Faculty Bibliography

: The first facial transplantation in 2005 ushered in a new era in reconstructive surgery, offering new possibilities for the repair of severe disfigurements previously limited by conventional techniques. Advances in allograft design, computerized preoperative planning, surgical technique, and postoperative revisions have helped push the boundaries in this new frontier of vascularized composite allotransplantation. Over the past 12 years, 40 of these procedures have been performed across the world, offering the field the opportunity to reflect on current outcomes. Successes achieved in the brief history of facial transplantation have resulted in a new set of obstacles the field must now overcome. In this review, we aim to highlight the achievements, major challenges, and future directions of this rapidly evolving field.

BACKGROUND:Vascularized bone tissue transfer, commonly used to reconstruct large mandibular defects, is challenged by long operative times, extended hospital stay, donor-site morbidity, and resulting health care. 3D-printed osseoconductive tissue-engineered scaffolds may provide an alternative solution for reconstruction of significant mandibular defects. This pilot study presents a novel 3D-printed bioactive ceramic scaffold with osseoconductive properties to treat segmental mandibular defects in a rabbit model. METHODS:Full-thickness mandibulectomy defects (12 mm) were created at the mandibular body of eight adult rabbits and replaced by 3D-printed ceramic scaffold made of 100% β-tricalcium phosphate, fit to defect based on computed tomography imaging. After 8 weeks, animals were euthanized, the mandibles were retrieved, and bone regeneration was assessed. Bone growth was qualitatively assessed with histology and backscatter scanning electron microscopy, quantified both histologically and with micro computed tomography and advanced 3D image reconstruction software, and compared to unoperated mandible sections (UMSs). RESULTS:Histology quantified scaffold with newly formed bone area occupancy at 54.3 ± 11.7%, compared to UMS baseline bone area occupancy at 55.8 ± 4.4%, and bone area occupancy as a function of scaffold free space at 52.8 ± 13.9%. 3D volume occupancy quantified newly formed bone volume occupancy was 36.3 ± 5.9%, compared to UMS baseline bone volume occupancy at 33.4 ± 3.8%, and bone volume occupancy as a function of scaffold free space at 38.0 ± 15.4%. CONCLUSIONS:3D-printed bioactive ceramic scaffolds can restore critical mandibular segmental defects to levels similar to native bone after 8 weeks in an adult rabbit, critical sized, mandibular defect model.

WE43 Mg alloy, composed of Mg, Yttrium, Rare Earth elements, and Zirconium, has proved to be a suitable candidate for production of resorbable osteosynthesis implants in both clinical and experimental settings. In a previous study we tested biocompatibility and degradation properties of untreated (as-cast) and artificially aged (T-5) WE43 Mg-alloys as subperiosteal implants on a maxillofacial sheep model. Both the alloy compositions showed excellent biocompatibility, however, with respect to degradation rate, the as-cast form showed increased degradability compared with the T-5. In the present study, we tested the same alloy composition (i.e. as-cast and T-5) to assess their biological behavior and degradation pattern when implanted as endosteal implants on a calvarial bone sheep model. Six implants in form of cylindrical discs were tested in 6 sheep, one per composition of each disc was placed in two monocortical cranial defect created with high speed trephine bur in the parietal bone. After euthanasia at 6 weeks histomorphological analysis of the bone/implant specimens was performed. WE43-as cast showed higher degradation rate, increased bone remodeling, gas pockets formation and osteolysis compared with the T5 alloy. WE43-T5 showed greater bone/implant interface stability, and seemed to be more suitable for fabrication of endosteal bone screws.

BACKGROUND:Despite the growing success of facial transplantation, organ donor shortages remain challenging. Educational health campaigns can effectively inform the general public and institute behavioral modifications. A brief educational introduction to facial transplantation may positively influence the public's position on facial donation. METHODS:The authors anonymously surveyed 300 participants, gathering basic demographic information, donor registration status, awareness of facial transplantation, and willingness to donate solid organs and facial allografts. Two-hundred of these participants were presented an educational video and subsequently resurveyed on facial donation. Factorial parametric analyses were performed to compare exposure responses before and after watching video exposure. RESULTS:Among participants completing the survey alone (control group), 49 percent were registered donors, 78 percent reported willingness to donate solid organs, and 52 percent reported willingness to donate facial allograft. Of participants who watched the video (video group) 52 percent were registered; 69 and 51 percent were willing to donate solid organs and face, respectively. Following educational intervention, 69 percent of participants in the video group reported willingness to donate facial tissue, an 18 percent increase (p < 0.05), that equated to those willing to donate solid organs. The greatest increase was observed among younger participants (23 percent); women (22 percent); Jewish (22 percent), Catholic (22 percent), and black/African American (25 percent) participants; and respondents holding a higher degree. No significant differences according to gender or ethnicity were observed. CONCLUSION/CONCLUSIONS:Educational interventions hold much promise for increasing the general public's awareness of facial transplantation and willingness to participate in donation of facial allografts.

