Abstract:

Objective

To compare the effect of silicone rubber vacuum sealing drainage system and traditional polyurethane vacuum sealing drainage system in treating acute skin defect in pigs.

Methods

Five Bama miniature pigs were selected to establish an acute skin injury model in pigs.Four wounds were constructed on the backs of the experimental Bama miniature pigs.The No.1 and No.3 wounds were sutured injury with a length of 7 cm and the deep from epidermis to the muscle layer （sutured wounds）， while the NO.2 and NO.4 wounds were cutting injury with 4 cm×4 cm full-thickness skin defect （incised wounds）.The NO.1 and NO.2 wounds were treated with silicone rubber vacuum sealing drainage system （experimental group）， while the NO.3 and NO.4 wounds were treated with polyurethane vacuum sealing drainage system（control group）.The dressings were changed every 5 days.On day 10 of the treatment， wound healing was assessed by measuring wound area and volume， the wounds were measured to compare the wound healing rate， adhesion and bleeding between the wound and dressing， and the angiogenesis and collagen formation were observed by hematoxylin-eosin staining， Masson staining， and CD31 immunohistochemical staining.

Results

The epidermis of suture injury wounds had healed on day 5 of the treatment both in experimental group and control group， but the results of hematoxylin-eosin staining and Masson staining showed that more collagen fiber connections between the two sides of the wounds was observed in experimental group.On day 10 of the treatment， the wound areas of cutting injury in both groups decreased， there was no significant difference between the two groups （41.13%±12.15% vs 34.14%±8.24%， t=-1.225， P=0.288）， while the wound volume reduction rate in experimental group was significantly higher than that in control group（72.47%±8.25% vs 51.12%±9.39%， t=5.061， P=0.007）.Capillary hyperplasia and collagen formation were both observed by CD31 immunohistochemical staining and Masson staining in the two groups， while the average optical density value of CD31 （1.00±0.05 vs 0.57±0.04， t=-19.806， P＜0.001） and collagen volume fraction of Masson staining （40.53%±10.71% vs 24.94%±7.68%， t=-3.154， P= 0.034） in experimental group were higher than that in control group.For suture injury，when changing the dressings on day 5， there was no adhesions in either group.When changing the dressings on day 10， there was no adhesion and bleeding in experimental group， while there were obvious adhesion and bleeding in control group（P＜0.05）.

Conclusion

The silicone rubber vacuum sealing drainage system used in acute fullthickness skin defect in pigs can accelerate the vascularization and collagen formation，promote wound healing， and reduce dressing adhesion during dressing changes.

Key words: Negative-pressure wound therapy, Bama miniature pig, Full-thickness skin defect, Silicone rubber, Polyurethane