Faculty Bibliography

With technological advances in magnetic resonance angiography (MRA), spatial resolution of 1-mm perforating vessels can reliably be visualized and accurately located in reference to patients' anatomic landmarks without exposing patients to ionizing radiation or iodinated contrast, resulting in optimal perforator selection, improved flap design, and increased surgical efficiency. As their experience with MRA in breast reconstruction has increased, the authors have made changes to their MRA protocol that allow imaging of the vasculature in multiple donor sites (buttock, abdomen, and upper thigh) in one study. This article provides details of this experience with multiple donor site contrast-enhanced MRA.

BACKGROUND: To date, only limited case reports involving isolated bilateral zygomatic arch fractures exist. This fracture pattern is defined by the presence of bilateral zygomatic arch fractures and the absence of any other facial fractures. The purpose of this study was to systematically review a large trauma database to determine whether this fracture pattern exists and, if so, to elucidate the mechanism of injury and associated concomitant injuries. METHODS: A retrospective review of all patients admitted to the R Adams Cowley Shock Trauma center from February of 1998 to December of 2009 was conducted. International Classification of Diseases, Ninth Revision coding of computed tomographic scans was used to identify patients with zygoma fractures. The facial computed tomographic scans of all patients coded with bilateral zygoma fractures were reviewed to determine whether any had isolated bilateral zygomatic arch fractures. Medical charts were reviewed extensively. RESULTS: Five patients (0.24 percent of all zygoma fractures, 3.18 percent of bilateral zygoma fractures) were found to have isolated bilateral zygomatic arch fractures. All five patients had evidence of skull impact with at least one skull fracture and one skull base fracture. Glasgow Coma Scale scores (range, 6 to 14; average, 8.2) were significantly lower (t test, two-sided, p=0.01) compared with all patients (average, 12.2) with facial trauma during the study period. CONCLUSIONS: Isolated bilateral zygomatic arch fractures do exist. The authors' findings suggest skull impacts as the inciting mechanism of injury and an intimate link with skull base force transmission. The severe nature of this injury warrants a search for concomitant injuries to the head, brain, and spinal cord.

BACKGROUND: Vascularized composite tissue allotransplantation has demonstrated clinical success with standard immunosuppression in hand and upper extremity transplantation. The authors developed a fibular vascularized composite tissue allotransplantation model in nonhuman primates to investigate healing and rejection patterns of bone and associated tissues. METHODS: Five fibular vascularized composite tissue allotransplantations were performed between mismatched cynomolgus macaques (Macaca fascicularis). Vascularized fibular segments with associated muscle and skin were transplanted to recipient forearm radius defects. Recipients were treated with either tacrolimus monotherapy or tacrolimus plus co-stimulatory blockade with a novel anti-CD28 antibody. Animals were followed for 6 months with serial radiographs, blood sample collection, and biopsies. At the study endpoint, angiographic, biomechanical, histologic, and immunologic assays were performed. RESULTS: All animals survived to the experimental endpoint of 180 days. Rapid or immediate skin loss was evident secondary to vascular compromise (n = 3) or rejection (n = 1) in four animals. Despite loss of nonbony segments and the development of transplant arteriopathy consistent with chronic rejection in two animals, serial radiologic imaging and histology demonstrated bone healing and donor-recipient bony union by 10 weeks in all animals. Histology confirmed the presence of viable cortical and marrow elements. Biomechanical analysis supported donor-recipient bony union. Short-tandem repeated genotypic analysis revealed that donor marrow had been completely replaced by recipient marrow. CONCLUSIONS: In contrast to successes in extremity vascularized composite tissue allotransplantation, the authors' nonhuman primate fibular vascularized composite tissue allotransplantation model showed early skin loss, replacement of donor bone marrow, and chronic rejection. Donor-recipient bone union did occur and supports the potential for reconstruction of bony continuity defects using isolated vascularized bone allotransplants.

