Objective To compare the effect of the composite skin graft consisting of spl it-thickness skin grafts (STSGs) and porcine acellular dermal matrix (PADM) with STSGs only, and to histologically observe the turnover of the PADM in rats. Methods Twenty female Sprague-Dawley rats, weighing 200-225 g, were included. The size of 4.0 cm × 2.5 cm PADM was implanted into hypoderm of the left side of Sprague-Dawley rats’ back. After 10-14 days, the size of 4.0 cm × 2.5 cm full-thickness skin defects were made on the left to expose the PADM under the skin and the same size of full-thickness skin defects were made on the right of the rats’ back. The excised full-thickness skin was made to STSGs about 0.2 mm by drum dermatome. The defects were grafted with composite skin (STSGs on the PADM, experimental group) and STSGs only (control group). The survival rate, the constraction degree of grafts, and the histological change in grafts area were observed at 2, 4, 8, and 20 weeks after operation. Results At 2 weeks after STSGs (0.2 mm) placed on vascularized PADM, STSGs and PADM adhered together and the composite skin had a good survival. The control group also had a good survival. Histological observations showed that STSGs and PADM grew together, neutrophil ic granulocytes and lymphocytes infiltrated in the PADM and some macrophages around the PADM. Fibrous connective tissues were filled under the STSGs in control group. At 4-8 weeks after transplantation, the composite skin had a good survival and the composite skin was thick, soft, and elastic. STSGs survived almost totally in control group, but the grafts were thin. Histological observations showed that inflammatory reactions of PADM faded gradually in experimental group; scar tissues formed under the STSGs in control group. At 20 weeks after transplantation, composite skin was flat, thick, and elastic in experimental group, but the STSGs were thinner and less elastic in control group. Histological observations showed that histological structures of the PADM were similar to the dermal matrix of rats, and the results showed that the collagen matrix of PADM was gradually replaced by the rats’ collagen matrix. Scar tissues were filled under the STSGs in control group. Wound heal ing rates of experimental group were lower than those of control group at 4 and 8 weeks (P﹤0.05); wound contraction rates of experimental group had lower tendency than those of control group, but showing no significant differences (P gt; 0.05). Conclusion Coverage wound with composite skin which composed of STSGs and PADM could improve wound heal ing qual ity; the composite skin is thicker and better elastic than STSGs only. The collagen matrix of PADM is gradually replaced by rats’ collagen matrix.
Objective To evaluate the cl inical effect and the pathological characteristics of acellular allogeneic dermal matrix in repairing unstable burn scar. Methods From January 2007 to June 2008, 19 cases of unstable burn scars (24 parts) were treated, including 16 males (20 parts) and 3 females (4 parts) with a median age of 27 years (range, 3-58 years). Theinjury was caused by flame (14 cases, 18 parts), electricity (4 cases, 5 parts), and hot water (1 case, 1 part). The unstable burn scars located on hands (8 cases), forearms (2 cases), thighs (3 cases), legs (2 cases), feet (2 cases), chest (1 case), and abdomen (1 case). Scar formed for 3 months to 1 year. The area of defect varied from 7 cm × 5 cm to 22 cm × 15 cm after scar removal. Defects were covered with acellular allogeneic dermal matrix and autogenous spl it-thickness skin graft. At 6-18 months after operation, the pathological observations of the epidermis, the basal membrane, and structural components of the dermis were done. Results All wounds healed by first intention. Scar ulcer disappeared completely in 18 cases and the composite skin grafts all survived. Some bl isters occurred in 1 case and were cured after dressing changing. All patients were followed up 10 months to 2 years (18 months on average). The grafted-skin was excellent in the appearance, texture, and elasticity. The function recovered well. Only superficial scar was observed at skin donor sites. Pathological observation showed that the epidermis and the basal membrane of the skin grafts were similar to that of normal skin, and no significant difference was found in newly capillaries between them. Collagen fibers arranged regularly, and there were few inflammatory cells in the matrix. Conclusion Acellular allogeneic dermal matrix with autogenous spl it-thickness skin graft may effectivly repair the wound after removing the unstable burn scar, and its structure is similar to that of normal skin.
