Total face, double jaw, and tongue transplant research procurement: an educational model

Ultrasound in Microsurgery: Current Applications and New Frontiers

Ultrasound has revolutionized reconstructive microsurgery, offering real-time imaging and enhanced precision allowing for preoperative flap planning, recipient vessel identification and selection, postoperative flap monitoring, and lymphatic surgery. This narrative review of the literature provides an updated evidence-based overlook on the current applications and emerging frontiers of ultrasound in microsurgery, focusing on free tissue transfer and lymphatic surgery. Color duplex ultrasound (CDU) plays a pivotal role in preoperative flap planning and design, providing real-time imaging that enables detailed perforator mapping, perforator suitability assessment, blood flow velocity measurement, and, ultimately, flap design optimization. Ultrasound also aids in recipient vessel selection by providing assessment of caliber, patency, location, and flow velocity of recipient vessels. Postoperatively, ultrasound enables real-time monitoring of flap perfusion, providing early detection of potential flap compromise and improved flap survival rates. In lymphatic surgery, ultra-high frequency ultrasound (UHFUS) offers precise mapping and evaluation of lymphatic vessels, improving efficacy and efficiency by targeting larger dilated vessels. Integrating ultrasound into reconstructive microsurgery represents a significant advancement in the utilization of imaging in the field. With growing accessibility of devices, improved training, and technological advancements, using ultrasound as a key imaging tool offers substantial potential for the evolution of reconstructive microsurgery.

International consensus recommendations on face transplantation: A 2-step Delphi study

Face transplantation is a viable reconstructive approach for severe craniofacial defects. Despite the evolution witnessed in the field, ethical aspects, clinical and psychosocial implications, public perception, and economic sustainability remain the subject of debate and unanswered questions. Furthermore, poor data reporting and sharing, the absence of standardized metrics for outcome evaluation, and the lack of consensus definitions of success and failure have hampered the development of a "transplantation culture" on a global scale. We completed a 2-round online modified Delphi process with 35 international face transplant stakeholders, including surgeons, clinicians, psychologists, psychiatrists, ethicists, policymakers, and researchers, with a representation of 10 of the 19 face transplant teams that had already performed the procedure and 73% of face transplants. Themes addressed included patient assessment and selection, indications, social support networks, clinical framework, surgical considerations, data on patient progress and outcomes, definitions of success and failure, public image and perception, and financial sustainability. The presented recommendations are the product of a shared commitment of face transplant teams to foster the development of face transplantation and are aimed at providing a gold standard of practice and policy.

Facial Transplantation: Principles and Evolving Concepts

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Appreciate the evolution and increasing complexity of transplanted facial allografts over the past two decades. 2. Discuss indications and contraindications for facial transplantation, and donor and recipient selection criteria and considerations. 3. Discuss logistical, immunologic, and cost considerations in facial transplantation, in addition to emerging technologies used. 4. Understand surgical approaches and anatomical and technical nuances of the procedure. 5. Describe aesthetic, functional, and psychosocial outcomes of facial transplantation reported to date.

SUMMARY

This CME article highlights principles and evolving concepts in facial transplantation. The field has witnessed significant advances over the past two decades, with more than 40 face transplants reported to date. The procedure now occupies the highest rung on the reconstructive ladder for patients with extensive facial disfigurement who are not amenable to autologous reconstructive approaches, in pursuit of optimal functional and aesthetic outcomes. Indications, contraindications, and donor and recipient considerations for the procedure are discussed. The authors also review logistical, immunologic, and cost considerations of facial transplantation. Surgical approaches to allograft procurement and transplantation, in addition to technical and anatomical nuances of the procedure, are provided. Finally, the authors review aesthetic, functional, and psychosocial outcomes that have been reported to date.

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.

Facial Transplantation for an Irreparable Central and Lower Face Injury: A Modernized Approach to a Classic Challenge

BACKGROUND

Facial transplantation introduced a paradigm shift in the reconstruction of extensive facial defects. Although the feasibility of the procedure is well established, new challenges face the field in its second decade.

