Facial and hand allotransplantation

The Global Experience of Laryngeal Transplantation: Series of Eleven Patients in Three Continents

BACKGROUND

The loss of laryngeal function affects breathing, swallowing, and voice, thus severely compromises quality of life. Laryngeal transplantation has long been suggested as a solution for selected highly affected patients with complete laryngeal function loss.

OBJECTIVE

To obtain insights regarding the advantages, weaknesses, and limitations of this procedure and facilitate future advances, we collected uniform data from all known laryngeal transplants reported internationally.

METHODOLOGY

A case series. Patients were enrolled retrospectively by each institutional hospital or clinic. Eleven patients with complete loss of laryngeal function undergoing total laryngeal transplantation between 1998 and 2018 were recruited.

RESULTS

After a minimum of 24 months follow-up, three patients had died (27%), and there were two graft explants in survivors, one total and one partial, due to chronic rejection. In the remaining cases, voice was functional in 62.5% and 50% achieved decannulation. Swallowing was initially restricted, but only one patient was gastrostomy-dependent by 6 months and all had normal or near-normal swallowing by the end of year two after transplantation. Median follow-up was 73 months. Functional (voice, swallowing, airway) recovery peaked between 12 and 24 months.

CONCLUSIONS

Laryngeal transplantation is a complex procedure with significant morbidity. Significant improvements in quality of life are possible for highly selected individuals with end-stage laryngeal disorders, including laryngeal neoplasia, but further technical and pharmacological developments are required if the technique is to be more widely applicable. An international registry should be created to provide better quality pooled data for analysis of outcomes of any future laryngeal transplants.

LEVEL OF EVIDENCE

IV Laryngoscope, 2024.

Immunosuppressant drug monitor: A non-invasive device to measure tacrolimus level in the saliva of transplanted patients

Solid organ and vascularized composite allograft transplantation are pivotal in enhancing both life expectancy and quality of life. However, the significant risk of donor tissue rejection requires lifelong immunosuppressive therapy. Tacrolimus, a common component of immunosuppressive regimens, offers effectiveness in preventing organ rejection but poses challenges due to its narrow therapeutic window and toxicity, making it essential to carefully monitor its concentration. Tacrolimus trough levels are currently measured in blood, requiring frequent blood draws from patients, and results are available after 3 to 6 h. To address the need for a fast, minimally-invasive, and simple method to monitor tacrolimus concentrations, we have assessed a new device for at-home analysis, the Immunosuppressant Drug Monitor (IDM) that can extract, identify and quantify tacrolimus in saliva within 15 min. We included males and females hospitalized at Massachusetts General Hospital Transplant Unit, between the ages of 21 and 65 years, and treated with Tacrolimus. Informed consent, demographic and treatment data were collected. Each subject was asked to provide a 5 mL saliva sample that was de-identified and processed by the IDM, while a 5 mL blood sample was drawn and supplied to the MGH clinical lab for analysis by the current standard, immunoassays. The predicted tacrolimus concentration found in saliva was compared to the blood trough level results. 62 samples from 31 different patients were obtained. The male to female ratio and ethnicity distribution were well balanced. The majority of patients were within 30 days of initiating tacrolimus treatment. After IDM calibration and exclusion, 21 samples were measured by the IDM. Using an exponential function fit, the IDM showed a correlation of R2 = 0.39 between the saliva Test Line absorption and the measured tacrolimus concentration in blood, with an average absolute error of 1.8 ng/mL. Our results demonstrate a clear correlation between blood and saliva measurements. The IDM provided promising results to monitor immunosuppressant drug concentrations in patients after transplantation. Future larger studies will further develop the correlation, and the IDM's potential impact on patient outcomes.

