Faculty Bibliography

BACKGROUND: The anatomy of the facial nerve and its branches has been well documented. The course of the extratemporal facial nerve, its anatomical planes, and the surface landmarks of the temporal division and marginal mandibular division are well known. However, the surface landmark of the middle division of the facial nerve has not been studied to date. METHODS: Eighteen hemifacial dissections in 10 fresh human cadavers were performed through a preauricular face-lift incision. An 18-gauge needle with brilliant green dye was used to mark the nerve through the skin before dissection. The exact location of the middle division branches of the facial nerve was documented in relation to the transcutaneous marking. RESULTS: The middle division branches of the facial nerve were found to lie at a mean of 2.3 mm from the tattooed point, with a range of 0 to 6 mm. A nerve branch was found directly tattooed by the needle seven of 18 times, inferior to the tattoo five of 18 times, and superior to the tattoo six of 18 times. CONCLUSIONS: The zygomatic/buccal motor branch that innervates the zygomaticus major muscle can be reliably found at the midway point on a line drawn from the root of the helix and the lateral commissure of the mouth. This study will help guide surgeons to the middle division of the facial nerve as it applies to facial surgery.

Frontal sinus mucoceles may present many years after traumatic injuries or surgical procedures involving the frontal bone, but have been rarely reported after fronto-orbital advancement. We describe a case of frontal sinus mucocele development in a 43-year-old patient with Apert syndrome who underwent fronto-orbital advancement as a child. This was treated with resection and free fibula osteomuscular flap reconstruction. Computer-aided design and manufacturing techniques were used to virtually plan the procedure and guide the osteotomies intraoperatively. Follow-up at 1 year postoperatively revealed no evidence of recurrence.

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.

BACKGROUND: Transplantation of a facial vascularized composite allograft is a highly complex procedure that requires meticulous planning and affords little room for error. Although cadaveric dissections are an essential preparatory exercise, they cannot simulate the true clinical experience of facial vascularized composite allograft recovery. METHODS: After obtaining institutional review board approval to perform a facial vascularized composite allograft research procurement, a 66-year-old, brain-dead donor was identified. The family graciously consented to donation of a total face, double jaw, and tongue allograft and multiple solid organs. RESULTS: A craniofacial computed tomographic angiogram was obtained preoperatively to define the vascular anatomy and facilitate virtual computerized surgical planning. The allograft was procured in 10 hours, with an additional 2 hours required for an open tracheostomy and silicone facial impression. The donor was coagulopathic throughout the recovery, resulting in an estimated blood loss of 1500 ml. Fluorescence angiography confirmed adequate perfusion of the entire allograft based on lingual and facial arterial and external jugular and thyrolinguofacial venous pedicles. The solid organ transplant team initiated abdominal organ isolation while the facial allograft procurement was in progress. After completion of allograft recovery, the kidneys and liver were recovered without complication. CONCLUSIONS: Before conducting a clinical face transplant, adequate preparation is critical to maximize vascularized composite allotransplantation outcomes and preserve solid organ allograft function. As more centers begin to perform facial transplantation, research procurement of a facial vascularized composite allograft offers a unique educational opportunity for the surgical and anesthesia teams, the organ procurement organization, and the institution.

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: 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.

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: 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: 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: 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.