25 research outputs found
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Amnion-Derived Multipotent Progenitor Cells Improve Achilles Tendon Repair in Rats
Objective: Tendon injuries produce considerable morbidity, long-lasting disability, and remain a considerable challenge for clinicians and patients. The objective of the study was to assess the effect of amnion-derived multipotent progenitor (AMP) cells and amnion-derived cell cytokine solution on Achilles tendon healing by using a rat model. Methods: Achilles tendons of Sprague-Dawley rats were exposed and transected. The distal and proximal ends were injected with either saline, amnion-derived cell cytokine solution, or AMP cells in a standardized fashion and then sutured by using a Kessler technique. Tendons from each group (n = 6-13) were collected at weeks 1, 2, and 4 postoperatively and assessed for material properties (ultimate tensile strength, Young modulus, yield strength, and breaking strength). Tendons were also evaluated histologically for cross-sectional area by using hematoxylin-eosin and trichrome stains. Results: Mechanical testing showed that the Young modulus was significantly higher in AMP cells–treated tendons at week 4 compared with both saline-treated and amnion-derived cell cytokine solution–treated tendons. Yield strength was significantly higher in the AMP cells–treated group compared with saline-treated controls at week 4. No significant differences were observed between the study groups at weeks 1 and 2. Discussion: Amnion-derived multipotent progenitor cells have a positive effect on healing tendons by improving mechanical strength and elastic modulus during the healing process. The presented findings suggest the clinical utility of AMP cells in facilitating the healing of ruptured tendons. Both the Young modulus and yield strengths of tendons increased significantly following treatment with AMP cells
Noninvasive Vascular Images for Face Transplant Surgical Planning
Objective: Face transplantation replaces substantial defects with anatomically identical donor tissues; preoperative vascular assessment relies on noninvasive imaging to separate and characterize the external carotid vessels and branches. The objective is to describe and illustrate vascular considerations for face transplantation candidates. Methods: Novel noninvasive imaging using computed tomography and magnetic resonance imaging over 3 spatial dimensions plus time was developed and tested in 4 face transplant candidates. Precontrast images assessed bones and underlying metal. Contrast media was used to delineate and separate arteries from veins. For computed tomography, acquisition over multiple time points enabled the computation of tissue perfusion metrics. Time-resolved magnetic resonance angiography was performed to separate arterial and venous phases. Results: The range of circulation times for the external carotid system was 6 to 14 seconds from arterial blush to loss of venous enhancement. Precontrast imaging provided a roadmap of bones and metal. Among the 4 patients, 3 had surgical clips, metal implants, or both within 1 cm of major vessels considered for surgery. Contrast-enhanced wide area detector computed tomographic data acquired in the axial mode separated these structures and provided arterial and venous images for planning the surgical anastomoses. Magnetic resonance imaging was able to distinguish between the large vessels from the external carotid systems. Conclusions: Vascular imaging maps are challenging in face transplantation because of the rapid circulation times and artifact from the initial injury, prior reconstructive attempts, or both. Nevertheless, face transplant candidates require high spatial and temporal resolution vascular imaging to determine those vessels appropriate for surgical anastomoses
Re-cognizing the new self: The neurocognitive plasticity of self-processing following facial transplantation.
