人工组织神经移植物辅加神经生长因子修复大鼠坐骨神经缺损

目的 探索壳聚糖与聚乙醇酸联合制成的人工组织神经移植物辅加神经生长因子（NGF）修复大鼠外周神经缺损的可能性。方法 壳聚糖套管和聚乙醇酸纤维制备成人工组织神经移植物并辅加NGF，修复大鼠的坐骨神经10mm缺失。术后24周，进行足迹试验，电生理学测试，形态学观察。用自体神经，硅胶管以及壳聚糖套管与聚乙醇酸纤维等分别作为对照组，结果 术后24周内，实验动物均未出现明显炎症及排斥反应。实验组的各检测指标均优于除自体神经组外的各对照。结论 壳聚糖和聚乙醇酸与外周神经组织有良好的生物相容性；辅加NGF的人工组织神经移植物对修复缺损的神经具有良好的桥梁作用和促神经生长作用。     

组织工程化人工神经修复周围神经缺损的实验研究

目的　研究雪旺细胞和生物降解支架材料复合后构建成的组织工程化人工神经修复神经缺损的效果。方法　将雪旺细胞制成 1× 1 0 8/ml的ECM (extracellularmatrix,ECM)凝胶 ,与PLA无纺纤维布复合培养 7d ,置入PLA中空纤维管中 ,构建成组织工程化人工神经。建立大鼠坐骨神经缺损 1 0mm的动物模型 ,A组为人工神经组 ;B组为雪旺细胞复合ECM凝胶组 ;C组为单纯ECM凝胶组 ;D组为自体神经移植组。术后 8周、1 2周 ,行神经电生理和组织学检测评价疗效。结果　术后 1 2周A组的再生神经纤维已越过远端缝合口 ,有髓神经纤维数和神经纤维密度稍差于D组 ,但再生神经组织的面积显著高于后者 ;A、D组的髓鞘厚度和dLAT、NCV、AMP、AREA均无显著差别 ,但明显高于B、C组。结论　雪旺细胞、ECM凝胶和PLA多孔材料与PLA中空纤维管组合后构建成的组织工程化人工神经 ,修复周围神经缺损的效果接近于自体神经移植     

Repairing peripheral nerve defects with tissue engineered artificial nerves in rats

Objective： To observe the effect of tissue engineered nerves in repairing peripheral nerve defects （ about 1. 5 cm in length） in rats to provide data for clinical application.
Methods： Glycerinated sciatic nerves （2 cm in length） from 10 Sprague Dawiey （SD） rats （aged 4 months） were used to prepare homologous dermal acellular matrix. Other 10 neonate SD rats （aged 5-7 days） were killed by neck dislocation. After removing the epineurium, the separated sciatic nerve tracts were cut into small pieces, then digested by 2.5 g/L trypsin and 625 U/nd collagenase and cultured in Dulbecco＇ s modified Eagle＇ s medium （DMEM） for 3 weeks. After proliferation, the Schwann cells （SCs） were identified and prepared for use. And other 40 female adult SD rats （ weighing 200 g and aged 3 months） with sciatic nerve defects of 1.5 cm in length were randomly divided into four groups： the defects of 10 rats bridged with proliferated SCs and homologous dermal acellular matrix （the tissue engineered nerve group, Group A）, 10 rats with no SCs but homologous dermal acellular matrix with internal scaffolds （Group B ）, 10 with autologous nerves （Group C ）, and the other 10 with nothing （the blank control group, Group D）. The general status of the rats was observed, the wet weight of triceps muscle of calf was monitored, and the histological observation of the regenerated nerves were made at 12 weeks after operation.
Results： The wounds of all 40 rats healed after operation and no death was found. No foot ulceration was found in Groups A, B and C, but 7 rats suffered from foot ulceration in Group D. The triceps muscles of calf were depauperated in the experimental sides in all the groups compared with the uninjured sides, which was much more obvious in Group D. The wet weight of triceps muscle of calf and nerve electrophysiologic monitoring showed no statistical difference between Group A and Group C, but statistical difference was found between Groups A and B and Groups B and     

Cavernous nerve graft reconstruction using an autologous nerve guide to restore potency

