同种异体复合组织移植的研究进展

长久以来,周围组织严重缺损的修复一直是个难题.临床上用于治疗周围组织严重缺损的方法中,患者自身组织移植术仍是最可靠的治疗手段,但是供区组织功能损失及某些组织自身无法提供是不可克服的缺点.同种异体复合组织移植对于修复周围组织严重缺损具有巨大的潜力和诱惑力.本文就同种异体复合组织移植在肢体、关节、喉及颜面移植中的动物实验、临床应用及免疫抑制方面作一综述.     

口腔颌面部复合组织缺损与同种异体复合组织移植

口腔颌面部大型复合组织缺损及其整复历来是人们关注的问题，本文综述了大型复合组织缺损的特点及自体组织移植的应用和不足，以及同种异体复合组织移植的研究进展。     

同种异体复合组织移植后神经再生的研究进展

同种异体复合组织移植是修复周围组织严重缺损的理想选择,而移植组织的功能包括感觉和运动功能,都依赖于移植神经的再生和功能恢复。本文就各种复合组织异体移植后移植神经的再生机制、动物试验和临床上神经再生状况以及免疫治疗方面的研究进展作一综述。     

兔同种异体颜面复合软组织瓣移植及组织瓣再血管化的研究

目的：建立兔同种异体颜面复合组织移植的动物模型,研究移植术后同种异体组织瓣的再血管化进程。方法：对日本大耳白兔和青紫蓝兔进行头颈部（主要是血管系统）解剖研究,并通过半侧颜面组织瓣的设计和移植,明确血管蒂所能营养组织块的最大范围,寻求最合适可靠的血管蒂,以最合适的血管蒂进行复合组织瓣移植。研究移植术后组织瓣的再血管化进程。结果：①兔头颈部的血管分支、走向与人相似,但颅内动脉及颅内、外动脉之间有丰富的交通吻合,结扎兔单侧颈总动脉,未引起偏瘫或死亡。②进行兔半侧颜面组织瓣移植最合适的血管蒂是颈外静脉和颈总动脉。③移植皮瓣的血管密度逐渐增加,约在术后10d达峰值,28d时移植皮瓣与受区相互吻合成网。结论：应用颈总动脉和颈外静脉为血管蒂进行兔同种异体颜面复合组织移植,可提高模型建立的成功率。移植后组织瓣与受区可达到良好的再血管化。     

犬下颌复合器官同种异体移植的实验研究

目的探索利用同种异体器官和组织移植方法修复下颌区大型缺损的可能性。方法１４只犬进行了三种类型的下颌复合器官同种异体原位移植。第一类型移植模型包括半侧下颌骨及其附着的牙齿、肌肉、皮肤和粘膜；第二类型在第一类型的基础上去除口腔粘膜；第三类型则去除粘膜和牙冠，用环孢霉素和甲基泼尼松配合抑制排斥反应。结果下颌区复合器官具有有效的循环回路，进行血管化的移植是可行的，２只存活时间最长的动物均为第三类型的移植模型，分别为术后６７天和７６天，环孢霉素可以有效地抑制排斥反应，延长移植物存活时间。结论同种异体下颌复合器官移植能最大限度地恢复下颌区大型缺损所造成畸形的容貌和丧失的功能。     

下颌骨缺损的外形修复与功能重建

<正>下颌骨缺损常常导致严重的功能丧失和颜面畸形。修复下颌骨缺损的方法较多,有自体肋骨或髂骨等移植,同种异体骨移植,病变下颌骨切除后冷冻或煮沸后再植,代用品植入以及人工生物材料植入。而最接近生理功能的为自体骨移植,又可分为游离骨移植和血管化骨移植。游离骨移植修复下颌骨缺     

应用牙周膜干细胞—牙囊干细胞复合细胞膜片同种异体移植修复比格犬牙周组织缺损的研究

目的 拟构建比格犬牙周缺损模型,观察牙周膜干细胞—牙囊干细胞复合细胞膜片修复牙周组织缺损的效果.方法 分离培养比格犬牙囊干细胞、牙周膜干细胞,制备牙囊干细胞细胞膜片、牙周膜干细胞细胞膜片以及以上2种细胞的复合细胞膜片,将膜片混合支架材料同种异体植入成年雄性健康比格犬牙周缺损模型,对照组只植入支架材料.分别于移植后1周、2周、4周、6周、8周、12周检测探诊深度、牙龈退缩、附着丧失情况.12周后观察分析牙周再生的组织形态学变化.结果 牙周临床检查及组织学形态学分析显示,3个膜片移植组牙周再生效果较对照组效果明显,其中复合细胞膜片移植组明显高于其余两个单一膜片移植组(P<0.05).结论 牙周膜干细胞—牙囊干细胞复合膜片同种异体移植更有利于修复比格犬牙周缺损.     

