Faculty Bibliography

Plastic surgery is a broad-based discipline with emphasis on areas such as breast, craniomaxillofacial, burn, aesthetic, and hand surgery as well as complex wounds and wound healing. Plastic surgery as a specialty captures a great deal of media attention over many other fields of medicine, so education, training, and credentialing have become an area of national interest. The purpose of this article was to provide information on the organization, basic requirements for training, fellowship, and volunteer opportunities within the specialty

INTRODUCTION: While several studies report that bone morphogenetic proteins (BMPs) and vascular endothelial growth factor (VEGF) can act synergistically to improve bone tissue engineering, others suggest that VEGF inhibits osteogenesis. The purpose of these experiments was therefore to evaluate the effect of dual transfection of these growth factors and potential mechanisms of interaction on gene expression and osteogenesis in vitro and in vivo. METHODS: Marrow-derived mesenchymal stem cells (MSCs) were exposed to recombinant VEGF protein or transfected with adenoviruses encoding BMP2, VEGF, or LacZ in a variety of ratios. Alterations in gene and protein expression in vitro as well as bone formation in vivo were assessed. RESULTS: MSC exposure to AdV-VEGF or recombinant VEGF inhibited BMP2 mRNA expression, protein production, and MSC differentiation. Coculture experiments revealed that BMP2 suppression occurs through both an autocrine and a paracrine mechanism, occurring at the transcriptional level. Compared to controls, cotransfection of VEGF and BMP2 transgenes prevented ectopic bone formation in vivo. CONCLUSION: VEGF is a potent inhibitor of BMP2 expression in MSCs, and supplementation or overexpression of VEGF inhibits osteogenesis in vitro and ectopic bone formation in vivo. Strategies to utilize MSCs in bone tissue engineering therefore require careful optimization and precise delivery of growth factors for maximal bone formation.

BACKGROUND: Since 2005, seven facial composite tissue allotransplantations have been performed in five different centers in three countries. Four teams have reported their outcomes in separate publications. The authors sought to review the first four global experiences and compare several factors. This review facilitates discussion of indications and future implications for facial composite tissue allotransplantation. METHODS: A thorough review of five publications by the four transplantation groups was conducted. Additional information gathered from official press releases or surgeon presentations was also included. Summary of data and comparative analysis were performed. RESULTS: Patient selection is of utmost importance; specifically, patient compliance with the immunosuppressive and postoperative regimen. Functional and aesthetic improvement must be achieved by composite tissue allotransplantation reconstruction to justify lifelong immunosuppression; therefore, patients with loss of perioral and/or periorbital structures have priority. Objective measures are required to monitor this functional restoration. The importance of viral mismatch was demonstrated by the severe cytomegalovirus viremia observed in the third facial transplant patient. Finally, the mucosa appears to be a predictor of rejection and is more antigenic than skin. Histopathologic diagnosis of mucosal rejection may allow early treatment and prevention of subsequent diffuse composite tissue allotransplant rejection. CONCLUSIONS: The pioneering teams that ventured into facial composite tissue allotransplantation offered their patients improved aesthetic, functional, and social outcomes not possible with conventional measures in a single procedure. In addition, these innovative facial composite tissue allografts have provided early data on important factors related to patient selection, donor/recipient matching, immunosuppressive protocols, objective measures of functional recovery, and monitoring of acute graft rejection.

Vascularized nerve grafts (VNG) were introduced in 1976 but since then, there have been no reports of their usage in lower extremity reconstruction systematically. The factors influencing outcomes as well as a comparison with conventional nerve grafts will be presented.Since 1981, 14 lower extremity nerve injuries in 12 patients have been reconstructed with VNG. Common peroneal nerve was injured in 12 and posterior tibial nerve in 5 patients. The level of the injury was at the knee or thigh. Twelve sural nerves were used as VNG with or without concomitant vascularized posterior calf fascia.All patients regained improved sensibility and adequate posterior tibial nerve function. For common peroneal nerve reconstructions, all patients with denervation time less than 6 months regained muscle strength of grade at least 4, even when long grafts were used for defects of 20 cm or more. Late cases, yielded inadequate muscle function even with the use of VNG.Denervation time of 6 months or less was critical for reconstruction with vascularized nerve graft. Not only the results were statistically significant compared with late cases, but also all early operated patients achieved excellent results. VNG are strongly recommended in traction avulsion injuries of the lower extremity with lengthy nerve damage

