Survival of island flaps after tissue expansion: a pig model.

Survival of island flaps after tissue expansion has been studied. Expanders were placed under each buttock flap of six minipigs and one side was expanded while the other was left empty as a control. Both flaps were then raised and isolated on their vascular pedicles in order to compare flap survival 7 days later. It was found that the survival lengths of the expanded flaps were approximately 50 percent greater than those of the delayed controls. Microangiography suggested that the diameter of the axial artery increased following expansion. In clinical practice this technique would provide a larger flap for reconstruction and the possibility of direct closure of the donor site. In addition, the observed increase in vessel caliber should facilitate the free tissue transfer of expanded flaps.