Biomechanical and histomorphological changes in expanded rabbit skin.

In 12 rabbits, biomechanical and histomorphological properties were determined in expanded, sham-operated and non-operated control skin. Results were evaluated in paired fashion. Both expanded and sham-operated skin showed a significant loss of stiffness of 60% and 35% respectively (rho less than 0.001 and rho less than 0.05). In addition, maximum stiffness in expanded skin was reached at a shorter extensibility than in sham-operated or non-operated control skin. Histomorphological examination revealed thickened dermal collagen bundles with loosened packing of collagen fibrils in both expanded and sham-operated skin. It is concluded that the surgical procedure of balloon implantation is responsible for a significant part of the reported biomechanical and histomorphological findings. Wound healing, in addition to the delay phenomenon, may therefore be a mechanism involved in skin expansion.