Hand Transplantation in Its Fourteenth Year: The Innsbruck Experience

Cellular activation pathways and interaction networks in vascularized composite allotransplantation

Vascularized composite allotransplantation (VCA) is an evolving field of reconstructive surgery that has revolutionized the treatment of patients with devastating injuries, including those with limb losses or facial disfigurement. The transplanted units are typically comprised of different tissue types, including skin, mucosa, blood and lymphatic vasculature, muscle, and bone. It is widely accepted that the antigenicity of some VCA components, such as skin, is particularly potent in eliciting a strong recipient rejection response following transplantation. The fine line between tolerance and rejection of the graft is orchestrated by different cell types, including both donor and recipient-derived lymphocytes, macrophages, and other immune and donor-derived tissue cells (e.g., endothelium). Here, we delineate the role of different cell and tissue types during VCA rejection. Rejection of VCA grafts and the necessity of life-long multidrug immunosuppression remains one of the major challenges in this field. This review sheds light on recent developments in decoding the cellular signature of graft rejection in VCA and how these may, ultimately, influence the clinical management of VCA patients by way of novel therapies that target specific cellular processes.

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.

Long-term outcome after hand and forearm transplantation - a retrospective study

Between 2000 and 2014, five patients received bilateral hand (n = 3), bilateral forearm (n = 1), and unilateral hand (n = 1) transplants at the Innsbruck Medical University Hospital. We provide a comprehensive report of the long-term results at 20 years. During the 6-20 years follow-up, 43 rejection episodes were recorded in total. Of these, 27.9% were antibody-related with serum donor-specific alloantibodies (DSA) and skin-infiltrating B-cells. The cell phenotype in rejecting skin biopsies changed and C4d-staining increased with time post-transplantation. In the long-term, a change in hand appearance was observed. The functional outcome was highly depending on the level of amputation. The number and severity of rejections did not correlate with hand function, but negatively impacted on the patients´ well-being and quality of life. Patient satisfaction significantly correlated with upper limb function. One hand allograft eventually developed severe allograft vasculopathy and was amputated at 7 years. The patient later died due to progressive gastric cancer. The other four patients are currently rejection-free with moderate levels of immunosuppression. Hand transplantation remains a therapeutic option for carefully selected patients. A stable immunologic situation with optimized and individually adopted immunosuppression favors good compliance and patient satisfaction and may prevent development of DSA.

Bilateral Proximal Forearm Transplantation: Case Report at 7 Years

BACKGROUND

Although return of function has been reported in patients undergoing proximal forearm transplantations (PFTs), reports of long-term function are limited. In this study, we evaluated the clinical progress and function 7 years postoperatively in a patient who underwent bilateral PFT.

CASE PRESENTATION

A 58-year-old man underwent bilateral PFT in May 2012. Transplantation involved all of the flexor and extensor muscles of the forearm. Neurorrhaphies of the median, ulnar, and radial nerves were epineural and 7 cm proximal to the elbow. Immunosuppressive maintenance medications during the first 3 years postoperatively were tacrolimus, mycophenolate, and steroids, and later, tacrolimus, sirolimus, and steroids. Forearm function was evaluated annually using the Disabilities of the Arm, Shoulder, and Hand; Carroll; Hand Transplantation Score System; Short Form-36; and Kapandji scales. We also evaluated his grip and pinch force.

RESULTS

Postoperatively, the patient developed hypertriglyceridemia and systemic hypertension. He experienced 6 acute rejections, and none were resistant to steroids. Motor function findings in his right/left hand were: grip strength: 10/13 kg; key pinch: 3/3 kg; Kapandji score: 6/9 of 10; Carroll score: 66/80; Hand Transplantation Score System score: 90/94. His preoperative Disabilities of the Arm, Shoulder, and Hand score was 50 versus 18, postoperatively; his Short Form-36 score was 90. This function improved in relation with the function reported in the second year.

CONCLUSIONS

Seven years following PFT, the patient gained limb strength with a functional elbow and wrist, although with diminished digital dexterity and sensation. Based on data presented by other programs and our own experience, PFT is indicated for select patients.

Transplants for non-lethal conditions: a case against hand transplantation in minors

Human allografts for life-threatening organ failure have been demonstrated to be lifesaving and are now considered to be standard of care for many conditions. Transplantation of non-vital anatomic body parts has also been accomplished. Hand transplantation after limb loss in adults has been shown to offer some promising benefits in both functional and psychological measures in preliminary studies. It has been suggested to expand eligibility criteria to include minors, with one such operation having already been performed. With this in mind, we examine the current state of hand transplantation research in the context of available alternatives. We examine the ethics of carrying out these operations in minors, including under the protections of clinical research. We argue that children should not be considered for this surgery due to the substantial risks of immunosuppressive medication, the likelihood that the graft will need to be replaced during the patient's lifetime and the lack of significant compensatory advantages over modern prosthetics.