BACKGROUND: The free anterolateral thigh (ALT) flap has become a reconstructive workhorse with great versatility throughout the body. However, the utility of the pedicled ALT flap is less described for complex defects. A skin paddle with reliable blood circulation and wide range of reach, low donor site morbidity along with the avoidance of many of the complications plaguing free flaps, are just some of the several benefits offered by the pedicled ALT flap. We investigated specific clinical examples within our ALT flap database where the pedicled ALT flap was used for coverage of complex wounds and highlight its advantages. METHODS: We conducted a retrospective chart review on those patients in whom a pedicled ALT flap was used for complex wound reconstruction over a 7-year period between July 2002 and October 2009 at The R Adams Cowley Shock Trauma Center performed by a single surgeon. RESULTS: : Four patients underwent a pedicled ALT flap as part of their reconstruction. Flaps ranged in size from 75 to 648 cm, and all but one were cutaneous in nature with the other one being fasciocutaneous. The flaps averaged 2 perforators (range, 1-3) and the donor sites were all closed primarily except for one. CONCLUSIONS: When faced with a complex defect in the abdominal-pelvic region, we propose that the pedicled ALT flap has several advantages to other types of tissue coverage and is an excellent option for the reconstructive surgeon.

Biologic prostheses have emerged to address the limitations of synthetic materials for ventral hernia repairs; however, they lack experimental comparative data. Fifteen swine were randomly assigned to 1 of 3 bioprosthetic groups (DermaMatrix, AlloDerm, and Permacol) after creation of a full thickness ventral fascial defect. At 15 weeks, host incorporation, hernia recurrence, adhesion formation, neovascularization, inflammation, and biomechanical properties were assessed. No animals had hernia recurrence or eventration. DermaMatrix and Alloderm implants demonstrated more adhesions, greater inflammatory infiltration, and more longitudinal laxity, but near identical neovascularization and tensile strength to Permacol. We found that porcine acellular dermal products (Permacol) contain following essential properties of an ideal ventral hernia repair material: low inflammation, less elastin and stretch, lower adhesion rates and cost, and more contracture. The addition of lower cost xenogeneic acellular dermal products to the repertoire of available acellular dermal products demonstrates promise, but requires long-term clinical studies to verify advantages and efficacy.

BACKGROUND: The aim of lower extremity reconstruction has focused on early wound coverage and functional recovery but rarely aesthetics. Free muscle flaps provide durable coverage; however, they require skin graft coverage and result in muscle atrophy limiting future revisions. Perforator-based flap reconstructions can be easily elevated to allow for both orthopedic and contouring procedures. The authors reviewed the role of secondary procedures in achieving improved functional and aesthetic results following perforator flap reconstruction of lower extremity defects. METHODS: A retrospective review identified 70 patients treated at R Adams Cowley Shock Trauma Center with 73 free perforator flaps for coverage of lower extremity wounds from 2002 to 2009. RESULTS: Seventy patients were identified who underwent reconstruction with a perforator flap: 65 with anterolateral thigh flaps and five with superficial circumflex iliac artery flaps. Nineteen of these patients underwent 32 refinement procedures of the reconstructed limb. Fifteen refinements were performed with suction-assisted lipectomy, 21 with complex tissue rearrangement, including sharp debulking, and one with tissue expanders. Twenty-seven of the 70 patients underwent 40 orthopedic-related secondary procedures in which the free flap was elevated. The most common reasons for the orthopedic interventions were tibial nonunion requiring bone grafting (n = 17) and osteomyelitis (n = 11). CONCLUSIONS: Limb salvage remains the primary goal of lower extremity reconstruction. Following convalescence and functional recovery, however, appearance becomes increasingly important with regard to quality of life. Initial flap selection with free perforator flaps, meticulous inset, and secondary refinements provide superior functional and aesthetic outcomes.

Vascularized composite allograft (VCA) transplantation (also referred to as composite tissue allotransplantation) has demonstrated clinical success in cases of hand, arm and face transplantation despite prior belief that skin provides an insurmountable barrier to allograft rejection. These overall good outcomes are facilitated by substantial immunosuppressive requirements in otherwise healthy patients, yet still demonstrate frequent rejection episodes. We developed a nonhuman primate model of facial segment allotransplantation to elucidate the unique pathophysiology and immunosuppressive requirements of VCA with addition of concomitant vascularized bone marrow (VBM). Heterotopically transplanted facial segment VCA with VBM treated only with tacrolimus and mycophenolate mofetil (MMF) demonstrated prolonged rejection-free survival, compared to VCA without VBM that demonstrated early rejection episodes and graft loss. While VCA with VBM demonstrated sporadic macrochimerism, acute and chronic rejection and graft loss occurred after discontinuation of immunosuppression. These data support an immunomodulatory role of VBM in VCA that reduces immunosuppressive requirements while providing improved outcomes.