Perspectives on Hand Transplantation

Perioperative management of a bilateral forearm allograft

Composite tissue allotransplantation (CTA) is a complex procedure requiring a multidisciplinary collaboration between surgeons, anesthetists, and transplantation specialists. We will describe the perioperative management of a bilateral forearm allograft performed at our facility. A 40-year-old man who lost both forearms was registered on the transplant waiting list; a suitable graft was available 11months later. Anesthesia required planning for vascular access, hemodynamic monitoring, fluid therapy management and prevention of deep vein thrombosis. Blood loss was not quantifiable, which made coagulation management challenging. Reperfusion syndrome required the use of vasopressors. Postoperatively, moderate rhabdomyolysis without acute renal failure was observed. No complications such as thrombosis, hemorrhage, or opportunistic infections occurred during the early postoperative period. A comprehensive, protocol-driven, patient care strategy is crucial for the proper conduct of the surgical procedure and graft survival.

Recipient screening and selection: who is the right candidate for hand transplantation

Hand transplantation is an elective non-life saving but quality of life-giving surgery for good candidates that is not without risk. Patient screening and selection is the most critical element to successful transplantation outcomes and cannot be overemphasized in terms of importance in the overall scheme of an active composite tissue allotransplantation (CTA) program. This article discusses the various criteria that are important in the selection of patients for CTA.

Systemic sclerosis as a model of chronic rejection in facial composite tissue transplantation

INTRODUCTION

Chronic rejection remains a potential significant long-term problem of facial allograft transplantation. Scleroderma parallels chronic rejection in terms of its immunological pathophysiology and its histopathological processes. Through the analysis of facial changes in scleroderma we demonstrate how chronic facial allograft rejection may present and progress.

METHODS

129 consecutive patients with a clinical diagnosis of scleroderma were recruited into the study. Static facial disease assessment was carried out through the analysis of digital photographs. Facial motion dysfunction was assessed using a modified House-Brackmann Grading Scale and an established maximal static response assay. Psychological evaluation comprised the Derriford Appearance Scale short-form (DAS), the Noticeability and Worry score and the Hospital Anxiety and Depression Scale (HADS).

RESULTS

Static disease severity as measured using an observer-rated disfigurement scale revealed all grades of disease in the scleroderma cohort - from mild through to severe. Significant positive correlations were seen between observer rated disfigurement and DAS24, Noticeability and Worry scores. No significant relationship could be seen between the indices of facial motion impairment and psychological scores.

CONCLUSIONS

Progressive facial deterioration seen over time in scleroderma provides a comprehensive spectrum of static and dynamic facial changes which may be encountered in chronic facial graft rejection. This study provides valuable insight into the potentially significant long-term sequelae of allogenic reconstructive transplantation.

[Composite allotransplantation in the upper extremity: from research to clinical reality]

Recent advancements in immunosuppression have made composite allotransplantation possible. To date, 38 hand allotransplantations have been performed in the world. Apart from the first case - amputated after voluntarily stopping the treatment- survival at 2-year follow-up has been 100%. After 2 years, 12 of the Chinese cases had to stop their treatment which led to complete loss of the transplanted parts. In 25 cases, results are known with a follow-up greater than 2 years. The transplanted patients all experienced one or more acute rejection episodes during the first postoperative year contrasting with only a 10% acute rejection rate following kidney transplantation. All these rejections were reversible with appropriate treatment. Extrinsic motor power was always restored, but intrinsic musculature only recovered in certain cases. Some sort of sensory discrimination was restored in 72% of the hands. All the patients had side effects related to immunosuppressive treatments, but none of these effects were life-threatening or impaired their quality of life. We think that composite allotransplantations should no longer be considered as clinical research and should be developed in accredited centres.

Cryopreservation of composite tissue transplants

Composite tissue allotransplantation holds great promise for upper extremity reconstruction but is limited by donor part availability. Cryopreservation may increase the availability of donor parts and even reduce antigenicity. The purpose of the study was to evaluate the viability of cryopreserved composite tissues and to demonstrate the feasibility of microvascular isotransplantation of cryopreserved composite flaps. Twenty epigastric flaps were harvested from Lewis rats. Ten flaps were analyzed fresh. Ten flaps were perfused with dimethyl sulfoxide (DMSO)/trehelose cryoprotectant agent (CPA), frozen by controlled cooling to -140 degrees C, and stored for 2 weeks. Flaps were evaluated by factor VIII endothelial staining and MTT tetrazolium salt assay. For the in vivo phase, 30 flaps were harvested. Ten were transplanted fresh to isogenetic recipient animals, ten were perfused with CPA and transplanted, and ten were cryopreserved for 2 weeks, thawed, and transplanted. All cryopreserved samples displayed intact vascular endothelia on factor VIII staining. On MTT analysis, the epithelial viability index for the cryopreserved samples was not significantly different from fresh controls (p = 0.12). All freshly transplanted flaps (10/10) were viable at 60 days. Nine of ten flaps in the perfused/transplanted group were viable at 60 days. Survival of cryopreserved/transplanted flaps ranged from 5 to 60 days. The skin and vascular endothelial components of composite tissue flaps appear to retain their viability after cryopreservation. The in vivo studies demonstrate that the long-term survival of cryopreserved composite tissue transplants is feasible and support an indirect injury, rather than direct injury from freezing or cryoprotectant agents, as the mechanism of flap loss.

