Marginal vascular change in pedicle skin flaps.

The changes of vascular patterns in pedicle skin flaps were studied in rats at various intervals after operation using microangiography, with the following results: (1) Vascular change was observed in the marginal area of the flap after operation, possibly related to the release of an angiogenic factor during anaerobic metabolism. (2) Both primary and secondary revascularization were observed in the flap, but the main process was found to be primary revascularization. (3) Four days after operation, revascularization was observed. (4) Longitudinal rearrangement of the vessels in the flap could not be observed. (5) At sutured areas where the stitches remained, severe vascular reaction continued for a longer period.