Philip S. Brazio

Facial transplantation: the first 9 years

Since the first facial transplantation in 2005, 28 have been done worldwide with encouraging immunological, functional, psychological, and aesthetic outcomes. Unlike solid organ transplantation, which is potentially life-saving, facial transplantation is life-changing. This difference has generated ethical concerns about the exposure of otherwise young and healthy individuals to the sequelae of lifelong, high-dose, multidrug immunosuppression. Nevertheless, advances in immunomodulatory and immunosuppressive protocols, microsurgical techniques, and computer-aided surgical planning have enabled broader clinical application of this procedure to patients. Although episodes of acute skin rejection continue to pose a serious threat to face transplant recipients, all cases have been controlled with conventional immunosuppressive regimens, and no cases of chronic rejection have been reported.

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

Background: Transplantation of a facial vascularized composite allograft is a highly complex procedure that requires meticulous planning and affords little room for error. Although cadaveric dissections are an essential preparatory exercise, they cannot simulate the true clinical experience of facial vascularized composite allograft recovery. Methods: After obtaining institutional review board approval to perform a facial vascularized composite allograft research procurement, a 66-year-old, brain-dead donor was identified. The family graciously consented to donation of a total face, double jaw, and tongue allograft and multiple solid organs. Results: A craniofacial computed tomographic angiogram was obtained preoperatively to define the vascular anatomy and facilitate virtual computerized surgical planning. The allograft was procured in 10 hours, with an additional 2 hours required for an open tracheostomy and silicone facial impression. The donor was coagulopathic throughout the recovery, resulting in an estimated blood loss of 1500 ml. Fluorescence angiography confirmed adequate perfusion of the entire allograft based on lingual and facial arterial and external jugular and thyrolinguofacial venous pedicles. The solid organ transplant team initiated abdominal organ isolation while the facial allograft procurement was in progress. After completion of allograft recovery, the kidneys and liver were recovered without complication. Conclusions: Before conducting a clinical face transplant, adequate preparation is critical to maximize vascularized composite allotransplantation outcomes and preserve solid organ allograft function. As more centers begin to perform facial transplantation, research procurement of a facial vascularized composite allograft offers a unique educational opportunity for the surgical and anesthesia teams, the organ procurement organization, and the institution. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Found in space: Computer-assisted orthognathic alignment of a total face allograft in six degrees of freedom

PURPOSE Full facial osteomyocutaneous transplantation requires correct 3-dimensional (3D) alignment of donor osseous structures to a new cranial base with minimal reference points and 6 degrees of potential movement. We investigated whether computer-assisted design and manufacturing (CAD/CAM) could enable accurate placement of the facial skeleton. MATERIALS AND METHODS A prospective single-cohort study of Le Fort III-based maxillary-mandibular segment allotransplantation was performed in 5 cadaver pairs and 1 clinical pair. The osteotomies were modeled using computed tomography (CT) data and 3D modeling software and then translated to the donor-recipient pairs using surgical navigation and osteotomy cutting guides. The predicted values were calculated about all rotational axes (pitch, yaw, and roll) and along all translational axes (vertical, horizontal, and anteroposterior) and used as the independent variable. The primary outcome variable of the actual postoperative CT values was compared for fidelity to the prediction using the intraclass correlation coefficient (ICC). The similarity to the donor versus recipient values was calculated as a secondary independent variable, and both predicted and actual measurements were compared with it as a percentage. RESULTS The postoperative fidelity to the plan was adequate to excellent (ICC 0.520 to 0.975) with the exception of lateral translation (2.94 ± 1.31 mm predicted left vs 3.92 ± 2.17 mm right actual displacement; ICC 0.243). The predicted and actual values were not consistently skewed toward the donor or recipient values. CONCLUSIONS We have demonstrated a novel application of CAD/CAM that enables orthognathic alignment of a maxillary-mandibular segment to a new cranial base. Quantification of the alignment in all 6 degrees of freedom delivers precise control compared with the planned changes and allows postoperative quality control.

