Face, Upper Extremity, and Concomitant Transplantation: Potential Concerns and Challenges Ahead:

Sex and Gender Differences in Face and Upper Extremity Allotransplantation: A Narrative Review of Implications and Impact

Sex and gender differences play a significant role in vascularized composite allotransplantation (VCA), impacting both surgical outcomes and postoperative care. While sex refers to biological distinctions and gender encompasses life experiences and behaviors, both factors are closely interrelated in transplantation. Biological sex differences, such as immune responses, hormonal fluctuations, and anatomical features influence graft adaptation and healing, while both sex and gender-specific factors affect psychological and functional recovery. Studies indicate that men have higher mortality and reoperation rates, whereas women are more susceptible to adverse effects from immunosuppressive therapies. Unlike solid organ transplantation (SOT), which is primarily lifesaving, VCA focuses on life-enhancing outcomes, requiring careful attention to patients' social, psychological, and functional well-being. Lifelong immunosuppression in VCA carries risks, including infections and cancer, complicating patient management. Psychological readiness is crucial for candidate selection and long-term success, with women often expressing greater concerns about outcomes. Although no significant gender differences in functional recovery have been observed, individualized rehabilitation plans based on anatomical and physiological differences remain essential for optimal recovery.

Delta waves as a sign of cortical plasticity after full-face transplantation

This study focused on detecting the reflections of healing and change in cortex activation in full-face transplantation and lesions patients on EEG activity. Face transplant patients have facial lesions before transplantation and, to identify pre-face transplant patients' brain activity in the absence of pre-transplant recordings, we used data obtained from pre-transplant facial lesion patients. Ten healthy, four facial lesion and three full-face transplant patients participated in this study. EEG data recorded for four different sensory stimuli (brush from the right face, right hand, left face, and left-hand regions) were analyzed using wavelet packet transform method. EEG waves were analyzed for standard bands. Our findings indicate significant change in the 2-4 Hz frequency range which may be a result of ongoing or previous cortical reorganization for face lesion and transplant patients. Alterations of the delta wave seen in patients with facial lesion and face transplant can also be explained by the intense central plasticity. Our findings show that the delta band differences might be used as a marker in the evaluation of post-transplant cortical plasticity in the future.

Immunologic Outcomes in Cross-Sex Solid Organ Transplants: A Systematic Review and Meta-Analysis to Inform Vascularized Composite Allotransplantation

BACKGROUND

Of nearly 90 hand and 50 face transplant recipients, only five have received a cross-sex vascularized composite allotransplantation (CS-VCA). CS-VCA has the potential to expand the donor pool and has been proven anatomically feasible and ethically acceptable in previous studies. However, there is a lack of immunologic data. This study evaluated the immunologic feasibility of CS-VCA through analysis of the solid organ transplant literature, given the paucity of CS-VCA data. The authors hypothesize that rates of acute rejection (AR) and graft survival (GS) in CS versus same-sex (SS) solid organ transplantation are similar.

METHODS

A systematic review and meta-analysis were performed. Studies comparing GS or AR episodes in CS and SS adult kidney (KT) and liver transplant (LT) populations were included. Odds ratios were calculated for overall GS and AR for all SS and CS transplant combinations [male-to-female (MTF), female-to-male, and overall].

RESULTS

A total of 693 articles were initially identified with 25 included in the meta-analysis. No significant difference in GS was noted between SS-KT versus CS-KT [OR, 1.04 (95% CI, 1.00 to 1.07); P = 0.07), SS-KT versus MTF-KT [OR, 0.97 (95% CI, 0.90 to 1.04); P = 0.41), and SS-LT versus MTF-LT [OR, 0.95 (95% CI, 0.91 to 1.00); P = 0.05). No significant difference in AR was noted between SS-KT versus MTF-KT [OR, 0.99 (95% CI, 0.96 to 1.02); P = 0.57), SS-LT versus CS-LT [OR, 0.78 (95% CI, 0.53 to 1.16); P = 0.22], or SS-LT versus female-to-male LT [OR, 1.03 (95% CI, 0.95 to 1.12); P = 0.47]. For the remaining pairings, GS was significantly increased and AR was significantly decreased in the SS transplants.

