Beneficial effects of pressure
therapy for
hypertrophic scars have been reported, but the mechanisms of action are not fully understood. This study evaluated
elastin and its contribution to
scar pliability. The relationship between changes in Vancouver
Scar Scale (VSS) scores of pressure-treated
scars and differential regulation of
elastin was assessed.
Hypertrophic scars were created and assessed weekly using VSS and biopsy procurement. Pressure treatment began on day 70 postinjury. Treated
scars were compared with untreated shams. Treatment lasted 2 weeks, through day 84, and
scars were assessed weekly through day 126. Transcript and
protein levels of
elastin were quantified. Pressure treatment resulted in lower VSS scores compared with
sham-treated
scars. Pliability (VSSP) was a key contributor to this difference. At day 70 pretreatment, VSSP = 2. Without treatment,
sham-treated
scars became less pliable, while pressure-treated
scars became more pliable. The percentage of
elastin in
scars at day 70 was higher than in uninjured skin. Following treatment, the percentage of
elastin increased and continued to increase through day 126. Untreated
sham scars did not show a similar increase. Quantification of Verhoeff-Van Gieson staining corroborated the findings and immunofluorescence revealed the alignment of
elastin fibers. Pressure treatment results in increased
protein level expression of
elastin compared with
sham-untreated
scars. These findings further characterize the extracellular matrix's response to the application of pressure as a
scar treatment, which will contribute to the refinement of rehabilitation practices and ultimately improvements in functional and psychosocial outcomes for patients.