Abstract In order to study the possibility of repairing bone defect by cryopreserved vascularized bone allograft, 8 dogs were divided into 2 groups. In the experimental group, 15% dimethylsulfoxide (DMSO) was used as a cryoprotective agent, the posterior segments of dog s rib, pedicled with intercostal vesseles, were cryopreserved by a two-step freezing procedure,stored in liquid nitrogen for 96 hours, and then transplanted as allografts to theiliac bone defects of recipients by vascular anastomosis. In the control group, the autografts were transplanted in the same procedure. Immunosuppersive agents were administrated postoperatively for 3 weeks. The specimens were analyzed by immune response monitoring (IL-2, T cell subsets), SPECT scanning, angiography and pathologic examination. The results showed that the allografts had good blood supply and active osteocyte metabolism, bone healing of the allografts was perfect at 3 months and no evidence of immunologic rejection. The process of bone healing of allografts should be further investigated.
Objective To investigate the long-term clinical results of treatment of adult unicameral bone cyst with cancellous allograft. Methods From 1993 to 1998, 15 patients with unicameral bone cyst were treated by allograft with lyophilized cancellous bone. Among 15 patients, there were 5 males and 10 females, aging 19-41 years with an average of 27 years. The average follow-up time was 7.5 years (6-11 years). The X-ray films were taken and the CT scanning were carried out. Results The X-ray films showed that the allograft particles became vague 2-3 months after operation, that the allograft particles fused and began to form new bone and the bone density increased 5 months after operation, and that new bone formation completed after 7 months of operation. At the end of follow-up, remodelling in new bone occurred. Reoccurrence was not found in all patients. The symptom of pain disappeared or relieved obviously. Conclusion Allograft of lyophilized cancellous bone is an effective treatment for adult unicameral bone cysts.
Objective To study the research advance in tracheal allografts undergoing revascularization and reepithelialization. Methods Therecent literature concerned was reviewed. The tracheal allografts are embedded in the omentum, which they were revascularized and reepithelialized by planting in self-epithelia, then the allografts with their omental pedicles were transplanted orthotopically to the cervical or the thoracic portion of the trachea. Results Compared withthe onestage tracheal allograft approach using the greater omentum, the twostage approach could increase the successful rate of revascularization and reepithelialization, and made the allografts accord with their physiology. Conclusion If the approach is successful, it can reduce graft-rejection, prevent graft-collapse and increase graft-viability after tracheal allograft.
Objective To investigate the risk factors of early allograft dysfunction (EAD) following C-Ⅱ donation after cardiac death (DCD) liver transplantation. Methods The data of 46 donors and recipients of C-ⅡDCD liver transplantation between March 2012 and August 2015 were retrospectively analyzed. The baseline data such as democracy, death cause, donor warm ischemic time (DWIT) and cold ischemic time (CIT) in EAD group and the non-EAD group (control group) was compared, and whether these factors were risk factors of EAD was investigated by univariate and multivariate analyses. Statistical cut-off values for significant factors of the unfavorable analysis were defined by receiver operating characteristics (ROC) analysis. The 6-month and 1-year graft survival rate were compared. Results The EAD group had a longer DWIT compared with the group [(17.6±4.7) and (12.7±6.2) minutes, P=0.009]; meanwhile, the EAD group had a longer CIT compared with the control group [(13.7±4.7) and (11.0±3.5) hours, P=0.020]. The other factors in both groups showed no statistical significance (P>0.05). The ROC curve revealed the cut-off values of DWIT and CIT were 17.50 minutes [area under the curve (AUC)=0.713, P=0.020] and 9.85 hours (AUC=0.723, P=0.015), respectively. The multivariate logistic regression analysis showed the DWIT [odds ratios (OR)=1.340, 95% confidence interval (CI)(1.042, 1.654), P=0.008] and CIT [OR=1.396, 95% CI (1.075, 1.698), P=0.015] were all independent risk factors of EAD. The 6-month and 1-year graft survival rate of the EAD group and the control group was 85.7% vs. 92.3% (P=0.607) and 71.4% vs. 84.6% (P=0.587), respectively. Conclusions EAD may occured in C-Ⅱ donors with DWIT≥17.50 minutes or CIT≥9.85 hours in DCD liver transplantation. The livers can be used as a resource for clinical use and also have a good outcome.