CONCLUSIONS

Published data suggest immunologic feasibility of CS-KT and CS-LT with the potential for generalization to the VCA population.

CLINICAL RELEVANCE STATEMENT

In theory, CS-VCA could expand the potential donor pool, ultimately leading to decreased wait times for recipients and improve the likelihood of establishing a immunologically favorable donor-recipient match.

Composite tissue xenopreservation: Preliminary results of staged VCA in rat to mouse model

BACKGROUND

The time between procurement and transplantation of composite tissues, especially regarding the limited donor pool, is a challenge effecting the outcomes of the transplantation. Current preservation techniques mainly include either cold preservation with a solution or machine perfusion using blood or certain oxygen-carrying solutions. However, none enables preservation beyond 24 h. Increasing this time to several days will provide better usage of the donor pool, safer transplantation of VCA with significant muscle content, and gives time to stabilize a patient before long surgical procedures. Herein, we described a novel strategy of xenopreservation (preservation via xenotransplantation) to preserve composite tissues for 7 days, followed by staged transplantation.

MATERIALS AND METHODS

We used two concordant species, female Sprague Dawley rats (n = 10) and female CF-1 mice (n = 10) in this study. Four of pair of animals are used for anatomical study. The groin flap of the rat was used as a xenograft and xenotransplanted to the neck area of the carrier mouse. Cyclosporine (CsA) was administered used as immunosuppressant. After 7 days of preservation on the mouse neck, xenotransplanted groin flap (called xenopreserved flap) was re-harvested, skin and vessels samples were collected for histopathological evaluation, and the xenopreserved flap was transplanted to the donor rat's opposite groin area. Anastomoses were performed between the flap's pedicle and the femoral vessels. Clinical observation regarding inflammation and tissue perfusion of the xenopreserved flap was monitored daily. Fifteen days after the second surgical procedure, the rats were euthanized, and skin and vessel samples were collected. Histologic evaluation, including inflammatory cell numbers, was performed. Wilcoxon test was used to compare the changes in inflammation severity and p < .05 was set for statistical significance.

RESULTS

All xenopreserved groin flaps except one survived. Mean lymphocyte count before the second operation (at the end of the xenopreservation procedure) was 20,22 ± 0.44 and reduced to 13,14 ± 0.47 at the end of 15 days, and the difference was statistically significant (p < .05).

CONCLUSION

This proof-of-concept study with preliminary results showed that xenotransplantation might be a novel strategy for preservation of VCA for a certain period of time. However, additional translational studies are needed to modulate the tissue changes following xenopreservation.

The First Successful Combined Full Face and Bilateral Hand Transplant

BACKGROUND

Vascularized composite allotransplantation has redefined the frontiers of plastic and reconstructive surgery. At the cutting edge of this evolving paradigm, the authors present the first successful combined full face and bilateral hand transplant.

METHODS

A 21-year-old man presented for evaluation with sequelae of an 80 percent total body surface area burn injury sustained after a motor vehicle accident. The injury included full face and bilateral upper extremity composite tissue defects, resulting in reduced quality of life and loss of independence. Multidisciplinary evaluation confirmed eligibility for combined face and bilateral hand transplantation. The operative approach was validated through 11 cadaveric rehearsals utilizing computerized surgical planning. Institutional review board and organ procurement organization approvals were obtained. The recipient, his caregiver, and the donor family consented to the procedure.

RESULTS

Combined full face (i.e., eyelids, ears, nose, lips, and skeletal subunits) and bilateral hand transplantation (i.e., forearm level) was performed over 23 hours on August 12 to 13, 2020. Triple induction and maintenance immunosuppressive therapy and infection prophylaxis were administered. Plasmapheresis was necessary postoperatively. Minor revisions were performed over seven subsequent operations, including five left upper extremity, seven right upper extremity, and seven facial secondary procedures. At 8 months, the patient was approaching functional independence and remained free of acute rejection. He had significantly improved range of motion, motor power, and sensation of the face and hand allografts.

CONCLUSIONS

Combined face and bilateral hand transplantation is feasible. This was the most comprehensive vascularized composite allotransplantation procedure successfully performed to date, marking a new milestone in plastic and reconstructive surgery for patients with otherwise irremediable injuries.

