Faculty Bibliography

BACKGROUND: With the transplantation of more extensive facial vascularized composite allografts, fundamental craniofacial and aesthetic principles become increasingly important. In addition, computer-assisted planning and intraoperative navigation may improve precision and efficiency in these complex procedures. METHODS: Ten mock face transplants were performed in 20 cadavers. The vascularized composite allograft consisted of all facial skin, mimetic muscles, the tongue, the midface by means of a Le Fort III osteotomy, and the mandible by means of sagittal split osteotomies. Craniofacial computed tomographic scans were obtained before and after the mock transplants. Surgical planning software was used to virtually plan the osteotomies, and a surgical navigation system guided the osteotomies intraoperatively. Cephalometric analyses were compared between the virtually planned transplants and the actual postoperative results. RESULTS: The combination of preoperative computerized planning and intraoperative guidance consistently produced a vascularized composite allograft that could be easily fixated to the prepared recipient, with only minimal burring of osteotomy sites necessary. Satisfactory occlusion was maintained, and postoperative computed tomography confirmed accurate skeletal fixation. Insignificant differences with regard to cephalometric analyses were noted when predicted and actual postoperative data were compared. CONCLUSIONS: The authors' experience treating severe craniofacial injury allowed consistent transfer of facial vascularized composite allografts, maintaining proper occlusion. Preoperative computer planning and intraoperative navigation ensured precise osteotomies and a good donor-recipient skeletal match, which greatly reduced the need for intraoperative adjustments and manipulation. This total facial vascularized composite allograft represents one of the most extensive described and is intended to represent a typical central facial demolition pattern.

BACKGROUND: Current literature describes the forehead as one aesthetic subunit of the face. We argue for the usefulness of aesthetic forehead subunits when microvascular flap reconstruction is required. Key to utilization of microvascular flaps for restoration of forehead subunits is an understanding of the patient population and defect characteristics most amiable to treatment. METHODS: We conducted an International Review Board-approved retrospective chart review of nine consecutive patients who had undergone free flap reconstruction for large forehead defects. RESULTS: The patients' foreheads included one paramedian defect; one central and paramedian defect; four central, paramedian, and lateral defects; and three lateral defects. Seven patients had ulnar forearm flaps and two had anterolateral thigh flaps. The success rate was 100%. CONCLUSION: A forehead subunit classification system has been devised that provides a suitable option for cases that benefit from distant tissue replacement in a single stage, while preserving the principles of aesthetic replacement.

BACKGROUND: Over the last several decades, there have been numerous advances in the fields of aesthetic, craniofacial, and microsurgery. Aesthetic units are no longer "skin deep" but are recognized as being composed of both soft and hard tissue. Indeed, hard tissue must complement the soft tissue to recreate the unit. In addition, revisionary procedures have become necessary to achieve the desired result. Here, the authors integrate seven critical concepts and provide a patient series illustrating their success. METHODS: The authors assembled a two-center, retrospective cohort review of patients who underwent free-tissue transfer of craniofacial defects at the R Adams Cowley Shock Trauma Center and the Johns Hopkins Hospital from 2003 to 2011. Patients were categorized by anatomic location, complications recorded, and illustrative cases selected. RESULTS: A total of 184 patients with craniofacial defects were identified: 79 female and 105 male patients, with a mean age of 44 years. Etiologies included cancer (51.6 percent), trauma (39.1 percent), congenital defects (6.5 percent), and infection (2.7 percent). Free-tissue transfers included 67 fibula, 42 anterolateral thigh, 41 ulnar, 18 groin, 14 iliac, three radius, and one vastus lateralis flaps. The success rate was 97.3 percent and complication rate was 10.8 percent. Secondary procedures included suction lipectomy, dermabrasion, tissue resuspension, and cutaneous flap excision followed by full-thickness skin grafting or tissue rearrangement. CONCLUSIONS: To achieve aesthetically pleasing results in free-flap facial reconstruction, the authors define seven critical concepts to guide the reconstruction: aesthetic-unit appearance, defect boundaries, tissue requirements, vascularized skeletal buttress framework, ample soft-tissue volume, early reconstruction, and local revisional procedures. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

BACKGROUND: Mandible subcondylar fractures may be treated via a traditional visible access incision; however, with the advances in surgical endoscopy surgeons are transitioning to a minimally invasive approach in an effort to reduce surgical morbidity and external facial scarring. We sought to design a clinically applicable teaching tool in a large animal model that would allow the operator to gain experience treating mandible subcondylar fractures via an endoscopic approach. METHODS: A large animal model was developed using the Churra sheep. Subcondylar fractures were created, reduced, and internally plated in ten specimens via an extraoral, two-port endoscopic approach. Animals were monitored for surgical success during the intraoperative and immediate postoperative periods. RESULTS: Mandibles were reduced and fixated successfully in each of the animals. Operative time was reduced from 70 to 40 min as the surgeons became more familiar with the surgical procedure. Each of the ten Churra sheep used in the study tolerated the surgeries without postoperative complications. CONCLUSIONS: Capitalizing on a mandibular anatomy similar to humans, the Churra sheep successfully demonstrated utility for the extraoral, endoscopic approach in treating mandibular condyle fractures. This model offers surgeons the opportunity to gain surgical endoscopic experience before treating clinical patients.

