Hrev_master Veins and Lymphatics 2016; volume 5:5984 [Veins and Lymphatics 2014; 3:5984] [page 9] Pressure therapy for post-burn scars: does it work? Mieke Flour,1 Mieke Anthonissen,2 Eric Van den Kerckhove2 1Phlebology and Chronic Wounds Clinic, Vascular Centre, University Hospital, St. Raphaël (KUV), Leuven; 2Department of Rehabilitation Sciences, Catholic University Leuven Research and Development, Leuven, Belgium Several controlled trials have accumulated evidence for the effectiveness of conservative strategies in the treatment of post-burn scars, including compression therapy.1 Randomized controlled trials using noninvasive instru- ments have assessed the effect of pressure on the 6 classical clinical parameters of post-burn scars: thickness, pigmentation, vascularity, pli- ability, color and overall aspect. There is world- wide acceptance for compression therapy and for silicone gel sheets in this specific indica- tion, although question marks remain regard- ing most appropriate dosage and about work- ing mechanisms. The most common working hypothesis is that pressure would induce ischemia and thus impair further growth of the scar. It is generally accepted that pressure impacts on the realignment of collagen fibers.2,3 The impact of pressure is most evi- dent of thickness of the scar. The mechanism of action of silicone was postulated as improv- ing skin hydration through occlusion and by reducing fibroblast’s activity and collagen for- mation.4 This working mechanism supports the effect of silicone on elasticity and redness of a hypertrophic scar. But how much compression pressure is needed? Data on a prospective study compar- ing 2 levels of pressure are presented: 20 vs 15 mmHg, during 3 months of pressure treatment in 76 burn scars, using the chromameter to assess redness and high resolution ultrasound (DermaScan™; Cortex Technology, Hadsund, Denmark) to measure thickness. Results of this study show that the higher pressure (20 mmHg) is more effective than the lower pres- sure (15 mmHg) and that this effect occurs sooner. This is in accordance with other pub- lished research which showed that the higher the amount of pressure, the better the effect on decrease of thickness.5,6 Nevertheless, there was no clear consensus about the mini- mum effective amount of pressure. Some authors suggested a pressure of at least 15 mmHg, while others recommended pressure of 24 mmHg to overcome capillary pressure. Higher pressure worn for 14 to 23 hours/day was more effective in flattening of burn scars and resulted in thinner scars. A compression pressure greater than 40 mmHg could result in complications such as paresthesia. Baseline selection differences between studies could explain the discrepancy of results concerning erythema (intervention time, time after burn injury, and the patient population: e.g. Asiatic vs Caucasian). Since silicone and pressure therapy had complementary modes of action, it appeared to be evident that their combined application would give complementary results. However a review of the literature yields vari- able outcomes, most probably due to differ- ences in study selection parameters. Finally, the authors tested what is the pressure added to the effect of silicone sheets, in several types of scars: post trauma, following surgery or burn injury. Results show the value of pressure treatment as a preventive measure against hypertrophy of scars: treated sites are less marked, and early treatment seemed to be more effective than a late start of the same therapy. In their experience, pitfalls of this treatment are the several factors, which inter- fere with steady pressure: like the anatomical contours e.g., the axilla or the chest, compli- ance (adherence to treatment), and pressure- loss of the garment. Therefore (=to counteract pressure loss) custom made pressure pads or 3D-fitted inflatable silicone inserts are used to adapt and to maintain pressure values in con- cave anatomical areas (Figure 1). On the other hand these can limit the mobility when used over a joint, and macerate the skin due to excessive sweating.7 Since pressure is more effective if high enough, above 20 mmHg, it is important to reg- ularly check and evaluate pressure garments, using a pressure sensor.8 Moreover, pressure loss of pressure garments needs to be taken into account. Their advice is to monitor objec- tively and to adapt pressure treatment if need- ed in order to maintain the pressure above 20 mmHg (Figure 2). Sharp et al. very recently published a best evidence statement on pressure therapy in the management of hypertrophic scarring.9 References 1. Anthonissen M, Daly D, Janssens T, Van den Kerckhove E. The effects of conserva- tive treatments on burn scars: a systemat- ic review. Burns 2016;pii:S0305- 4179(15)00396-4. 2. Costa M, Peyrol S, Pôrto C, et al. Mechanical forces induce scar remodel- ing. Am J Pathol 1999;155:1671-9. 3. Kischer C, Shetlar M, Shetlar C. Alteration of hypertrophic scars induced by mechani- Correspondence: Mieke Flour, Schoonzichtlaan 43, B-3020 Herent, Belgium. Tel. +32.478.566780. E-mail: mie.flour@skynet.be This work is licensed under a Creative Commons Attribution 4.0 License (by-nc 4.0). ©Copyright M. Flour et al., 2016 Licensee PAGEPress, Italy Veins and Lymphatics 2016; 5:5984 doi:10.4081/vl.2016.5984 Figure 1. Combination of pressure device and custom made inflatable silicone insert system in concave anatomical regions. Figure 2. Monitor the scar and the inter- face pressure with objective and reliable tools and adjust the pressure therapy when needed. No n c om me rci al us e o nly Conference presentation [page 10] [Veins and Lymphatics 2016; 5:5984] cal pressure. Arch Dermatol 1975;111:60-4. 4. Li-Tsang C, Lau J, Choi J, et al. A prospec- tive randomized clinical trial to investigate the effect of silicone gel sheeting (Cica- Care) on post-traumatic hypertrophic scar among the Chinese population. Burns 2006;32:678-83. 5. Van den Kerckhove E, Stappaerts K, Fieuws S, et al. The assessment of erythe- ma and thickness on burn related scars during pressure garment therapy as a pre- ventive measure for hypertrophic scarring. Burns 2005;31:696-702. 6. Engrav L, Heimbach D, Rivara F, et al. 12- Year within-wound study of the effective- ness of custom pressure garment therapy. Burns 2010;36:975-83. 7. Van den Kerckhove E, Stappaerts K, Boeckx W, et al. Silicones in the rehabilita- tion of burns: A review and overview. Burns 2001;27:205-14. 8. Van Den Kerckhove E, Fieuws S, Massagé P, et al. Reproducibility of repeated meas- urements with the Kikuhime pressure sensor under pressure garments in burn scar treatment. Burns 2007;33:572-8. 9. Sharp P, Pan B, Yakuboff K, Rothchild D. Development of a best evidence statement for the use of pressure therapy for man- agement of hypertrophic scarring. J Burn Care Res 2015 [Epub ahead of print]. No n c om me rci al us e o nly