Study on vacuumª²assisted closure accelerated granulation tissue formation in pig¬ðs infected soft tissue blast injury

    LI Wangª²Zhou, LI Jinª²Qing, CHEN Shaoª²Zong, LI Xueª²Yong

    Department of Plastics surgery and Burns, Tangdu Hospital, Fourth Military Medical University, Xi¬ðan 710038, China

    ¡¾Abstract¡¿ AIM: To investigate the mechanism by which vacuumª²assisted closure (VAC) accelerated the granulation tissue formation of pig¬ðs infected soft tissue blast injury. METHODS: Sixteen blast wounds, established by explosion of a specific type of electric detonators which were fixed at 1 cm over the skin of the shoulders and hips of 4 small white domestic pigs, were divided into 2 groups randomly: Group A was treated with conventional therapy, and group B was treated with VAC with a pressure of -15 kPa. All the wounds were left untreated until the third day after explosion when they were infected. Specimens of wound bed were collected at time points immediately before treatment, 1, 3, 6, 9, 14, 19 and 24 d after treatment and were processed for immunohistochemistry of VEGF and flkª²1. RESULTS: The expression of vascular endothelial growth factor (VEGF) and fltª²1 were similar. Three days after explosion, the number of VEGF positive cells was (9.9¡À1.5) in group A and (8.4¡À2.9) cells per high power fields (400¡Á) in group B, while that of flkª²2 was (29.9¡À3.5) in group A and (28.8¡À3.2) in group B. One day after the V.A.C. treatment, the number of VEGF positive cells and that of fltª²1 positive cells increased to (52.9¡À4.9) and (162.7¡À15.2) cells per high power fields (400¡Á) in group A, while those in group B were (9.7¡À4.9) and (31.7¡À4.2) cells per high power fields; nine days after treatment in group B, the number of VEGF positive cells and that of fltª²1 positive cells began to increase to (49.8¡À25.4) and (137.2¡À27.2) cells per high power field. The peak expression of VEGF and flkª²1 of group B was earlier than that of group A (P<0.01). CONCLUSION: The mechanism by which VAC accelerates the granulation tissue formation might be related to the improving effects of VAC on the expression of both VEGF and flkª²1. ......