Objective: Reconstruction of traumatic ventral hernias often requires additional techniques to the abdominal wall component separation, such as the use of interpositional reconstruction with an acellular dermal matrix or other mesh to bridge the defect. Methods: We have developed a new value termed the "Component Separation Index" to evaluate ventral hernia defects. Choosing a fixed point on a preoperative axial computed tomographic scan (aorta) and the medial leading edges of the rectus abdominus muscles, we determined the angle of diastasis of the hernia. This angle is divided by 360 degrees giving a relative value of the transverse defect size as compared to the estimated circular body habitus for that specific patient. A retrospective review of 36 cases of ventral hernia repairs was performed. The Component Separation Index was calculated from the preoperative computed tomographic scans obtained before repair. Group 1 (n = 18) required component separation for closure. Group 2 (n = 18) required component separation and placement of interpositional mesh to span the hernia defect. Results: The Component Separation Index values were then compared using the student t test for each group. The mean Component Separation Index for group 1 was 0.11 with standard deviation of 0.06. The mean Component Separation Index for group 2 was 0.21 with standard deviation of 0.04 (P < .0001). As this value approaches 0.21, the likelihood of an interpositional repair in addition to component separation becomes much greater. Conclusions: While there is no substitute for clinical acumen when evaluating these defects, objective measurements can provide a valuable additional tool for the surgeon facing these challenging cases.

BACKGROUND: Clinical vascularized composite allografts (VCA), although performed with good success, have been characterized by rejection episodes and postoperative graft edema. We investigated lymphatic donor-recipient reconstitution and lymphatic regeneration in a nonhuman primate facial VCA model. METHODS: Heterotopic partial face (n = 9) VCAs were performed in cynomolgus macaques. Grafts were monitored for rejection episodes and response to immunosuppressive therapies as previously described. Donor and recipient lymphatic channels were evaluated using a near-infrared handheld dual-channel light-emitting diode camera system capable of detecting fluorescence from indocyanine green injections. Graft lymphatic channels were serially evaluated from postoperative day 0 to 364. RESULTS: Preoperative imaging demonstrated superficial lymphatic anatomy similar to human anatomy. Initial resolution of facial allograft swelling coincided with superficial donor-recipient lymphatic channel reconstitution. Reconstitution occurred despite early acute rejection episodes in 2 animals. However, lymphatic channels demonstrated persistent functional and anatomic pathology, and graft edema never fully resolved. No differences in lymphatic channels were noted between grafts that developed transplant vasculopathy (n = 3) and those that did not (n = 6). Dynamic changes in patterns of lymphatic drainage were noted in 4 animals following withdrawal of immunosuppression. CONCLUSIONS: Donor-recipient lymphatic channel regeneration following VCA did not result in resolution of edema. Technical causes of graft edema may be overcome with alternative surgical techniques, allowing for direct investigation of the immunologic relationship between VCA graft edema and rejection responses. Mechanisms and timing of dynamic donor-recipient lymphatic channel relationships can be evaluated using fluorescent imaging systems to better define the immunologic role of lymphatic channels in VCA engraftment and rejection responses, which may have direct clinical implications.

BACKGROUND: This study was to evaluate the sensory recovery in the lower lip and chin in patients who underwent segmental mandibulectomy involving inferior alveolar nerve and simultaneous reconstruction with fibular osteoseptocutaneous flap and interposition sural nerve graft. MATERIAL AND METHOD: From 1993 to 2004, a total of 20 patients underwent segmental mandibulectomy, simultaneous fibula osteoseptocutaneous flap reconstruction and interpositional sural nerve graft. Twelve patients were available for the study. There were seven male and five female patients with average age of 35.8 years (16-52 years). The sense at the lower lip and chin was measured by two-point discrimination both at the operated and non-operated side at an average of 64.3 months (12-146 months). RESULT: The operated side revealed an average of 13.7 mm for static (STPD) and 13.3 mm for moving two-point discrimination (MTPD) at the lower lip and 13.7 mm for static and 13.4 mm for MTPD at the chin. Data from the non-operated side averaged 3.4 mm for static and 3.2 mm for MTPD at lower lip and 5.1 mm for static and 4.5 mm for moving discrimination at the chin. All patients recovered better than protective sensation on the operated side, which was sufficient to prevent self-mutilation, preserve comprehensible speech and maintain oral competence. No patient complained of significant donor site morbidity. CONCLUSION: Simultaneous reconstruction of a segmental mandibulectomy involving inferior alveolar nerve with a fibula osteoseptocutaneous flap and interpositional sural nerve graft offers simultaneous replacement of mandibular architecture and restoration of protective perioral sensation.

