Composite tissue allotransplantation: past, present and future-the history and expanding applications of CTA as a new frontier in transplantation

Immune Tolerance Induction Using Cell-Based Strategies in Liver Transplantation: Clinical Perspectives

Liver transplantation (LT) has become the best chance and a routine practice for patients with end-stage liver disease and small hepatocellular carcinoma. However, life-long immunosuppressive regimens could lead to many post-LT complications, including cancer recurrence, infections, dysmetabolic syndrome, and renal injury. Impeccable management of immunosuppressive regimens is indispensable to ensure the best long-term prognosis for LT recipients. This is challenging for these patients, who probably have a post-LT graft survival of more than 10 or even 20 years. Approximately 20% of patients after LT could develop spontaneous operational tolerance. They could maintain normal graft function and histology without any immunosuppressive regimens. Operational tolerance after transplantation has been an attractive and ultimate goal in transplant immunology. The liver, as an immunoregulatory organ, generates an immune hyporesponsive microenvironment under physiological conditions. In this regard, LT recipients may be ideal candidates for studies focusing on operative tolerance. Cell-based strategies are one of the most promising methods for immune tolerance induction, including chimerism induced by hematopoietic stem cells and adoptive transfer of regulatory T cells, regulatory dendritic cells, regulatory macrophages, regulatory B cells, and mesenchymal stromal cells. The safety and the efficacy of many cell products have been evaluated by prospective clinical trials. In this review, we will summarize the latest perspectives on the clinical application of cell-based strategies in LT and will address a number of concerns and future directions regarding these cell products.

A Unique Method for Total Nasal Defect Reconstruction - Prefabricated Innervated Osteocutaneous Radial Forearm Free Flap

A 52-Year-old woman underwent a two-stage total nose reconstruction for complete nasal defect due to skin cancer. In the 1^st stage, innervated osteocutaneous radial forearm flap (“Neo nose”) was raised with the help of a 3D template. In the 2^nd stage, well vascularised “Neo-nose” was transferred to the face and covered with pre-expanded forehead flap.

Upregulation of PIM2 by Underexpression of MicroRNA-135-5p Improves Survival Rates of Skin Allografts by Suppressing Apoptosis of Fibroblast Cells

BACKGROUND It has been reported that miR-135-5p is involved with many diseases. In this study, we aimed at define the relationship between miR-135-5p level and burn patient survival after skin transplantation. MATERIAL AND METHODS Expression of miR-135-5p and PIM2 was measured using real-time PCR and Western blot analysis in the skin samples collected from burn patients who received skin graft or in the fibroblast cells transfected with miR-135-5p mimics or inhibitors. The regulatory association between miR-135-5p and PIM2 was verified using bioinformatics analysis and luciferase assay. RESULTS The expression level of miR-135-5p was determined in 60 tissue samples divided into 2 groups based on the presence of rejection (long survival n=30, and short survival n=30). We found that miR-135-5p was substantially downregulated in the long survival group. We then searched the miRNA database online with the "seed sequence" located within the 3'-UTR of the target gene, and then validated PIM2 to be the direct gene via luciferase reporter assay system. We also established the negative regulatory relationship between miR-135-5p and PIM2 via studying the relative luciferase activity. We also conducted real-time PCR and Western blot analysis to study the mRNA and protein expression level of PIM2 among different groups (long survival n=30, short survival n=30) or cells treated with scramble control, miR-135-5p mimics, PIM2 siRNA, and miR-135-5p inhibitors, indicating the negative regulatory relationship between MiR-135-5p and PIM2. We also conducted experiments to investigate the influence of miR-135-5p and PIM2 on viability and apoptosis of cells. The results showed miR-135-5p reduced the viability of cells, while PIM2 negatively interfered with the viability of cells, and miR-135-5p inhibited apoptosis and PIM2 suppressed apoptosis. CONCLUSIONS MiR-135-5p is involved with the prognosis of burn patients after skin transplantation. PIM2 is a virtual target of miR-135-5p, and there is a negative regulatory relationship between miR-135-5p and PIM2. MiR-135-5p and PIM2 interfered with the viability and apoptosis in cells.