BACKGROUND: The supraclavicular artery island flap is a useful regional option in head and neck reconstruction. Previous studies have recorded pedicle length, caliber, and ink injection studies of the supraclavicular artery. This study presents a three- and four-dimensional appraisal of the vascular anatomy and perfusion of the supraclavicular artery island flap using a novel computed tomographic technique. METHODS: Ten supraclavicular artery island flaps were harvested from fresh cadavers. Each flap was injected with contrast media and subjected to dynamic computed tomographic scanning using a GE Lightspeed 16-slice scanner. Static computed tomographic scanning was also undertaken using a barium-gelatin mixture. Images were viewed using both General Electric and TeraRecon systems, allowing the appreciation of vascular territory (three-dimensional) and analysis of perfusion flow (four-dimensional). RESULTS: The entire skin paddle was perfused in the majority (nine of 10) of flaps. One of the flaps was perfused only 50 percent. In this case, the pedicle artery was found to be much smaller than the other flap pedicles. Direct linking vessels and recurrent flow by means of the subdermal plexus were found to convey the flow of contrast between adjacent perforators. This explains how perfusion extends to adjacent perforators by means of interperforator flow, and how perfusion is maintained all the way to the distal periphery of the flap. CONCLUSIONS: Using this imaging technique, the authors elucidated the vascular anatomy of the supraclavicular artery island flap. This study confirms previous clinical findings that the supraclavicular artery island flap is a reliable option and gives surgeons new information for future flap refinement.

BACKGROUND AND OBJECTIVE: In the field of bone implant surfaces, the effects of nanoscale modifications have received significant attention. In the present study, bone cell activity on 2 implant surfaces with similar microtopography but distinct chemistry and nanotopography (sandblasted/acid-etched surface as control group, and calcium phosphate (CaP) low impregnated surface (Ossean) as test group, both from Intra-Lock, Boca Raton, FL) were evaluated. STUDY DESIGN: The 2 surfaces were characterized by X-ray photoelectronic spectroscopy (XPS) and scanning electron microscopy (SEM) up to x200,000 magnification. The micrometer level roughness profiles were evaluated by means of computer software. Cell adhesion, proliferation, and alkaline phosphatase activity were assessed with human SaOS-2 osteoblasts and bone mesenchymal stem cells in nonosteogenic culture conditions. RESULTS: The XPS and SEM results showed that the Ossean surface presented low levels of CaP impregnation within the titanium oxide layer and texturization at the nanometer scale (nanoroughness) compared with the control surface. Moreover Ossean surface induced significantly higher cell differentiation levels than the control (P < .01). CONCLUSION: This study showed that both homogeneous nanoroughness and CaP low impregnation differently affected in vitro bone cell behavior compared with the control moderately rough surface with less texturing in the nanometer scale. However, the relative importance of nanotopography and surface chemistry in cell reactions is yet to be determined.