Mycophenolic Acid for Topical Immunosuppression in Vascularized Composite Allotransplantation: Optimizing Formulation and Preliminary Evaluation of Bioavailability and Pharmacokinetics

Mycophenolic acid (MPA), is the active form of the ester prodrug mycophenolate mofetil (MMF). MMF is an FDA approved immunosuppressive drug that has been successfully used in systemic therapy in combination with other agents for the prevention of acute rejection (AR) following solid organ transplantation (SOT) as well as in vascularized composite allotransplantation (VCA). Systemic use of MMF is associated with gastrointestinal adverse effects. Topical delivery of the prodrug could thus provide graft-targeted immunosuppression while minimizing systemic drug exposure. Our goal was to develop a topical formulation of MPA with optimal in vitro/in vivo characteristics such as release, permeation, and tissue bioavailability to enable safety and efficacy evaluation in clinical VCA.

Permeation studies were performed with a solution of MPA (10 mg/ml). In vitro release and permeation studies were performed for different semisolid formulations (Aladerm, Lipoderm, emollient, and VersaBase) of MPA (1% w/w) using a Franz Diffusion Cell System (FDCS). In vivo pharmacokinetic characterization of MPA release from Lipoderm was performed in rats.

MPA in solution exhibited a steady state flux (3.8 ± 0.1 µg/cm²/h) and permeability (1.1 × 10⁻⁷ ± 3.2 × 10⁻⁹ cm/s). MPA in Lipoderm exhibited a steady state flux of 1.12 ± 0.24 µg/cm²/h, and permeability of 6.2 × 10⁻⁰⁹ ± 1.3 × 10⁻⁹ cm/s across the biomimetic membrane. The cumulative release of MPA from Lipoderm, showed a linear single-phase profile with a R² of 0.969. In vivo studies with MPA in Lipoderm showed markedly higher local tissue MPA levels and lower systemic MPA exposure as compared to values obtained after intravenous delivery of the same dose of drug (p < 0.05).

We successfully developed for the first time, a topical formulation of MPA in Lipoderm with optimal in vitro/in vivo permeability characteristics and no undesirable local or systemic adverse effects in vivo. Our study provides key preliminary groundwork for translational efficacy studies of topical MPA in pre-clinical large animal VCA models and for effectiveness evaluation in patients receiving VCA.

Functional and Psychosocial Outcomes of Hand Transplantation Compared with Prosthetic Fitting in Below-Elbow Amputees: A Multicenter Cohort Study

Background

Hand-transplantation and improvements in the field of prostheses opened new frontiers in restoring hand function in below-elbow amputees. Both concepts aim at restoring reliable hand function, however, the indications, advantages and limitations for each treatment must be carefully considered depending on level and extent of amputation. Here we report our findings of a multi-center cohort study comparing hand function and quality-of-life of people with transplanted versus prosthetic hands.

Methods

Hand function in amputees with either transplant or prostheses was tested with Action Research Arm Test (ARAT), Southampton Hand Assessment Procedure (SHAP) and the Disabilities of the Arm, Shoulder and Hand measure (DASH). Quality-of-life was compared with the Short-Form 36 (SF-36).

Results

Transplanted patients (n = 5) achieved a mean ARAT score of 40.86 ± 8.07 and an average SHAP score of 75.00 ± 11.06. Prosthetic patients (n = 7) achieved a mean ARAT score of 39.00 ± 3.61 and an average SHAP score of 75.43 ± 10.81. There was no significant difference between transplanted and prosthetic hands in ARAT, SHAP or DASH. While quality-of-life metrics were equivocal for four scales of the SF-36, transplanted patients reported significantly higher scores in “role-physical” (p = 0.006), “vitality” (p = 0.008), “role-emotional” (p = 0.035) and “mental-health” (p = 0.003).

Conclusions

The indications for hand transplantation or prosthetic fitting in below-elbow amputees require careful consideration. As functional outcomes were not significantly different between groups, patient’s best interests and the route of least harm should guide treatment. Due to the immunosuppressive side-effects, the indication for allotransplantation must still be restrictive, the best being bilateral amputees.

Vascularized Composite Allotransplantation: Medical Complications

The objective of this review is to summarize the collective knowledge regarding the risks and complications in vascularized composite tissue allotransplantation (VCA), focusing on upper extremity and facial transplantation. The field of VCA has entered its second decade with an increasing experience in both the impressive good outcomes, as well as defining challenges, risks, and experienced poor results. The limited and selective publishing of negative outcomes in this relatively new field makes it difficult to conclusively evaluate outcomes of graft and patient survival and morbidities. Therefore, published data, conference proceedings, and communications were summarized in an attempt to provide a current outline of complications. These data on the medical complications of VCA should allow for precautions to avoid poor outcomes, data to better provide informed consent to potential recipients, and result in improvements in graft and patient outcomes as VCA finds a place as a therapeutic option for selected patients.