Preliminary Study Of Histological Changes Ans Wouns Healing Quality Of Wounss After Artificial Dermis Transplantation

PART ?:PRELIMINARY STUDY OF HISTOLOGICAL CHANGES OF WOUNSS AFTER ARTIFICIAL DERMIS TRANSPLANTATIONObjective: Observe the preliminary study of histological changes of wounds and scars after artificial dermis(PELNAC)transplantation.Methods: Research objects are children in the Department of Burn and Plastic Surgery of Children's Hospital affiliated to Chongqing Medical University,from April 2014 to December 2017.Criteria and the number of cases are listed as follows : 12 cases of mature granulation tissue after being treated with artificial dermal(PELNAC),10 cases of mature granulation tissue;7 cases of scars for 6 months to 2 years after artificial dermis transplantation;11 cases of hypertrophic scars;14 cases of normal skin tissue.Pathological staining,immunohistochemistry and Transmission Electron Microscope were performed in each group.Results: Histology: HE staining: PELNAC under low magnification,no epidermis.under high magnification,a large number of collagen fibers,fibroblast cells,neutrophils,lymphocytes and new capillaries SA under Low magnification,the epidermis is thin,the epidermis is short or not seen.The collagen fiber of the scar tissue is hyperplastic,thicker and almost parallel.There are no sweat glands,muscles,sebaceous glands and other skin attachments visible under high magnification.In some cases,collagen fibers arrange in parallel near the epidermal.In the deep parts,collagen fibers were nodular.There are a quantity of fibroblasts,scattered lymphocytes,neutrophils and other inflammatory cell infiltration.AB-PAS: Acid mucopolysaccharides were found in all the "dermis" layers of each group.A few neutral mucopolysaccharides were found.OS: No obvious elastic fibers were observed in all groups.CK1: Positive or basal layer of SA positive;CK10: Positive or basal layer of SA epidermis positive;FN expressed in all groups,mainly in the basal layer,"dermis",or around the skin adnexa,and vascular or glandular endothelium Cells;Collagen ? and Collagen ? were expressed in the "dermis" of each group;FN,Collagen ?,and Collagen ? expressions showed that the expression intensity of the three groups showed no significant difference between SA-HS and PELNAC-GT groups.Transmission electron microscopy: PELNAC: The endoplasmic reticulum of fibroblasts is abundant and active,collagen fibers are sparse,collagen fibrils are arranged in parallel,and plasma cells and autophagy are seen;SA fibroblasts are rich in endoplasmic reticulum,fibroblasts are active,collagen Fibroblasts are dense,parallel and visible.There are also lymphocytes.Conclusion: Histology suggests preliminarily that the wounds after artificial dermal transplantation for 2~3 weeks have the component of dermal,but has no special difference in structure compared with mature granulation tissue The structure of scars after artificial dermis transplantation is rather more similar to hypertrophic scars than the normal skin structure.Part ?:PRELIMINARY STUDY OF HEALING QUALITY OF WOUNS AFTER ARTIFICIAL DERMIS TRANSPLANTATIONObjective: Follow up and evaluate the healing quality after artificial dermis(PELNAC)transplantation preliminarily.Research into the feasibility of Shear Wave Elastography(SWE)to evaluate the quality of scar and skin preliminarily.Methods: From January 2014 to December 2017,a total of 12 patients were followed up after artificial dermal transplantation,including 8 girls,4 boys,who were(5.23 ± 2.98)years old.22 scars in different parts of the body were detected.The shortest postoperative time was 1 month and the longest postoperative time was 22 months.The patients were observed carefully by orthopaedists and scored by the Vancouver Scar Scale(VSS).Meanwhile the Young's modulus was measured by Shear Wave Elastography.Results: VSS score was 8±1.41,with a minimum score of 3 points and a maximum of 14 points.The desquamation of scars accounted for 68.18% of the total sites,91.67% of the total people;the presence of pruritus symptoms accounted for 72.73% and 66.67%.The occurrence of dysfunction accounted for 45.45% and 66.67%.The correlation coefficient between scars' Young's modulus and VSS was r=0.539(p=0.01),which was statistically significant.Conclusion: The cases we studied had scar hyperplasia in different degrees after artificial dermis transplantation;large,deep and infectious wounds may develope into serious hypertrophic scars.Shear wave elastography is expected to become a method for detecting the quality of scar and skin.