Delay Phenomenon by Lipo-PGE1 in Single Perforator-based Abdominal Skin Flap of Rat

ABSTRACT

The perforator based flap has been used successfully as a pedicle or free flap and has gained popularity in clinical use. Although Lipo-PGE1 effect on survival rate of musculocutaneous flap is good, but effect on survival rate of perforator based flap is not well known. Therefore, the purpose of this study is to find pharmacological delay effect by using Lipo-PGE1 in abdominal skin perforator flap of rats. Thirty Sprague- Dawley rats were divided into 3 groups. Perforator flaps were designed in rectangular shape, sized 3x7cm to 4x8 cm on abdomen. Flap incision was made deeply enough to the panniculus carnosus, from lateral to medial side and we found four musculocutaneous perforators at each side. Right second cranial perforator was saved, and the others were electrocauterizied. The experimental groups included group I(control) no procedure before the flap elevation; group II(surgical delay) right second cranial perforator was saved, one week before the flap elevation, the others cauterizied. But left four perforators were not injuried.; Group III(pharmacological delay) before the flap elevation, Lipo-PGE1(0.5microgram) was given intraperitoneally for 5 days. On the seventh day after operation, the results were evaluated and compared in terms of flap survival area, vessel counts by Hematoxylin-Eosin stain and Vascular Endothelial Growth Factor (VEGF) protein expression by Western blot. The results were as followings. First, The mean percentages of the flap survival area in Group II(83.75+/-11.07%) and Group III(76.95+/-11.99%) were significantly higher than that in Group I(44.06+/-15.29%)(p<0.05). Second, The vessel counts of Group II(4.4+/-0.84) and Group III(4.3+/-0.82) were significantly higher than that of Group I(2.0+/-0.67) significantly(p<0.05) Third, The VEGF expression is increased in two experimental groups than that of control group. In conclusion, the use of Lipo-PGE1 could increase flap survival area in rat skin perforator flap model, as likely as surgical delay. This phenomenon is thought to be due to choke vessel dilatation and new vessel formation. Therefore, we expect that Lipo-PGE1 can increase rate of flap survivability in perforator based flap as well as that of musculocutaneous flap, only short term use.