Key psychosocial challenges in vascularized composite allotransplantation

Psychosocial factors are important elements in the assessment and follow-up care for vascularized composite allotransplantation (VCA) and require multidisciplinary evaluation protocols. This review will highlight differences between VCA with solid organ transplantation (SOT), provide information on the psychosocial selection of VCA candidates, ethical issues, psychological outcomes, and on the need for multicenter research. VCA is primarily a life-enhancing procedure to improve recipients' quality of life and psychological well-being and it represents a potential option to provide reproduction in case of penile or uterine transplantation. The risk benefit ratio is distinctly different than SOT with candidates desiring life enhancing outcomes including improved body image, return to occupations, restored touch, and for uterine transplant, pregnancy. The Chauvet Workgroup has been convened with membership from a number of transplant centers to address these issues and to call for multicenter research. A multicenter research network would share similar evaluation approaches so that meaningful research on psychosocial variables could inform the transplant community and patients about factors that increase risk of non-adherence and other adverse psychosocial and medical outcomes.

Engendering allograft ignorance in a mouse model of allogeneic skin transplantation to the distal hind limb

OBJECTIVE

The aim of this study was to demonstrate lymphatic isolation in a model of hind limb lymph node (LN) excision, consisting of ipsilateral popliteal and inguinal LN excision and to evaluate the immunologic response to allogeneic skin transplanted onto this region of lymphatic isolation.

METHODS

To study lymphatic flow, C57BL/6 mice underwent lymphadenectomy (n = 5), sham lymphadenectomy (n = 5), or no intervention (n = 5), followed by methylene blue injection. Mice were dissected to determine whether methylene blue traveled to the iliac LN. To study host response to skin transplantation, C57BL/6 mice underwent allogeneic skin transplantation with LN excision (n = 6), allogeneic skin transplantation alone (n = 6), or syngeneic skin transplantation (n = 4). Skin grafts were placed distal to the popliteal fossa and mice were euthanized at day 10. Grafts were stained for endothelial cell and proliferation markers (CD31 and Ki67, respectively). Secondary lymphoid tissues (spleen, ipsilateral axillary LN, and contralateral inguinal LN) were removed and rechallenged with BALB/c alloantigen in vitro with subsequent assay of interferon-γ and interleukin 4 cell expression using ELISPOT technique.

RESULTS

Mice that underwent LN excision had no evidence of methylene blue in the iliac nodes; mice without surgical intervention or with sham LN excision consistently had methylene blue visible in the ipsilateral iliac nodes. Mice treated with allogeneic skin transplantation and LN excision had lower expression of interferon-γ and interleukin 4 in the secondary lymphoid tissues.

CONCLUSIONS

Lymph node excision completely interrupts lymphatic flow of the hind limb. This model of lymphatic isolation impairs the ability of the transplant recipient to acutely mount a Th1 or Th2 response to allogeneic skin transplants.

Facial transplantation: historical developments and future directions

Objective:

To present the clinical outcomes obtained by the first facial transplant teams worldwide, reviewing current practice and addressing controversies.

Methods:

A bibliographic search of Medline and Embase databases was performed, and a comparative analysis of all articles published from 1980 to the present was conducted. Two independent investigators screened the manuscripts in accordance with pre-defined criteria.

Results:

A total of 12 partial and 5 full facial transplants were recorded in the literature. Procedures included partial and near-total facial myocutaneous flaps, and complex osteomyocutaneous grafts. Fifteen patients had fully vascularised grafts, and two patients died of transplant-related and infectious complications.

Conclusion:

Facial transplantation can restore quality of life and enable the social re-integration of recipients. Results published by the first facial transplant teams are promising. However, long-term reports of aesthetic and functional outcomes are needed to more precisely define outcomes. In addition, significant technical, medical and ethical issues remain to be solved.

Changing attitudes toward hand allotransplantation among North American hand surgeons

OBJECTIVES

Although more than 70 hand transplants have been performed worldwide, the appropriate clinical indications for this operation are still being determined. Cost and patient exposure to the challenges of lifelong immunosuppression for what is a quality of life-improving (but not life-saving) operation are the focus of the ongoing discussion. A study performed in 2007 showed that surgeons' opinions on the issue varied widely. Recently, more information has been made available regarding long-term patient outcomes, and significant improvements in immunotherapy protocols have been reported. In light of this, we sought to examine changing attitudes regarding hand allotransplantation and its indications by surveying hand surgeons.

METHODS

An email-based survey was sent to members of the American Society for Surgery of the Hand. Demographic information and practice profiles were identified, followed by their risk assessment of hand allotransplants and endorsement of performing the operation in different clinical scenarios. Additional questions focused on the appropriate indications for hand allotransplantation, as well as the procedure's associated ethical and financial implications.