OBJECTIVE: To present our experience of cavernous nerve graft reconstruction, using an autologous nerve vein-guide technique, to restore potency. PATIENTS AND METHODS: Prostate cancers frequently require radical resection involving one or both cavernous nerves that usually results in erectile dysfunction; nerve grafting has been used to restore erectile function, but clinical results are unsatisfactory owing to inadequate surgical techniques. In all, eight patients with prostate cancer who required radical resection involving one cavernous nerve had sural nerve grafting, with two or three sutures using the autologous vein-guide technique, in our unit between 2004 and 2005. Because of the difficulty of performing microsurgical manoeuvres deep within the pelvic cavity, the nerve anastomosis might be unsatisfactory. RESULTS: Seven of the eight patients had spontaneous erectile activity after grafting and six of these patients were able to have intercourse. CONCLUSION: Sural nerve grafting using the autologous vein-guide technique is simple, has minimal morbidity, and yields good outcomes.     

Approaches to tissue engineered peripheral nerve

The late 1980s and early 1990s brought excitement to the idea that we would be able to replace body tissues and organs through the field of tissue engineering. This enthusiasm was soon replaced by the realization of the limitations in our knowledge for specific tissue types and replication efforts. Such is the case with nerve tissue. We have progressed in this field of knowledge; however, full elucidation to the complex interactions of nerve repair falls short.     

A collagen matrix derived from bladder can be used to engineer smooth muscle tissue

We have previously demonstrated that a collagen matrix derived from lamina propria, commonly known as bladder submucosa (BSM matrix), is a suitable biomaterial for several urologic applications, including reconstruction of the bladder and urethra in experimental models and clinical trials. In the present study, we evaluated the physical properties of BSM as well as its biocompatibility, cellular interactions, and ability to support the formation of functional tissue in order to determine whether this biomaterial could serve as a matrix for urinary smooth muscle tissue engineering. BSM matrix resembles the extracellular matrix of bladder submucosa in its native structure, composition, and mechanical properties. BSM matrix supported normal mitochondrial metabolic and proliferative functions of human urinary smooth muscle cells and did not induce cytotoxic effects in vitro. When implanted in vivo, BSM matrix promoted the regeneration of urinary smooth muscle tissues with contractility, which is a smooth muscle-specific tissue function. These results suggest that BSM matrix would be a useful biomaterial for urinary smooth muscle reconstruction.     

Peripheral nerve reconstruction with collagen tubes filled with denatured autologous muscle tissue in the rat model

Conventional nerve conduits lack cellular and extracellular guidance structures critical for bridging larger defects. In this study, an exogenous matrix for axonal regeneration was provided by pretreated muscle tissue. In 24 rats, 14-mm sciatic nerve segments were resected and surgically reconstructed using one of the following methods: autograft (AG); bovine type I collagen conduit; (MDM) collagen tube filled with modified denatured autologous muscle tissue. For 8 weeks, functional regeneration was evaluated by footprint and video gait analysis. Evaluation was complemented by electrophysiology, as well as qualitative and quantitative structural assessment of nerves and target muscles. Group AG was superior both structurally and functionally, showing higher axon counts, a more normal gait pattern, and less severe muscle atrophy. Fiber quality (fiber size and myelin thickness) was highest in group MDM, possibly related to the myelin-producing effect of muscular laminin. However, axon count was lowest in this group, and ultrastructural analysis of the denatured muscle tissue showed areas of incomplete denaturation that had acted as a mechanical barrier for regenerating axons. In light of these results, the often advocated use of muscular exogenous matrix for peripheral nerve reconstruction is reviewed in the literature, and its clinical application is critically discussed. In conclusion, combined muscle tubes may have a positive influence on nerve fiber maturation. However, muscle pretreatment is not without risks, and denaturation processes need to be further refined.     

The response of nerve tissue to chymopapain

Summary This study was undertaken to clarify the effects of topically injected chymopapain on the spinal cord and peripheral nerves in rabbits, and also the effect of ganglioside on sciatic nerves which had been damaged by chymopapain. There were no abnormal macroscopic or microscopic findings when chymopapain was injected around the sciatic nerve sheath or around the spinal dura mater, but when it was injected directly into the nerve sheath there was immediate paralysis and severe axonal necrosis; the Schwann sheath remained intact and there was haemorrhage. Injection into the dura resulted in massive haemorrhage, perivascular neutrophil infiltration and necrosis of grey matter. In those treated with ganglioside, regeneration of the damaged sciatic nerve was shorter than in those not so treated.

