Estimates indicate that each year around 100 million people in the developed world acquire scars following elective surgery and surgery for trauma. Of these, approximately 15% have excessive or unaesthetic scars.
Physical Edge recognises the need for better post operative scar management for aesthetic and comfort reasons. For some clients unsightly scars can be source of embarrassment or a reminder of the injury/ operation they might otherwise like to forget. Silicon Gel Sheeting (SGS) has been used in scar management for over 30 years and is often considered the “Gold Standard” non-invasive treatment of scars.
What happens in normal skin healing?
When skin is cut a repair process starts. The body lays down a layer of epithelial cells to create a protective barrier and prevent infection. Once the initial inflammatory phase completes a repair process begins. Cells called Dermal Fibroblasts are attracted into the wound from the skin tissue adjacent to the wound. They produce collagen which draws the margins of the wound together to fortify the repaired tissue. It is during this remodelling phase when scars form. It can take a year or longer for scars to mature and, therefore, can continue to transform over this period.
Skin injury which extends deep into the dermal and subdermal tissue, such as invasive surgical incisions, can lead to highly contracted scar tissue. In extreme cases this can lead to physical restrictions to movement.
There are many factors which will influence how a person will respond to scarring. This will include age, ethnicity, skin type, wound size and location. Dark skinned individuals can be prone to keloid scarring (https://bit.ly/2MORekO) and white skinned individuals to hypertrophic scarring (https://bit.ly/2DHB8G3). In Keloid scarring the scar extends beyond the boundary of the wound. In hypertrophic scarring the scar stays within the boundaries of the wound. Hypertrophic scarring can form in areas under tension such as shoulders, ankles, knees and neck.
How does Silicon work?
The epidermis can take 2 weeks to regenerate after a surgical wound. High levels of collagen are required at this time and any form of intervention will have little or no effect.
After 2 weeks the surface of the wound is covered by immature stratum corneum (outer most layer of skin). This allows for abnormally high levels of water loss and dehydration. Dehydration signals fibroblasts to synthesise and release collagen. Collagen can aid in water retention. Excessive production of collagen can cause undesirable scarring.
SGS covers the stratum corneum and normalises hydration of the scar to that of healthy skin. Theoretically, this may inhibit the instruction of fibroblasts to produce excessive collagen.
Normalising hydration levels of skin is the primary mechanism of SGS. Other proposed mechanisms include transferring tension at the lateral edges of the wound bed to the SGS, inhibit an increase in skin capillaries to reduce blood flow and an exaggerated healing process, and to generate a negatively charged static electric field resulting in involution of raised scars.
The optimum time to see results from SGS is constant wear for 6-12 months. Reevaluate scars at 4-8 weeks post surgery to decide if scar management procedures should continue or be terminated. The use of compression with SGS may be indicated if excessive scarring shows after 3 months.
To measure the effectiveness of SGS you can assess several properties of the scar. These include the height (scar elevation index, SEI), colouration, pliability, pain, discomfort, irritation, and itching. All may improve with SGS.
SGS are skin friendly. They are atraumatic to remove, biocompatible, resistant to microbial growth, do not absorb water, can be repositioned easily and worn 24 hours per day. They can be removed, cleaned and reused without compromising integrity of the product.
The main limitation of SGS is keeping it on the scar. Some products provide adhesive tape to secure the SGS in place. Another possible side effect is skin irritation especially in hot weather. In these situations SGS would be contraindicated.
Does the evidence support the use of SGS?
A search of the literature identifies studies which conclude that SGS works. Many of these studies a sponsored by medical companies who have an invested interest in selling SGS or the studies are of poor design and low subject numbers.
A Cochrane systematic review in 2013 concluded, ”There is weak evidence of a benefit of silicone gel sheeting as a prevention for abnormal scarring in high-risk individuals but the poor quality of research means a great deal of uncertainty prevails. Trials evaluating silicone gel sheeting as a treatment for hypertrophic and keloid scarring showed improvements in scar thickness and scar colour but are of poor quality and highly susceptible to bias.”
A further paper published in 2018 concluded, “There was statistical significance in the effectiveness of silicone gel and silicone gel sheeting on the prevention of keloids or hypertrophic scars, especially in skin lesion wounds. However, most of the trials evaluating silicone gel sheeting or silicone gel as a prevention of hypertrophic scars and keloids had poor quality with high or uncertain risk of biases either in study design or in conduct.”
SGS has been used in scar management for over 30 years
There is weak evidence to suggest it can be useful in scar management
More high quality evidence is required
SGS is non invasive, low cost and low risk with potentially significant benefits
The alternatives to SGS are invasive (Steroids injections, Skin grafts, surgical revision, Dermal fillers, and Laser) and abnormal scarring may return
The choice to use SGS is a clinical decision with no guarantees of working
Bleasdale B, Finnegan S, Murray K, Kelly S, Percival S. The use of silicon adhesives for scar reduction. Adv Wound Care. July 1 2015, 4(7): 422-430
Khuei-Chang Hsu, Chih- Wei L, Yi-Wen Tsai. Review of silicon gel sheeting and silicon gel for the prevention of hypertrophic scars and keloids. Wounds: a compendium of clinical research and practice. May 2017, 29(5): Citation only
McCarty M, Del Rosso J. An evaluation of evidence regarding application of silicon gel sheeting for the management of hypertrophic scars and keloids. November 2010, 3(11): 39-43
Mahnoush M, Farhad H, Hossein R, Hamid K. Effects of silicon gel on burn scars. Burns: Journal of the International Society for Burn Injuries. August 2008, 35(1):70-4
Medhi B, Sewal R K, Kaman L, Kadhe G, Mane A. Efficacy and safety of an advanced formula silicon gel for prevention of post-operative scars.Dermatol Ther (Heidelb). December 2013, 3(2): 157-167
Monstrey S, Middelkoop E, Vranckx J, Bassetto F, Ziegler U, Meaume S, Teot L. Updated scar management practical guidelines: non- invasive and invasice measures. Journal of Plastic, Reconstructive & Aesthetic Surgery. August 2014, 67(8): 1017-1025
O‘Brien L, Jones DJ. Silicon gel sheeting for preventing the development of hypertrophic and keloid scars and for treating existing hypertrophic and keloid scars. Cochrane database if systematic reviews. 12 Sept 2013
Puri N, Talwar A. The efficacy of silicon Gel for the treatment of hypertrophic scars and keloids. J Cutan Aesthet Surg. Jul-Dec 2009, 2(2): 104-106