Vascularized Composite Allograft Versus Prosthetic for Reconstruction After Facial and Hand Trauma: Comparing Cost, Complications, and Long-term Outcome

ABSTRACT

In the past decade, vascularized composite allotransplantation (VCA) has become clinical reality for reconstruction after face and hand trauma. It offers patients the unique opportunity to regain form and function in a way that had only been achieved with traditional reconstruction or with the use of prostheses. On the other hand, prostheses for facial and hand reconstruction have continued to evolve over the years and, in many cases, represent the primary option for patients after hand and face trauma. We compared the cost, associated complications, and long-term outcomes of VCA with prostheses for reconstruction of the face and hand/upper extremity. Ultimately, VCA and prostheses represent 2 different reconstructive options with distinct benefit profiles and associated limitations and should ideally not be perceived as competing choices. Our work adds a valuable component to the general framework guiding the decision to offer VCA or prostheses for reconstruction after face and upper extremity trauma.

Long-Term Survival and Functional Recovery of Cryopreserved Vascularized Groin Flap and Below-the-Knee Rat Limb Transplants

Effective cryopreservation of large tissues, limbs, and organs has the potential to revolutionize medical post-trauma reconstruction options and organ preservation and transplantation procedures. To date, vitrification and directional freezing are the only viable methods for long-term organ or tissue preservation, but are of limited clinical relevance. This work aimed to develop a vitrification-based approach that will enable the long-term survival and functional recovery of large tissues and limbs following transplantation. The presented novel two-stage cooling process involves rapid specimen cooling to subzero temperatures, followed by gradual cooling to the vitrification solution (VS) and tissue glass transition temperature. Flap cooling and storage were only feasible at temperatures equal to or slightly lower than the VS Tg (i.e., -135°C). Vascularized rat groin flaps and below-the-knee (BTK) hind limb transplants cryopreserved using this approach exhibited long-term survival (>30 days) following transplantation to rats. BTK-limb recovery included hair regrowth, normal peripheral blood flow, and normal skin, fat, and muscle histology. Above all, BTK limbs were reinnervated, enabling rats to sense pain in the cryopreserved limb. These findings provide a strong foundation for the development of a long-term large-tissue, limb and organ preservation protocol for clinical use.

Cell Therapy in Vascularized Composite Allotransplantation

Allograft rejection is one of the obstacles in achieving a successful vascularized composite allotransplantation (VCA). Treatments of graft rejection with lifelong immunosuppression (IS) subject the recipients to a lifelong risk of cancer development and opportunistic infections. Cell therapy has recently emerged as a promising strategy to modulate the immune system, minimize immunosuppressant drug dosages, and induce allograft tolerance. In this review, the recent works regarding the use of cell therapy to improve allograft outcomes are discussed. The current data supports the safety of cell therapy. The suitable type of cell therapy in allotransplantation is clinically dependent. Bone marrow cell therapy is more suitable for the induction phase, while other cell therapies are more feasible in either the induction or maintenance phase, or for salvage of allograft rejection. Immune cell therapy focuses on modulating the immune response, whereas stem cells may have an additional role in promoting structural regenerations, such as nerve regeneration. Source, frequency, dosage, and route of cell therapy delivery are also dependent on the specific need in the clinical setting.

Modified Le Fort II approach of adequate vascularization preservation in midface allotransplantation: Mock surgery

INTRODUCTION

It is critical to preserve adequate vascularization in midface allotransplantation, the major complication of which is inadequate blood supply in palate area supplying mainly by internal maxillary artery. Therefore, the aim of this study is to explore a modified Le Fort II approach entailing midface vascularization enhancement.

MATERIALS AND METHODS

Ten cadaveric heads were used in mock surgery. A conventional approach was used on seven cadaveric heads to harvest external carotid artery-facial artery-internal maxillary artery axis. On the remaining three cadaveric heads, modified Le Fort II approach was applied where the internal maxillary artery was harvested after cutting off zygomatic arches and rami of the mandible.

RESULTS

The conventional approach had difficulty harvesting internal maxillary artery, which left the facial artery the only blood supply to midface. Modified Le Fort II approach with Computerized surgical planning (CSP) assisted, on the other hand, could completely unveil and harvest intact internal maxillary artery after osteotomy of mandibular ramus.