Two Decades of Hand Transplantation: A Systematic Review of Outcomes

ABSTRACT

Hand transplantation for upper extremity amputation provides a unique treatment that restores form and function, which may not be achieved by traditional reconstruction and prosthetics. However, despite enhancing quality of life, hand transplantation remains controversial, because of immunological complications, transplant rejection, and medication effects. This systematic literature review sought to collect information on current experiences and outcomes of hand transplants to determine the efficacy and utility of hand transplants. The databases PubMed, Scopus, and Embase were analyzed with combinations of "hand" or "upper extremity" or "arm" and "transplant" or "allograft," with information collected on recipient characteristics, details of transplant, immunological outcomes, functional outcomes, and complications. Functional outcomes, as measured by Disabilities of Arm, Shoulder and Hand score, were compared between patient groups using Wilcoxon signed-rank test or 1-way analysis of variance test and post hoc Tukey test. Within the 108 articles that fulfilled inclusion and exclusion criteria, there were 96 patients with 148 hand transplants. There were 57 patients who experienced acute rejection and 5 patients with chronic rejection. Disabilities of the Arm, Shoulder and Hand scores significantly decreased after hand transplantation and were significantly lower for distal transplants compared with proximal transplants. There were 3 patients with concurrent face transplantation and 2 patients with simultaneous leg transplants. Sixteen patients experienced amputation of the hand transplant, and there were 5 deaths. This study found that hand transplantation provides significant restoration of function and form, especially for proximal transplants. Reduction in complications, such as rejection and amputation, can be achieved by decreasing medication cost and patient education.

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.

Characterization of Face Transplant Candidates Evaluated at Cleveland Clinic and Algorithm to Maximize Efficacy of Screening Process

INTRODUCTION

As a high-volume referral center for facial transplantation, we have learned significantly from the screening, evaluation, and enrollment process. This report analyzes our algorithm for the assessment of potential face transplant candidates referred to our institution.

METHODS

After institutional review board approval in 2004, a prospectively maintained database was created for patients who were referred face transplant. Records were reviewed for the nature of tissue defect, functional deficit, surgical and medical history, and expert recommendations.Our algorithm begins with a review of a patient's file with a focus on institutional review board criteria. After screening, a phone interview is conducted, and transplantation is discussed. Patients are presented to the team to analyze the medical, psychiatric, and surgical history; support network; and geographic location. Eligible patients are invited for an in-person evaluation, and the case is reviewed again with the team. If approved, the patient can provide consent for transplantation.

RESULTS

More than 200 patients were referred for transplant evaluation at the Cleveland Clinic from 2004 to 2016. Sixty were eligible for further evaluation for face transplantation based on preliminary screening. Thirteen (6.5% of original cohort) were invited for in-person evaluation and physical examination. Five (2.5% of original cohort, 38.4% invited cohort) of these 13 patients underwent face transplantation, of whom, 3 (1.5% of original cohort, 23.1% invited cohort) underwent face transplantation at our institution. All 3 patients who were ultimately transplanted were referred by a physician.

DISCUSSION

As the availability of public information on face transplant increases, it is likely that an increase in self-referral for face transplantation will occur. Thus, it is critical that institutions adopt a systematic approach to triage in order to identify appropriate patients. Our algorithm allowed for a high enrollment and transplantation ratio to save patient and institution time and resources. This could be easily adopted by other institutions to save time, money, and resources.

Facial Transplantation

Facial transplantation represents a unique surgical solution for challenging facial injury patterns in which conservative reconstructive techniques fail to provide a satisfactory functional and aesthetic result. With advances in the field of vascularized composite allotransplantation over the past 15 years, more than 40 of these procedures have been performed worldwide with two recent reports of facial re-transplantation. In this article we discuss the multidisciplinary approach that is required for successful transplantation as well as the surgical techniques used and postoperative management. With ongoing research, recent technological innovation, and increased efforts to promote greater generalizability and transparency in this field, patients with these complex injuries will continue to see improvements in their treatment options, and thus quality of life.

