Effect of Prostaglandin E1 and the Surgical Delay on the Survival of the Transverse Rectus Abdominis Musculocutaneous Flap in the Diabetic Rat

ABSTRACT

Transverse rectus abdominis musculocutaneous (TRAM) flap is one of the best flap in breast reconstruction. Even though many trials have been attempted to increase the rate of the flap survival, the necrosis of distal flap area due to vascular compromise is troublesome. The aim of this study was to evaluate the effect of prostaglandin E1(PGE1), surgical delay and the combined procedure on TRAM flap survival rate in vascular compromised rat by diabetes. Left inferior epigastric vessel pedicled TRAM flaps(5.0 x 2.5 cm) were elevated in 40 Sprague-Dawley rats. In control group(N=10), there was no procedure before the flap elevation. In surgical delay group(N=10), the left superior epigastric vessels and the contralateral rectus perforators were ligated 2 weeks before the flap elevation. In PGE1 injection group(N=10), PGE1(0.5microgram) was given intraperitoneally for 2 weeks before the flap elevation daily. In combined procedure group(N=10), the same surgical delay and injection of PGE1 were done simultaneously. On the seventh postoperative day, we evaluated and compared the flap survival rates, the vessel distribution status through Microfil casts, the vessel area rates by histomorphometric analysis in each group. The results were as follows 1) The mean percentages of surviving flap areas of surgical delay group(73.41+/- 10.43%), PGE1 injection group(68.95 +/- 7.13%) and combined procedure group(79.39 +/- 13.44%) were greater than that of control group(44.85 +/- 18.08%) with a statistical significance(p< 0.05). 2) The vessel distributions of each procedure group were more abundant than those of control group in Microfil casts. 3) The mean percentages of vessel areas of surgical delay group(2.74 +/- 0.23%), PGE1 injection group(2.58 +/- 0.49%) and combined procedure group(3.15+/- 0.25) were greater than that of control group(1.24 +/- 0.40%) with a statistical significance(p< 0.05). The results indicated that PGE1 injection or surgical delay procedure could be used to increase the TRAM flap survival area in diabetic condition and the effect of PGE1 was comparable to that of surgical delay procedure. But, the synergistic effect of surgical delay and PGE1 injection was not observed statistically.