Effect of the delay phenomenon in the rat single-perforator-based abdominal skin flap model

During the last decade, innovations in reconstructive surgery have presented a new type of flap called the "perforator-based flap." Perforator-based flaps became useful alternatives for solving difficult problems. In the authors' previous study, they created a single musculocutaneous perforator-based abdominal skin flap. In their current study they evaluate the effect of various surgical delay procedures on this model. They divided 32 Sprague-Dawley rats equally into four groups (one control group and three delay groups). Three different delay procedures were employed in the delay groups. In one group, only the flap boundaries were incised (delay group 1). In the other delay groups, flap boundaries were incised and the contralateral (opposite side of the pedicle, delay group 2) or ipsilateral (pedicle side, pedicle left intact; delay group 3) musculocutaneous perforators were ligated. The period of delay was 1 week in all groups. After 1 week, a single-perforator-based abdominal skin flap was elevated as in the control group. One week after the final procedure, surviving skin areas were calculated and microangiograms were acquired. The mean surviving skin area was 75% +/- 3% (standard deviation) in the control group, 97% +/- 3% in delay group 1, 81% +/- 6% in delay group 2, and 96% +/- 3% in delay group 3. Delay group 2 showed substantial necrosis 1 week after the delay procedure and was thus excluded from the study. Results were analyzed using one-way analysis of variance, and post hoc analyses were performed using Tukey's multiple comparison test. The authors observed the advantages of the delay phenomenon in the two delay groups (p < 0.05). Microangiograms were examined grossly, and a marked difference between the two delay groups and the control group was observed. Many dilated choke vessels were seen in delay groups 1 and 3. Incising the flap boundaries with or without ligating the ipsilateral perforators (keeping the pedicle intact) 1 week before harvesting single-perforator-based abdominal skin flaps in the rat results in a delay effect. Conversely, incising the flap boundaries and ligating the contralateral perforators have no delay effect in this model.