Objective To investigate the application and effect of the crossbridge vascular anastomosis free flap transplantation for tissue defects of extremities. Methods From May 1982 to November 2005, 110 cases of tissue defects of extremities were treated with cross-bridgevascular anastomosis free tissue transplantation. Of 110 patitents, 80 were male and 30 were female with a median age of 30 years(5 to 54 years). Tissue defects were caused by traffic accidents (59 cases), machine injuries (32 cases) and mangled injuries (19 cases). The locations were the forearms in 2 cases and the legs in 108 cases. And 69 cases had simple soft tissue defects, 6 cases had simple bone defects, and 35 cases had complicated defects. The length of bone defectranged from 5 cm to 19 cm and the area of soft tissue defect ranged from 6 cm×10 cm to 15 cm×35 cm. The graft tissue included latissimus dorsi musculocutaneous flap, vastus anterolateral flap,cutaneous fibula flap, osseous fibula flap, and cutaneous iliac flap. The cross-bridge of the two lower extremities wasperformed in 106 cases, the cross-bridge of the two upper extremities in 2 cass, and the crossbridge of the upper-lower extremities in 2 cases. The compoite tissue transplantation was used if the graft tissues were two or more. The wounds of donor site was directly sutured in 67 cases, and partly sutured with skingrafting in 43 cases. Results Vascular crisis occurred in 9 cases. Vascular crisis was relieved in 5 cases and grafting tissues was survival after exploring the vessel; 4 cases failed. The graft tissue was survival in 101 cases, and the survivalrate was 96.4%. The follow-up time was 4 months to 22 years with an average of 6.3 years. Graft bone healed and mean healing time was 4 months. The flap appearance was satisfactory and extremity function was restored to normal. One case became necrosis in the edge of the flap and cured by debridement, dressing and skingrafting, the other got primary healing at 2-3 weeks after operation. Conclusion The application of the cross-bridge vascular anastomosis free tissue transplantation for tissue defects of extremities is an effective method, when extremities have no vessel anastomosed.
Objective To investigate the outcome and histological changes of transplantation of acellular xeno-dermis combined with suspended keratinocytes.Methods Forty-two nude mice with full-thickness skin defect on the back were randomly divided into 2 groups, then acellular xeno-dermisand and suspended keratinocytes were adopted to cover the skin defect in the experimental group, pure suspended keratinocytes in the control group. The area of wound healing was calculated2, 3 and 5 weeks after transplantation, and the rates of wound contraction werealso calculated,and biopsy for histological examination was performed 3, 6and 12 weeks after transplantation. Results Compared with the experimental group,the control group showed delayed wound healing (P＜0.05), intensive wound contraction (P＜0.05), poor durability, elasticity, and cosmetic appearances as well asdisordered collagen fibers. In contrast, it was observed that the proliferationof collagen fibers was regularly organized, with no obvious acute immuno-rejection responses in the experimental group. Conclusion The composite transplantation of acellular xenodermis and suspended keratinocytes could promote the woundhealing with a satisfactory outcome.
OBJECTIVE This experimental study was aim to investigate the osteogenesis of ceramic-like xenogeneic bone (CXB) combining with bone marrow (BM). METHODS The CXB combining BM was implanted into the sacrospinalis muscle of rabbits, and CXB implanted alone was used as control. Eighteen Japanese rabbits with long ear were used. The size of CXB was 5 mm x 5 mm x 5 mm, and the implanted materials were taken out at 2, 4, 8, 12, 16 and 24 weeks after implantation. The histological and histochemical characteristics were investigated. RESULTS There existed cartilage and new bone in the groups of CXB combining BM in 2 weeks. Later, be cartilage turned out to the bone and in eight weeks the medullary cavity appeared. However, as the time went on, new bone formation increased and typical osteogenesis could be found. While in the groups of CXB alone, no formation of new bone or cartilage was found. CONCLUSION The implantation of CXB combined with BM could result in new bone formation in the way of osteoconduation, osteoinduction, and providing, osteoblasts or chondroblasts. It could be an ideal bone substitute, and its clinical use in future seemed very hopeful.