CONCLUSION

The modified Le Fort II approach with CSP and ultrasonic bone cutter assisted can maximally preserve internal maxillary system with ease. This approach optimizes midface allotransplantation in clinical practice in future.

Patient-reported outcomes measures used in facial vascularized composite allotransplantation: A systematic literature review

BACKGROUND

Facial vascularized composite allotransplantation (fVCA) is a life-enhancing procedure performed to improve quality of life (QOL). Patient-reported outcome measures (PROMs) are tools used to assess QOL from the patients' perspective, and are increasingly recognized as an important clinical metric to assess outcomes of treatment. A systematic literature review was performed to identify and appraise the content of PROMs used in fVCA.

METHODS

We searched PUBMED/Medline, CINAHL, Embase, PsychInfo, and Web of Science from their inception through to June 2020. Included studies used a PROM in candidates and recipients of fVCA of any gender or age. We excluded abstracts, reviews, editorials, and dissertations. Items from each PROM were extracted and coded, using top-level codes and subcodes, to develop a preliminary conceptual framework of QOL concerns in fVCA, and to guide future PROM selection.

RESULTS

Title and abstract screening of 6089 publications resulted in 16 studies that met inclusion criteria. Review of the 16 studies identified 38 PROMs, none of which were developed for fVCA. Review of the coded content for each PROM identified six top-level codes (appearance, facial function, physical, psychological and social health, and experience of care) and 16 subcodes, making up the preliminary conceptual framework.

CONCLUSION

There are currently no PROMs designed to measure QOL concerns of fVCA candidates and recipients. Findings from this systematic review will be used to inform an interview guide for use in qualitative interviews to elicit and refine important concepts related to QOL in fVCA.

Hand Transplantation-Risks and Benefits

Composite tissue allotransplantation (CTA) is the culmination of progress in transplantation, allowing the reconstruction of the hand in amputees. Worldwide, more than 100 procedures have been performed. The aim of this work was to understand the hand allotransplantation approach, making known current aspects, risks, and benefits. A PubMed research was realized between October 2018 and March 2019, including terms like "Hand transplantation" AND "Composite tissue allotransplantation," "Hand transplantation" AND "Functional outcomes," "Hand transplantation" AND "Immunosuppression," "Hand prosthetics," "Hand Transplantation" AND "Ethics." There were included papers between 1995 and 2018, with English language, amputee human adults, systematic reviews, and clinical studies. Seventy-two papers were fully evaluated. There are technical aspects that influence the procedure like team coordination or surgical technique. It requires a long-life treatment, which has risks such as toxicity or infections. However, it allows the recovery of fine movements, and independence, to perform detailed tasks. The indications must be carefully considered, because some patients benefit from the use of prosthesis. CTA has become an option for amputees so it is important to do more research, to determine the benefits of this procedure. It is not considered a life-saving procedure, so there is an ethical debate because of the risks.

Large Animal Models of Vascularized Composite Allotransplantation: A Review of Immune Strategies to Improve Allograft Outcomes

Over the past twenty years, significant technical strides have been made in the area of vascularized composite tissue allotransplantation (VCA). As in solid organ transplantation, the allogeneic immune response remains a significant barrier to long-term VCA survival and function. Strategies to overcome acute and chronic rejection, minimize immunosuppression and prolong VCA survival have important clinical implications. Historically, large animals have provided a valuable model for testing the clinical translatability of immune modulating approaches in transplantation, including tolerance induction, co-stimulation blockade, cellular therapies, and ex vivo perfusion. Recently, significant advancements have been made in these arenas utilizing large animal VCA models. In this comprehensive review, we highlight recent immune strategies undertaken to improve VCA outcomes with a focus on relevant preclinical large animal models.

[Immunosuppressive effect of mitomycin C-treated peripheral mononuclear blood cells (MICs) in vascularised composite allotransplantation]

BACKGROUND

Vascularized Composite Allotransplantation (VCA) enables the restoration of complex tissue defects. Since the first successful hand and face transplants were performed, clinical and experimental research has consistently improved immunosuppressive therapies. The incubation of peripheral blood mononuclear cells (PBMCs) with mitomycin C (MMC) results in immunomodulatory cells (MICs). In previous studies, the systemic application of MICs on the day of allogeneic hind limb transplantation led to a significant immunosuppression in rats. The aim of this study is to further investigate the optimal point in time of MIC application in a complex VCA model.

