To investigate the effect of Vacuum-assisted closure(VAC) technology on deep partial-thickness burn wound of pigs.

A total of 18 deep partial-thickness burn wounds were established by the temperature and pressure controlled perm instrument on 3 ordinary pigs back symmetrically, 6 per pig. The wounds were randomly divided into 3 groups: which were treated by vacuum-assisted closure therapy with continuous model, discontinuous model or treated by conventional dressing therapy corresponding. The wounds were placed without any treatment in 24 hours, after that, the two VAC therapy groups were given corresponding modes of vacuum-assisted closure treatment with the pressure of -125mmHg, while conventional dressing therapy group received iodophor vaseline gauze dressing treatment. The dates of wound area, wound healing rate were collected and analyzed at right away、3、6、9、14 days post treatment. Specimens from wounds were harvested for histopathology observation, including cell proliferation index and the number of vascular endothelial cells. The dates were analyzed by one way ANOVA and multiple group comparison with LSD-t test.

(1)On the third day after treatment, the healing rate of VAC therapy group with continuous model and discontinuous model were (18.51±4.38)%, (14.26±5.98)%, which were higher than the conventional dressing therapy group(3.86±2.35)%(t =56.552、40.139, P﹤0.05, =0.001). On 3 d, the healing rate of both VAC therapy group were(24.74±3.25)%, 20.55±3.43)%, which were still higher than the conventional dressing therapy group(13.41±4.08)%(t=5.473, 3.432, P﹤0.05, =0.004). On 9 d, those were (49.81±3.88)%, (46.96±3.16)%, which were higher than the conventional dressing therapy group(34.29±6.69)%(t=5.563, 4.541, P﹤0.05). (2)The healing time of VAC therapy group of continuous model was (11.67 ± 0.52) d, while that discontinuous model was (11.50 ± 1.05) d, both were statistically difference compared to the conventional dressing therapy group (13.00 ± 0.89) d(t=2.715, 3.055, P=0.016, 0.008). There was no statistically difference between the both VAC therapy groups (t =0.340, P=0.739). (3)On the third day after treatment, the infiltration of inflammatory cells in wounds of the conventional dressing therapy group were higher than that in both VAC therapy groups, which was peaked on 9 d and faded on 14 d. (4) On the third day after treatment, the cells PI of the both VAC therapy groups were increased, which were higher than conventional dressing therapy group (t=10.413, 9.080, P﹤0.05). The cells PI of the both VAC therapy groups were peaked on 6 d, which were still higher than conventional dressing therapy group (t=4.549, 5.557, P﹤0.05). No statistically significant difference was founded between the 3 groups on the ninth and fourteenth day after treatment(F=0.488, 0.630, P=0.621, 0.542). (5) On the third and sixth day after treatment, the numbers of vascular endothelial cells of the both VAC therapy groups were higher than conventional dressing therapy group (P﹤0.05). No statistically significant difference was founded between the 3 groups on the treatment of 9 d and 14 d (F=1.639, 1.711, P=0.218, 0.205).

Compared with conventional dressing change, vacuum-assisted closure therapy can speed up the removal of necrotic tissue, accelerate wound inflammation subsided, promote the healing process of deep partial-thickness burn wounds.