The face is a defining feature of our individuality, crucial for our social interactions. But what happens when the face connected to the self is radically altered or replaced? We address the plasticity of self-face recognition in the context of facial transplantation. While the of a new face following facial transplantation is a medical fact, the of a new identity is an unexplored psychological outcome. We traced the changes in self-face recognition before and after facial transplantation to understand if and how the transplanted face gradually comes to be perceived and recognized as the recipient's own new face. Neurobehavioral evidence documents a strong representation of the pre-injury appearance pre-operatively, while following the transplantation, the recipient incorporates the new face into his self-identity. The acquisition of this new facial identity is supported by neural activity in medial frontal regions that are considered to integrate psychological and perceptual aspects of the self
Absence of Rejection in a Facial Allograft Recipient with a Positive Flow Crossmatch 24 Months after Induction with Rabbit Anti-Thymocyte Globulin and Anti-CD20 Monoclonal Antibody
Background. Donor-specific antibodies (DSA) to human leukocyte antigen increase the risk of accelerated rejection and allograft damage and reduce the likelihood of successful transplantation. Patients with full-thickness facial burns may benefit from facial allotransplantation. However, they are at a high risk of developing DSA due to standard features of their acute care. Case Presentation. A 41-year-old male with severe disfigurement from facial burns consented to facial allotransplantation in 2014; panel reactive antibody score was 0%. In August of 2015, a suitable donor was found. Complement-dependent cytotoxicity crossmatch was negative; flow cytometry crossmatch was positive to donor B cells. An induction immunosuppression strategy consisting of rabbit antithymocyte globulin, rituximab, tacrolimus, mycophenolate mofetil (MMF), and methylprednisolone taper was designed. Total face, scalp, eyelid, ears, and skeletal subunit allotransplantation was performed without operative, immunological, or infectious complications. Maintenance immunosuppression consists of tacrolimus, MMF, and prednisone. As of posttransplant month 24, the patient has not developed acute rejection or metabolic or infectious complications. Conclusions. To our knowledge, this is the first report of targeted B cell agents used for induction immunosuppression in skin-containing vascularized composite tissue allotransplantation. A cautious approach is warranted, but early results are promising for reconstructive transplant candidates given the exceptionally high rate of acute rejection episodes, particularly in the first year, in this patient population
Absence of Rejection in a Facial Allograft Recipient with a Positive Flow Crossmatch 24 Months after Induction with Rabbit Anti-Thymocyte Globulin and Anti-CD20 Monoclonal Antibody
Background. Donor-specific antibodies (DSA) to human leukocyte antigen increase the risk of accelerated rejection and allograft damage and reduce the likelihood of successful transplantation. Patients with full-thickness facial burns may benefit from facial allotransplantation. However, they are at a high risk of developing DSA due to standard features of their acute care. Case Presentation. A 41-year-old male with severe disfigurement from facial burns consented to facial allotransplantation in 2014; panel reactive antibody score was 0%. In August of 2015, a suitable donor was found. Complement-dependent cytotoxicity crossmatch was negative; flow cytometry crossmatch was positive to donor B cells. An induction immunosuppression strategy consisting of rabbit antithymocyte globulin, rituximab, tacrolimus, mycophenolate mofetil (MMF), and methylprednisolone taper was designed. Total face, scalp, eyelid, ears, and skeletal subunit allotransplantation was performed without operative, immunological, or infectious complications. Maintenance immunosuppression consists of tacrolimus, MMF, and prednisone. As of posttransplant month 24, the patient has not developed acute rejection or metabolic or infectious complications. Conclusions. To our knowledge, this is the first report of targeted B cell agents used for induction immunosuppression in skin-containing vascularized composite tissue allotransplantation. A cautious approach is warranted, but early results are promising for reconstructive transplant candidates given the exceptionally high rate of acute rejection episodes, particularly in the first year, in this patient population
Ocular Considerations in Face Transplantation: Report of 2 Cases and Review of the Literature
Purpose: Periorbital injuries are common in face transplantation (FT) candidates. It is therefore essential that the ophthalmologist play a central role in the multidisciplinary treatment of these patients. In this study, the authors perform a comprehensive review of all procedures involving periorbital components, provide an update for the ophthalmology community regarding the current state of the field, and present 2 cases.
Methods: A comprehensive review of the literature for all FT procedures including periorbital components was performed. The authors also present 2 patients who received FT including periorbital components for extensive facial disfigurement. One patient sustained high-energy avulsive ballistic injury and underwent a total face, double jaw, and tongue transplant in 2012. The second patient received a total face, eyelids, ears, and skeletal subunits transplant for extensive facial burns in 2015.
Results: Literature review demonstrated that 22 (54%) of the 41 patients undergoing FT received allografts containing periorbital components. Only 14 cases (64%) reported on the presence of ocular and periocular complications. The most common complications consisted of lower eyelid ectropion and lagophthalmos, and nearly all required revisional procedures. Both patients presented with significant periorbital scarring and demonstrated good visual acuity and aesthetic outcomes at postoperative follow up between 6 and 28 months.
Conclusions: Face transplantation can address extensive facial and periorbital disfigurement with satisfactory functional and aesthetic outcomes. The majority of FT performed to date have included periorbital components, and postoperative ocular and periocular complications are common. It is critical for ophthalmologists to play a central role in the care of these patients