MATERIAL AND METHODS

In six groups, 60 allogeneic hind limb transplantations were performed. Fully mismatched rats were used as hind limb donors [Lewis (LEW)] and recipients [Brown-Norway (BN)]. Group A received donor-derived MICs seven days preoperatively. Group B received no immunosuppression; group C received untreated PBMCs seven days prior to transplantation. Animals in group D received cell culture media, whereas group E was treated with a standard immunosuppression consisting of tacrolimus and prednisolone. In group F, syngeneic hind limb transplantations (BN→BN) were performed. Transplant rejection was assessed clinically and histologically.

RESULTS

Group A showed a significantly earlier onset of allograft rejection after 3.5 ± 0.2 days (p < 0.01) when compared with control groups B, C and D (5.5 ± 0.7, 5.3 ± 0.7 und 5.7 ± 0.5). Groups E and F showedno allograft rejection.

CONCLUSION

This study shows that the time of application determines the immunomodulatory effects of MICs. Whereas the systemic application of MICs on the day of transplantation led to a significant immunosuppression in previous studies, this study demonstrates that preoperative injections of MICs lead to an acceleration of allotransplant rejection. Follow-up studies are necessary to investigate further modifications of application time as well as dose-effect relations and cell characteristics of these potential immunosuppressive cells.

Giving, receiving … and forgetting? On the social conditions of receiving an anonymous face transplant

In 2004, the French National Consultative Ethics Committee expressed strong misgivings about the proposal to include the face among body parts that can be removed from deceased donors for organ transplantation. Yet, the first face transplant was performed a few months later. How do medical teams and patients deal with the singular nature of the face? I argue that what the face represents - from the medium of the donor's personal identity to an interchangeable organ - is not fixed. It emerges through the practices and can evolve through the interactions between medical professionals and patients. In the postoperative time, I show that patients receive potentially contradictory recommendations about how to integrate the organ: to consider it theirs and forget the donor, but also to thank the donor for the donation and never forget the origin of the graft. Based on the plurality of relationships developed by the patients with their donor, I revisit Maussian interpretative analyses of organ reception. The effects of giving a face vary both in terms of reciprocity and identity: the feeling of debt is variably felt and can be interpreted negatively or positively, and the experience is more or less transformative.

Establishing Photographic Standards for Facial Transplantation: A Systematic Review of the Literature

Photography provides a means for objective assessment and dissemination of clinical information. The American Society of Plastic Surgeons (ASPS) and Plastic Surgery Foundation (PSF) published photography guidelines in 2006 to optimize its clinical use. However, photographic documentation of outcomes in facial transplantation (FT) continues to lack standardization. We therefore appraised the current state of FT photography in the peer-reviewed literature.

Methods

A PubMed search was conducted from July 2005 to July 2019. Studies containing photographs of partial or full FT recipients were included. Non-English language articles, cadaveric and animal studies, technique papers, and case reports were excluded. Data were extracted from 91 articles. Adherence rates were calculated to determine whether published FT photographs followed ASPS/PSF guidelines. Proposed photographic standards particular to FT were then formulated to guide standardization of practice.

Results

Only 28.6% (26/91) of articles adhered to the photographic conventions of preparation, positioning, and views. Of 162 patient appearances in the 91 articles, 95% (154/162) met the criteria for preparation, 98.8% (160/162) met the criteria for positioning, but only 24.7% (40/162) met the criteria for views.

Conclusions

Photographic documentation of FT outcomes in the peer-reviewed literature is limited, with inconsistent adherence to ASPS/PSF guidelines. There is substantial deficiency in provision of alternative views, with the majority of publications only depicting the frontal view. FT photography standards should specifically incorporate alternative views, proper lighting and framing, and elimination of distractions, and accommodate for remote patient self-photography. This will promote a transparent and consistent longitudinal evaluation of the surgical results.