---

Résumé Cette étude a été entreprise pour clarifier les effets de la chymopapaïne injectée localement sur la moëlle épinière et les nerfs périphériques du lapin et ceux de la ganglioside sur les nerfs sciatiques endommagés par la chymopapaïne. Aucun aspect anormal macro — ou microscopique n'est observé quand la chymopapaïne est injectée autour de la gaine du nerf sciatique ou autour de la duremère. Par contre si le produit est injecté directement dans la gaine du nerf la paralysie est immédiate et on observe une grave nécrose des axones. La gaine de Schwann reste intacte et des hémorragies se produisent. L'injection à l'intérieur de la dure-mère entraîne une hémorragie massive, une infiltration périvasculaire de polynucléaires neutrophiles et une nécrose des faisceaux gris. Dans les cas traités par ganglioside la régénération du nerf sciatique est plus lente à 6 semaines que dans ceux qui ne sont pas traités.

     

Microsurgical reconstruction of large nerve defects using autologous nerve grafts

Between 1986 and 1993, 643 patients with peripheral nerve trauma were treated in our clinic. Primary neurorraphy was performed in 431 of these patients and nerve grafting in 212 patients. We present the functional results after nerve grafting in 93 patients with large nerve defects who were followed for more than 2 years. Evaluation of function was based on the Medical Research Council (MRC) classification for motor and sensory recovery. Factors affecting functional outcome, such as age of the patient, denervation time, length of the defect, and level of the injury were noted. Good results according to the MRC classification were obtained in the majority of cases, although function remained less than that of the uninjured side. © 1994 Wiley-Liss, Inc.     

自体脂肪颗粒移植后转归的临床观察

目的 通过对临床应用自体脂肪颗粒移植患者术后转归的观察,明确脂肪移植后产生的各种变化,确定脂肪颗粒移植后成活的状态.方法 自1998年1月至2010年4月,共对477例患者行自体脂肪颗粒移植术,回顾性分析其临床应用情况,对患者进行随访并处理并发症,收集移植后组织材料并进行病理切片检查,观察移植组织的转归情况.结果 本组患者477例,随访2个月至7年,出现不同并发症者17例,对获取的组织切片检查显示各种不同转归.结论 脂肪颗粒移植是一种有效的填充缺损、凹陷的手段,移植成活后的脂肪颗粒其组织结构与正常脂肪组织结构无异,但是大体标本不完全相同,小部分坏死组织并不一定会引起感染,大量的组织液化多数也被包膜包裹.     

Soft tissue contouring using autologous tissue for hemifacial atrophy

Summary Numerous methods for the restoration of facial symmetry in patients with hemifacial atrophy have been described. Most recently, the use of autologous tissue for augmentation has been employed. Experience gained from the use of free-tissue transplantation with microvascular anastomosis and injection of liposuctioned fat are presented in this paper. In 19 patients, reconstruction was performed using microsurgical tissue transfer, while in 3 patients, autologous fat transplantation alone was used. Indications, operative techniques together with the advantages as well as disadvantages associated with each procedure are described.     

Peri-epineurial tissue to supplement laser welding of nerve

The principal difficulty with laser repair of nerves has been the inability to provide enough initial tensile strength to prevent separation of nerve ends. In previous experimental studies, dehiscence rates of laser-repaired nerves ranged between 12 to 25% whereas that for conventional epineurial suture repair was 0%. In our study, sciatic nerves of rats were transected bilaterally. Results of anastomosis by conventional epineurial suture on one side were compared with those of tissue welding by the CO2 laser using peri-epineurial sheath as a structural adjunct on the other side. At the time of reexploration at 7, 12, and 16 weeks, there was no dehiscence in nerves of either the laser with peri-epineurial sheath group or the suture repair groups. Electrophysiological and morphometric values after use of peri-epineurial tissue as an adjunct to tissue welding by the CO2 laser were comparable to those of conventional suture repair.     

Attempts at autologous transplantation of sliced liver to the subcutaneous tissue

Sliced rat liver was autologously transplanted to subcutaneous tissue. Morphology of the hepatocytes in transplants was investigated for up to 1 year after auto-transplantation; the effect of partial hepatectomy on the autografts was studied. Autografts with approximately one-tenth of the original weight were found alive in subcutaneous tissue for as much as 1 year after transplantation. Partial hepatectomy did not lead to greater weight.     

