Comparing various surgical delay methods with ischemic preconditioning in the rat TRAM flap model

Both surgical delay and ischemic preconditioning (IP) have been shown to be effective in improving the survival of flaps. We used a variety of flap delay methods and IP to increase the surviving area of the transverse rectus abdominis musculocutaneous (TRAM) flap in rats, and the results are compared in between. A 6-× 3-cm-sized TRAM flap in 40 Wistar rats was allocated into five groups. Group 1: TRAM flap was elevated from nondominant pedicle, and the flap was sutured to the original bed. Group 2: Left superior deep epigastric vessels (SDEV) were cut; 1 week later, TRAM flap was elevated. Group 3: Only skin incision was done; 1 week later, TRAM flap was elevated. Group 4: Skin incision was done, and the left SDEV were cut; 1 week later, TRAM flap was elevated. Group 5: TRAM flap was elevated; IP was performed using three cycles of 10 minutes of repeated ischemia/reperfusion (I/R) periods, and the flap was sutured to the original bed. The surviving area of the flap was statistically significant between the control and groups 2, 4, and 5 (p < 0.001), and groups 4 and 2 were superior to group 5. Although preconditioning has been intensively studied for the last two decades and partly provided its beneficial effects in I/R injury, we determined the IP increased the surviving area of the TRAM flap but not effective as much as surgical delay method.