Delivery of Rapamycin Using In Situ Forming Implants Promotes Immunoregulation and Vascularized Composite Allograft Survival

Vascularized composite allotransplantation (VCA), such as hand and face transplantation, is emerging as a potential solution in patients that suffered severe injuries. However, adverse effects of chronic high-dose immunosuppression regimens strongly limit the access to these procedures. In this study, we developed an in situ forming implant (ISFI) loaded with rapamycin to promote VCA acceptance. We hypothesized that the sustained delivery of low-dose rapamycin in proximity to the graft may promote graft survival and induce an immunoregulatory microenvironment, boosting the expansion of T regulatory cells (T_reg). In vitro and in vivo analysis of rapamycin-loaded ISFI (Rapa-ISFI) showed sustained drug release with subtherapeutic systemic levels and persistent tissue levels. A single injection of Rapa-ISFI in the groin on the same side as a transplanted limb significantly prolonged VCA survival. Moreover, treatment with Rapa-ISFI increased the levels of multilineage mixed chimerism and the frequency of T_reg both in the circulation and VCA-skin. Our study shows that Rapa-ISFI therapy represents a promising approach for minimizing immunosuppression, decreasing toxicity and increasing patient compliance. Importantly, the use of such a delivery system may favor the reprogramming of allogeneic responses towards a regulatory function in VCA and, potentially, in other transplants and inflammatory conditions.

Composite tissue allotransplantation: opportunities and challenges

Vascularized composite allotransplants (VCAs) have unique properties because of diverse tissue components transplanted en mass as a single unit. In addition to surgery, this type of transplant also faces enormous immunological challenges that demand a detailed analysis of all aspects of alloimmune responses, organ preservation, and injury, as well as the immunogenicity of various tissues within the VCA grafts to further improve graft and patient outcomes. Moreover, the side effects of long-term immunosuppression for VCA patients need to be carefully balanced with the potential benefit of a non-life-saving procedure. In this review article, we provide a comprehensive update on limb and face transplantation, with a specific emphasis on the alloimmune responses to VCA, established and novel immunosuppressive treatments, and patient outcomes.

Enhanced Drug Delivery to the Skin Using Liposomes

Background:

Enhancing drug delivery to the skin has importance in many therapeutic strategies. In particular, the outcome in vascularized composite allotransplantation mainly depends on systemic immunosuppression to prevent and treat episodes of transplant rejection. However, the side effects of systemic immunosuppression may introduce substantial risk to the patient and are weighed against the expected benefits. Successful enhancement of delivery of immunosuppressive agents to the most immunogenic tissues would allow for a reduction in systemic doses, thereby minimizing side effects. Nanoparticle-assisted transport by low temperature–sensitive liposomes (LTSLs) has shown some benefit in anticancer therapy. Our goal was to test whether delivery of a marker agent to the skin could be selectively enhanced.

Methods:

In an in vivo model, LTSLs containing doxorubicin (dox) as a marker were administered intravenously to rats that were exposed locally to mild hyperthermia. Skin samples of the hyperthermia treated hind limb were compared with skin of the contralateral normothermia hind limb. Tissue content of dox was quantified both via high-performance liquid chromatography and via histology in skin and liver.

Results:

The concentration of dox in hyperthermia-treated skin was significantly elevated over both normothermic skin and liver. (P < 0.02).

Conclusions:

We show here that delivery of therapeutics to the skin can be targeted and enhanced using LTSLs. Targeting drug delivery with this method may reduce the systemic toxicity seen in a systemic free-drug administration. Development of more hydrophilic immunosuppressants in the future would increase the applicability of this system in the treatment of rejection reactions in vascularized composite allotransplantation. The treatment of other skin condition might be another potential application.

