A number of clinical disorders of free vascularized flap are presumed to re
flect insufficient blood flow (BF) or an inadequate range of vascular respo
nsiveness. We compared the changes in BF in a pedicled and free epigastric
flap, directly after and 90 min after performing microsurgical artery anast
omoses. We used the clamping method and laser Doppler flowmetry in six Spra
gue-Dawley rats. The BF response curves shortly after re-anastomosing of th
e artery differ markedly from those in a pedicled flap model and curves reg
istered 90 min after performing the anastomosis. We conclude that the clamp
ing method is reliable and reproducible when studying the short-term autore
gulatory BF patterns of epigastric pedicled and free flaps.