The Revascularization Interface in Flap Prefabrication: A Quantitative and Morphologic Study of the Relationship Between Carrier Size and Surviving Area

ABSTRACT

To make a quantitative assessment of the relationship between size of vascular carrier and surviving area in a prefabricated flap, vascular carriers composed of the superficial epigastric arteriovenous bundles and a surrounding fascial patch with varying sizes were transferred under a 7- × 7-cm bipedicled abdominal skin flap in a rat model. Seven days later, the abdominal flaps were raised as composite island flaps connected only by the superficial epigastric vascular pedicle, transferred, and then sutured back into place. Immediately after replacement, the degree of revascularization was assessed using quantitative skin fluo-rometry, after intravenous injection of sodium fluorescein. At 7 days after elevation as an island flap, the area of skin flap surviving was recorded and plotted on a map depicting the original flap surface. High levels of fluorescence appeared on the flap surface where the carrier was tacked underneath. The prefabricated island flaps survived with a circular shape up to approximately 4 times the radius of the vascular carrier. When the distance was converted into area, theoretically, an area 13 times the area of the vascular carrier survived, regardless of its size in this experimental model. Histologic examination revealed connections of fine capillaries between the carrier and flap.