[Vacuum sealing drainage promotes experimental pig explosive abdomen wound healing].

OBJECTIVE: To explore the roles of vacuum sealing drainage (VSD) in controlling infection and promoting healing on the experimental pigs with blast injury in the abdomen and exposed internal organs.

METHODS: All animals with full-thickness abdominal wall defect were randomly divided into experimental group (VSD group) and control group (saline gauze group). Debridement was performed 6 hours after wounding. VSD devices (-125 mmHg) were imbedded on animals in the experimental group, while in the control group gauzes with saline solution were used to cover the wound and conventional treatment of dressing change was done. Specimens of muscle tissue in the wound were collected respectively from the two groups to make bacteria quantification 6 hours before the treatment and on the 1st, 3rd, 5th, and 7th day of treatment. Specimens of abdominal drainage fluid were collected respectively on the 1st, 3rd, 5th, and 7th day of treatment to detect inflammatory cytokines (TNF-α, IL-1, IL-6) using ELISA kit. Specimens of the skin and muscle tissues were collected respectively from the two groups on the 7th day to detect target genes (VEGF, bFGF, EGF, and MMP-9) using qRT-PCR.

RESULTS: The bacteria counts (CFU/g) in the VSD group on the 1st, 3rd, 5th, and 7th day of treatment were significantly less than those in the control group at the corresponding time points, and the differences between the two groups were statistically significant (P<0.01). There were no distinct differences between the two groups in the expressions of TNF-α, IL-1 and IL-6 in the abdominal drainage fluid of pig on the 1st day of treatment. The expressions of TNF-α, IL-1 and IL-6 on the 3rd, 5th, and 7th day of treatment in the VSD group were significantly lower than those in the control group at the corresponding time points (P<0.01). The expressions of VEGF, EGF and bFGF in the skin and soft tissues in the VSD group on the 7th day was higher than those in the control group (P<0.01), while the expression of MMP-9 showed no statistical significant difference between the two groups (P>0.05).

CONCLUSION: VSD can effectively control the amount of bacteria in the wound, and reduce the expressions of pro-inflammatory factors such as TNF-α, IL-1 and IL-6 in drainage fluid. VSD also promotes the expressions of growth factors in the wound.