Improvement of TRAM flap viability using human VEGF-induced angiogenesis: a comparative study of delay techniques.

Despite the success with transverse rectus abdominis musculocutaneous (TRAM) flap breast reconstruction, ischemia-related complications, including fat necrosis and partial flap loss, continue to occur in 5 to 28 percent of reported series. The associated vascular problems of the TRAM flap stimulated several authors to study the effect of surgical delay, aiming to improve the viability of the flap. The present study investigated the potential effect of human vascular endothelial growth factor (hVEGF) in the induction of angiogenesis in the TRAM flap model and compared its effect with the surgical delay model. The rat model was used to demonstrate the effect of VEGF angiogenesis. Thirty male Sprague-Dawley rats were individually assigned to one of six groups (n = 5 in each group). One control group and five delay groups were established. A variety of flap delay techniques were used to increase the viable surface area of the flap. The flap mean viable surface area for the control group was 50 percent. The surgical delay group (group 2) had a mean viability of 83 percent. The group with the highest percentage of viable flap surface area was group 3, in which both surgical delay and intramuscular injection of VEGF were used (96.6 percent mean flap viability). The mean viable flap surface area in groups 4 (surgical delay and intraarterial VEGF), 5 (intramuscular VEGF), and 6 (intraarterial VEGF) were 90.6 percent, 87 percent, 90.6 percent, respectively. Statistically significant differences were obtained in all groups in comparison to the control group (p < 0.05). No significant differences were seen among the five treatment groups, however. The findings reported in the present study indicate that the use of VEGF to improve the viability of the TRAM flap proved to be beneficial and statistically significant in comparison to the control group.