同种异体舌移植的研究进展

先天或后天原因所致舌严重畸形、缺损或缺失是口腔颌面外科临床中常见问题。目前常规方法修复存在很多问题,效果尚不能令人满意。学者们逐渐将目光转向同种异体舌移植。本文就舌同种异体移植外科技术方面及抑制免疫排斥反应等方面的研究进展作一综述。     

同种异体神经行面神经缺损修复的初步应用

目的:探讨化学去细胞同种异体神经移植修复人体面神经缺损的效果。报告3例同种异体神经成功修复面神经缺损的体会。方法:对3例面神经损伤,应用化学去细胞同种异体神经移植,修复神经缺损,术后定期对患者进行运动功能检查。结果:所有患者在同种异体神经后无异常反应,切口愈合良好。1名患者术后9个月运动功能部分恢复。结论:化学去细胞神经同种异体移植修复人体面神经缺损,能够恢复神经功能,避免了切取自体神经的弊端,在临床上应用是可行的。     

同种胚胎骨移植在口腔颌面外科的应用

口腔颌面部骨骼缺损常造成面部畸形和生理功能障碍,给患者带来严重痛苦。修复颌面部骨骼的缺损,恢复颜面形态和机能,最常用的修复方法是骨移植术。骨移植术包括自体骨移植、同种异体骨移植和异种骨移植。这几类骨移植均具不同的优缺点,一般认为,自体骨移植效果较好,但受植者必须     

Immunobiology of face transplantation

Fourteen face transplants have been performed worldwide since the procedure was successfully introduced in 2005. Vascularized composite tissue allotransplantation may now be considered a viable option for the repair of complex craniofacial defects, for which the results of autologus reconstruction remain suboptimal. However, the benefits must be balanced against the risks inherent in major surgery and the adverse effects of lifelong immunosuppression. In this article, we review the current practice and areas of controversy in facial vascularized composite tissue allotransplantation with particular respect to the unique immunobiology of this procedure. We also describe promising recent advances in immunotherapy and tolerance induction strategies that may soon reach clinical application.     

Facial transplantation: a comprehensive review of the literature.

PURPOSE: Composite tissue allotransplantation has become a clinical reality and a major breakthrough in reconstructive surgery. The current boundary of dispute on composite tissue allotransplantation is regarding the full-face transplantation. The aim of this article is to provide a comprehensive overview of how facial allotransplantation has been approached in the scientific literature. MATERIAL AND METHODS: The selection of articles was conducted using PubMed at between January 2000 and September 2005. The search terms were "facial graft," "facial transplantation," and "facial allotransplant." The criteria of analysis were the category of articles and the presence of 6 items: 1) issues regarding the donor; 2) psychological impact on the recipient; 3) surgical risks; 4) immunologic risks; 5) socio-cultural aspects; and 6) expense. RESULTS: Thirty-eight articles were included. The first article was published in 2002. Most articles over the last 4 years dealt with issues of medical ethics. The annual rate of basic research articles was relatively stable. Conversely, the rate of 'view points,' notably regarding ethics aspects, increased dramatically in 2004. The issues regarding the donor were found in 26% of the articles, the psychological echo on the recipient in 53% of the articles but in 81% of the medical ethics papers, the immunologic risks in 81% of the articles, the surgical risks in 66% of the articles, socio-cultural aspects in 34% of the articles, and expense problems in 5% of the articles. CONCLUSION: Psychological, immunologic, and surgical risks are the problems addressed most in the literature. Cost, donor, social, and cultural aspects are least addressed. There is a lack of hard data in the literature regarding those problems.     

犬同种异体下颌区复合器官移植后排斥反应的组织学特征

目的本研究探讨了犬下颌区复合器官移植后排斥反应的组织学特征。方法通过光镜和电镜观察，同种异体下颌区复合器官移植后早期不同器官和组织的组织学变化。结果发现同种异体下颌复合器官移植后不同组织的排斥反应过程是不同的，皮肤、粘膜、肌肉和血管是抗原性较强的组织，皮肤排斥反应过程最为严重且难以控制，肌肉显示出严重的退行性改变和明显的血管炎。牙髓均呈纤维化改变、网状变性或坏死，牙周的反应不十分强烈。长期存活者各个组织如皮肤、肌肉和血管均表现出接近正常的组织学形态。结论如果组织配型和免疫抑制药物得到改善，在将来下颌复合器官的移植的临床应用是完全可能的。感染是移植后局部严重的并发症，其可加重排斥反应对组织的破坏。     

Intraosseous territory of the facial artery in the maxilla and anterior mandible: Implications for allotransplantation

AimThe aim of this anatomical study was to define the intraosseous vascular territory of the facial artery. The clinical issue is whether ipsilateral facial artery anastomosis will guarantee blood supply to the ipsi- and contralateral mandibular symphyses and maxillae in allotransplantation.Material and methodsOf 10 human cadaveric heads, the left facial artery was injected with a positive contrast agent. The maxillae and mandibular symphyses were investigated with cone-beam computed tomography (CBCT).ResultsEach ipsilateral maxilla and mandibular bone segment showed contrast medium in the intraosseous vessels. In 50% of cases, this was also the case on the contralateral side of the maxilla and anterior mandible.ConclusionsThe maxillae and the mandibular symphyses receive ipsilateral blood supply from the facial artery and, in 50% of cases, also from the contralateral facial artery. Internal maxillary artery anastomosis is not required for a vascularized maxillary bone flap. Additionally, involvement of the submental artery is not needed for a mandibular symphyseal bone flap.     