Equity in access to facial transplantation

We examine ethical considerations in access to facial transplantation (FT), with implications for promoting health equity. As a form of vascularised composite allotransplantation, FT is still considered innovative with a relatively low volume of procedures performed to date by a small number of active FT programmes worldwide. However, as numbers continue to increase and institutions look to establish new FT programmes, we anticipate that attention will shift from feasibility towards ensuring the benefits of FT are equitably available to those in need. This manuscript assesses barriers to care and their ethical implications across a number of considerations, with the intent of mapping various factors relating to health equity and fair access to FT. Evidence is drawn from an evolving clinical experience as well as published scholarship addressing several dimensions of access to FT. We also explore novel concerns that have yet to be mentioned in the literature.

Anesthetic Considerations in Facial Transplantation: Experience at NYU Langone Health and Systematic Review

Anesthetic considerations are integral to the success of facial transplantation (FT), yet limited evidence exists to guide quality improvement. This study presents an institutional anesthesia protocol, defines reported anesthetic considerations, and provides a comprehensive update to inform future directions of the field.

Nonhuman Primates: A Vital Model for Basic and Applied Research on Female Reproduction, Prenatal Development, and Women's Health

The comparative biology of reproduction and development in mammalian species is remarkable. Hence, because of similarities in environmental and neuroendocrine control of the reproductive axis, the cyclic function of the ovary and reproductive tract, establishment and control of the maternal-fetal-placental unit during pregnancy, and reproductive aging from puberty through menopause, nonhuman primates (NHPs) are valuable models for research related to women's reproductive health and its disorders. This chapter provides examples of research over the past 10+ years using Old World monkeys (notably macaque species), baboons, and to a lesser extent New World monkeys (especially marmosets) that contributed to our understanding of the etiology and therapies or prevention of: (1) ovarian disorders, e.g., polycystic ovary syndrome, mitochondrial DNA-based diseases from the oocyte; (2) uterine disorders, for example, endometriosis and uterine transplantation; and (3) pregnancy disorders, for example, preterm labor and delivery, environmental factors. Also, emerging opportunities such as viral (e.g., Zika) induced fetal defects and germline genomic editing to generate valuable primate models of human diseases (e.g., Huntington and muscular dystrophy) are addressed. Although the high costs, specialized resources, and ethical debate challenge the use of primates in biomedical research, their inclusion in fertility and infertility research is vital for continued improvements in women's reproductive health.

The miracle of face transplantation after 10 years

INTRODUCTION

At the 10th year anniversary of the first face transplantation, there are currently 36 patients worldwide, who are the recipients of faces coming from human donors.

AREAS OF AGREEMENT

Despite the initial debates and ethical concerns, face transplantation became a clinical reality with satisfactory functional outcomes.

AREAS OF CONTROVERSY

The areas of controversy still include the impact of lifelong immunosuppression on otherwise healthy patients as well as the selection process of face transplant candidates.

GROWING POINTS

Other concerns include financial support for this new generation of transplants as well as social reintegration and patients return to work after face transplantation.

AREAS TIMELY FOR DEVELOPING RESEARCH

Based on over 20 years of research experience in the field of vascularized composite allotransplantation, and clinical experience as a leading surgeon of the US first face transplantation, this review will summarize the well-known facts as well as unexpected outcomes and challenges of face transplantation.

Lessons learned from the first quadruple extremity transplantation in the world

BACKGROUND

Limb transplantation is emerging as a promising area of surgery and is an indispensable alternative for prosthetic rehabilitation of amputees, the severity of which is increasing because of combat-related injuries. Successful unilateral and bilateral limb transplantations have already been performed before this operation.

METHODS

We performed the first ever quadruple limb transplantation in February 2012. The limbs procured from a 40-year-old man heart-beating donor were transplanted to a 27-year-old male patient who was a quadruple amputee for the last 14 years because of an electrical injury.

RESULTS

To shorten the ischemic period to a minimum, 3 separate microsurgery teams worked simultaneously. All extremities were reperfused within 8 hours of procurement, and the operation lasted for 12 hours. Metabolic load was managed by hemodialysis. One hour after the completion of the operation, cardiac arrest developed, resuscitation of which necessitated median sternotomy and temporary partial cardiopulmonary support. Despite the removal of the transplanted limbs and all efforts including continuous hemodialysis, plasmapheresis, and extracorporeal membrane oxygenation, the patient died on the fourth day after transplantation in a clinical condition of severe systemic inflammation.

