The Effect of Duration of Lipo-PGE1 Administration on Flap Survival in a Rat TRAM Model

ABSTRACT

This study was designed to find out an effective duration of pharmacological delay using Lipo-PGE1 to prevent the ischemic compromise of TRAM flap in rats. Fifty Sprague-Dawley rats were divided into 5 groups evenly and a left inferior epigastric vessel pedicled TRAM flap, sized 5.0 X 3.5 cm was created on the abdomen. Experimental groups included group I(control) no procedure before the flap elevation; group II, III, IV and V(pharmacological delay groups) Lipo-PGE1(0.5mug) was given daily intraperitoneally for 3, 5, 7 and 14 days before the flap elevation. On the seventh day after the operation, we evaluated and compared the results of flap survival rate, vessel distribution through Barium microangiography and histological findings by the hematoxylin-eosin stain and the VEGF immunohistochemistry. The results were as follow 1) The mean percentage of the flap survival area of group II(52.84 +/-27.03%), III(63.15+/- 16.57%), IV(63.53+/- 13.15%), V(61.44+/- 17.17%) were higher than that of group I(30.42 +/- 14.58%) significantly (p < 0.05). 2) The vessel distribution of the pharmacologic delay groups were more abundant than that of the control group. 3) the vascularity of the pharmacological delay groups were more diffused than that of the control group in the hematoxylin-eosin stain. 4) There was no difference in the expression of VEGF protein within the endothelial cell between the control and the pharmacological delay groups. In conclusion, the use of Lipo-PGE1 for a relatively short term period(about 3-5 days) could remarkably increase the flap survival area in rat TRAM model compared to the surgical delay(2 weeks).