METHODS

The authors' team has successfully treated patients with extensive thermal and ballistic facial injuries with allotransplantation. The authors further validate facial transplantation as a reconstructive solution for irreparable facial injuries. Following informed consent and institutional review board approval, a partial face and double jaw transplantation was performed in a 25-year-old man who sustained ballistic facial trauma. Extensive team preparations, thorough patient evaluation, preoperative diagnostic imaging, three-dimensional printing technology, intraoperative surgical navigation, and the use of dual induction immunosuppression contributed to the success of the procedure.

RESULTS

The procedure was performed on January 5 and 6, 2018, and lasted nearly 25 hours. The patient underwent hyoid and genioglossus advancement for floor-of-mouth dehiscence, and palate wound dehiscence repair on postoperative day 11. Open reduction and internal fixation of left mandibular nonunion were performed on postoperative day 108. Nearly 1 year postoperatively, the patient demonstrates excellent aesthetic outcomes, intelligible speech, and is tolerating an oral diet. He remains free from acute rejection.

CONCLUSIONS

The authors validate facial transplantation as the modern answer to the classic reconstructive challenge imposed by extensive facial defects resulting from ballistic injury. Relying on a multidisciplinary collaborative approach, coupled with innovative emerging technologies and immunosuppression protocols, can overcome significant challenges in facial transplantation and reinforce its position as the highest rung on the reconstructive ladder.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Computerized Approach to Facial Transplantation: Evolution and Application in 3 Consecutive Face Transplants

Face transplant (FT) candidates present with unique anatomic and functional defects unsuitable for autologous reconstruction, making the accurate design and transplantation of patient-specific allografts particularly challenging. In this case series, we present our computerized surgical planning (CSP) protocol for FT.

Perioperative Nursing Management of Donor and Recipient Patients Undergoing Face Transplantation

Individuals with debilitating facial injuries and deformities have achieved significant improvement of aesthetic form and function after undergoing a face transplantation. The involvement of surgical technologists and perioperative nurses in the care of the recipient and donor plays a critical role in the success of these procedures. There are unique challenges that staff members may be presented with when caring for a donor and recipient undergoing a face transplantation, including less comfort with and knowledge of the surgical procedure and instrumentation, an increased amount of equipment and personnel in the OR, donor and recipient admission and discharge care, and increased shift length. At New York University Langone Medical Center, New York, we have developed a comprehensive process to prepare staff members to care for patients undergoing face transplantation.

Combining Virtual Surgical Planning, Intraoperative Navigation, and 3-Dimensional Printing in Prosthetic-Based Bilateral Microtia Reconstruction

Reconstructing auricular deformities for bilateral microtia is a demanding challenge especially after failed autologous reconstruction. This case report presents a novel application of virtual surgical planning, computer-assisted design, and intraoperative surgical navigation to preplan and execute placement of custom-tailored silicone auricular prostheses and titanium osseointegrated implants for a bone-anchored hearing aid system in a patient with Treacher Collins syndrome in whom autologous reconstruction had previously failed. Through a collaborative approach between the reconstructive surgeon and anaplastologist, the implementation of advanced digital technologies may offer a superior esthetic and functional outcome to patients with previously failed reconstruction.

Preoperative Planning of Virtual Osteotomies Followed by Fabrication of Patient Specific Reconstruction Plate for Secondary Correction and Fixation of Displaced Bilateral Mandibular Body Fracture

This paper describes the course of treatment of a severely diplaced bilateral mandibular body fracture, where the first osteosynthesis failed. The subject developed an open bite due to a posterior rotation of the distal part of the mandible and anterior rotation of the proximal parts of the mandible. This situation was evaluated with CBCT and the facial skeleton was segmented using computer software. Correct occlusion was virtually established by bilateral virtual osteotomies in the fracture areas of the mandible. After segmentation, the mandible was virtually rotated back into position and the open bite was closed. A patient specific mandibular reconstruction plate was outlined and fabricated from the new virtual situation and the plate was thereafter installed utilizing the preoperative plan. Osteotomy- and drill-guides was used and thus simplified the surgery resulting in uneventful healing. Virtual planning and patient specific implants and guides were valuable in this case of secondary reconstructive trauma surgery.

