162 An Examination of Scar Modelling and Assessment Methods for the Evaluation of Scar Treatments

Introduction Scarring is the final common pathway for healing within the skin. Scars can be itchy, painful, tight, and disfiguring. Despite advances in surgery there is currently no reliably effective treatment for reducing or preventing scarring. The primary aim of this research is to assess the currently available models for scarring and evaluate/further develop the utility of current assessment tools, in an effort to design a pilot randomised control trial (RCT) for silicone gel treatment of scars. Method A systematic review of scar models in humans and animals. Examination of currently used subjective and objective scar assessment tools in a plastic surgery scar clinic. A retrospective cohort study assessing long-term scar outcomes in paediatric burn patients. Results Limitations and drawbacks of many existing methods to assess scar treatments were found. No statistically significant difference in long-term scarring outcomes was found between paediatric burns patients treated surgically versus conservatively. A RCT for silicone gel sheeting in the treatment of scars was set up and successful in recruitment. Conclusions Here, we have demonstrated difficulties in establishing a scientific scar treatment model; and created a pilot study that will help to provide high-quality evidence for the efficacy of silicone gel sheeting as a treatment for scars.

32 Does the Use of Silicone Gel Sheeting Impact the Overall Physiology of Hypertrophic Scar Development? A Feasibility Trial Using Laser Doppler Imaging to Assess Perfusion in Native Skin and Immature Burn Scar

Introduction The use of silicone gel sheeting (SGS) has long been observed clinically as an effective modality in reducing hypertrophic scar (HTS) formation. Although the use of SGS is widely accepted, the exact mechanism is not fully understood. Prevailing theory suggests silicone suppresses collagen production in immature active scar. Collagen production is enhanced as blood flow increases in areas of scar hyperemia. Reduction of blood perfusion to the immature scar may act as a potential mechanism in limiting excessive scar proliferation. Methods Laser Doppler Imaging (LDI) was used to assess 2 areas in 2 subjects (85% TBSA w/ CEA and native skin control): A control site and SGS testing site were traced on the skin of each subject and 5 LDI scans were performed on both subjects: 1) initial without SGS; 2) initial with SGS applied; 3) 4-hours post-SGS application with SGS on; 4) 4-hours post-SGS application immediately after removal; 5) 15-minutes post-SGS removal. The control and testing site for both subjects were then analyzed using the LDI software and the average perfusion units (PU) over the region of interest (ROI1: testing site; ROI2: control site) areas were calculated for each scan. Results Perfusion within both ROI had a marked increase in perfusion for HTS scans after 4-hours when compared to the initial scan. However, after initial SGS application to ROI1, the mean PU decreased by 23.1% while the perfusion to ROI2 remained relatively constant (-5.8%). Subsequently, the ROI2 increased in mean PU by 23.4% 4-hours after the initial scan while the ROI1 showed a blunted response in perfusion in comparison increasing by only 2.3%. Conclusions Perfusion for both NS and HTS were notably decreased when SGS was applied compared to the matched ROI without SGS. In addition, prolonged SGS application created a greater difference in perfusion between silicone (less perfusion) and non-silicone sites (greater perfusion) for both NS and HTS when compared to initial SGS application demonstrating a greater effect on perfusion the longer SGS was worn.

Emerging and Novel Therapies for Keloids

Keloids are abnormal fibroproliferative scars with aggressive dermal growth expanding beyond the borders of the original injury. Different therapeutic modalities, such as corticosteroids, surgical excision, topical silicone gel sheeting, laser therapy, cryotherapy, photodynamic therapy and radiotherapy, have been used to treat keloids; however, none of these modalities has proven completely effective. Recently, researchers have devised several promising anti-keloid therapies including anti-hypertensive pharmaceuticals, calcineurin inhibitors, electrical stimulation, mesenchymal stem cell therapy, microneedle physical contact and ribonucleic acid-based therapies. The present review summarises emerging and novel treatments for keloids. PubMed® (National Library of Medicine, Bethesda, Maryland, USA), EMBASE (Elsevier, Amsterdam, Netherlands) and Web of Science (Clarivate Analytics, Philadelphia, Pennsylvania, USA) were searched for relevant literature published between January 1987 to June 2020. A total of 118 articles were included in this review. A deeper understanding of the molecular mechanisms underlying keloid scarring pathogenesis would open further avenues for developing innovative treatments. KEYWORDS Keloid; Treatment; Fibroblast; Scar; Dermatology.

Treatment of Immature Scars: Evidence-Based Techniques and Treatments

Severe scarring is known for causing severe functional, aesthetic, and psychosocial impairments. During the last years, treatment of mature scars has evolved significantly; however, researchers and clinicians are more and more focused on preventing excessive scarring altogether, thus avoiding long and strenuous treatment. While some forms of scar prevention have been known and used for decades, others are relatively new and have yet to prove themselves. Pressure garments have long been successfully used in widespread burn scar prevention. However, reduced compliance, large treatment costs, and little hard evidence are points that should be taken into consideration regarding this well-established form of treatment. Silicone gel sheeting has also been used for a long time, and it is well regarded for its efficacy in reducing scar height and improving pliability while boasting little side effects. Its mode of action, however, remains unclear. Recently, lasers have become a new focus in the effort to prevent pathological scarring. Here, the older pulsed dye laser, as well as newer, fractional ablative and nonablative lasers, is increasingly employed for the treatment of fresh scars, where initial research is showing significant promise.This chapter explores the currently available methods for scar prevention and examines their application and the evidence regarding their efficacy.