Accommodation and related conditions in vascularized composite allografts

PURPOSE OF REVIEW

The outcome of vascularized composite allografts (VCA) often appear unrelated to the presence of donor-specific antibodies (DSA) in blood of the recipient or deposition of complement in the graft. The attenuation of injury and the absence of rejection in other types of grafts despite manifest donor-specific immunity have been explained by accommodation (acquired resistance to immune-mediated injury), adaptation (loss of graft antigen) and/or enhancement (antibody-mediated antigen blockade). Whether and how accommodation, adaptation and/or enhancement impact on the outcome of VCA is unknown. Here we consider how recent observations concerning accommodation in organ transplants might advance understanding and resolve uncertainties about the clinical course of VCA.

RECENT FINDINGS

Investigation of the mechanisms through which kidney allografts avert antibody-mediated injury and rejection provide insights potentially applicable to VCA. Interaction of DSA can facilitate replacement of donor by recipient endothelial cells, modulate or decrease synthesis of antigen, mobilize antigen that in turn blocks further immune recognition and limit the amount of bound antibody, allowing accommodation to ensue. These processes also can explain the apparent dissociation between the presence and levels of DSA in blood, deposition of C4d in grafts and antibody-mediated rejection. Over time the processes might also explain the inception of chronic graft changes.

SUMMARY

The disrupted tissue in VCA and potential for repopulation by endothelial cells of the recipient establish conditions that potentially decrease susceptibility to acute antibody-mediated rejection. These conditions include clonal suppression of donor-specific B cells, and adaptation, enhancement and accommodation. This setting also potentially highlights heretofore unrecognized interactions between these 'protective' processes.

The combination of mitomycin-induced blood cells with a temporary treatment of ciclosporin A prolongs allograft survival in vascularized composite allotransplantation

BACKGROUND

Vascularized composite allotransplantation (VCA) is a rapidly expanding field of transplantation and provides a potential treatment for complex tissue defects. Peripheral blood mononuclear cells (PBMCs) shortly incubated with the antibiotic and chemotherapeutic agent mitomycin C (MMC) can suppress allogeneic T cell response and control allograft rejection in various organ transplantation models. MMC-incubated PBMCs (MICs) are currently being tested in a phase I clinical trial in kidney transplant patients. Previous studies with MICs in a complex VCA model showed the immunomodulatory potential of these cells. The aim of this study is to optimize and evaluate the use of MICs in combination with a standard immunosuppressive drug in VCA.

METHODS

Fully mismatched rats were used as hind limb donors [Lewis (RT1¹)] and recipients [Brown-Norway (RT1ⁿ)]. Sixty allogeneic hind limb transplantations were performed in six groups. Group A received donor-derived MICs combined with a temporary ciclosporin A (CsA) treatment. Group B received MICs in combination with a temporarily administered reduced dose of CsA. Group C served as a control and received a standard CsA dose temporarily without an additional administration of MICs, whereas Group D was solely medicated with a reduced CsA dose. Group E received no immunosuppressive therapy, neither CsA nor MICs. Group F was given a continuous standard immunosuppressive regimen consisting of CsA and prednisolone. The endpoint of the study was the onset of allograft rejection which was assessed clinically and histologically.

RESULTS

In group A and B, the rejection-free interval of the allograft was significantly prolonged to an average of 23.1 ± 1.7 and 24.7 ± 1.8 days compared to the corresponding control groups (p < 0.01). Rejection in groups C, D, and E was noted after 14.3 ± 1.1, 7.8 ± 0.7, and 6.9 ± 0.6 days. No rejection occurred in control group F during the follow-up period of 100 days. No adverse events have been noted.

CONCLUSION

The findings of this study show that the combination of MICs with a temporary CsA treatment significantly prolongs the rejection-free interval in a complex VCA model. The combination of MICs with CsA showed no adverse events such as graft-versus-host disease. MICs, which are generated by a simple and reliable in vitro technique, represent a potential therapeutic tool for prolonging allograft survival through immunomodulation.