Optimizing Reconstruction with Periorbital Transplantation: Clinical Indications and Anatomic Considerations

Complex periorbital subunit reconstruction is challenging because the goals of effective reconstruction vary from one individual to another. The purpose of this article is to explore the indications and anatomic feasibility of periorbital transplantation by reviewing our institutional repository of facial injury.

METHODS

Institutional review board approval was obtained at the R Adams Cowley Shock Trauma Center for a retrospective chart review conducted on patients with periorbital defects. Patient history, facial defects, visual acuity, and periorbital function were critically reviewed to identify indications for periorbital or total face (incorporating the periorbital subunit) vascularized composite allotransplantation. Cadaveric allograft harvest was then designed and performed for specific patient defects to determine anatomic feasibility. Disease conditions not captured by our patient population warranting consideration were reviewed.

RESULTS

A total of 7 facial or periorbital transplant candidates representing 6 different etiologies were selected as suitable indications for periorbital transplantation. Etiologies included trauma, burn, animal attack, and tumor, whereas proposed transplants included isolated periorbital and total face transplants. Allograft recovery was successfully completed in 4 periorbital subunits and 1 full face. Dual vascular supply was achieved in 5 of 6 periorbital subunits (superficial temporal and facial vessels).

CONCLUSIONS

Transplantation of isolated periorbital structures or full face transplantation including periorbital structures is technically feasible. The goal of periorbital transplantation is to re-establish protective mechanisms of the eye, to prevent deterioration of visual acuity, and to optimize aesthetic outcomes. Criteria necessary for candidate selection and allograft design are identified by periorbital defect, periorbital function, ophthalmologic evaluation, and defect etiology.

Procurement strategies for combined multiorgan and composite tissues for transplantation

PURPOSE OF REVIEW

The purpose of this article is to identify the unique aspects of combined multiorgan and vascularized composite allograft (VCA) procurement from deceased donors and outline the steps essential for success.

RECENT FINDINGS

Transplantation of nonsolid organ composite tissues is becoming a viable option for reconstruction of massive tissue defects. With the United Network for Organ Sharing designation of VCAs as organs, placing them under the domain of the Organ Procurement and Transplantation Network, a systematic method for combined solid organ and VCA procurement is required. Several centers have reported experience with successful procurement strategies including sequential and simultaneous retrievals. The published literature describing donor screening, sequence of procurement with relation to solid organs and allocation is reviewed.

SUMMARY

With the 2013 classification of VCAs as organs, the Organ Procurement and Transplantation Network and United Network for Organ Sharing are better suited to aligning procurement and allocation policies. As VCA transplantation becomes more commonplace, protocol guidelines will ensure smooth integration with existing procurement infrastructure.

Computer-assisted, Le Fort-based, face-jaw-teeth transplantation: a pilot study on system feasiblity and translational assessment

PURPOSE

Le Fort-based face-jaw-teeth transplantation (FJTT) attempts to marry bone and teeth geometry of size-mismatched face-jaw-teeth segments to restore function and form due to severe mid-facial trauma. Recent development of a computer-assisted planning and execution (CAPE) system for Le Fort-based FJTT in a pre-clinical swine model offers preoperative planning, and intraoperative navigation. This paper addresses the translation of the CAPE system to human anatomy and presents accuracy results.

METHODS

Single-jaw, Le Fort-based FJTTs were performed on plastic models, one swine and one human, and on a human cadaver. Preoperative planning defined the goal placement of the donor's Le Fort-based FJTT segment on the recipient. Patient-specific navigated cutting guides helped achieve planned osteotomies. Intraoperative cutting guide and donor fragment placement were compared with postoperative computed tomography (CT) data and the preoperative plan.