Objective To construct chemically extracted acellular nerve allograft (CEANA) with Schwann cells (SCs) from different tissues and to compare the effect of repairing peripheral nerve defect. Methods Bone marrow mesenchymal stem cells (BMSCs) and adi pose-derived stem cells (ADSCs) were isolated and cultured from 3 4-week-old SD mice with weighing 80-120 g. BMSCs and ADSCs were induced to differentiated MSC (dMSC) and differentiated ADSC (dADSC) in vitro.dMSC and dADSC were identified by p75 protein and gl ial fibrillary acidic protein (GFAP). SCs were isolated and culturedfrom 10 3-day-old SD mice with weighing 6-8 g. CEANA were made from bilateral sciatic nerves of 20 adult Wistar mice with weighing 200-250 g. Forty adult SD mice were made the model of left sciatic nerve defect (15 mm) and divided into 5 groups (n=8 per group) according to CEANA with different sources of SCs: autografting (group A), acellular grafting with SCs (5 × 105) (group B), acellular grafting with dMSCs (5 × 105) (group C), acellular grafting with dADSCs (5 × 105) (group D), and acellular grafting alone (group E). Motor and sensory nerve recovery was assessed by Von Frey and tension of the triceps surae muscle testing 12 weeks after operation. Then wet weight recovery ratio of triceps surae muscles was measured and histomorphometric assessment of nerve grafts was evaluated. Results BMSCs and ADSCs did not express antigens CD34 and CD45, and expressed antigen CD90. BMSCs and ADSC were differentiated into similar morphous of SCs and confirmed by the detection of SCs-specific cellsurface markers. The mean 50% withdrawal threshold in groups A, B, C, D, and E was (13.8 ± 2.3), (15.4 ± 6.5), (16.9 ± 5.3), (16.3 ± 3.5), and (20.0 ± 5.3) g, showing significant difference between group A and group E (P lt; 0.01). The recovery of tension of the triceps surae muscle in groups A, B, C, D, and E was 87.0% ± 9.7%, 70.0% ± 6.6%, 69.0% ± 6.7%, 65.0% ± 9.8%, and 45.0%± 12.1%, showing significant differences between groups A, B, C, D, and group E (P lt; 0.05). No inflammatory reactionexisted around nerve graft. The histological observation indicated that the number of myel inated nerve fiber and the myel in sheath thickness in group E were significantly smaller than that in groups B, C, and D (P lt; 0.01). The fiber diameter of group B was significantly bigger than that of groups C and D (P lt; 0.05) Conclusion CEANA supplementing with dADSC has similar repair effect in peripheral nerve defect to supplementing with dMSC or SCs. dADSC, as an ideal seeding cell in nerve tissue engineering, can be benefit for treatment of peripheral nerve injuries.
Objective To investigate the preparing procedures for the larger chemically acellular nerve allografts (CANA) and to establish an evaluation criteria and the preparation method.Methods The sciatic nerves ofthe dogs were exposed by a muscle-splitting incision and were isolated free of the underlying fascia. The 50-mm-long segments of the nerve were made. The proximal and distal ends of the nerve segments were labelled and stabilized by pinning the ends to a thin plastic support, and then they were treated according to the following decellularization processes: The nerve segments were rinsed with the distilled water for 9h, transferred in a 3% Triton-100 solution for 12 h, soaked in 7% sodium deoxycholate for 12 h, and washed in the distilled water for 6 h. All the decellularization steps were performed at room temperature. The nerve segments were divided into 5 subgroups. In Group Ⅰ, Group Ⅱ and Group Ⅲ, the nerve segments were decellularized for 2, 3 and 4 times, respectively. In Group Ⅳ and Group Ⅴ, the two ends of the nerve segments were ligated with a silk line and were decellularized for 2 and 3 times, respectively. Each nerve segment was subdivided into 5 portions from the proximal end to the distal end. The degrees of decellularization, activity of Laminin, degrees of demyelination, and integrity of the nerve fiber tube were observed under microscope and were assessed by a scoring system. Results In all the groups the activity of Laminin was present and the degrees of decellularization were complete. As for the demyelination of the nerve segments, the myelin sheath in Groups Ⅰ, Ⅱ and Ⅲ was partially preserved, but it completely disappeared in Groups Ⅳ and Ⅴ. The structure of the nerve fiber tube in Groups Ⅰ and Ⅳ was almost normal. The total score for the degrees of decellularization, demyelination, and structural integrity was the lowest in Group Ⅳ but the quality was the best. Conclusion The degrees of demyelination are not parallel to the times of decellularization processes. In the quality control of CANA, we should consider the following 4 factors: activity of Laminin, degrees of decellularization, demyelination, and structural integrity. For the larger CANA,ligation of the two ends of the nerve segments during the decellularization procedure may be a better method of ensuring the quality of the decellularization.
