Research status and progress on limb preservation technology / 器官移植

Limb replantation and transplantation is the optimal treatment for traumatic limb amputation. Safe and effective limb preservation is the key factor to determine the success of limb replantation and transplantation. Currently, static cold storage is the gold standard of limb preservation. However, the preservation time is short, which may no longer meet clinical requirements. With rapid development of organ preservation in recent years, novel preservation technologies, such as ultra-low temperature preservation, supercooling preservation and mechanical perfusion preservation, have successively emerged. However, at present, these techniques are primarily applied to the preservation of solid organs rather than composite tissue allografts with blood vessels including limbs. In this article, research status and progress on the application of static cold storage and mechanical perfusion preservation in limb preservation were reviewed, aiming to provide reference for clinical application of limb preservation technology and promote the development of limb replantation and transplantation.

Diagnostic criteria and research progress on Banff classification of allograft pathology in composite tissue allotransplantation / 器官移植

Composite tissue allotransplantation (CTA) is a novel transplantation discipline to treat functional tissue or limb defects. Since a majority of CTA grafts were vascularized grafts, it is also known as vascularized composite allotransplantation (VCA). The grafts of CTA/VCA consist of two or more types of allogeneic skin, subcutaneous tissue, bone, muscle, nerve and vessel, etc. Most of CTA/VCA grafts contain skin tissues, which possess the highest antigenicity. Acute rejection after transplantation is the primary obstacle leading to CTA/VCA graft failure and primary graft dysfunction. Hence, histopathological characteristics of skin rejection in CTA/VCA grafts have become the primary hotspot. In this article, pathological features of CTA/VCA rejection, Banff classification in 2007 and related research progress were reviewed, aiming to provide reference for the diagnosis and treatment of rejection and other complications of CTA/VCA.

Inducción de tolerancia inmunológica: alotrasplantes compuestos vascularizados y trasplantes de órgano sólido / Immune tolerance induction: vascularized composite allografts and solid organ transplants

Resumen Introducción. La inducción de tolerancia inmunológica solucionaría los problemas asociados con la inmunosupresión de por vida, necesaria para evitar el rechazo de aloinjertos. Objetivos. Revisar aspectos inmunológicos, modelos clínicos utilizados y resultados obtenidos en la tolerancia y comparar los resultados obtenidos con trasplante de órgano sólido y alotrasplante compuesto vascularizado. Materiales y métodos. Se realizó una búsqueda en la base de datos PubMed que arrojó 299 resultados; se revisaron las bibliografías de los artículos y se consultaron las referencias pertinentes. Al final se seleccionaron 83 artículos. Resultados. Existen mecanismos centrales y periféricos para mantener la tolerancia a antígenos propios; en la práctica clínica, la tolerancia central ha sido más utilizada, esto se ha hecho mediante estrategias que utilizan trasplante conjunto de medula ósea. Varios ensayos clínicos, la mayoría en pacientes con trasplante renal, han mostrado resultados prometedores pero inconsistentes. Conclusiones. En trasplantes renales fue posible suspender de forma exitosa la inmunosupresión, mientras que en trasplantes de mano se logró disminuirla considerablemente. El quimerismo inmunológico parece ser indispensable para el desarrollo de tolerancia a aloinjertos, por lo que es necesario desarrollar protocolos para inducir quimerismo mixto persistente.

Abstract Introduction: Immune tolerance induction could solve problems associated with lifelong immunosuppression, necessary to avoid allograft rejection. Objectives: To review immunological aspects, clinical models used and results achieved and to compare the results with solid organ transplantation and vascularized composite allotransplants. Materials and methods: A literature review was made in the PubMed database, yielding 299 results. The bibliography of the articles was reviewed and the pertinent documents were consulted. Finally, 83 articles were selected. Results: There are central and peripheral mechanisms to maintain tolerance to self-produced antigens. In clinical practice, central tolerance has been widely used through strategies that involve bone marrow transplantation. Several clinical trials, mostly in kidney transplant patients, have shown promising but inconsistent results. Conclusions: Immunosuppression was successfully suspended in renal transplantation patients, while its use was reduced considerably in hand transplantation patients. Immunological chimerism seems to be essential to develop tolerance to allografts, so it is necessary to elaborate protocols to induce persistent mixed chimerism.

Review of Current Facial Allotransplantation and Future Aspects

Limb Transplantation: Indications and Recent Results

Hand is very important for daily living so most activities is impossible in bilateral amputation of the hand. Hand allotransplantation which was performed firstly in 1998 was epochal method for reconstruction of amputated hand to nearly normal hand. According to long term follow-up beyond 12 years, functional recovery of transplanted hand was inspiring and it was equal or even better than the result of replantation. The satisfactory results of transplantation spread it to worldwide and expand the consensus about the allotransplantation. But immunosuppressive therapy which followed consequently by transplantation induced many complications including infections, metabolic disease and cancer. Transplantation enhanced the quality of life but side effects of immunosuppressant threatened the life itself. So debate is ongoing about the ethical justification and indications of transplantation. This article reviews the recent results of hand transplantation and complications of immunosuppressive therapy.

