Experimental pretransfer expansion of free-flap donor sites: II. Physiology, histology, and clinical correlation.

There is a statistically significant increase in blood flow into expanded cutaneous and myocutaneous flaps in a pig model over controls. The vascular trees within flaps enlarge following expansion, and pronounced neovascularization is seen in the papillary dermis and capsular layers. Experimentally, there is differential thinning of all tissue layers except the epidermis. A successful clinical application of this technique, by free-tissue transfer of an expanded fasciocutaneous scapular flap, is described. The technique is applicable when altered flap size or contour is desired.