RESULTS

Intraoperative measurement error with respect to postoperative CT was less than 1.25 mm for both mock transplants and 3.59 mm for the human cadaver scenario. Donor fragment placement (as compared to the planned position) was less accurate for the human model test case (2.91 mm) compared with the swine test (2.25 mm) and human cadaver (2.26 mm).

CONCLUSION

The results indicate the viability of the CAPE system for assisting with Le Fort-based FJTT and demonstrate the potential in human surgery. This system offers a new path forward to achieving improved outcomes in Le Fort-based FJTT and can be modified to assist with a variety of other surgeries involving the head, neck, face, jaws and teeth.

Establishing cephalometric landmarks for the translational study of Le Fort-based facial transplantation in Swine: enhanced applications using computer-assisted surgery and custom cutting guides

BACKGROUND

Le Fort-based, maxillofacial allotransplantation is a reconstructive alternative gaining clinical acceptance. However, the vast majority of single-jaw transplant recipients demonstrate less-than-ideal skeletal and dental relationships, with suboptimal aesthetic harmony. The purpose of this study was to investigate reproducible cephalometric landmarks in a large-animal model, where refinement of computer-assisted planning, intraoperative navigational guidance, translational bone osteotomies, and comparative surgical techniques could be performed.

METHODS

Cephalometric landmarks that could be translated into the human craniomaxillofacial skeleton, and that would remain reliable following maxillofacial osteotomies with midfacial alloflap inset, were sought on six miniature swine. Le Fort I- and Le Fort III-based alloflaps were harvested in swine with osteotomies, and all alloflaps were either autoreplanted or transplanted. Cephalometric analyses were performed on lateral cephalograms preoperatively and postoperatively. Critical cephalometric data sets were identified with the assistance of surgical planning and virtual prediction software and evaluated for reliability and translational predictability.

RESULTS

Several pertinent landmarks and human analogues were identified, including pronasale, zygion, parietale, gonion, gnathion, lower incisor base, and alveolare. Parietale-pronasale-alveolare and parietale-pronasale-lower incisor base were found to be reliable correlates of sellion-nasion-A point angle and sellion-nasion-B point angle measurements in humans, respectively.

CONCLUSIONS

There is a set of reliable cephalometric landmarks and measurement angles pertinent for use within a translational large-animal model. These craniomaxillofacial landmarks will enable development of novel navigational software technology, improve cutting guide designs, and facilitate exploration of new avenues for investigation and collaboration.

Chest wall, thymus, and heart vascularized composite allograft proof of concept cadaveric model for heart transplantation

The use of vascularized composite allografts allows for the reconstruction of complex scenarios that previously have required multistaged operations. Heart transplantation often follows a series of previous operations leading to chest wall deformities and significant mediastinal adhesions that can limit the use of larger hearts, making it difficult to find a suitable donor. Further, research has shown that the use of vascularized bone marrow and vascularized thymus in transplantation potentially prolongs graft survival with decreased immunosuppression requirements. The authors propose using a vascularized composite allograft of the chest wall consisting of sternum and thymus in conjunction with the heart for cardiac transplantation to allow for more flexibility from the donor pool, maintain chest wall integrity and physiology, and potentially immunoregulate the concomitant solid organ transplant.

Overcoming cross-gender differences and challenges in Le Fort-based, craniomaxillofacial transplantation with enhanced computer-assisted technology

BACKGROUND

Sex-specific anthropometrics, skin texture/adnexae mismatch, and social apprehension have prevented cross-gender facial transplantation from evolving. However, the scarce donor pool and extreme waitlist times are currently suboptimal. Our objective was to (1) perform and assess cadaveric facial transplantation for each sex-mismatched scenario using virtual planning with cutting guide fabrication and (2) review the advantages/disadvantages of cross-gender facial transplantation.

