Faculty Bibliography

In preparation for the donor and recipient facial vascularized composite allotransplant (VCA), the marginal mandibular nerve branch should be identified and co-apted to the recipient's nerve to allow for re-innervation. We describe a method to identify the marginal mandibular branch of the facial nerve in facial VCA donors and recipients. Through cadaver dissections, the posterior facial vein was traced posteriorly to identify the marginal mandibular branch of the facial nerve. In cases where we were unable to use this relationship, we found the posterior facial venous system to be diminutive. This technique is useful for finding the marginal mandibular branch when dissecting anterograde to the parotid gland.

PURPOSE: A core concept in plastic surgery has been the replacement of "like-with-like" tissue. Applying this concept to the lower extremity, the anterolateral thigh (ALT) perforator flap has become a frequently used free flap for restoration of soft tissue defects involving the distal lower extremity. The objective of this study was to evaluate the rate of early postoperative complications associated with the ALT perforator free flap for coverage of high-energy traumatic open fractures of the lower extremity (Gustilo IIIB) and explore related patient risk factors. METHODS: A retrospective chart review of 74 patients undergoing free tissue transfer for lower extremity limb coverage was performed. Early postoperative complications were defined as any 1 or more of the following having occurred within 6 months from surgical reconstruction: hematoma, wound infection, deep venous thrombosis, thromboembolism, partial flap loss, complete flap loss, continued osteomyelitis, and progression to amputation occurring within the first 6 months after the injury. Statistical analyses were performed using GraphPad software. Fisher exact test was performed to identify risk factors associated with greater morbidity. RESULTS: Of all patients, 26 (35%) were identified as those habitually using tobacco product and 48 (64%) were identified as nonusers of tobacco product. Moreover, 10 patients (14%) had other risk factors for atherosclerotic disease and 64 patients (86%) did not have other risk factors for atherosclerosis. Mean (SD) time to reconstruction was 4.74 (1.3) days (range, 3-8 days). Of all defects, 34 (46%) were reconstructed using adipocutaneous flaps and 40 (54%) were reconstructed using fasciocutaneous flaps. The most frequent complication was partial flap loss or superficial epidermolysis 4 (5.4%). Fisher exact test was performed, showing that patients who used tobacco product (cigarette smokers) and had other risk factors for atherosclerosis were significantly more at risk for complications (P < 0.001). CONCLUSIONS: In this retrospective review, those patients who had a positive history of tobacco use at the time of injury and those with risk factors for atherosclerosis had a significantly increased risk of flap complications. Although this is not surprising given the vasoconstrictive effects of nicotine and the impaired blood flow to the lower extremity in patients with atherosclerosis, this study will allow the surgeon to better counsel patients who have a history of tobacco use through complex reconstruction of the lower extremity. This analysis is a preliminary investigation into the safety and efficacy of the ALT fasciocutaneous or adipocutaneous flap to reconstruct high-energy open fractures of the lower extremity.

PURPOSE: The aim of this article was to assess how regional facial fracture patterns predict mortality and occult intracranial injury after blunt trauma. METHODS: Retrospective chart review was performed for blunt-mechanism craniofacial fracture patients who presented to an urban trauma center from 1998 to 2010. Fractures were confirmed by author review of computed tomographic imaging and then grouped into 1 of 5 patterns of regional involvement representing all possible permutations of facial-third injury. Mortality and the presence of occult intracranial injury, defined as those occurring in patients at low risk at presentation for head injury by Canadian CT Head Rule criteria, were evaluated. Relative risk estimates were obtained using multivariable regression. RESULTS: Of 4540 patients identified, 338 (7.4%) died, and 171 (8.1%) had intracranial injury despite normal Glasgow Coma Scale at presentation. Cumulative mortality reached 18.8% for isolated upper face fractures, compared with 6.9% and 4.0% for middle and lower face fractures (P < 0.001), respectively. Upper face fractures were independently associated with 4.06-, 3.46-, and 3.59-fold increased risk of death for the following fracture patterns: isolated upper, combined upper, panfacial, respectively (P < 0.001). Patients who were at low risk for head injury remained 4 to 6 times more likely to suffer an occult intracranial injury if they had involvement of the upper face. CONCLUSIONS: The association between facial fractures, intracranial injury, and death varies by regional involvement, with increasing insult in those with upper face fractures. Cognizance of the increased risk for intracranial injury in patients with upper face fractures may supplement existing triage tools and should increase suspicion for underlying or impending neuropathology, regardless of clinical picture at presentation.