RESULTS

A total of 385 surgeons responded to the survey (14% response rate). The majority (82%) considered hand transplantation to be a high-risk operation (as opposed to 27% in hand replantation), with 78% citing lifelong immunosuppression as the primary factor impacting their overall risk assessment. The most commonly accepted indication for hand vascularized composite allotransplantation was loss of bilateral hands (80% in favor). Dominant hand loss (with an intact contralateral hand) was a far less frequently accepted indication (36% in favor). Patient adherence to immunosuppressive regimens (51%) and expectations of functional/aesthetic outcome (38%) were the most frequently chosen top psychosocial issues that must be addressed by the surgical/medical teams involved in the operation.

CONCLUSIONS

Our study's results demonstrate increasing overall support for hand allotransplantation and increasing acceptance of today's immunosuppressive regimens compared to prior literature. Bilateral hand loss remains the primary agreed-upon indication for transplantation. Despite increasing acceptance in the surgical community, the dangers of chronic immunosuppression, cost and patient adherence continue to be the primary concerns hindering its broader acceptance.

Adipose-derived stromal cells promote allograft tolerance induction

Amputations and unsalvageable injuries with devastating tissue loss are common in the combat wounded. Reconstructive transplantation in the civilian setting using vascular composite allotransplants (VCAs) with multiple tissues (skin, muscle, nerve, bone) combined with long-term multidrug immunosuppression has been encouraging. However, skin rejection remains a critical complication. Adipose-derived stromal/stem cells (ASCs) are easily obtained from normal individuals in high numbers, precluding ex vivo expansion. The reparative function and paracrine immunomodulatory capacity of ASCs has gained considerable attention. The present study investigated whether ASCs facilitate long-term skin allograft survival. ASCs were isolated from fresh human subcutaneous adipose lipoaspirate. Full-thickness skin grafts from BALB/c mice were transplanted onto the dorsal flanks of C57BL/6 mice treated with five doses of anti-CD4/CD8 monoclonal antibodies (10 mg/kg) on days 0, +2, +5, +7, and +14 relative to skin grafting. A single nonmyeloablative low dose of busulfan (5 mg/kg) was given on day +5. Seven days after skin transplantation, ASCs (3×10(6)) were infused i.v. with or without donor bone marrow cells (BMCs; 5×10(5)). ASC+BMC coinfusion with minimal conditioning led to stable lymphoid and myeloid macrochimerism, deletion of alloreactive T cells, expansion of regulatory T cells, and long-term allograft survival (>200 days). ASCs constitutively produced high levels of anti-inflammatory/immunoregulatory factors such as prostaglandin E2, indoleamine 2,3-dioxygenase, APO-1/Fas (CD95), and programmed cell death-1 ligand-2. These findings serve as a foundation for developing a translational advanced VCA protocol, embodying both ASCs and low-dose donor BMCs, in nonhuman primates, with the goal of enhancing functional outcomes and eliminating the complications associated with long-term immunosuppression.

Surgical-allogeneic facial reconstruction: facial transplants

Several factors including cancer, malformations and traumas may cause large facial mutilation. These functional and aesthetic deformities negatively affect the psychological perspectives and quality of life of the mutilated patient. Conventional treatments are prone to fail aesthetically and functionally. The recent introduction of the composite tissue allotransplantation (CTA), which uses transplanted facial tissues of healthy donors to recover the damaged or non-existent facial tissue of mutilated patients, resulted in greater clinical results. Therefore, the present study aims to conduct a literature review on the relevance and effectiveness of facial transplants in mutilated subjects. It was observed that the facial transplants recovered both the aesthetics and function of these patients and consequently improved their quality of life.

Two-stage face transplantation: a new concept in vascularized composite allotransplantation

BACKGROUND

Animal models and clinical cases of facial allotransplantation have been performed as a single stage procedure. A staged surgery might offer some advantages in selected cases. In this study, a two-stage face transplantation approach was performed on rat and the feasibility and safety were evaluated.

METHODS

Brown Norway rats were used as donors and Lewis rats as recipients in the allotransplantation groups. A total of 33 hemiface-scalp transplantations were performed. Syngeneic orthotopic transplantations were performed either in one-stage (one single stage surgery; N = 3), local two-stage [heterothopic transplantation to the neck during the first stage and graft rotation as a pedicled flap to cover the facial defect on postoperative day (POD) 2; N = 3], or distant two-stage approaches (heterothopic transplantation to the groin during the first stage and free graft transfer to the face on postoperative day 2; N = 3). In the allotransplantation groups using the same approaches, 12 received no treatment (N = 4 each subgroup) and 12 received the same tapering dose of cyclosporine (10 to 2 mg/Kg/day; N = 4 each subgroup). Graft survival and the rejection grades were assessed clinically and pathologically.