METHODS

Cross-gender facial transplantation feasibility was evaluated through 2 mock, double-jaw, Le Fort-based cadaveric allotransplants, including female donor-to-male recipient and male donor-to-female recipient. Hybrid facial-skeletal relationships were investigated using cephalometric measurements, including sellion-nasion-A point and sellion-nasion-B point angles, and lower-anterior-facial-height to total-anterior-facial-height ratio. Donor and recipient cutting guides were designed with virtual planning based on our team's experience in swine dissections and used to optimize the results.

RESULTS

Skeletal proportions and facial-aesthetic harmony of the transplants (n = 2) were found to be equivalent to all reported experimental/clinical sex-matched cases by using custom guides and Mimics technology. Cephalometric measurements relative to Eastman Normal Values are shown.

CONCLUSIONS

On the basis of our results, we believe that cross-gender facial transplantation can offer equivalent, anatomical skeletal outcomes to those of sex-matched pairs using preoperative planning and custom guides for execution. Lack of literature discussion of cross-gender facial transplantation highlights the general stigmata encompassing the subject. We hypothesize that concerns over sex-specific anthropometrics, skin texture/adnexae disparity, and increased immunological resistance have prevented full acceptance thus far. Advantages include an increased donor pool with expedited reconstruction, as well as size-matched donors.

Vascular communications between donor and recipient tissues after successful full face transplantation

The vascular reorganization after facial transplantation has important implications on future surgical planning. The purpose of this study was to evaluate blood flow (BF) after full face transplantation using wide area-detector computed tomography (CT) techniques. Three subjects with severe craniofacial injury who underwent full face transplantation were included. All subjects underwent a single anastomosis bilaterally of the artery and vein, and the recipient tongue was preserved. Before and after surgery, dynamic volume CT studies were analyzed for vascular anatomy and blood perfusion. Postsurgical CT showed extensive vascular reorganization for external carotid artery (ECA) angiosome; collateral flows from vertebral, ascending pharyngeal or maxillary arteries supplied the branches from the recipient ECAs distal to the ligation. While allograft tissue was slightly less perfused when the facial artery was the only donor artery when compared to an ECA-ECA anastomosis (4.4 ± 0.4% vs. 5.7 ± 0.7%), allograft perfusion was higher than the recipient normal neck tissue. BF for the recipient tongue was maintained from contralateral/donor arteries when the lingual artery was sacrificed. Venous drainage was adequate for all subjects, even when the recipient internal jugular vein was anastomosed in end-to-end fashion on one side. In conclusion, dynamic CT identified adequate BF for facial allografts via extensive vascular reorganization.

Vascularization of the facial bones by the facial artery: implications for full face allotransplantation

BACKGROUND

The maxillary artery is recognized as the main vascular supply of the facial bones; nonetheless, clinical evidence supports a codominant role for the facial artery. This study explores the extent of the facial skeleton within a facial allograft that can be harvested based on the facial artery.

METHODS

Twenty-three cadaver heads were used in this study. In 12 heads, the facial, superficial temporal, and maxillary arteries were injected. In one head, facial artery angiography was performed. Ten facial allografts were raised. The soft tissues were dissected to show the arterial anastomotic connections. Radiographs and computed tomographic scans were obtained.

RESULTS

Constant anastomosis between the facial, inferior alveolar, and infraorbital arteries at the mental and infraorbital foramina were found. The facial artery vascularized the homolateral mandibular symphysis, body, and ramus. The condylar and coronoid processes were vascularized in 67 percent of the allografts. The homolateral maxilla was contrasted in all allografts. The alveolar and palatine processes contained the contrast in 83 percent of specimens. The maxillary process of the zygomatic bone was perfused in all allografts, followed by the body, frontal (83 percent), and temporal processes (67 percent). The nasal lateral wall and septum were vascularized in 83 percent of the allografts. The medial and lateral orbital walls and the orbital floor were stained in all specimens. The zygomatic process of the temporal bone was the least perfused bone.

CONCLUSION

A composite allograft containing 90 to 95 percent of the facial bones can be based on bilateral facial arteries.