Immunological and inflammatory mapping of vascularized composite allograft rejection processes in a rat model

BACKGROUND

Hand and face vascularized composite allotransplantation (VCA) is an evolving and challenging field with great opportunities. During VCA, massive surgical damage is inflicted on both donor and recipient tissues, which may contribute to the high VCA rejection rates. To segregate between the damage-induced and rejection phase of post-VCA responses, we compared responses occurring up to 5 days following syngeneic versus allogeneic vascularized groin flap transplantations, culminating in transplant acceptance or rejection, respectively.

METHODS

The immune response elicited upon transplantation of a syngeneic versus allogeneic vascularized groin flap was compared at Post-operative days 2 or 5 by histology, immunohistochemistry and by broad-scope gene and protein analyses using quantitative real-time PCR and Multiplex respectively.

RESULTS

Immune cell infiltration began at the donor-recipient interface and paralleled expression of a large group of wound healing-associated genes in both allografts and syngrafts. By day 5 post-transplantation, cell infiltration spread over the entire allograft but remained confined to the wound site in the syngraft. This shift correlated with upregulation of IL-18, INFg, CXCL9, 10 and 11, CCL2, CCL5, CX3CL1 and IL-10 in the allograft only, suggesting their role in the induction of the anti-alloantigen adaptive immune response.

CONCLUSIONS

High resemblance between the cues governing VCA and solid organ rejection was observed. Despite this high resemblance we describe also, for the first time, a damage induced inflammatory component in VCA rejection as immune cell infiltration into the graft initiated at the surgical damage site spreading to the entire allograft only at late stage rejection. We speculate that the highly inflammatory setting created by the unique surgical damage during VCA may enhance acute allograft rejection.

Long-term Tolerance Toward Haploidentical Vascularized Composite Allograft Transplantation in a Canine Model Using Bone Marrow or Mobilized Stem Cells

BACKGROUND

The development of safe and reliable protocols for the transplantation of the face and hands may be accomplished with animal modeling of transplantation of vascularized composite allografts (VCA). Previously, we demonstrated that tolerance to a VCA could be achieved after canine recipients were simultaneously given marrow from a dog leukocyte antigen-identical donor. In the present study, we extend those findings across a dog leukocyte antigen mismatched barrier.

METHODS

Eight recipient dogs received total body irradiation (4.5 cGy), hematopoietic cell transplantation (HCT), either marrow (n = 4) or granulocyte-colony stimulating factor mobilized peripheral blood stem cells (n = 4), and a VCA transplant from the HCT donor. Post grafting immunosuppression consisted of mycophenolate mofetil (28 days) and cyclosporine (35 days).

RESULTS

In 4 dogs receiving bone marrow, 1 accepted both its marrow transplant and demonstrated long-term tolerance to the donor VCA (>52 weeks). Three dogs rejected both their marrow transplants and VCA at 5 to 7 weeks posttransplant. Dogs receiving mobilized stem cells all accepted their stem cell transplant and became tolerant to the VCA. However, 3 dogs developed graft-versus-host disease, whereas 1 dog rejected its stem cell graft by week 15 but exhibited long-term tolerance toward its VCA (>90 weeks).

CONCLUSIONS

The data suggest that simultaneous transplantation of mobilized stem cells and a VCA is feasible and leads to tolerance toward the VCA in a haploidentical setting. However, there is a higher rate of donor stem cell engraftment compared with marrow HCT and an increase in the incidence of graft-versus-host disease.

The neurology of solid organ transplantation

Transplantation is the rescue treatment for end-stage organ failure with more than 110,000 solid organs transplantations performed worldwide annually. Recent advances in transplantation procedures and posttransplantation management have improved long-term survival and quality of life of transplant recipients, shifting the focus from acute perioperative critical care needs toward long-term chronic medical problems. Neurologic complications affect up to 30-60 % of solid organ transplant recipients. Common etiologies include opportunistic infections and toxicities of antirejection medications, and wide spectrum of toxic and metabolic disturbances. Most complications are common to all allograft types, but some are relatively specific for individual allograft types (e.g., central pontine myelinolysis in liver transplant recipients). Close collaboration between neurologists and other transplant team members is essential for effective management. Early recognition of complications and accurate diagnosis leading to timely treatment is essential to reduce the morbidity and improve the overall transplant outcome.

