Alexandre Marchac

Cranium and midface distraction osteogenesis: current practices, controversies, and future applications.

Background The adaptation of distraction osteogenesis (DO) to the midface and cranium in the 1990s and the advancements that followed at the turn of the century resulted in a shift of paradigm in craniofacial surgery. Because skeletal advancement was not sudden anymore, but incremental, the monobloc advancement became safer to perform. Because bone was generated in the distraction gap, bone grafts were no longer needed, and younger patients could benefit from craniofacial advancement. Today, DO is the most powerful tool to simultaneously correct both exorbitism and the respiratory impairment of the faciocraniosynostosis, but practices vary greatly between teams. Methods Current practices, controversies, and near-term future applications will be outlined and discussed. Results Our current treatment strategy for faciocraniosynostosis is based on early intervention (<18 months of age) to prevent irreversible brain damage. In the first 6 months of life, infants with faciocraniosynostosis receive posterior vault decompression. We currently use posterior vault distraction, using 2 internal distractors. Around 18 months of age, a frontofacial monobloc advancement with DO is performed. It further decompresses the brain, improves respiratory function, and corrects exorbitism. Because we operate at such an early age, we favor internal over external distractors. In severe faciocraniosynostosis, when midface hypoplasia causes major exorbitism endangering the eye or causes respiratory distress requiring a tracheotomy, we do not hesitate to perform a frontofacial monobloc advancement with DO before the age of 18 months, reinforcing the frontozygomatic junction with a plate and placing a transzygomatic pin. The pin is then connected to a traction rope. We frequently use the external distractors, which allow precise control over the rotation of the maxilla and are well tolerated after 5 years of age. When midface hypoplasia is very severe, we combine external and internal distractors. Conclusions The ongoing debate between proponents of internal versus external distractors or 1-stage versus 2-stage approach is based mostly on anecdotal data. Multicenter prospective studies are necessary to bring objective data to answer these questions.

Ethical Issues in Pediatric Face Transplantation: Should We Perform Face Transplantation in Children?

Background: In 2005, face transplantation ceased to be fiction and became a scientific reality. Today, 10 teams from six different countries have performed 32 face transplantations. Immunosuppressive treatments are similar to other solid organ transplants, and patients have experienced a significant functional improvement. The authors are logically considering expanding face transplantation to children; however, children are not simply small adults. Methods: The authors searched for pediatric patients in need of restoration of fundamental functions of the face, such as orbicularis oris or oculi muscle closure by, first, selecting cases from a pediatric plastic surgery reference center and, second, analyzing the feasibility of face transplantation in those patients. The authors then identified the specific problems that they would encounter during a pediatric face transplant. The authors identified three potential candidates for pediatric face transplantation. Results: Children’s youth imposes additional ethical and psychological considerations, such as the balance of risk to benefit when it is quality of life, not life itself, that is at stake; the process of informed consent; the selection process; and the protection of privacy against media exposure. The question becomes not whether children should be included as candidates for face transplantation but whether any ethical barriers should preclude children as candidates for a full face transplant. Conclusion: After careful consideration of the physical, psychological, and ethical aspects of such a procedure, the authors found no such barrier that would either disqualify such vulnerable subjects as profoundly disfigured children or conflict with their best interests.

Correction of alveolar cleft with calcium-based bone substitutes.

