Faculty Bibliography

BACKGROUND: Elbow extension is important for the elbow joint, and it is more difficult to restore with microsurgery than elbow flexion. The purpose of this article is to describe the experience of the authors with elbow extension reconstruction in obstetric brachial plexus palsy patients. The outcomes were analyzed in relation to the type of brachial plexus lesion, timing of surgery, and the type of nerve reconstruction. METHODS: Fifty-five children with obstetric brachial plexus palsy who underwent nerve reconstruction for elbow extension restoration were studied. The mean follow-up period was 6.4 years (range, 2-22 y). Reinnervation of the triceps muscle was accomplished with indirect neurotization of the posterior cord from intraplexus donors or with direct neurotization from extraplexus donors, such as the contralateral C7 and the intercostal nerves. RESULTS: Thirty-seven (67%) of the 55 cases showed good or excellent results (>or=M3+). The average postoperative muscle grading for the triceps was 3.34+/-0.99 compared with 1.19+/-1.29 preoperatively (P<0.0001). Patients with C5 to C7 palsy achieved significantly stronger elbow extension than those with C5 to T1 palsy. In addition, the timing of surgery significantly influenced the final outcome. CONCLUSIONS: Elbow extension is one of big challenges to be restored, especially in obstetric brachial plexus palsy. In early cases (within 6 mo) intraplexus reconstruction of the posterior cord can give excellent results. In later cases, or in cases of multiple avulsions, extraplexus motor donors, which selectively targeted the triceps, can give variable results

OBJECTIVES/HYPOTHESIS: AlloDerm (LifeCell Corp., Branchburg, NJ) is commonly employed for reconstruction of ablative soft tissue and mucosal defects following surgical resections. Although devoid of growth factors, AlloDerm may serve as an adhesive matrix for binding of growth factors, increasing local angiogenesis, and wound healing. We hypothesized that AlloDerm would enhance angiogenesis and might be altered with autologous blood products to enhance initiation of the angiogenic response. METHODS: We used a human placental vein in a fibrin-thrombin clot-based angiogenesis model. Four groups, human placental vein (HPVM), HPVM with AlloDerm, HPVM with AlloDerm plus platelet-poor plasma, and HPVM with AlloDerm plus platelet-rich plasma were evaluated. Endothelial cell growth was evaluated visually (40x). Hematoxylin and eosin staining and immunofluorescent staining for growth within the AlloDerm matrix were also performed. To assess human umbilical vein endothelial cell (HUVEC) sites of attachment to AlloDerm, we incubated HUVEC cells with AlloDerm for a period of 2 weeks and evaluated attachment with anti-factor VIII immunofluorescence. RESULTS: Angiogenic initiation decreased in the combined placental vein with AlloDerm group (P < .0001 at day 7, 14, 21). Additionally, initiation in the AlloDerm plus platelet-poor plasma group was significantly better than the AlloDerm alone group when placentas 2 and 3 were compared (P < .0001). On hematoxylin and eosin staining and immunofluorescent factor VIII staining, no endothelial growth into the AlloDerm was noted in the samples analyzed. CONCLUSIONS: AlloDerm may be enriched with platelet-poor plasma to stimulate greater initiation and wound healing; however, AlloDerm inhibits angiogenic initiation in this model.

The viability of fat grafts harvested with an established technique after cryopreservation remains unknown. This study was conducted in vitro to evaluate the viability of autologous fat grafts harvested with the Coleman technique and subsequently preserved with our preferred cryopreservation method. Eight adult females were enrolled in this study. In each patient, 10 mL of fat grafts were harvested with the Coleman technique by a single surgeon from the lower abdomen. In group 1, 5 mL of fresh fat grafts were mixed with cryoprotective agents and underwent cryopreservation with controlled slow cooling and fast rewarming. In group 2, 5 mL of fresh fat grafts without cryopreservation from the same patient served as a control. The fat graft samples from both groups were evaluated with trypan blue vital staining, glycerol-3-phophatase dehydrogenase assay, and routine histology. Viable adipocyte counts were found similar in both group 1 and group 2 (3.46 +/- 0.91 vs. 4.12 +/- 1.11 x 10/mL, P = 0.22). However, glycerol-3-phophatase dehydrogenase activity was significantly lower in group 1 compared with group 2 (0.47 +/- 0.09 vs. 0.66 +/- 0.09 u/mL, P < 0.001). Histologically, the normal structure of fragmented fatty tissues was found primarily in both groups. Our results indicate that autologous fat grafts harvested with the Coleman technique and preserved with our preferred cryopreservation method have a normal histology with near the same number of viable adipocytes as compared with the fresh fat grafts. However, those cryopreserved fat grafts appear to have a less optimal level of adipocyte specific enzyme activity compared with the fresh ones and thus may not survive well after they are transplanted without being optimized

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,!

Soft-tissue reconstruction of traumatic patella and proximal tibial defects is challenging. Pedicled perforator-based adipocutaneous rotation flaps are a versatile local option as they have axial perfusion and greater freedom of transposition compared with random-pattern flaps, and replace the ideal tissue properties of this anatomic region.Experimental: Anatomic dissections were performed on 15 fresh cadaver legs and location of the dominant perforator measured. Clinical: A retrospective review was conducted at the University of Maryland/R Adams Cowley Shock Trauma Center evaluating patients over a 3-year period.Experimental: Cadaver dissections confirmed a principal perforator at 11.4 +/- 1.6 cm inferior to the patella. This vessel is consistently suitable in length and caliber for large rotation flap design. Clinical: Anterior tibial artery perforator flaps were performed on 4 patients following Gustilo IIIB wounds to the patella and tibial plateau. Two patients had rotation flap reconstructions to salvage failed gastrocnemius muscle flaps. All flaps were successful, however, one patient had overwhelming hardware infection several months later despite successfully healed flap.Local anterior tibial artery perforator flaps based on predictable perforators provide reliable coverage of patella and knee defects, bestowing versatility and flexibility to the reconstructive surgeon's armamentarium.

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: 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.

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.