RESULTS

All syngeneic transplants survived for the follow-up period of 180 days. The mean rejection-free survival and total survival of the allograft in the no treatment group was 6 ± 0.3 and 14.3 ± 4.5 days in the one-stage group, 6 ± 0.4 and 18.5 ± 1 days in the local two-stage group and 6 ± 0.2 and 14.3 ± 5.7 (P > 0.05). All allografts in the treatment groups did not develop rejection during the 42 days follow-up period.

CONCLUSIONS

It is feasible, reliable, reproducible, and safe to perform a two-stage face transplantation in rats. This novel approach has the potential to be applied in research and eventually in selected clinical cases of facial allotransplantation.

Psychological aspects of hand transplantation

PURPOSE OF REVIEW

Psychosocial aspects are important indicators for reconstructive hand transplantation (RHT). They warrant further research attention given the influence of psychosocial factors on the success of RHT. This review will contrast RHT with solid organ transplantation, provide information to guide selection of RHT candidates and ethical implications, share information on psychological outcomes, and address the importance of a multicenter research approach.

RECENT FINDINGS

Previously published RHT reports have tried to identify psychosocial factors that are essential to guide selection of RHT candidates and that predict psychosocial outcomes. These issues in RHT are receiving increased attention, but standardized psychosocial evaluation and follow-up protocols are still needed. Recent study highlights the potential for a multicenter research approach that uses standardized assessment strategies and also emphasizes the need for a shared assessment approach to understand psychosocial outcomes.

SUMMARY

RHT combines the technical rigors of hand surgery and microsurgery with the complex multidisciplinary care that defines modern transplantation medicine. As recent work has provided a more complete picture of the complexities of the psychosocial factors in RHT, a psychosocial assessment protocol developed with input across the centers currently performing this procedure would capitalize on the collective diverse clinical experiences and standardize the assessment and follow-up protocol. With such standardized procedures in place, psychosocial risk factors for both poor psychosocial and medical/surgical outcomes can be identified which can inform the selection or preparation of future candidates.

Upper extremity transplantation: current concepts and challenges in an emerging field

Loss of an isolated upper limb is an emotionally and physically devastating event that results in significant impairment. Patients who lose both upper extremities experience profound disability that affects nearly every aspect of their lives. While prosthetics and surgery can eventually provide the single limb amputee with a suitable assisting hand, limited utility, minimal haptic feedback, weight, and discomfort are persistent problems with these techniques that contribute to high rates of prosthetic rejection. Moreover, despite ongoing advances in prosthetic technology, bilateral amputees continue to experience high levels of dependency, disability, and distress. Hand and upper extremity transplantation holds several advantages over prosthetic rehabilitation. The missing limb is replaced with one of similar skin color and size. Sensibility, voluntary motor control, and proprioception are restored to a greater degree, and afford better dexterity and function than prosthetics. The main shortcomings of transplantation include the hazards of immunosuppression, the complications of rejection and its treatment, and high cost. Hand and upper limb transplantation represents the most commonly performed surgery in the growing field of Vascularized Composite Allotransplantation (VCA). As upper limb transplantation and VCA have become more widespread, several important challenges and controversies have emerged. These include: refining indications for transplantation, optimizing immunosuppression, establishing reliable criteria for monitoring, diagnosing, and treating rejection, and standardizing outcome measures. This article will summarize the historical background of hand transplantation and review the current literature and concepts surrounding it.

Cell lineage in vascularized bone transplantation

BACKGROUND

The biology behind vascularized bone allotransplantation remains largely unknown. We aim to study cell traffic between donor and recipient following bone auto-, and allografting.

METHODS

Vascularized femoral transplantation was performed with arteriovenous bundle implantation and short-term immunosuppression. Twenty male Piebald Virol Glaxo (PVG; RT1(c) ) rats received isotransplants from female PVG (RT1(c) ) rats and 22 male PVG rats received allografts from female Dark Agouti rats (DA, RT1(a) ), representing a major histocompatibility mismatch. Both groups were randomly analyzed at 4 or 18 weeks. Bone remodeling areas (inner and outer cortical samples) were labeled and laser capture microdissected. Analysis of sex-mismatch genes by real-time reverse transcription-polymerase chain reaction provided the relative Expression Ratio (rER) of donor (female) to recipient (male) cells.

