Abstract
The Transverse rectus abdominis musculocutaneous (TRAM) flap has been commonly used for autologous breast reconstruction. Despite these clinical usefulness, the TRAM flap is prone to partial flap or fat necrosis in especially pedicled flap. To improve flap survival, the surgical delay procedures and pharmacological treatments have been developed. In many studies for the pharmacological treatment, Lipo-$PGE_1$ has demonstrated a marked ability to improve flap survival and it's effect has been proved similar to surgical delay procedure. The purpose of this study is to determine the most effective route of Lipo-$PGE_1$ administration as a pharmacological treatment in TRAM flap of the rat. Fifty male Sprague-Dawley rats weighing 300-350 gm were divided into five groups, One week before flap elevation, Lipo-$PGE_1$($2{\mu}g/kg$) was injected three times in a week and than the left inferior epigastric vessel based TRAM flap ($5.0{\times}3.0cm$) elevated; group I: no procedure before flap elevation; group II: intraperitoneal injection; group III: intravenous injection; group IV: subcutaneous injection; group V: topical application. A flap was assessed at postoperative 7 days by comparison of flap survival rate, vessel counts(H-E stain), and vascular endothelial growth factor(VEGF) protein expressed by Western blot. The results demonstrated that the mean percentages of the flap survival area in group III were significantly higher than that of any other group(p<0.05). The vessel counts of all experimental groups were statistically higher than that of control group(p<0.05). Only in group III, the VEGF protein expression was increased significantly than control group and there are no difference in other experimental groups. In conclusion, the intravenous administration of the Lipo-$PGE_1$ is the most effective on flap survival, and the VEGF induced by Lipo-$PGE_1$ has some positive effects on new vessel formation and flap survival.