gms | German Medical Science

Introduction: Pressure therapy, usually applied as pressure garments, is used for at least three decades and is accepted as a first-line therapy to affect the maturation rate and to modify the appearance of hypertrophic burn scars [1]. So far, the explanation of the working mechanism of pressure remains merely hypothetical and the question of the efficacy and the benefits of the garments unanswered. Also the optimal level of pressure required remains controversial [2].

Recent publications however show some evidence in vitro that cell apoptosis of fibroblasts are induced and scar forming wound healing mediators are down regulated in models were fibroblasts are compressed for at least 18 hours a day with 20 mmHg pressure as a minimum [3], [4].

With regard to the clinical assessment of the effect of pressure on burn scars Anzarut in 2008 conducted a literature review and found 6 publications that were randomized controlled trails showing evidence for thickness of the scar [5]. Only one of these articles did use only objective assessment tools (e.g. colorimetry for erythema) and monitored the pressure during treatment [6]. This last study is discussed hereafter.

Material and methods: In a prospective randomised controlled trial 76 spontaneously healed scars in 60 patients (mean age: 37,5y, mean TBSA: 8,5%) at the forearm or calve were randomly assigned to a lower (15mmHg) or higher (20mmHg) pressure group. Pressure garment therapy was assessed as a preventive measure.

Assessment of the scars was done on a monthly basis for three months using the Minolta Chromameter CR-300 for erythema and Dermascan C (high frequency ultrasound measurement) for thickness. Measurement of pressures was done in an indirect way by measuring the pressure of the stockings in a textile lab before and after use.

A multiregression model was used to analyse the differences between groups and the limit of significance wa set on p<0,05.

Results: A significant difference was found between both groups from the first month of application of the garments in favour of the higher pressure group for thickness of the scar. This advantage was maintained after three months of therapy (p=0.027).

The study revealed that a strong correlation was present between erythema and thickness of the scar over time as well as at every test moment.

Discussion: This study shows that erythema is a predictor and indicator of hypertrophic scarring and that pressure garment therapy as a preventive measure is effective with regard to thickness of the scar. In this study, it accelerates scar maturation.

Conclusion: Although the optimal amount of pressure is not defined yet, pressure garment therapy with a pressure of at least 20 mmHg pressure is an effective measure in the prevention of thickening of a burn scar. Therefore the use of pressure can be recommended on the basis of some clinical findings as long as the amount of pressure is closely monitored in clinical circumstances and the assessment is done with objective instruments [7].