RESULTS

The rER was 0.456 ± 0.266 at 4 weeks and 0.749 ± 0.387 at 18 weeks (p = 0.09) in allotransplants. In isotransplants, the rER was 0.412 ± 0.239 and 0.467 ± 0.252 at 4 and 18 weeks, respectively (p = 0.21). At 4 weeks, the rER at the outer cortical area of isotransplants was significantly lower in isotransplants as compared with allotransplants (0.247 ± 0.181 vs. 0.549 ± 0.184, p = 0.007). Cells in the inner and outer cortical bone remodeling areas in isotransplants were mainly donor derived (rER < 0.5) at 18 weeks, whereas allotransplants contained mainly recipient-derived cells (rER > 0.5) at 18 weeks.

CONCLUSIONS

Applying novel methodology, we describe detailed cell traffic in vascularized bone transplants, elaborating our comprehension on bone transplantation.

Evolution and trends in reconstructive facial surgery: an update

Surgical correction of congenital and acquired facial deformities has transcended the primitive era of using non biologic materials to current attempts at own face growing through biotechnology. A summative account of this trend is still lacking in the literature. The objective of this article is to present an update on current knowledge in the strides to achieve functionally and aesthetically perfect facial reconstruction. It highlights the impact of advancements in 3D imaging, stereolithographic biomodelling, microvascular surgical tissue transplantation and tissue biotechnology in the surgical efforts to solve the problems of facial disfigurement whether congenital or acquired.

An overview of psychosocial assessment procedures in reconstructive hand transplantation

There have been more than 90 hand and upper extremity transplants performed worldwide. Functional and sensory outcomes have been reported in several studies, but little is known about the psychosocial outcomes. A comprehensive systematic literature review was performed, addressing the psychosocial impact of reconstructive hand transplantation. This review provides an overview of psychosocial evaluation protocols and identifies standards in this novel and exciting field. Essentials of the psychosocial assessment are discussed and a new protocol, the 'Chauvet Protocol', representing a standardized assessment protocol for future multicenter psychosocial trials is being introduced.

Tolerance and chimerism and allogeneic bone marrow/stem cell transplantation in liver transplantation

The liver has particular tolerogenic properties that allow its spontaneous acceptance in some animal species. Liver structure is considered to favor a tolerogenic environment. The peripheral tolerance mechanisms also play a role in spontaneous tolerance to liver graft. In a clinical setting, the main challenge nowadays facing liver transplantation is minimization of immunosuppression with the goal of donor-specific tolerance. Mechanisms involved in tolerance to transplanted organs are complex and partly unknown. A significant mechanism in tolerance induction is chimerism. Chimerism can be induced through transplantation of allogeneic donor bone marrow/stem cells under appropriate host conditioning. This review focuses on the tolerance mechanisms in liver transplantation and highlights the role of chimerism and allogeneic bone marrow/stem cell transplantation in tolerance development.

Bilateral transfemoral lower extremity transplantation: result at 1 year

Upper limb transplantation has become a treatment option for upper limb amputees with good midterm results. Lower extremity transplantation has never been considered for fear of poor results. The authors present a bilateral transfemoral transplantation of lower extremities performed to a 22-year patient at 12 months of follow-up. The donor was a full HLA-mismatched female multiorgan donor. CMV status was D-/R-. A primary CMV infection coincident with an acute rejection occurred at 3 months and responded to treatment. At 1 year, the Tinel's sign is at malleolar level, there is active knee extension and active plantar flexion of the foot. The patient is walking between parallel bars. Further substantial improvements are expected with longer rehabilitation and follow-up.

Simultaneous bone marrow and composite tissue transplantation in rats treated with nonmyeloablative conditioning promotes tolerance

BACKGROUND

Approaches to safely induce tolerance in vascularized composite allotransplantation (VCA) with chimerism through bone marrow transplantation (BMT) are currently being pursued. However, VCA was historically performed sequentially after donor chimerism was established. Delayed VCA is not clinically applicable due to the time constraints associated with procurement from deceased donors. A more clinically relevant approach to perform both BMT and VCA simultaneously was evaluated.

METHODS

Wistar Furth (RT1A) rats were treated with a short course of immunosuppressive therapy (anti-αβ-TCR monoclonal antibody, FK-506, and anti-lymphocyte serum). One day before BMT, rats were treated with varying doses of total body irradiation (TBI) followed by transplantation of heterotopic osteomyocutaneous flaps from hindlimbs of August Copenhagen Irish (RT1A) rats.

