VSD To Promote The Study Of Experimental Pig Explosive Abdomen Wound Healing

Objective: To establish an animal model of injury wound-induced abdominalwall defects. To explore the hurt of explosion with internal organs exposed in pigabdomen, and the use of the Vacuum sealing drainage (VSD) can control abdominalwound infection, and promote wound healing in exploding abdomen in order to seekthe optimaltime of second operation in abdominal blast injury.Methods: Using12clean and healthy small white domestic pigs and each pig wasburst, which making with homemade abdominal viscera guards and1g PETNexplosives, approximately4cm×5cm blast injury wounds in the left abdomen of pig. Atotal of12blast injury wounds in the same location of each pig,12pigs of the generalsituation were observed after injury. All animals were randomly divided intoexperimental group (VSD group) and the control group (saline gauze group): theexperimental group (VSD group) are to be placed in the pressure-125mmHg of VSDdevice after six hours debridement, the control group (saline gauze group) are to usesaline gauze to cover the wound after6hours debridement applying the conventionaldressing therapy. Two Specimen about muscle tissue were individually collected tomake analysis of two groups of bacteria before6hours of treatment and after thetreatment of wounds on1st,3rd,5th,7th day. Two specimen about abdominal drainagefluid were individually collected on0,1,3,5,7days to detect inflammatory cytokines(tumor necrosis factor-a, interleukin-1, interleukin-6) using Elisa kit. Two specimenabout the skin and muscle tissue were individually collected on7th day to makeanalysis of target gene (vascular endothelial cell growth factor, matrixmetalloproteinase-9,epidermal growth factor)using real-time quantitative PCR. Results: All experimental animals were formed after injury, injuries areconsistent with full-thickness abdominal wall defect associated with internal organsexposed abdominal blast injury in animal models.The amount of bacteria of thepre-treatment of laboratory animals are1107.VSD treatment on1,35,7days of woundbacteria number (CUF/g), was respectively (637.45±108.27,121.95±30.02,32.83±8.52,1.04±0.39),which were significantly lower than the control group at the sametime point (19306.01±1042.43,11503.03±777.82,6280,01±130.11,2397.01±52.32), the differences between the two groups have statistically significant (P <0.01).There was no distinct difference between the two groups in expression.of Pigsabdominal drainage fluid TNF-alpha, IL-1, IL-6levels after the1st day of injurytreatment.The differences between the two groups have no statistically significant(P>0.05). The expression of TNF-alpha, IL-1, IL-6in the3rd,5th,7th day of treatment ofthe VSD group were (154.26±3.16ng/L、135.00±3.40ng/L、135.92±2.97ng/L)respectively, they were lower than the same time point of the control group (215.±6.02ng/L,189.83±1.70ng/L,200.68±3.19ng/L), the differences between thetwo treatment groups have statistically significant (P <0.001); the expression of VEGF,EGF and BFGF of VSD treatment after7th day in the skin and soft tissue werehigher than control group (P <0.01), the expression of MMP-9of the two groupsshowed no significant differencestatistically (P>0.05).Conclusion: Although all of the animal models were serious in trauma andpollution of experimental pigs abdominal blast injury combined with internal organsexposed, vital signs are relatively stable after injury, and to ease fixe and survival ofanimals in long time, which initially confirmed the reliability and reproducibility of themodel. According to this experiment, firstlty, it can be seen that VSD can control woundeffective applied in early explosive abdomen wound, and reduce the pro-inflammatoryfactor TNF-a, IL-1, IL-6expression in drainage fluid. These factors are conducive to theearly control of the wound and abdominal infection, and reduce the pigs abdominal blastinjury wounds between the ecological organization of secondary necrosis. Secondly,VSD not only alleviate the wound swelling but also promote wound growth factorexpression, granulation tissue formation and short wound healing time. Using the VSDon7days in the abdomen explosion wounds, these above factors provide the optimalopportunity in second operation to close the abdominal wound.