Algorithm for Total Face and Multiorgan Procurement From a Brain‐Dead Donor

Procurement of a facial vascularized composite allograft (VCA) should allow concurrent procurement of all solid organs and ensure their integrity. Because full facial procurement is time–intensive, “simultaneous–start” procurement could entail VCA ischemia over 12 h. We procured a total face osteomyocutaneous VCA from a brain–dead donor. Bedside tracheostomy and facial mask impression were performed preoperative day 1. Solid organ recovery included heart, lungs, liver, kidneys, and pancreas. Facial dissection time was 12 h over 15 h to diminish ischemia while awaiting recipient preparation. Solid organ recovery began at 13.5 h, during midfacial osteotomies, and concluded immediately after facial explantation. Facial thoracic and abdominal teams worked concurrently. Estimated blood loss was 1300 mL, requiring five units of pRBC and two units FFP. Urine output, MAP, pH and PaO2 remained normal. All organs had good postoperative function. We propose an algorithm that allows “face first, concurrent completion” recovery of a complex facial VCA by planning multiple pathways to expedient recovery of vital organs in the event of clinical instability. Beginning the recipient operation earlier may reduce waiting time due to extensive recipient scarring causing difficult dissection.

Harmonic scalpel versus electrocautery for harvest of radial artery conduits: Reduced risk of spasm and intimal injury on optical coherence tomography

OBJECTIVE Vasospasm is the primary obstacle to widespread adoption of the radial artery as a conduit in coronary artery bypass grafting. We used optical coherence tomography, a catheter-based intravascular imaging modality, to measure the degree of radial artery spasm induced by means of harvest with electrocautery or a harmonic scalpel in patients undergoing coronary artery bypass grafting. METHODS Radial arteries were harvested from 44 consecutive patients with a harmonic scalpel (n = 15) or electrocautery (n = 29). Vessels were imaged before harvesting and after removal from the arm, with saphenous vein tracts serving as internal controls. Optical coherence tomographic findings for the degree of harvesting-induced injury were validated against histologic measures. RESULTS Optical coherence tomographic measures of endovascular dimensions and injury correlated strongly with histologic findings. Mean luminal volume, a measure of vasospasm, decreased significantly less after harvesting with a harmonic scalpel (9% +/- 7%) than with electrocautery (35% +/- 6%, P = .015). Completely intact intima was present in 11 (73%) of 15 radial arteries harvested with a harmonic scalpel (73%) compared with 9 of 29 arteries harvested by means of electrocautery (31%, P = .011). Intraoperative flow measurements and patency rates at 5 days postoperatively were not significantly different among groups. CONCLUSIONS Optical coherence tomography provides a level of speed and accuracy for quantifying endothelial injury and vasospasm that has not been described for any other modality, suggesting potential as an intraoperative quality assurance tool. Our optical coherence tomographic findings suggest that the harmonic scalpel induces less spasm and intimal injury compared with electrocautery.

Regulatory T cells are not predictive of outcomes in a nonhuman primate model of vascularized composite allotransplantation.

Background T regulatory cells (Tregs) have been associated with prolonged allograft survival and tolerance across a wide variety of species and organ types. We used our nonhuman primate model of facial vascularized composite allotransplantation (VCA) to study the association of Tregs with graft outcomes. Methods We quantified Tregs in peripheral blood and allograft biopsies from nonhuman primates after heterotopic partial facial segment allotransplantation from major histocompatibility complex class I–mismatched donors using flow cytometry and immunohistochemistry. Immunosuppression consisted of tacrolimus and mycophenolate mofetil without induction or depletional therapies. Circulating and graft skin Treg values were compared with graft outcomes and with histologic grade from concurrent biopsies. Results Treg proportion in peripheral blood ranged from 0.156% to 9.00% with a mean of 3.34%±0.22%. FoxP3 staining was observed in 3 of 29 graft biopsies. Median circulating Treg value did not predict time to Banff grade II rejection (hazard ratio, 0.9; confidence interval, 0.4–2.2) or graft loss (hazard ratio, 0.5; confidence interval, 0.01–5.3). Animals that experienced rejection did not have significantly different peripheral blood or graft skin Treg values from those that did not. Biopsy specimens with grade I or II rejection were more likely to contain Tregs (25% vs. 0%; P=0.044) despite no difference in concurrent circulating Tregs (3.56% vs. 3.36%; P=0.704). Conclusions These findings in a clinically relevant model suggest that Tregs may have limited prognostic value with standard immunosuppressive protocols used in VCA. Further studies are necessary to determine the specific role of Tregs in VCA and any role of Treg monitoring in clinical practice.