RESULTS

Eighty percent of rats conditioned with 300 cGy TBI and 40% of rats receiving 400 cGy TBI accepted the VCA. Mixed chimerism was detected in peripheral blood at 1 month after VCA, but chimerism was lost in all transplant recipients by 4 months. Most peripheral donor cells originated from the BMT and not from the VCA. Acceptors of VCA were tolerant of a donor skin graft challenge and no anti-donor antibodies were detectable, suggesting a central deletional mechanism for tolerance. Regulatory T cells (Treg) from spleens of acceptors more potently suppressed lymphocyte proliferation than Treg from rejectors in the presence of donor stimulator cells.

CONCLUSIONS

These studies suggest that simultaneous BMT and VCA may establish indefinite allograft survival in rats through Treg-mediated suppression and thymic deletion of alloreactive T cells.

Facial transplantation: a concise update

Objectives: Update on clinical results obtained by the first worldwide facial transplantation teams as well as review of the literature concerning the main surgical, immunological, ethical, and follow-up aspects described on facial transplanted patients. Study design: MEDLINE search of articles published on “face transplantation” until March 2012. Results: Eighteen clinical cases were studied. The mean patient age was 37.5 years, with a higher prevalence of men. Main surgical indication was gunshot injuries (6 patients). All patients had previously undergone multiple conventional surgical reconstructive procedures which had failed. Altogether 8 transplant teams belonging to 4 countries participated. Thirteen partial face transplantations and 5 full face transplantations have been performed. Allografts are varied according to face anatomical components and the amount of skin, muscle, bone, and other tissues included, though all were grafted successfully and remained viable without significant postoperative surgical complications. The patient with the longest follow-up was 5 years. Two patients died 2 and 27 months after transplantation. Conclusions: Clinical experience has demonstrated the feasibility of facial transplantation as a valuable reconstructive option, but it still remains considered as an experimental procedure with unresolved issues to settle down. Results show that from a clinical, technical, and immunological standpoint, facial transplantation has achieved functional, aesthetic, and social rehabilitation in severely facial disfigured patients.

Key words:Face transplantation, composite tissue transplantation, face allograft, facial reconstruction, outcomes and complications of face transplantation.

Quality of life considerations in upper limb transplantation: review and future directions

PURPOSE

As reconstructive transplantation emerges as an increasingly viable option for upper limb amputees, a better understanding of quality of life (QOL) outcomes is needed to evaluate the benefits and risks of the procedure from the patient perspective.

METHODS

To address this need, we searched PubMed (1998-2011) to characterize QOL outcomes among upper limb transplant recipients. We identified 27 articles reporting on QOL outcomes in hand transplantation. Common instruments to assess domains of QOL in hand transplantation include the Disabilities of the Arm, Shoulder, and Hand questionnaire, the Medical Outcomes Study Short Form-36, and the International Registry on Hand and Composite Tissue Transplantation's Hand Transplantation Score System.

RESULTS

Preliminary reports using standardized measures indicate that most hand transplant recipients described improved QOL. Several studies also qualitatively reported that recipients expressed satisfaction with cosmetic, sensory, functional, and social outcomes after transplantation. However, our review suggests that the measurement of QOL in hand transplantation is limited, although it is largely driven by QOL considerations.

CONCLUSIONS

This review highlights the need for improved measurement of QOL in hand transplantation. The preliminary QOL findings across published hand transplantation articles will aid in improving the future assessment of QOL in hand transplantation.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic III.

The gracilis myocutaneous free flap in swine: an advantageous preclinical model for vascularized composite allograft transplantation research

Vascularized composite allotransplantation (VCA) has become a clinical reality, prompting research aimed at improving the risk-benefit ratio of such transplants. Here, we report our experience with a gracilis myocutaneous free flap in Massachusetts General Hospital miniature swine as a preclinical VCA model. Fourteen animals underwent free transfer of a gracilis myocutaneous flap comprised of the gracilis muscle and overlying skin, each tissue supplied by independent branches of the femoral vessels. End-to-end anastomoses were performed to the common carotid artery and internal jugular vein, or to the femoral vessels of the recipients. Thirteen of fourteen flaps were successful. A single flap was lost due to compromise of venous outflow. This model allows transplantation of a substantial volume of skin, subcutaneous tissue, and muscle. The anatomy is reliable and easily identified and harvest incurs minimal donor morbidity. We find this gracilis myocutaneous flap an excellent pre-clinical model for the study of vascularized composite allotransplantation.