CONCLUSIONS

The problems we faced were difficulty of vascular access for invasive monitoring and fluid replacement, and the severe systemic inflammation effects of which could not be dealt with, despite aggressive supportive treatment. We hope that our experience will enlighten the surgeons who are willing to extend the limits of limb transplantation and serve the success of future operations.

The Macrophage-depleting Agent Clodronate Promotes Durable Hematopoietic Chimerism and Donor-specific Skin Allograft Tolerance in Mice

Hematopoietic chimerism is known to promote donor-specific organ allograft tolerance; however, clinical translation has been impeded by the requirement for toxic immunosuppression and large doses of donor bone marrow (BM) cells. Here, we investigated in mice whether durable chimerism might be enhanced by pre-treatment of the recipient with liposomal clodronate, a macrophage depleting agent, with the goal of vacating BM niches for preferential reoccupation by donor hematopoietic stem cells (HSC). We found that liposomal clodronate pretreatment of C57BL/6 mice permitted establishment of durable hematopoietic chimerism when the mice were given a low dose of donor BM cells and transient immunosuppression. Moreover, clodronate pre-treatment increased durable donor-specific BALB/c skin allograft tolerance. These results provide proof-of-principle that clodronate is effective at sparing the number of donor BM cells required to achieve durable hematopoietic chimerism and donor-specific skin allograft tolerance and justify further development of a tolerance protocol based on this principle.

A novel rat full-thickness hemi-abdominal wall/hindlimb osteomyocutaneous combined flap: influence of allograft mass and vascularized bone marrow content on vascularized composite allograft survival

Vascularized bone marrow transplantation (VBMT) appears to promote tolerance for vascularized composite allotransplantation (VCA). However, it is unclear whether VBMT is critical for tolerance induction and, if so, whether there is a finite amount of VCA that VBMT can support. We investigated this with a novel VCA combined flap model incorporating full-thickness hemiabdominal wall and hindlimb osteomyocutaneous (HAW/HLOMC) flaps. Effects of allograft mass (AM) and VBMT on VCA outcome were studied by comparing HAW/HLOMC VCAs with fully MHC-mismatched BN donors and Lewis recipients. Control groups did not receive treatments following transplantation. Treatment groups received a short course of cyclosporine A (CsA), antilymphocyte serum, and three doses of adipocyte-derived stem cells (POD 1, 8, and 15). The results showed that all flaps in control allogeneic groups rejected soon after VCAs. Treatment significantly prolonged allograft survival. Three of eight recipients in HLOMC treatment group had allografts survive long-term and developed donor-specific tolerance. Significantly higher peripheral chimerism was observed in HLOMC than other groups. It is concluded that the relative amount of AM to VBMT is a critical factor influencing long-term allograft survival. Accordingly, VBMT content compared with VCA mass may be an important consideration for VCA in humans.

Vascularized Composite Allografts: Procurement, Allocation, and Implementation

Vascularized composite allotransplantation is a continuously evolving area of modern transplant medicine. Recently, vascularized composite allografts (VCAs) have been formally classified as 'organs'. In this review, key aspects of VCA procurement are discussed, with a special focus on interaction with the procurement of classical solid organs. In addition, options for a matching and allocation system that ensures VCA donor organs are allocated to the best-suited recipients are looked at. Finally, the different steps needed to promote VCA transplantation in society in general and in the medical community in particular are highlighted.

Sustained delivery of VEGF maintains innervation and promotes reperfusion in ischemic skeletal muscles via NGF/GDNF signaling

Tissue reinnervation following trauma, disease, or transplantation often presents a significant challenge. Here, we show that the delivery of vascular endothelial growth factor (VEGF) from alginate hydrogels ameliorates loss of skeletal muscle innervation after ischemic injury by promoting both maintenance and regrowth of damaged axons in mice. Nerve growth factor (NGF) and glial-derived neurotrophic factor (GDNF) mediated VEGF-induced axonal regeneration, and the expression of both is induced by VEGF presentation. Using both in vitro and in vivo modeling approaches, we demonstrate that the activity of NGF and GDNF regulates VEGF-driven angiogenesis, controlling endothelial cell sprouting and blood vessel maturation. Altogether, these studies produce evidence of new mechanisms of VEGF action, further broaden the understanding of the roles of NGF and GDNF in angiogenesis and axonal regeneration, and suggest approaches to improve axonal and ischemic tissue repair therapies.