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. (c) 2013 S. Karger AG, Basel.

PURPOSE: Blunt internal carotid artery injuries (BCAIs) can result from craniofacial trauma, yet the association between craniofacial fractures and BCAIs is poorly understood. MATERIALS AND METHODS: A retrospective cohort study of patients with blunt-mechanism facial fracture(s) presenting to a large trauma center was undertaken to identify facial fracture patterns predictive of BCAIs. Predictor variables included specific facial fracture patterns. Additional variables included demographic, injury mechanism, and associated injury classifications. Outcome variables included the presence or absence of BCAIs. All radiographic fracture patterns were confirmed by author review of computed tomographic imaging. BCAIs were confirmed and graded using the Biffl system. Differences in fracture patterns and demographic parameters in patients who presented with versus without concomitant BCAIs were compared, and relative risks for BCAI were calculated. Existing Eastern Association for the Surgery of Trauma Level III Blunt Cerebrovascular Injury (BCVI) screening criteria then were applied to the dataset to determine if additional fracture patterns would be useful in BCAI screening as determined by alterations in screening sensitivity and specificity. RESULTS: Seventy BCAIs were identified in 54 of 4,398 patients with facial fractures (1.2%). Bilateral fractures in each facial third, complex midface, Le Fort, and subcondylar fractures, fractures in association with the cervical spine, and basilar skull fractures were high risk for concomitant BCAI. Twenty percent of BCAIs would not have been captured by existing Eastern Association for the Surgery of Trauma Level III BCVI screening criteria. When patients meeting these screening criteria were removed from the study population, Le Fort I and subcondylar fractures were the only fracture patterns conferring increased risk for BCAI. Addition of these criteria to existing criteria improved the screening negative predictive value. CONCLUSION: Specific facial fracture patterns, including bilateral fractures in any facial third and complex midface, Le Fort I, and subcondylar fractures, confer increased risk of BCAI, especially in association with basilar skull fractures. Suspicion for BCAI in these patients may improve diagnosis and enable prompt therapeutic intervention. Addition of Le Fort I fractures to existing BCAI screening criteria improves sensitivity and may be of clinical utility in ruling out BCAIs.

BACKGROUND: There has been rising interest in computer-aided design/computer-aided manufacturing for preoperative planning and execution of osseous free flap reconstruction. The purpose of this study was to compare outcomes between computer-assisted and conventional fibula free flap techniques for craniofacial reconstruction. METHODS: A two-center, retrospective review was carried out on patients who underwent fibula free flap surgery for craniofacial reconstruction from 2003 to 2012. Patients were categorized by the type of reconstructive technique: conventional (between 2003 and 2009) or computer-aided design/computer-aided manufacturing (from 2010 to 2012). Demographics, surgical factors, and perioperative and long-term outcomes were compared. RESULTS: A total of 68 patients underwent microsurgical craniofacial reconstruction: 58 conventional and 10 computer-aided design and manufacturing fibula free flaps. By demographics, patients undergoing the computer-aided design/computer-aided manufacturing method were significantly older and had a higher rate of radiotherapy exposure compared with conventional patients. Intraoperatively, the median number of osteotomies was significantly higher (2.0 versus 1.0, p = 0.002) and the median ischemia time was significantly shorter (120 minutes versus 170 minutes, p = 0.004) for the computer-aided design/computer-aided manufacturing technique compared with conventional techniques; operative times were shorter for patients undergoing the computer-aided design/computer-aided manufacturing technique, although this did not reach statistical significance. Perioperative and long-term outcomes were equivalent for the two groups, notably, hospital length of stay, recipient-site infection, partial and total flap loss, and rate of soft-tissue and bony tissue revisions. CONCLUSION: Microsurgical craniofacial reconstruction using a computer-assisted fibula flap technique yielded significantly shorter ischemia times amidst a higher number of osteotomies compared with conventional techniques. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