Mitomycin-C-treated peripheral blood mononuclear cells (PBMCs) prolong allograft survival in composite tissue allotransplantation

BACKGROUND

Composite tissue allotransplantation (CTA) was introduced as a potential treatment for complex reconstructive procedures and has become a clinical reality. Hand and face transplantation, the most widely recognized forms of CTA, have intensified immunological research in this emerging field of transplantation. Mitomycin C (MMC) is an alkylating agent that suppresses allogeneic T-cell responses. MMC-treated dendritic cells/PBMCs have been shown to induce donor-specific tolerance in solid organ allograft transplantations.

METHODS

Fully mismatched rats were used as hind limb donors [Lewis (RT1(1))] and recipients [Brown-Norway (RT1(n))]. Fifty-five allogeneic hind limb transplantations were accomplished in six groups. Group A (n = 10) received donor-derived MMC-treated PBMCs on transplantation day. Group B (n = 10) rats received no immunosuppression, group C (n = 10) received FK506 and prednisolon, group D consisted in isograft transplantation without immunosuppression, group E (n = 10) received non-treated PBMCs, and group F (n = 5) received PBS without any donor-derived cells. Rejection was assessed clinically and histologically.

RESULTS

In group A, the survival times of the allografts were prolonged to an average of 8.0 d. Rejection was significantly delayed compared with the averages of the corresponding control groups B, E, and F (5.5, 5.9, and 5.8 d). No rejection was seen in control groups C and D.

CONCLUSION

These results demonstrate that MMC-treated donor PBMCs significantly prolong allograft survival when administered systemically on the day of transplantation. However, the immunomodulatory effect is relatively modest with further research being required to clarify dose-effect relations, cell characteristics, and an optimized mechanism and timing for cell application.

Sensitized recipients exhibit accelerated but not hyperacute rejection of vascularized composite tissue allografts

BACKGROUND

Currently, the donor-recipient matching process for vascularized composite tissue allotransplantation (VCTA) closely follows the standard practices for solid organ transplantation. Sensitization is considered a contraindication to VCTA. However, the role of sensitization in VCTA rejection is largely unstudied.

METHODS

Major histocompatibility-mismatched ACI (RT1) donors and Wistar Furth (WF) (RT1) recipients were used to determine whether sensitization would lead to hyperacute rejection in VCTA as in other organs, such as kidneys. WF rats were presensitized to ACI antigens by skin transplantation and received heterotopic osteomyocutaneous VCTA flaps. Kidney transplants served as controls.

RESULTS

Production of anti-donor antibody was detected in WF recipients after rejection of the ACI skin grafts. Sensitized WF rats rejected VCTA grafts from ACI rats significantly faster (P<0.05) than unsensitized recipients, but not hyperacutely. Rejection in the sensitized recipients was not prevented by immunosuppression with FK506 and mycophenolate mofetil. In contrast, kidney allografts from ACI rats were hyperacutely rejected within 30 min by sensitized recipients. To confirm the role of antibody-mediated rejection in the sensitized recipients, serum from presensitized rats was adoptively transferred into naïve WF rats. Hyperacute rejection occurred only in transplanted kidneys but not VCTA. Histologic examination of tissues from acceleratedly rejected VCTA showed dense lymphocytic infiltrates, and no antibody deposition.

CONCLUSIONS

VCTA are rejected in an accelerated fashion but not hyperacutely in the presence of allosensitization and preformed anti-donor antibody. The rejection of VCTA in sensitized recipients is mainly cell mediated and differs mechanistically from that for renal transplants.

The current state of hand transplantation

Hand transplantation is the most common form of modern composite tissue allotransplantation. Successful application of this technology requires a multidisciplinary approach incorporating not only skilled hand surgeons, transplant surgeons, and transplant immunologists, but also hand therapists, psychiatrists, medical specialists, anesthesiologists, and others. Functional outcomes can be life changing for properly selected candidates. Hand transplantation is becoming more common, with more centers offering this relatively new reconstructive modality. Its success depends on proper patient selection, a technically successful operation, postoperative rehabilitation, and an immunotherapy protocol that prevents rejection but has minimal or acceptable morbidity.

The history and evolution of hand transplantation

Hand transplantation has proven itself to be a viable treatment option for upper extremity reconstruction. It has grown through advancements in several critical areas: microsurgery, transplant immunology, and hand surgery. The field has also benefited from a global effort with active transplant centers in 3 different continents. The early struggles and breakthroughs of hand transplantation's past have shaped and formed its current state. This article traces the events of the modern era of hand transplantation.