植入自体雪旺氏细胞的胚胎神经修复上肢神经缺损

目的 研究修复上肢神经缺损新的手术方法。方法 应用植入自体雪旺氏细胞的胚胎神经复合型神经桥接体，修复上肢神经缺损46例（52条），术后1年进行神经功能评定。结果 本组46例随访40例，随访时间12－36个月，接Seddon的周围神经损伤术后恢复评定标准进行评定，优良率为69．57％。植入自体雪旺氏细胞的胚胎神经复合型神经桥接体移植，是一种修复上肢神经缺损的新方法，具有进一步深入研究和临床应用的前景。     

Interposed autologous nerve segment stimulates nerve regeneration in peripheral nerve allografts in a rat model

The ability of autologous nerve segments interposed between allografts, to increase the total nerve-gap distance, was studied. Sciatic nerve allografts were carried out in a rat model. A 15-mm nerve gap was repaired with a 25-mm nerve graft (interposed group: allo-auto-allograft; control group: allo-allo-allograft). Cyclosporin was given for 12 weeks. Nerve regeneration was evaluated using the weight of the anterior tibial muscle and histologic, morphometric and immunohistochemical analyses at 12, 13, 14, 15, 16, 20, and 24 weeks. Nerve regeneration in the interposed group was statistically significantly better than that in the control group. The authors concluded that a nerve allograft with interposed autograft may enhance nerve regeneration in this model, because of the migration of host-derived Schwann cells into the graft from not only the proximal and distal host nerve stumps, but also the interposed autograft.     

同种异体软骨细胞与自体骨髓基质干细胞混合共培养构建软骨皮下移植的可行性研究

背景：软骨组织工程的种子细胞问题是目前研究的热点和难点,如何找到一种既能够避免对自体软骨进行取材又能够达到稳定软骨构建目的的方法呢？本研究尝试利用少量同种异体羊软骨细胞作为软骨诱导微环境提供者,与扩增后的羊自体BMSC混合共培养并植入皮下环境,探讨利用同种异体软骨细胞共培养构建软骨皮下移植的可行性。方法：本实验对山羊软骨细胞和BMSC分别进行取材和分离培养扩增,并将以上细胞分为以下四组进行混合并接种在PGA支架材料上：A组：100%自体软骨细胞;B组：30%自体软骨细胞＋70%自体BMSCs;C组：30%同种异体软骨细胞＋70%自体BMSCs;D组：100%同种异体软骨细胞。经过体外构建6周后植入羊皮下进行体内构建12周,对所形成的组织块进行大体观察和组织学染色等评价。结果：自体软骨细胞组和自体软骨细胞混合自体BMSC组皮下移植后可见成熟软骨组织形成,但同种异体软骨细胞参与的两组（包括同种异体软骨细胞混合自体BMSC的实验组和单纯异体软骨细胞组）在皮下环境中都因为较强的免疫反应未能形成软骨组织。结论：同种异体软骨细胞以及PGA支架材料的存在对于组织工程软骨在羊皮下环境的构建有负面影响。     

A comparative study of autologous peripheral nerve grafts

Forty-five Sprague-Dawley rats were divided into four groups. The first two groups were subjected to primary epineural anastomoses, with and without tension. In the remaining two groups, sciatic nerve defects were produced and femoral cable grafts were then performed with and without making an epineural sheath defect on the edge of the recipient nerves. Five functional evaluation criteria (sensation, push-off, fanning of claws, cubital ulcer, and leg atrophy) were used along with histological findings. It has been found that the recovery of sensation was the least in the tension group, as was other functional recovery. Animals with epineural and fascicular sutures ranked highest in functional recovery while cable grafts followed at 4th, 10th, and 12th week of observation.     

Recurrent carotid stenosis after autologous tissue patching

This study was carried out to evaluate two techniques of widening the carotid bifurcation with autologous material after endarterectomy to determine whether the incidence of recurrent stenosis could be reduced. As a control, a similar series was performed without patching. Autologous saphenous vein was used as a patch in one group of patients, whereas in another, the bifurcation was widened by suturing the external carotid to the internal carotid artery, advancing the bifurcation by several centimeters, a technique we termed bifurcation advancement. All three groups were studied at least 1 year after operation by means of Doppler ultrasonography. We found no difference in either of the patched techniques compared with unpatched controls. Significant recurrent stenosis (greater than 50% diameter reduction) was found in 12.5% of reconstructions with a vein patch, 12.5% of those with bifurcation advancement, and 16.6% of those with simple closure. The overall incidence of significant recurrent stenosis was 13.8%, with symptoms occurring in 2.7%.