Orthotopic Hind Limb Transplantation in the Mouse

In vivo animal model systems, and in particular mouse models, have evolved into powerful and versatile scientific tools indispensable to basic and translational research in the field of transplantation medicine. A vast array of reagents is available exclusively in this setting, including mono- and polyclonal antibodies for both diagnostic and interventional applications. In addition, a vast number of genotyped, inbred, transgenic, and knock out strains allow detailed investigation of the individual contributions of humoral and cellular components to the complex interplay of an immune response and make the mouse the gold standard for immunological research. Vascularized Composite Allotransplantation (VCA) delineates a novel field of transplantation using allografts to replace "like with like" in patients suffering traumatic or congenital tissue loss. This surgical methodological protocol shows the use of a non-suture cuff technique for super-microvascular anastomosis in an orthotopic mouse hind limb transplantation model. The model specifically allows for comparison between established paradigms in solid organ transplantation with a novel form of transplants consisting of various different tissue components. Uniquely, this model allows for the transplantation of a viable vascularized bone marrow compartment and niche that have the potential to exert a beneficial effect on the balance of immune acceptance and rejection. This technique provides a tool to investigate alloantigen recognition and allograft rejection and acceptance, as well as enables the pursuit of functional nerve regeneration studies to further advance this novel field of transplantation.

Emerging Implications for Extracellular Matrix-Based Technologies in Vascularized Composite Allotransplantation

Despite recent progress in vascularized composite allotransplantation (VCA), limitations including complex, high dose immunosuppression regimens, lifelong risk of toxicity from immunosuppressants, acute and most critically chronic graft rejection, and suboptimal nerve regeneration remain particularly challenging obstacles restricting clinical progress. When properly configured, customized, and implemented, biomaterials derived from the extracellular matrix (ECM) retain bioactive molecules and immunomodulatory properties that can promote stem cell migration, proliferation and differentiation, and constructive functional tissue remodeling. The present paper reviews the emerging implications of ECM-based technologies in VCA, including local immunomodulation, tissue repair, nerve regeneration, minimally invasive graft targeted drug delivery, stem cell transplantation, and other donor graft manipulation.

Preparing for a Face Transplant: Development of a Comprehensive Nursing Educational Program

To date, more than 30 face transplants have been performed worldwide. This innovative procedure has restored the functional and aesthetic aspects of the face in patients with cancer, congenital, and trauma-related deformities where the results of traditional reconstructive surgery have been deficient. The importance of nursing involvement in the care of these patients is undeniable; however, little has been published about how to properly prepare a nursing department to undertake such an important role. Although the care of patients undergoing face transplants has many similarities to the care of patients undergoing traditional head and neck flap procedures, patients undergoing face transplant provide unique challenges, including immunosuppression, allograft rejection, communication impairment, and psychosocial needs. Staff at New York University's Langone Medical Center have devised a specific plan of action to properly inform, educate, and prepare the nursing staff for this exciting endeavor.

Engineered composite tissue as a bioartificial limb graft

The loss of an extremity is a disastrous injury with tremendous impact on a patient's life. Current mechanical prostheses are technically highly sophisticated, but only partially replace physiologic function and aesthetic appearance. As a biologic alternative, approximately 70 patients have undergone allogeneic hand transplantation to date worldwide. While outcomes are favorable, risks and side effects of transplantation and long-term immunosuppression pose a significant ethical dilemma. An autologous, bio-artificial graft based on native extracellular matrix and patient derived cells could be produced on demand and would not require immunosuppression after transplantation. To create such a graft, we decellularized rat and primate forearms by detergent perfusion and yielded acellular scaffolds with preserved composite architecture. We then repopulated muscle and vasculature with cells of appropriate phenotypes, and matured the composite tissue in a perfusion bioreactor under electrical stimulation in vitro. After confirmation of composite tissue formation, we transplanted the resulting bio-composite grafts to confirm perfusion in vivo.