ABSTRACT
Using a method of vascular pedicle ligation without skin incision, some minor differences
were found between the progress of neovascularization in microvascular free skin-fat
flaps and island flaps, both with and without 1-hr ischemia in rats. Viable flap areas
were established following vascular pedicle ligation (both vessels or only artery
or vein), on the third day after flap replantation in both island and free flaps.
Vascular pedicle occlusion on the fifth day after operation resulted in complete survival
of free flaps only. Island flaps survived completely following vascular pedicle ligation
on the seventh postoperative day. A clear correlation existed between the timing of
vascular pedicle ligation and the necrosis and shrinkage rates. In free flaps, clinical
signs of viability disturbances were seen earlier in single or total vascular pedicle
occlusions, on the third or fourth day compared with island flaps. Insufficiency of
the pedicle vein in island or free flaps was tolerated earlier than arterial or total
pedicle occlusion. Venous occlusion three days after flap replantation caused significantly
higher necrosis and shrinkage rates (p < 0.05) in free flaps than in island flaps.