Rapamycin-conditioned, alloantigen-pulsed dendritic cells promote indefinite survival of vascularized skin allografts in association with T regulatory cell expansion

Clinically-applicable protocols that promote tolerance to vascularized skin grafts may contribute to more widespread use of composite tissue transplantation. We compared the properties of alloantigen (Ag)-pulsed, rapamycin (Rapa)-conditioned and control bone marrow-derived host myeloid dendritic cells (DCs) and their potential, together with transient immunosuppression (anti-lymphocyte serum+cyclosporine), to promote long-term, vascularized skin graft survival in Lewis rats across a full MHC barrier. Both types of DCs expressed low levels of CD86, but Rapa DC expressed lower levels of MHC II and CD40 and were less stimulatory in MLR. While both Rapa and control DCs produced low levels of IL-12p70 and moderate levels of IL-6 and IL-10 following TLR ligation, Rapa DC secreted significantly lower levels of IL-6 and IL-10 in response to LPS. Donor Ag-pulsed Rapa DC, but not control DC, induced long-term skin graft survival (median survival time >133 days) when administered 7 and 14 days post-transplant. Circulating T cells in hosts with long-surviving grafts were hyporesponsive to donor alloAg stimulation, but proliferated in response to third-party stimulation and produced IFN-gamma and IL-10. When recipients of long-surviving grafts were challenged with skin grafts, donor but not third-party grafts were prolonged, suggesting underlying regulatory mechanisms. Both flow cytometry and immunohistochemical analysis revealed that donor Ag-pulsed Rapa DC infusion expanded CD4+ Foxp3+ Treg in recipients' spleens, graft-associated lymph nodes and the graft. These data demonstrate for the first time that pharmacologically-modified, donor Ag-pulsed host DC administered post-transplant can promote indefinite vascularized skin graft survival, associated with Treg expansion.

Allotransplantation de face: étude anatomique, techniques de prélèvement partiel ou total de face, indications potentielles en clinique humaine

The authors evaluated the technical aspects of harvesting facial tissues in order to perform a facial allotransplantation by conducting dissections in 15 fresh cadavers. They developped anatomical models of harvesting the inferior two thirds and the totality of the face. The approach consisted in harvesting the totality of the facial soft tissues including the muscles and their innervation, in that way harvesting is fast and associated to minimal tissular trauma. The vessels were dissected at their origin at the level of the external carotid artery and the internal jugular vein. The vascular anatomy within the facial flaps was evaluated by transillumination and radiographic (Rx) studies and the authors concluded that the vascular network is rich and sufficient in both partial and full size face transplants. Another important aspect of that study was the restauration of the donor's face. This was achieved in a fast and aesthetically satisfying way with the use of a resin mask. After switching the facial soft tissues on the bony structures of the different subjects, the facial appearence that they observed was rather mixed. In conclusion, that study showed that a face allotransplantation is sound from a technical point of view and could achieve good results in selected cases which are discussed.

Cellular Therapies for Prolongation of Composite Tissue Allograft Transplantation

Complex musculoskeletal defects resulting from cancer, congenital absence, and trauma represent a unique reconstructive challenge. Autologous tissue is often unavailable to reconstruct these deformities. Composite tissue allograft transplantation represents a unique solution for these clinical problems. Face, hand, or limb transplants can be performed in a single procedure. However, the use of chronic nonspecific systemic immunosuppression can lead to side effects such as drug toxicity, opportunistic infections, and malignancies. This article explores various cell-based therapies that represent promising modalities to reduce chronic immunosuppression and alter the risk/benefit ratios for the prospect of composite tissue allograft transplantation.

Hand transplantation: the state-of-the-art

The feasibility of hand transplantation has been demonstrated, both surgically and immunologically. Levels of immunosuppression comparable to regimens used in solid organ transplantation are proving sufficient to prevent graft loss. Many patients have achieved discriminative sensibility and recovery of intrinsic muscle function. In addition to restoration of function, hand transplantation offers considerable psychological benefits. The recipient's pre-operative psychological status, his motivation and his compliance with the intense rehabilitation programme are key issues. While the induction of graft specific tolerance represents a hope for the future, immunosuppression currently remains necessary and carries significant risks. Hand transplantation should, therefore, only be considered a therapeutic option for a carefully selected group of patients.

Informed consent for facial transplantation

Now that partial face transplantation has been performed, attention is focused on likely functional, aesthetic and immunological outcomes, and full facial transplantation is the likely next step. Facial transplantation has been the source of ethical debate, a key part of which focuses on valid informed consent. We review the process of informed consent in health settings, assessing how applicable the current standards are for facial transplantation. The factors which need to be assessed during the screening programme are outlined. We conclude that both individual and process factors are important in obtaining consent for radical new procedures, and outline our own gold standard for ensuring informed consent in facial transplantation.

Risk acceptance in composite-tissue allotransplantation reconstructive procedures

Composite-tissue allotransplantation (CTA) is a new therapeutic modality to reconstruct major tissue defects of the face, larynx, and extremities. Unlike most life-saving organ-transplantation procedures, CTA is considered to improve quality of life. Therefore, the question arises, do the risks posed by the immunosuppression drugs that patients must take to prevent rejection justify the benefits of these procedures? The purpose of this study was to assess the relative risk that individuals are willing to accept in order to receive the benefits of CTA procedures. We used a psychometrically reliable and valid instrument to question two primary populations of individuals: those who live with the risks of immunosuppression, and healthy individuals. The level of risk acceptance for the seven transplant procedures tested (foot, single hand, double hand, larynx, kidney, hemiface, and full face) showed significant differences in research participants' risk acceptance for the different transplant procedures, but no significant differences between groups. Based on these findings, we conclude that certain CTA procedures convey benefits to recipients that are perceived by subjects, including individuals who live with the risks of immunosuppression, to warrant the risks of these procedures.