Objective To find out the recent progress in research of cl inical appl ication of fascia lata allograft. Methods The domestic and international articles were reviewed to summarize the princi pal properties, processing techniques, and various uses of fascia lata allograft. Results Histologically fascia lata is composed of parallel and compact bundles of collagen fibers with few cells and immunologically it is low-antigenic. After varied tissue processing and storage techniques, fascia lata, as the scaffold only with the extracellular matrix, has been used in cl inical practice and achieved good results, such as ophthalmology, urology, and orthopaedics. Conclusion Because of these unique properites in repairing defects and reconstructing functions, fascia lata allograft, as a natural biomaterial, is promising to be used in more aspects withthe development of the biomedical techniques.
Objective To investigate the efficacy of freeze-driedcancellous allograft in the treatment of spinal tuberculosis. Methods From January 1999 to August 2004, there were 31 cases of spinal tuberculosis who underwent surgery. The freeze-dried cancellous allograft was used as grafting material in all the cases.The cancellous allograft was packed in a titanium mesh cage or an artificial vertebrae, and then used as a strut graft anteriorly to implant into the bone defect after the redical debridement, and the instrumentation was done. Results Twenty-three cases were followed up 1.5 years to 5 years (3.7 years on average), and bonyfusion was achieved in 21 cases 6 months later. In 2 cases ceasing antituberculous therapy after 2 months of operation, the local recurrence was obvious. The loosened screw was noticed in one of these two cases, who had tuberculosis in lumbar spine. When antituberculous therapy continued, the bony fusion was observed in these two cases 12 months later. No further position change of the instrument wasnoticed in the patient carrying loosened screw, but the kyphosis of the thoracolumbar spine aggravated. Conclusion Freeze-dried cancellous allograft could be usedin the treatment of spinal tuberculosis. To achieve good results of allograft incorporation and remodeling, the rigid instrumentation should be performed, postoperative antituberculous therapy is also important.
OBJECTIVE: To evaluate the results of limb function and the methods of bone and soft tissue reconstruction of patients treated with allografting. METHODS: From May 1992 to January 1999, 90 patients suffered from bone malignant tumor were treated with allografting in different methods of internal fixations. The average follow-up was 37.5 months. The limb postoperative function, complications related to different surgical methods were compared according to Enneking evaluation system. RESULTS: Skin necrosis, infection, non-union, fracture of allograft were the main complications which affect patients’ limb postoperative functions. Of the 90 fresh-frozen allografting procedures, the final results of operation showed that hip joints and knee joints were better than the shoulder joints. More than 80% of the patients treated with interlocked intramedullary nail and allograft-prosthesis combination led to an over-all result that was excellent and good. Interlocked intermedullary nail was of recommended method of internal fixation. Early exercises of operative limbs could promote function recovery. CONCLUSION: Using of interlocked intramedullary nail and allograft-prosthesis combination are of recommended operation method and can be applied with better results, and early exercises of operative limbs will lead to better functions.
Objective To study and summarize the clinical experience and significance of the skeleton reconstruction of human hand allografts. Methods From January 2001 to October 2003, human hand allografts were appliedto treat 4 cases of traumatic hand defect(6 hands) at different levels. During operation, the ulna and radius were reduced anatomically and fixed firmly with 3.5 mm AO-plates and screws according to AO internal fixation principle. The X-ray films were taken periodically andthe function recovery of hand allografts was observed and estimated. Results The 4 cases were followed up for 4-36 months postoperatively. The clinical healing of fracture in 4 cases(6 hands) was achieved after 9 weeks,and by means of comprehensive assessment including the joint function, muscle strength, sensation, appearance, sequela and the ability of work, the satisfactory effects were gained eventually. Conclusion It is significant forhuman hand allografts to reconstruct skeleton firmly.