science underlying negative pressure wound therapy, as well as specific maxillofacial procedures that could benefit from negative pressure wound therapy.