下颌复合组织移植实验的显微外科解剖学基础研究

同种异体下颌区复合器官和组织移植的研究刚刚起步,为了了解下颌区复合器官和组织移植的显微外科解剖基础,在犬、兔和猴进行了下颌区及颈部血管解剖比较研究。结果发现,在下颌区域,颌外动脉、颌内动脉、颌外静脉和颌内静脉形成闭合的循环回路。在此基础上可以确定下颌复合器官移植的范围并使移植手术得以进行。     

Ethical questions raised by the first allotransplantations of the face: A survey of French surgeons

IntroductionMore than any other allograft, the allotransplantation of the face has a symbolic character, which raises a large number of questions. The objective of this article is to make an analysis through a survey carried out among French surgeons.MethodsA file of 909 e-mail addresses of surgeons was created so as to send out a questionnaire regarding 10 ethical issues.ResultsBeyond the technical prowess, the surgeons ethical reflection initially focused on the notion of consent to donation and care. They attached equal importance to all ethical questions. They spontaneously raised the issue of over-mediatization of these first transplants and the place of the transplant surgeons and their patients in the medical information.ConclusionOver two thirds of the surgeons attached importance to ethical issues regarding the donor and recipient of a facial allograft. Some of the principal questions facing facial transplantation is of an ethical nature as it is an unprecedented procedure that is challenged by the axiom to first do no harm and the need of modern medicine to limit risk to as close to zero as possible. For the non-specialist, accepting psychologically the face of another individual appears to be a real issue. Contrary to that, the main demand expressed by the facial transplant recipients appears to be related to facial functions rather than appearance.     

Optimization of resilience and stress distribution in porcelain veneers for the treatment of crown-fractured incisors

The present study was conducted to define, when restoring extensive loss of dentin, the configuration of the restoration that will best reproduce the biomechanical properties of the intact original tooth in terms of resilience and stress distribution. The treatment of 1/3-crown fractures and 2/3-crown fractures was investigated using different designs of facial porcelain veneers with and without underlying composite buildup. The stress distribution and tooth compliance were assessed in a numeric model reproducing a 2-dimensional buccolingual cross section of an incisor. A 50-N facial force was applied to simulate an incisal impact situation. The facial surface tangential stresses were calculated, and the maximum displacement (horizontal direction) at the most incisal node of the enamel surface was also recorded and used to calculate the tooth compliance (i.e., displacement/load or resilience) for each test condition. Tensile stresses were generated on the facial surface of the porcelain laminates with a similar pattern for all test conditions, the cervical part of the crown being the most quiescent area. Substantial differences appeared in the incisal half of the crown, the lowest stresses being observed for extensively fractured teeth restored without composite buildup (facial peaks at approximately 33 MPa). Fractured teeth restored with minimal veneers and a "dentin-like" composite buildup showed stress patterns similar to the intact tooth (facial peaks at approximately 50 MPa). The natural tooth gave the highest tooth compliance or flexibility. All restorative designs featured increased tooth stiffness. However, the original tooth compliance was almost restored when composite was used to replace the missing dentin, with the porcelain acting only as a facial and incisal enamel substitute. When restoring crown-fractured incisors, tooth compliance and stress distribution can be modulated by the combination of composite and ceramics. Optimized configurations can be reached to reproduce the original biomechanical behavior of the intact tooth. The use of ceramic alone generates low stress concentrations, but also less compliant restored teeth.     

Hemiforehead flap for reconstruction of composite facial defects

Composite defects overlap 2 or more facial units. It is difficult to reconstruct composite defects with adequate shape, color, and texture. Because it is non-hair bearing, is relatively thin, and has a color and texture similar to that of the rest of the face, the skin of the forehead possesses excellent characteristics for nasal reconstruction and repair of other facial areas. The authors developed an extended thin forehead flap (hemiforehead flap) that includes half of the total forehead skin and is based on supratrochlear vessels. In the patient reported here, a hemiforehead flap was used to reconstruct composite defects of the lower lid, cheek, nose, and upper lip. Acceptable aesthetic and functional results were achieved. This flap may serve as an alternative for reconstruction of composite facial defects.