[Experimental research of the relationship between the safety of expanded flap and expansion volume]

To investigate the relationship between the survival rate of expanded flap and expansion volume.

The minipigs were used and divided into 5 groups according to different expansion volume of the tissue expanders: injection to full content, 50% over content, 100% over content, 0% content and normal control. In each animal, 4 expanders (100 ml) were designed to be implanted at the bilateral side of back. Normal skin control was also designed at the back. The skin histologic change and flap survival rate were detected and analyzed when the expansion volume changed.

The flap survival rate increased along with the increase of expansion volume. While the survival rate decreased when the expansion volume was exceeded to 100% over content.

In soft tissue and skin expansion, the flap survival rate and the flap size increased as the expansion is over the standard volume, while over-expansion to 100% over content may cause decreased survival rate of expanded flap.