A Clinical Study Of Heterogeneous Biological Dressing Combined With Negative-pressure Wound Therapy To Promote Wound Healing

Objective:To investigate the feasibility and mechanism of heterogeneous aseptic bio-protective membrane combined with vacuum-assisted drainage technique to promote the growth of granulation tissue in a small area of exposed bone or tendon wounds.Methods:From September 2016 to December 2018,82 patients with skin and soft tissue defects caused by trauma with bone or tendon exposure were randomly divided into the experimental groups and the control groups.There were 41 cases in each group and all were performed with 2 times of operations.The first operation was debridement.The length and width of wounds area with exposed bone or tendon were measured during the operation.Then,the experimental group covered the wound with a perforated heterogeneous aseptic bio-protective film to cover the negative pressure drainage material,and the control group covered the wound with a medium-size celec-like Vaseline gauze to cover the negative pressure drainage material.The negative pressure drainage were removed on the 5th day after operation,and the wounds were only covered with M-type Cerro-like Vaseline gauze and sterile bio-protection membrane,and the dressings were changed once every two days.Two weeks later,the second operation was performed.The M-type Cerro-like Vaseline gauze and the sterile bio-protective film were removed.The two-dimensional diameter of each group of exposed bone or tendon exposed wounds was measured again,and the wound healing rate was calculated.The wound granulation tissue was taken for Hematoxylin and Eosin(HE)staining,and granulation tissue growth examination under light microscope.Parallel immunohistochemical examination,detection of CD4,CD8 and CD34 antibody expression in granulation tissue were performed.The wounds were repaired with skin graft or adjacent flap according to wound granulation tissue coverage.Results:The wound healing rate of the experimental group was significantly higher than that of the control group(P<0.05).There was no significant difference in the wound healing rate between the exposed bone and the exposed tendon(P>0.05).The tissues taken from the experimental group and the control group were all granulation tissue.A large number of inflammatory cell infiltration and new capillary vessels were observed under light microscope.The number of CD4+T cells in the experimental group was significantly higher than that of the control group(P>0.05).The number of CD8+T cells in the experimental group was significantly higher than that of the control group(P>0.05).The number of CD34 antigen-positive cells in the experimental group was significantly higher than that of the control group,and the difference was statistically significant(P>0.05).Conclusions:Sterile bio-protective membrane combined with vacuum-assisted drainage technology can promote the growth of granulation tissue on the wounds with exposed to bone or tendon,promote wound healing,and make the wound more quickly closed,reducing complication of operation and patient's suffering.The application of sterile bio-protective membrane combined with vacuum-assisted drainage technology could induce granulation hyperplasia,infiltration of inflammatory cells,indicating that the sterile bio-protection membrane has obvious granulation tissue induction effect,and its mechanism of promoting granulation tissue growth is the body's rejective reaction of the sterile bio-protection membrane.