It was previously shown that CEACAM1 on melanoma cells strongly predicts poor outcome. Here, we show a statistically significant increase of serum CEACAM1 in 64 active melanoma patients, as compared to 48 patients with no evidence of disease and 37 healthy donors. Among active patients, higher serum CEACAM1 correlated with LDH values and with decreased survival. Multivariate analysis with neutralization of LDH showed that increased serum CEACAM1 carries a hazard ratio of 2.40. In vitro, soluble CEACAM1 was derived from CEACAM1(+), but neither from CEACAM1(-) melanoma cells nor from CEACAM1(+) lymphocytes, and directly correlated with the number of CEACAM1(+) melanoma cells. Production of soluble CEACAM1 depended on intact de novo protein synthesis and secretion machineries, but not on metalloproteinase function. An unusually high percentage of CEACAM1(+) circulating NK and T lymphocytes was demonstrated in melanoma patients. CEACAM1 inhibited killing activity in functional assays. CEACAM1 expression could not be induced on lymphocytes by serum from patients with high CEACAM1 expression. Further, expression of other NK receptors was impaired, which collectively indicate on a general abnormality. In conclusion, the systemic dysregulation of CEACAM1 in melanoma patients further denotes the role of CEACAM1 in melanoma and may provide a basis for new tumor monitoring and prognostic platforms.

OBJECTIVE: To evaluate the effects of clinically relevant variables on the maximum principal stress (MPS) in the veneer layer of an anatomically correct veneer-core-cement-tooth model. METHODS: The average dimensions of a mandibular first molar crown were imported into CAD software; a tooth preparation was modeled by reducing the proximal walls by 1.5 mm and the occlusal surface by 2.0 mm. 'Crown systems' were composed by varying characteristics of a cement layer, structural core, and veneer solid, all designed to fit the tooth preparation. The main and interacting effects of proximal wall height reduction, core material, core thickness, cement modulus, cement thickness, and load position on the maximum stress distribution were derived from a series of finite element models and analyzed in a factorial analysis of variance. RESULTS: The average MPS in the veneer layer over the 64 models was 488 MPa (range = 248-840 MPa). MPS increased significantly with the addition of horizontal load components and with increasing cement thickness. In addition, MPS levels varied as a function of interactions between: proximal wall height reduction and load position; load position and cement thickness; core thickness and cement thickness; cement thickness and proximal wall height reduction; and core thickness, cement thickness and proximal wall height reduction. CONCLUSION: Rational design of veneered structural ceramics must consider the complex geometry of the crown-tooth system and integrate the influence of both the main effects and interactions among design parameters

Introduction: Bioengineering osseous tissue requires recapitulating the cellular, matrix, and lacunocanalicular components of bone. A construct must have a microvascular network which requires simultaneous co-culture of endothelial and osteogenic cells. Recreation of the matrix requires optimization of composition and microarchitecture. Engineering of constructs large enough to solve actual clinical problems requires novel strategies that address chemotransportative requirements by replicating lacunocanalicular flow. Methods: Cells: Adipose-derived mesenchymal stem cells (MSCs) were isolated and expanded from human lipoaspirate and differentiated into osteoprogenitor-rich (OPC) and endothelioprogenitor-rich (EPC), confirmed by RT-PCR. Normal human osteoblasts (NHOst) and human umbilical vein endothelial cells (HUVEC) served as terminally differentiated cell lines. The effects of coculture (e.g OPC + HUVEC, OPC + EPC etc) on capacity for bone formation was evaluated by von Kossa assay. Matrix: Murine alveolar defects were created. Scaffolds composed of either absorbable collagen sponge (ACS) or biphasic hydroxyapatite/tri-calcium phosphate (HA-TCP) in a 15/85 ratio were constructed and implanted. HA-TCP scaffolds were further investigated, comparing 15/85 and 60/40 HA/TCP in a rabbit calvarial model. Scaffold pore size (380/180 microns) and strut size (250/180 microns) were also investigated. New bone formation was analyzed histomorphometrically using micro-CT. Lacunocanalicular flow: We have developed a novel flow perfusion bioreactor designed to mimic lacunocanalicular flow. To validate, murine femurs were explanted to the bioreactor for 14 days. Viability and function were evaluated using thiazolyl blue tetrazolium bromide (MTT), DNA quantification, alkaline phosphatase (ALP) assay, and tetracycline labelling. Furthermore, optimal culture conditions were tested with MSC-seeded custom thick 3D HA-TCP scaffolds cultured in static conditions or in flow perfusion. Cellularity was assessed by SEM,!