Would you be a face transplant donor? A survey of the Turkish population about face allotransplantation

With the technical advancement in face allotransplantation, we decided to survey the Turkish population to gain perspective into their thoughts and reactions toward face transplantation. A questionnaire was given to 1000 volunteers, regarding data about demographics, educational status, religious, and behavioral preferences. Their attitudes about donating their faces, knowledge about the pros and cons of this procedure, and personal desire for face transplantation if needed were inquired.The results of the survey demonstrated that knowing more about the procedure increases its acceptance but even so, the majority would rather undergo multiple operations with self-tissues before getting a facial transplantation (FT). When the risks of immunosuppression were exposed, less people agreed to FT, thinking it was not worth the risks.The cultural, ethnical, religious, and social background of different societies may influence the way FT is perceived and accepted. As this procedure is thought to challenge many ethical, physiological, and social points of views, we believe that it is important for a surgical team to have insight into their population's perception and general thoughts concerning the issue.

Composite tissue allotransplantation and dysregulation in tissue repair and regeneration: a role for mesenchymal stem cells

Vascularized composite tissue allotransplantation is a rapidly evolving area that has brought technological advances to the forefront of plastic surgery, hand surgery, and transplant biology. Composite tissue allografts (CTAs) may have profound functional, esthetic, and psychological benefits, but carry with them the risks of life-long immunosuppression and the inadequate abilities to monitor and prevent rejection. Allografts may suffer from additional insults further weakening their overall benefits. Changes in local blood flow, lack of fully restored neurologic function, infection, inflammation with subsequent dysregulated regenerative activity, and paucity of appropriate growth factors may all be involved in reducing the potential of CTAs and therefore serve as new therapeutic targets to improve outcomes. Strategies involving minimized immunosuppression and pro-regenerative therapy may provide a greater path to optimizing long-term CTA function. One such strategy may include mesenchymal stem cells (MSCs), which can provide unique anti-inflammatory and pro-regenerative effects. Insights gained from new studies with MSCs on composite allografts, advances in tissue regeneration reported in other MSC-based clinical studies, as well as consideration of newly described capacities of MSCs, may provide new regenerative based strategies for the care of CTAs.

Surgical angiogenesis with short-term immunosuppression maintains bone viability in rabbit allogenic knee joint transplantation

BACKGROUND

Vascularized composite allotransplantation has the potential for reconstruction of joint defects but requires lifelong immunosuppression, with substantial risks. This study evaluates an alternative, using surgical angiogenesis from implanted autogenous vessels to maintain viability without long-term immunotherapy.

METHODS

Vascularized knee joints were transplanted from Dutch Belted donors to New Zealand White rabbit recipients. Once positioned and revascularized microsurgically, a recipient-derived superficial inferior epigastric fascial flap and a saphenous arteriovenous bundle were placed within the transplanted femur and tibia, respectively, to develop a neoangiogenic, autogenous circulation. There were 10 transplants in group 1. Group 2 (n = 9) consisted of no-angiogenesis controls with ligated flaps and arteriovenous bundles. Group 3 rabbits (n = 10) were autotransplants with patent implants. Tacrolimus was used for 3 weeks to maintain nutrient flow during angiogenesis. At 16 weeks, the authors assessed bone healing, joint function, bone and cartilage mechanical properties, and histology.

RESULTS

Group 1 allotransplants had more robust angiogenesis, better healing, improved mechanical properties, and better osteocyte viability than ligated controls (group 2). All three groups developed knee joint contractures and arthritic changes. Cartilage thickness and quality were poorer in allograft groups than in autotransplant controls.

CONCLUSIONS

Surgical angiogenesis from implanted autogenous tissue improves bone viability, healing, and material properties in rabbit allogenic knee transplants. However, joint contractures and degenerative changes occurred in all transplants, regardless of antigenicity or blood supply. Experimental studies in a larger animal model with improved methods to maintain joint mobility are needed before the merit of living joint allotransplantation can be judged.