A historical, clinical, and ethical overview of the emerging science of facial transplantation

In the past 5 years, a total of 16 facial transplantation surgeries have been performed in France, China, Spain, and the United States. Facial transplantation has become a surgical option in clinical situations in which soft tissue and bone loss is accompanied by severe cosmetic, sensory, and functional deficiencies due to disease, trauma, or congenital malformations. With the introduction of facial tissue transplantation surgery came complex clinical, technological, and ethical patient care issues. These complex issues included determining patient selection criteria, refining donor tissue procurement techniques, predicting expected functional outcomes, appreciating the limitations of obtaining a fully informed consent for an innovative procedure, and deliberating the immunological response and postoperative immunosuppressant requirements of the recipient. In addition, psychological implications for the patient, societal consequences, and ethical concerns have been discussed. The short-term results have been positive. Results to date indicate that the clinical, technical, and immunological patient care issues in this emerging science appear to mirror those of other reconstructive and organ transplantation procedures. The long-term physical, emotional, and psychological effects on the recipient patient, as well as long-term consequences to the donor's family, are yet to be validated.

Shock wave treatment in composite tissue allotransplantation

INTRODUCTION

Composite tissue allotransplantation is a newly emerged field of transplantation. Shock wave technology has already been used in the treatment of urologic and orthopedic disorders. Recent studies demonstrated a suppression of the early proinflammatory immune response.

METHODS

50 allogeneic hindlimb transplantations were performed on rats in 5 different groups. Group A (n = 10), (Lewis → Brown-Norway) received 500 impulses of extracorporeal shock wave. Groups B, C, D, and E served as control groups with group B (n = 10) receiving no immunosuppression, group C (n = 10) receiving FK506 and prednisolone, group D (n = 10) receiving no immunosuppression with isograft transplantations (Brown-Norway → Brown-Norway) and group E receiving 500 impulses of extracorporeal shock wave on the contralateral hindlimb.

RESULTS

Rejection of the allogeneic hindlimb occurred on average 7.12 days after transplantation in group A (extracorporeal shock wave). Rejection was significantly delayed compared to the control groups B (no immunosuppression) and E (contralateral hindlimb), where rejection of the allogeneic hindlimb occurred on average 5.49 and 5.6 days after transplantation (t test, P < .01). No rejection was seen in groups C and D.

CONCLUSIONS

For the first time, shock waves have been applied in a composite tissue allotransplantation model and resulted in a significant immunosuppressive effect. These promising first results have showed that shock wave treatment is clinically relevant in composite tissue allotransplantation and justify subsequent research to improve the experimental and clinical outcome.

Microsurgery of the upper extremity

In the past 50 years, hand surgeons have made considerable contributions to microsurgery. The unique demands of complex upper extremity care have driven many of the technical and scientific advances of this discipline, including functional muscle transfers, nerve transfers, and composite tissue allotransplantation. The purpose of this article was to review the current applications of microsurgery to the upper extremity.

Bilateral trans-humeral arm transplantation: result at 2 years

Unilateral and bilateral hand transplantations have been performed worldwide with good mid-term functional results. An above-elbow bilateral transplantation was performed in a 29-year-old male patient from a fully HLA-mismatched donor. Alemtuzumab induction and steroid-free maintenance immunosuppression with tacrolimus and mycophenolate was used. Due to acute rejection, steroids were introduced at 6 months. Three acute rejection episodes occurred, one treated with alemtuzumab. New-onset diabetes after transplant, dyslipemia and worsening of previous high blood pressure required treatment. At 26 months post-transplantation, the patient has excellent elbow active movement, active flexion and extension of the thumb and fingers, useful sensation and a gainful job. Based on the functional results of the case reported, bilateral trans-humeral transplantation could be a viable treatment for selected bilateral above-elbow amputees.

Composite tissue allotransplantation: hand transplantation and beyond

Recent advances in transplant immunology are shifting the focus from immunosuppression to immunoregulation, making composite tissue allotransplantation with novel and less potent immunosuppressive regimens a possibility. Hand transplantation has been the most frequently performed human composite tissue allotransplantation, with more than 50 upper extremity-based transplants done worldwide. Further research is needed regarding immunomodulating protocols, and careful oversight and individualized screening procedures will be required as patients seeking improved quality of life through human composite tissue allotransplantation come to accept a certain level of risk in these experimental procedures. Still, composite tissue allotransplantation offers to advance transplant medicine and reconstructive surgery.