Purpose: Facial composite defects resulting from trauma can cause devastating and life limiting deformities. Full face transplants have been restoring the oral cavity and the upper airway in a single stage procedure. Literature on face transplants mostly consists of detailed surgical techniques and allograft selection, but do not constitute a compilation of data on postoperative outcomes such as swallow function. This is the first reported case of systematic review of the swallowing rehabilitation course post-facial transplantation. Method(s): Fourty one-year old male with oropharyngeal dysphagia after full face vascularized allotransplant is presented. Videofluoroscopic swallow study (VFSS) was conducted prior to surgery and at 8 time points post-operatively (day 13, 26, 48, 63, 77, 105, 6 months and 9 months) to assess swallow function. Outcome measures included Penetration Aspiration Scale (PAS) and ordinal ratings of residue in the valleculae and pyriform sinuses for 3 and 5 ml thin liquid boluses. Worst PAS scores categorized subject as unsafe (>=3) or safe (<=2). Result(s): Despite rigorous daily swallow treatment, the patient's liquid dysphagia did not imrpove. Unsafe PAS (>=3) were present in the first 7 VFSS post-operatively for 3 ml and 5 ml thin liquid boluses. Worse residue was noted in pyriform sinuses vs. valleculae in all VFSS. Conclusions (Including Clinical Relevance): Early swallow treatment is crucial for safety and successful oral intake of thin liquid postfull facial transplantation. Future analyses will examine the relationship between post-operatively edema and residue with the longterm goal of maximizing therapeutic protocols

PURPOSE: Orthopedic and maxillofacial bone fractures are routinely treated by titanium internal fixation, which may be prone to exposure, infection or intolerance. Magnesium (Mg) and its alloys represent promising alternatives to produce biodegradable osteosynthesis devices, with biocompatibility and, specifically, hydrogen gas production during the degradation process, being the main drawback. Aim of this study is to test and compare biocompatibility, degradation rate and physiscochemical properties of two Mg-alloys to identify which one possesses the most suitable characteristics to be used as resorbable hardware in load-bearing fracture sites. MATERIALS AND METHODS: As-cast (WE43) and T5 Mg-alloys were tested for biocompatibility, physical, mechanical and degradation properties. Microstructure was assessed by optical microscopy, scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS); mechanical properties were tested utilizing quasi-static compression and failure analysis. Locoregional biocompatibility was tested by sub-periosteal implantation on the fronto-nasal region of large-animal model (sheep): regional immunoreaction and metal accumulation was analyzed by LA-ICP of tributary lymph-nodes, local reactions were analyzed through histological preparation including bone, implant and surrounding soft tissue. RESULTS: Mechanically, T5 alloy showed improvement in strength compared to the as-cast. Lymph-node Mg accumulation depicted no differences between control (no implant) and study animals. Both alloys showed good biocompatibility and osteogenesis-promoting properties. CONCLUSION: This study demonstrated excellent biocompatibility and osteogenesis-promoting capabilities of the tested alloys, providing a platform for further studies to test them in a maxillofacial fracture setting. T-5 alloy displayed more stability and decreased degradation rate than the as-cast.

BACKGROUND: The purpose of this study was to investigate whether lymphatic reconstitution and regeneration occurs after clinical facial transplantation using indocyanine green lymphography and immunohistochemical markers. METHODS: Allograft skin biopsies at multiple posttransplant time points were stained with Lyve1 lymphatic antibody and other endothelial antibodies. Staining intensity was interpreted on a scale of none, mild, moderate, and strong by 2 investigators and consolidated by a third party for final interpretation. Standardized real-time lymphography was performed at various posttransplant time points to evaluate lymphatic reconstitution and regeneration. RESULTS: Forty-two biopsies were evaluated at 15 different time points from posttransplant days 7 to 420. Strong Lyve1 staining was observed in 52.4%, moderate staining in 14.3%, and weak staining in 33.3% of biopsies. Strong staining was present on days 7, 10, 44, 79, 269, 402, and 420. Three lymphographic studies were conducted at 8.5, 30, and 35 months posttransplant. Initial drainage via distinct lymphatic channels with abrupt dermal splash and lymphostasis was observed at 8.5-month posttransplant. At 30- and 35-month posttransplant, communication of multiple lymphatic channels between donor tissue and recipient tissue was evident with distinct drainage into native recipient cervical lymph nodes. This correlated with ongoing clinical resolution of facial edema and was unaffected by 3 episodes of acute rejection. CONCLUSIONS: These findings support ongoing lymphatic reconstitution between the donor facial allograft and recipient native tissue. Donor lymphatic regeneration begins after facial transplantation and continues long term. This mechanism may be responsible for the temporal and spatial process of lymphatic reconstitution with recipient lymphatic channels.