Anesthetic management in upper extremity transplantation: the Pittsburgh experience

BACKGROUND

Hand/forearm/arm transplants are vascularized composite allografts, which, unlike solid organs, are composed of multiple tissues including skin, muscle, tendons, vessels, nerves, lymph nodes, bone, and bone marrow. Over the past decade, 26 upper extremity transplantations were performed in the United States. The University of Pittsburgh Medical Center has the largest single center experience with 8 hand/forearm transplantations performed in 5 recipients between January 2008 and September 2010. Anesthetic management in the emerging field of upper extremity transplants must address protocol and procedure-specific considerations related to the role of regional blocks, effects of immunosuppressive drugs during transplant surgery, fluid and hemodynamic management in the microsurgical setting, and rigorous intraoperative monitoring during these often protracted procedures.

METHODS

For the first time, we outline salient aspects of upper extremity transplant anesthesia based on our experience with 5 patients. We highlight the importance of minimizing intraoperative vasopressors and improving fluid management and blood product use.

RESULTS

Our approach reduced the incidence of perioperative bleeding requiring re-exploration or hemostasis and shortened in-hospital and intensive care unit stay. Functional, immunologic and graft survival outcomes have been highly encouraging in all patients.

CONCLUSIONS

Further experience is required for validation or standardization of specific anesthetic protocols. Meanwhile, our recommendations are intended as pertinent guidelines for centers performing these novel procedures.

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.

Uterus transplantation: animal research and human possibilities

Uterus transplantation research has been conducted toward its introduction in the human as a treatment of absolute uterine-factor infertility, which is considered to be the last frontier to conquer for infertility research. In this review we describe the patient populations that may benefit from uterus transplantation. The animal research on uterus transplantation conducted during the past two decades is summarized, and we describe our views regarding a future research-based human attempt.

Craniomaxillofacial reconstruction using allotransplantation and tissue engineering: challenges, opportunities, and potential synergy

The face is composed of an intricate underlying bony/cartilaginous framework that supports muscle, secretory organs, and sophisticated skin/subcutaneous structures. These components are attached through numerous ligaments and interact dynamically with a vast neurovascular network. The most sophisticated autologous reconstructive techniques, utilizing composite free-tissue flaps, are often inadequate to restore extensive maxillofacial defects. Massive craniomaxillofacial (CMF) defects resulting from trauma, oncologic resection, or congenital deformity present a unique challenge to reconstructive surgeons. Therefore, recent advances in craniofacial surgery and immunotherapy spurred the innovation of composite tissue allotransplantation (CTA), which permits reconstruction with tissue composed of all necessary components. However, CMF allotransplantation carries with it side effects of lifelong immunosuppression. Furthermore, the donor skeletal framework may not provide an ideal match, resulting in less than ideal occlusion and soft-tissue anthropometrics. An alternative to transplantation, tissue engineering, has provided hope for regenerating missing tissue and avoiding the need for immunosuppression. Many tissue subtypes, including bone and cartilage, have been successfully created, with sparse reports of clinical application. Tissue-engineered composite tissue required for complete CMF reconstruction continues to elude development, with vascular supply and tissue interactions posing the largest remaining obstacles. We report herein the current status and limitations of CTA and tissue engineering. Furthermore, we describe for the first time our vision of hybridization of CTA and engineering, utilizing the strengths of each strategy.

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.

Logistics and strategy of multiorgan procurement involving total face allograft

The face is the latest body structure to be added to the field of transplantation and the learning curve is ongoing. In the scenario of multiorgan recovery, the face is a nonvital 'organ' structure compared with other life-saving organs. To date, the face has been the first 'organ' to be procured in a multiorgan procurement. A technique for simultaneous recovery of the whole face, heart, lungs, liver, pancreas and kidneys is described. Thirty professionals participated in the procedure, of whom 13 were surgeons. No tracheotomy was performed. A mask of the donor's face was made from a mold impression. Duration of the procedure from skin incision to the end of surgery was 7.3 h. The face was perfused with Wisconsin solution through a cannula inserted into the aortic arch between the origin of the brachiocephalic arterial trunk and the left subclavian artery. Blood requirements consisted of 4 units of packed red blood cells. After the procedure, the mask was placed on the donor's face. All recovered grafts functioned immediately. In summary, simultaneous multiorgan procurement including the whole face is feasible, effective and saves time without jeopardizing life-saving organs and without the need for tracheotomy.