Objective To review the research progress of composite tissue allotransplantation (CTA), analyzethe superiority and the inferiority, and inform the possible direction of further research. Methods Literature concerningCTA was reviewed and analyzed in terms of the l imits of conventional reparative and reconstructive surgery, the definitionof CTA, potential advantages, and treatment risks. Results The cl inical research of CTA both at home and abroad proved that the therapeutic effect of CTA was better than that of conventional reparative and reconstructive surgery. However, therisks resulting from immunosuppressive therapy were still the primary factors restraining the wide cl inical appl ication ofCTA. Conclusion The development of immunosuppressive therapy explores a great development potential for the CTA, and how to decrease the treatment risk of immunosuppressive therapy will be the main research direction in the field of CTA.
Ceramiclike xenogeneic bone (CXB) was obtained from the fresh bone of pig ribs being treated by physical and chemical methods to deprive of its organic substance. The CXB possessed the same natural porous network system as that of the human. The CXB was cultured with the bone marrow stromal cells of rabit. When the marrow cells had integrated with the CXB, thus a new material was obtained. (CXB-BM), and was implanted sacro-spinal muscle of rabbit. The specimens were observed under phase microscope, light microscope and electronic scanning microscope. The results showed that: at the 2nd week after the implantation of CBX-BM composite material there began the new bone formation, and the rate of bone formation was increased with time. There was evident new bone formation after 24 weeks. The process of the new bone formation were quite similar to the composite graft of HAP red autogenous and marrow, but the former degraded faster and formed typical cancellous structure earlier. There was no new bone formation when CXB was implanted alone in the control. Both the mechanism of osteogenetic potential and its clinical application were discussed.
Objective To evaluate the ability of inductive osteogenesis of allgraft demineralized bone containing basic fibroblast growth factor (bFGF/ALB) in repairing bone defect. Methods Thirty-two New Zealand white rabbits were randomly divided into four groups (groups A,B,C and D, n=8). A segmental bone defect of15 mm inlength was made on the bilateral radius respectively and the defects filled with ALB/bFGF in group A, with ALB in group B, with bFGF in group C and without any materials in group D serving as blank control. At 2, 4, 6 and 8 weeks after operation, all restored bones were evaluated by roentgenography, histological observation and Ca2+detection of osteotylus. Results The X-ray films showed that groups A and B had a little shadow of bone formation at 2 weeks, while groups C and D had transparent shadow; that group A had denser shadow and new bone formation at 4 weeks and 6 weeks, groups B and C had a little increase of shadow and group D had little shadow at fractured ends; and that group A had formation of bone bridge at 8 weeks, the new formed bone in fractured ends of group B closed with each other, the gap still existed in group C, and the defects filled with the soft tissue in group D. The Ca2+content of group A was higher than that of groups B, C and D at 4 weeks (Plt;0.05) and 8 weeks (Plt;0.01). The histological observaton showed that the degree of bone restoration of group A was superior to that of groups B, C and D. Conclusion bFGF/ALB is a good material to improve bone restoration.
15 patients suffering thromboangiitis obliterans with the occlusion of three branches below popliteal artery were treated by the operation of vein-arterification compounded femoral and popliteal planes at this hospital from 1990 to 1995. It is proved by clinical observation and correspondence with 15 patients that the symptoms ammeliated quickly and surely at the near future and forward blood supply lasted so as to avoid the complications of limb edema and heart failure. So the authors consider that the composite vein-arterification has a good anatomical and physical basis and suits to sufferers with the occlusion below popliteal vessels caused by different reasons, the principle of vein-arterification is to select the trunk artery of no pathological changes and not the collateral deep vein, but should select small-median superficial vein far away from pathological artery.
It is in urgent need clinically to look for an ideal substance for the coverage of burn wounds owing to shortage of autografts or allografts. After the cadaveric skin was extracted with acetic acid, salted out with NaCl and freeze-dried to prepare a porous collagen membrane. The membrane was seeded with allo-epidermal cells and allo-fibroblasts on its two sides, respectively, and then was cultured to achieve an artificial composite allograft. The artificial composite allograft was then transplanted onto ten severly burned wounds. One-year follow-up showed satisfactory results and the histological examination confirmed that the composite allograft could improve the adherence and growth of the epidermal cells and was helpful for blood vessels and healing of non-inflammatory connective tissues in the wounds.
