EFFECTS OF SUBCUTANEOUS EXPANSION ON THE MECHANICAL-PROPERTIES OF PORCINE SKIN

The purpose of this study was to determine the effects of conventional and intraoperative tissue expansion on the biomechanical properties o f skin. Two 200-cc silicone tissue expanders were inserted subcutaneou sly in each of six young pigs. One expander was inflated conventionall y (4 weeks) and the other intraoperatively (three times within 1 hr). A skin specimen was excised from each expansion site and each contrala teral control site and tested under tension to failure. The sites were closed and allowed to heal for 4 weeks at which time another biopsy s pecimen was taken from each site. Histological observations and bioche mical analyses were conducted. Also, tangent modulus and ultimate stre ss were determined from the mechanical response of each specimen. Resu lts indicated an initial decrease in stiffness and ultimate strength f or conventionally expanded skin. The mechanism for this decrease could not be explained via our current biochemical and histological techniq ues. Mechanical properties for conventionally expanded skin, after hea ling, were not significantly different than controls. The mechanical p roperties for intraoperatively expanded skin were not significantly al tered with respect to controls, either at initial expansion or after 4 weeks of healing. The tissue ''generated'' as a result of intraoperat ive expansion in the porcine model is likely tissue recruited from the surrounding skin. (C) 1996 Academic Press, Inc.