Recellularization via the bile duct supports functional allogenic and xenogenic cell growth on a decellularized rat liver scaffold

ABSTRACT Recent years have seen a proliferation of methods leading to successful organ decellularization. In this experiment we examine the feasibility of a decellularized liver construct to support growth of functional multilineage cells. Bio-chamber systems were used to perfuse adult rat livers with 0.1% SDS for 24 hours yielding decellularized liver scaffolds. Initially, we recellularized liver scaffolds using a human tumor cell line (HepG2, introduced via the bile duct). Subsequent studies were performed using either human tumor cells co-cultured with human umbilical vein endothelial cells (HUVECs, introduced via the portal vein) or rat neonatal cell slurry (introduced via the bile duct). Bio-chambers were used to circulate oxygenated growth medium via the portal vein at 37C for 5-7 days. Human HepG2 cells grew readily on the scaffold (n = 20). HepG2 cells co-cultured with HUVECs demonstrated viable human endothelial lining with concurrent hepatocyte growth (n = 10). In the series of neonatal cell slurry infusion (n = 10), distinct foci of neonatal hepatocytes were observed to repopulate the parenchyma of the scaffold. The presence of cholangiocytes was verified by CK-7 positivity. Quantitative albumin measurement from the grafts showed increasing albumin levels after seven days of perfusion. Graft albumin production was higher than that observed in traditional cell culture. This data shows that rat liver scaffolds support human cell ingrowth. The scaffold likewise supported the engraftment and survival of neonatal rat liver cell slurry. Recellularization of liver scaffolds thus presents a promising model for functional liver engineering.

Infused Bone Marrow Fails to Prevent Vascularized Composite Allograft Rejection in Nonhuman Primates

Vascular composite allografts (VCA) are highly antigenic as demonstrated by near universal rejection rates. Nonetheless, substantial immunosuppressive therapy has permitted VCA to survive currently between 10 (face) and 15 (hand) years. The field of VCA has placed major emphasis on investigating in preclinical and clinical trials whether infused bone marrow combined with standard immunosuppression may improve immunologic outcomes. In contrast to solid organ transplant protocols utilizing bone marrow cells (BMC) and nonmyeloblative conditioning, tolerance (or even the absence of rejection on immunosuppression) has not been observed in any VCA trials (1–3). The lack of controlled trials directly evaluating infused BMC as a cellular adjunct leads to ongoing ambiguity regarding the role of BMC infusion without preconditioning in VCA (4).

Early Microchimerism After Face Transplantation Detected by Quantitative Real-time Polymerase Chain Reaction of Insertion/Deletion Polymorphisms.

V composite allografts (VCA), such as hand and face transplants, offer an alternative approach to complex reconstructive scenarios that otherwise require multiple complex operations. Multiple face transplants with various components of skin, muscle, and bone have been performed worldwide, with the most extensive including mandible and maxilla, tongue, and skin performed in 2012 at the University of Maryland Medical Center. Microchimerism, defined as the presence of low levels of donor-derived cells (<1%), has not been definitively associated with improved immunologic outcomes. We investigated the presence of chimerism in our clinical full-face VCA with upper and lower jaw vascularized bone marrow components using established techniques of flow cytometry and short tandem repeat analysis without detecting any evidence of macrochimerism. We subsequently analyzed postoperative whole blood samples from our face transplant recipient using a commercial assay (AlleleSEQR) that screens and quantifies DNA by quantitative polymerase chain reaction (PCR) using insertion/deletion (InDel) polymorphisms as genetic markers sensitive to 0.001%.

Engineering Bone Grafts with Enhanced Bone Marrow and Native Scaffolds

The translation of tissue engineering approaches to the clinic has been hampered by the inability to find suitable multipotent cell sources requiring minimal in vitro expansion. Enhanced bone marrow (eBM), which is obtained by reaming long bone medullary canals and isolating the solid marrow putty, has large quantities of stem cells and demonstrates significant potential to regenerate bone tissues. eBM, however, cannot impart immediate load-bearing mechanical integrity or maintain the gross anatomical structure to guide bone healing. Yet, its putty-like consistency creates a challenge for obtaining the uniform seeding necessary to effectively combine it with porous scaffolds. In this study, we examined the potential for combining eBM with mechanically strong, osteoinductive trabecular bone scaffolds for bone regeneration by creating channels into scaffolds for seeding the eBM. eBM was extracted from the femurs of adult Yorkshire pigs using a Synthes reamer-irrigator-aspirator device, analyzed histologically, and digested to extract cells and characterize their differentiation potential. To evaluate bone tissue formation, eBM was seeded into the channels in collagen-coated or noncoated scaffolds, cultured in osteogenic conditions for 4 weeks, harvested and assessed for tissue distribution and bone formation. Our data demonstrates that eBM is a heterogenous tissue containing multipotent cell populations. Furthermore, coating scaffolds with a collagen hydrogel significantly enhanced cellular migration, promoted uniform tissue development and increased bone mineral deposition. These findings suggest the potential for generating customized autologous bone grafts for treating critical-sized bone defects by combining a readily available eBM cell source with decellularized trabecular bone scaffolds.