Experimental Hind Limb & Inguinal-Femur Osteocutaneous Flap Model in Rats for Composite Tissue Transplantation

PURPOSE: Composite tissue allotransplantation (CTA) is a newly raised field as a treatment of severe body disfigurements. But in the point that it is transplant of functional organ not vital organ, it has limitation of using immunosuppressant for lifetime. Therefore, recent studies on CTA are focused on the reduction of risk of immunosuppression by inducing immunotolerance, developing new regimen and so on. So, appropriate experimental models to solve the problems are needed. We have performed CTA experiment using hind limb of rats which is frequently used CTA animal model. There were many trials and errors when actually conducting experiment. Hence the authors are to state the experiences in our own experiments. METHODS: Total 13 Sprague Dawley rats (SD rats) were used. In 10 rats, hind limb allotransplantation were performed and in 3 rats, inguinal-femur osteocutanoeus flap operation were conducted. RESULTS: Out of total 13 rats, on the day of operation 4 rats died, and 1dayafter operation 2 rats died. The remainder 7 rats were euthanized on the 3rd day after operation. Autophagy occurred in 3 rats. The dead experimental models were experienced in the early stage of study. CONCLUSION: We could increase survival rate through appropriate anesthesia, maintaining body temperature, supplement of water and pain control.

A New Facial Composite Flap Model(Panorama Facial Flap) with Sensory and Motor Nerve from Cadaver Study for Facial Transplantation

PURPOSE: The purpose of this study was to investigate the possibility that a dynamic facial composite flap with sensory and motor nerves could be made available from donor facial composite tissue. METHODS: The faces of 3 human cadavers were dissected. The authors studied the donor faces to assess which facial composite model would be most practicable. A "panorama facial flap" was excised from each facial skeleton with circumferential incision of the oral mucosa, lower conjunctiva and endonasal mucosa. In addition, the authors measured the available length of the arterial and venous pedicles, and the sensory nerves. In the recipient, the authors evaluated the time required to anastomose the vessels and nerve coaptations, anchor stitches for donor flaps, and skin stitches for closure. RESULTS: In the panorama facial flap, the available anastomosing vessels were the facial artery and vein. The sensory nerves that required anastomoses were the infraorbital nerve and inferior alveolar nerve. The motor nerve requiring anstomoses was the facial nerve. The vascular pedicle of the panorama facial flap is the facial artery and vein. The longest length was 78mm and 48mm respectively. Sensation of the donor facial composite is supplied by the infraorbital nerve and inferior alveolar nerve. Motion of the facial composite is supplied by the facial nerve. Some branches of the facial nerve can be anastomosed, if necessary. CONCLUSION: The most practical facial composite flap would be a mid and lower face flap, and we proposed a panorama facial flap that is designed to incorporate the mid and lower facial skin with and the unique tissue of the lip. The panorama facial composite flap could be considered as one of the practicable basic models for facial allotransplantation.

Evaluation of Reliability and Validity of the Louisville Instrument for Transplantation(LIFT) in Korean Population

PURPOSE: Composite tissue allotransplantation has emerged as a new therapeutic modality to reconstruct major tissue defects of the head, neck and extremities. A questionnaire-based instrument, the Louisville Instrument for Transplantation(LIFT), has been developed to objectively assess the risk-versus-benefit ratio for composite tissue allotransplantation procedures. The objective of this study is to assess if the LIFT is a useful, reliable and valid tool to apply to the Korean population. METHODS: Seventy-three medical students and 60 lay public completed the LIFT questionnaire(translated to Korean) over the period from February 2010 to April 2010. Internal consistency was assessed using Cronbach's alpha. Test-retest reliability was analyzed using Pearson's correlation coefficient. Construct validity was assessed by comparing Pearson's correlation coefficients between perceived improvements in quality of life and responses to risk tolerance questions concerning organ transplants. RESULTS: Measurements of the test-retest reliability showed that Pearson's correlation coefficients ranged from 0.241 to 0.902, and Cronbach's alphas ranged from 0.52 to 0.80 for medical students and from 0.63 to 0.83 for the lay public. Pearson's correlation coefficients showed significant correlations between perceived improvements in quality of life and responses to risk tolerance questions concerning organ transplants. Hand transplant showed a significant correlation in medical students. Foot, hand, two hands, larynx, partial face transplants showed significant correlations for the lay public. CONCLUSION: The applicability of the LIFT to the Korean population was found to be reliable and valid. The LIFT may serve as a useful tool for clinical application in the Korean population.