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 study the effect of combined application of external cyclosporine A (CsA) and CTLA4Ig in inhibiting rejection and inducing immune tolerance in composite tissue allograft. METHODS: The auricles with vessel pedicle were transplanted from Lewis rats to BN rats under microsurgery. CsA was spreaded on the surface of grafts in combination with administration of CTLA4Ig intraperitoneally after transplantation. The rejection response and survival time of grafts were observed, and the IL-2 level in serum was measured. RESULTS: The mean survival time was (7.8 +/- 1.7) days in control group. It was (15.2 +/- 1.9) days when recipients treated by CsA and (16.6 +/- 2.1) days by CTLA4Ig. Under the combination of CsA and CTLA4Ig, the mean survival time was significantly prolonged to (28.8 +/- 3.5) days (P lt; 0.05) with the lowest level of IL-2 in serum of recipients. CONCLUSION: The combined application of external CsA and CTLA4Ig inhibits rejection of allograft effectively, which can be a favorable therapy on composite tissue allo-transplantation.
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 To study cl inical effects of the graft material of allogenic cancellus combined with autologousred marrow in the treatment of traumatic bone defect. Methods From February 2002 to April 2006, 38 patients of traumaticbone defect, 25 males and 13 females, aged 21-68 years old (38 on average), were treated with allogenic cancellus combined with autologous red marrow. Among them, there were 11 cases of bone nonunion caused by failure of internal fixation, 13 of serious comminuted fracture, 9 of bone defect caused by open fractures or bone infection, 5 of old fracture in need of graft. Of these fractures, there were 8 cases of shaft of humerus, 4 of intercondylar comminuted fracture of humerus, 8 of intercondylar comminuted fracture of femur, 5 of shaft of femur, 4 of open tibia fracture (Gustilo I, II type) and 9 of tibial plateau fracture. They included 17 cases of fresh fracture and 21 of old fracture. There were 23 cases of l imitations of bone defect, and the range was 3 cm × 3 cm × 2 cm - 7 cm × 4 cm × 3 cm; and the range of the large bone defect was less than 3 cm in 15 cases. According to AO/ASIF classification, there were 5 cases of type B2, 10 of type B3, 16 of type C2 and 7 of type C3. The time from fresh fracture to operation was 5-17 days (8 days on average), and the time from old fracture to operation was 5-13 months (7.5 months on average). The amount of the allograft implantation was 20-50 g (28 g on average). Results The wounds in all 38 cases obtained heal ing by first intention. All the patients were followed up for 8 months to 4 years (3.2 years on average). The X-ray films at reexamination showed that 36 patients had bone heal ing, with fresh fracture heal ing time of 2-6 months (4 months on average) and old fracture heal ing time of 3-10 months (7 months on average). The allogenic cancellus particles began to be fused with autogenous bone through creeping substitution 6-8 weeks after operation. One case, which had delayed infection, had bone union by removing internal fixation, placing irrigating tube and grafting after local stabil ity. During the follow-up of 25 months, no relapse was found. Another case had nonunion because of plate loosening. According to the Mankin and Komender standard evaluation, there were 36 cases with satisfaction (94.7%) and 2 with dissatisfaction (5.3%). Conclusion The composite graft material of allogenic cancellus combined with autologous red marrow is safe and effective for repairing fractures and bone defect.
OBJECTIVE: To observe the clinical effect of acellular allogenic dermis with split-thickness autogenous skin graft for coverage of wound. METHODS: Acellular allogenic dermis with split-thickness autogenous skin graft was used to repair 34 wounds of head, neck, trunk and extremities. The area of wounds was from 5 cm x 10 cm to 12 cm x 19 cm. Out of 34 wounds, there were 2 due to old granulation, 4 due to excision of giant pigmented nevus, 6 due to excision of capillary hemangioma of skin and 22 due to excision of scar. RESULTS: All grafts survived and had the smooth surface without obvious pigmentation and with slight wound contraction. CONCLUSION: Acellular allogenic dermis with autologous epithelium for coverage of various wounds is an ideal procedure.