PURPOSE: To investigate whether complex midface fractures have a greater association with death and intracranial injury than simple midface fractures. MATERIALS AND METHODS: A retrospective chart review was performed for patients with blunt-mechanism midface fractures who had presented to an urban trauma center from 1998 to 2010. The survival and intracranial injury status was evaluated for patients with simple and complex midface fractures, including Le Fort, naso-orbitoethmoid, and/or zygomaticomaxillary fractures. Intracranial injury included hemorrhage and brainstem injury. Patients with upper face fractures were excluded to minimize confounding. Adjusted relative risk estimates were obtained using multivariate regression analysis. RESULTS: Of 3,291 patients with midface fractures, 213 (6.3%) died and 693 (21.3%) had an intracranial injury. The cumulative mortality reached 11.6% in patients with complex midface fractures and 5.1% in those with simple midface fractures (P < .001). Patients with complex midface fractures were 57% more likely to die (relative risk = 1.57; P < .005). Specifically, Le Fort II fractures independently conferred a 94% increased risk of death (relative risk = 1.94; P < .01), but Le Fort I and III fractures were not significantly associated with death. Among patients presenting without neurologic impairment, those with Le Fort II and III fractures remained 2.88-fold (P < .01) and 2.54-fold (P < .001) more likely to have an underlying intracranial injury, respectively. CONCLUSIONS: Le Fort II fractures are associated with increased mortality. Furthermore, Le Fort II and III fractures are associated with serious intracranial injury, even in the absence of alterations in consciousness. These patients should be monitored with heightened vigilance and followed up closely during hospitalization, regardless of the presenting clinical findings.

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.

BACKGROUND: The purpose of this study was to investigate whether a delay in operative management of frontal sinus fractures is associated with increased risk of serious infections. METHODS: Retrospective chart review was performed of 242 consecutive patients with surgically managed frontal sinus fractures who presented to the R Adams Cowley Shock Trauma Center between 1996 and 2011. Collected patient characteristics included demographics, surgical management, hospital course, and complications. All computed tomographic imaging was reviewed to evaluate involvement of the posterior table and nasofrontal outflow tract. Serious infections included meningitis, encephalitis, brain abscess, frontal sinus abscess, and osteomyelitis. Delayed operative interventions were defined as procedures performed more than 48 hours after admission. Adjusted relative risk estimates were obtained using multivariable regression. RESULTS: There were 14 serious infections (5.8 percent). All patients with serious infections had both involvement of the posterior table and nasofrontal outflow tract injury. The cumulative incidence of serious infection in these patients was 10.8 percent. After adjustments for confounding, multivariable regression showed that operative delay beyond 48 hours was independently associated with a 4.03-fold (p < 0.05) increased risk for serious infection; external cerebrospinal fluid drainage catheter use and local soft-tissue infection conferred a 4.09-fold (p < 0.05) and 5.10-fold (p < 0.001) increased risk, respectively. Antibiotic use beyond 48 hours postoperatively was not associated with fewer infections. CONCLUSIONS: Delay in operative management of frontal sinus fractures in patients requiring operative intervention is associated with an increased risk for serious infections. Continued antibiotic prophylaxis beyond the perioperative period provides little benefit in preventing serious infections. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.

BACKGROUND: Chronic rejection of vascularized composite allografts (VCA) is an emerging phenomenon that may decrease long-term allograft survival and impair allograft function. Although intimal hyperplasia has been reported in human hand transplants, chronic changes in VCAs remain poorly described. METHODS: We developed a nonhuman primate model of face transplantation to evaluate the effect of various immunosuppressive regimens on allograft survival that we have previously reported. Nineteen grafts were successfully transplanted and serially biopsied to assess for rejection. Five VCA grafts with long-term survival (>200 days) were weaned off immunosuppression. We performed additional histologic and immunohistochemical studies on previously collected samples. RESULTS: All five grafts developed features consistent with chronic rejection, including neointimal proliferation, transplant vasculopathy, vessel wall fibrosis, progressive luminal occlusion, and tertiary lymphoid follicles. Review of 186 serial allograft skin and subcutaneous tissue biopsies revealed that tertiary follicles and vascular changes developed in the absence of acute skin rejection. No relationship was found between alloantibody production and these changes. CONCLUSIONS: Recognition of these characteristics of VCA chronic rejection is important for diagnosis in clinical hand and face transplantation. Studies directed towards minimizing VCA chronic rejection responses may be required to improve long-term outcomes.