SCAR OUTCOMES FOLLOWING PRESSURE GARMENT THERAPY CESSATION

Pressure garment therapy is commonly used to treat hypertrophic scarring following burn injury, with improvements reported in scar appearance, scar height and erythema, and reduced contractures. Unfortunately, patients often state that the garments are uncomfortably hot and itchy, and this contributes to decreased patient compliance. The total suggested duration of pressure garment therapy ranges from 4–6 months to 2 years, with 1 year as the most common recommendation. Maintaining patient compliance throughout this period is a major challenge. The goal of this study was to examine changes in scar properties after early cessation of pressure garment therapy. Full thickness burns (1 x 1 in) were created on female red Duroc pigs. Burns were excised and grafted with split-thickness autograft, meshed and expanded 1.5:1. Pressure garments were applied within 1 week and maintained at 20 ± 2 mm Hg. Treatment groups included: continuous pressure group, which received pressure for a total of 29 weeks; pressure release group, which received pressure for 17 weeks, then pressure was removed for an additional 12 weeks; and a control group that did not receive pressure (n=8 scars/group). Scar contraction, height, surface roughness, scar anatomy, extracellular matrix composition/organization and biomechanics were monitored over the course of the study. Pressure garment therapy significantly reduced contraction, scar height, and roughness vs. controls at 17 weeks post-grafting. When garments were removed, scars in the pressure release group rapidly contracted, with scar area in the continuous group 75% greater than controls and the release group only 31% larger than controls at week 21 (4 weeks post garment removal). This trend continued, with scar area at the conclusion of the study, 29 weeks, 22% greater than controls in the pressure release group and 86% greater versus controls in the continuous pressure group (p < 0.001). Scar height also increased 2-fold after pressure release (p < 0.05). After pressure was removed the scars became harder with no significant difference detected between the pressure release group and controls. In addition, massive collagen fiber reorientation was observed after therapy was ceased with fibers oriented parallel to the surface during therapy and perpendicular to the surface following release. Pressure garments reduced scar height, surface roughness, and contraction and improved biomechanical properties of scars after 4 months of use; however, when therapy was stopped, scars rapidly contracted and became thicker. To maximize clinical benefit, pressure garment therapy should be applied for longer durations or until the scar has fully matured.