BACKGROUND: Adjuvant chemotherapy is often required for the treatment of bone cancers after tumor resection, which often results in a large continuity defect. The immunosuppressive side effects could instead be exploited to allow immediate reconstruction with a composite tissue allograft (CTA) that would provide for replacement of tissues. We used a short course of doxorubicin to achieve a novel method of immunosuppression in a rat model undergoing CTA to create an immunological environment for allograft survival. MATERIALS & METHODS: The Institutional Animal Care and Use Committee-approved protocol consisted of 3 experimental groups. Groups 2 and 3 consisted of Brown Norway rats (n = 5) as allograft donors and Lewis rats (n = 5) as transplant recipients. An abdominal wall CTA was harvested off the superficial inferior epigastric vessels. Doxorubicin therapy was administered in group 3 animals. Survival of the CTA was assessed by physical examination and histological analysis. RESULTS: Allotransplant without treatment showed complete clinical and histologic rejection by day 7. Allotransplant rats treated with doxorubicin had clinically and histologically normal grafts through day 10. Kaplan-Meier survival analysis showed a statistically significant difference, with increased CTA survival time to end point with doxorubicin treatment, from a mean of 8.8 days in group 2 to 16.4 days in group 3. CONCLUSIONS: Allotransplant flaps without treatment developed complete clinical and histological rejection. The allotransplant group which received doxorubicin showed a delay of allograft rejection with an 86% increased CTA graft survival time. This demonstrates the feasibility of the immunosuppression side effect caused by chemotherapy to prevent rejection of a CTA.

The role of vascularized bone marrow in promoting composite allograft survival can be assessed by intrinsically chimeric flaps. In this study, we introduce a significant modification to a previously described rat model of combined superficial inferior epigastric artery (SIEA) myocutaneous/vascularized femur transplantation. We previously noted autocannibalization in orthotopic myocutaneous SIEA allotransplants, which complicated clinical and histologic evaluation of rejection. We therefore designed syngeneic experiments in eight Lewis (RTl(1) ) rat pairs to explore the feasibility of tunneling the SIEA component of chimeric SIEA myocutaneous/vascularized femur flaps to the recipient dorsum. Vascularized SIEA myocutaneous/femur transplants survived in their entirety to POD 63 study endpoint with patent anastomoses in seven of eight (87.5%) transplants as confirmed clinically, histologically, and via near-infrared fluorescent angiography. Tunneling of the SIEA component of SIEA myocutaneous/vascularized femur flaps to the recipient dorsum can be achieved with high success rate and acceptable operative times, and is a technically easy method to study the role of vascularized bone marrow in composite allografts. This modification facilitates SIEA component monitoring, removes it from constant contact with cage bedding, and places it in a location where autocannibalization is unlikely.

BACKGROUND: Injuries to the face can potentially lead to destruction of vital structures, with devastating sequelae to the patient. Facial fractures, especially of the midface, are often complicated by ocular injuries. The purpose of this study was to systematically review the literature to better understand specific fracture patterns associated with ocular injuries, including visual impairment and blindness. METHODS: The PubMed, EMBASE, and Cochrane databases from January of 2004 to April of 2010 were systematically reviewed to identify relevant studies. Only those that investigated facial fractures with concomitant ocular injuries, visual impairment, and/or blindness were included. Studies that described nonfacial fractures or those that only focused on the function of extraocular muscles were excluded. Case reports, nonsystematic reviews, and studies with fewer than 10 patients were also excluded. RESULTS: Eleven articles met study criteria and were included for analysis. There were a total of 14,535 patients, with an average of 1211 patients (range, 39 to 4426) per study. Level of evidence included levels II (n = 1 study), III (n = 1), and IV (n = 9). The mean reported rate of acute visual loss was 1.7 percent. Periorbital and orbital blowout fractures were more often complicated by ocular injuries compared with other facial fracture patterns. High-impact zygomatic fractures were most commonly associated with blindness. CONCLUSIONS: Existing studies exploring ocular injuries, visual impairment, and blindness associated with facial fractures offer conflicting data. Specifically directed studies are required so that significant correlations between specific fracture patterns and specific ocular injuries can be drawn. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, IV.