In the article entitled ‘‘Correction of alveolar cleft with calciumbased bone substitute,’’ Lazarou et al report the use of Stimulan (Biocomposites, Staffordshire, UK) as a substitute to autologous bone in primary alveolar cleft bone grafting. In their study, 10 infants with complete unilateral cleft lip and palate underwent gingivoperiosteoplasty (GPP) between 9 and 12 months of age (the cleft lip had been previously repaired in a separate procedure). During the GPP, after the closure of the nasal and oral mucosa, calcium sulfate powder and/or pellets were stacked in the alveolar cavity, and then the GPP pocket was closed. No fistula or infection occurred. Mean follow-up was 5.1 years. In each patient, deciduous tooth eruption occurred in the cleft area. Panorex and occlusal radiography, performed at the age of 4 years, documented bone formation. None of the patients required secondary bone grafting at the end of the study period. The authors conclude that primary grafting of Stimulan allows tooth eruption and that this ‘‘off-theshelf’’ material presents a significant advantage over other biomaterials and autologous tissue in the correction of alveolar clefts. Lazarou et al are rightly addressing a complex problem in cleft surgery, and they should be commended for their effort. Around the world, alveolar cleft are treated with a wide array of techniques, and despite the lack of preclinical data, some centers provide off-label, noncontrolled treatment for patients with congenital alveolar clefts. Although the initial data from these human reports are exciting, they are largely uncontrolled, and the patients are not randomized. Without adequate study design and appropriate controls, the skeptic is left wondering whether a new approach is any better than an older one. Currently, the 3 main approaches to alveolar cleft are (1) secondary alveolar bone grafting during mixed dentition (aged between 7 and 9 y), (2) presurgical orthopedics with primary GPP at the time of primary lip repair, and (3) early alveolar bone grafting in the first year of life with autogenous bone graft. Secondary autologous bone grafting during mixed dentition has a 68% to 96% rate of success and is the most common technique around the world. Preoperative orthopedic molding is designed to reduce the alveolar gap so that a primary gingivoperiosteoplasty is possible. With optimal preoperative molding and primary GPP, 41% to 73% of patients have sufficient alveolar bone formation for eruption of the adult teeth or implant placement. To achieve optimal results, this approach requires an experienced team, including a craniofacial orthodontist to closely approximate the alveolar segments (G1 mm) with a custommade appliance before the GPP and a skilled cleft surgeon to operate in a small space to elevate the tissues only at the edge of the cleft margin and avoid damage to the tooth buds. Bone grafting is not necessary in this procedure because the periosteum serves as an osteogenic substrate, but patients for whom a primary GPP is unsuccessful will require secondary bone grafting at age 7 to 9 years. Early alveolar bone grafting without presurgical orthodontics leads to bone formation if the alveolar cleft is narrow; however, there tends to be a high incidence of maxillary hypoplasia because of the extensive subperiosteal dissection necessary to close the alveolar cleft. Furthermore, if the alveolar cleft is wide, the central portion of the graft is unlikely to be revascularized. Although each technique may produce satisfactory results in experienced hands, none has indisputably been shown to be superior. For many surgeons today, bone grafting of the alveolar cleft remains the standard of care. Although many surgeons will argue that cancellous iliac bone graft can be harvested in a 7-year-old in less than 15 minutes through a 1-cm incision with minimal bleeding, minimal postoperative pain, and no functional sequelae, such a harvest is more challenging in an infant. Corticocancellous bone harvested from the ribs or the calvaria is less likely to be revascularized than cancellous bone harvested from the ilium or the tibial crest. Moreover, harvesting bone from the lower extremity weakens the anterior cortical of the tibia increasing the risk of postoperative tibial fractures. In sum, avoiding bone-graft donor site morbidity at any age is a goal in alveolar cleft surgery. In their study, Lazarou et al used an acellular scaffold marketed under the name of Stimulan. Stimulan is a medicaland implantgrade calcium sulfate (CaSO4), a compound better known as plaster of Paris, created by heating gypsum to 150-C (the large gypsum deposit at Montmartre in Paris is the source of the name). Plaster of Paris has been widely used in orthopedic surgery since the mid 19th century to build casts to immobilize fractures. In 1959, Peltier used it to fill large bone defects. Biocomposites (Staffordshire, UK) started to offer a decade ago high-quality synthetic implantable CaSO4 for orthopedic indications (fractures, filling of aneurismal bone cyst sites, filling of benign giant cell tumor sites, and osteomyelitis), obtaining European Community and US Food and Drug Administration approvals in the above-mentioned indications. In this alveolar cleft study, Stimulan is used as an off-label device. Synthetic high-purity calcium sulfate acts as an acellular scaffold, to be colonized by osteoprogenitor cells and grow new bone, in a manner similar to the mineral-based osteoconductive calcium phosphate ceramics scaffold that we and others are currently investigating in the laboratory. The chemical anisotropic materials most often used to construct polycrystalline ceramics are hydroxyapatite (HA) and tricalcium phosphate (TCP). These ceramics have been targeted because they have the native composition of bone, mechanical features similar to bone, controlled absorption, and biologically active properties that are believed to facilitate osteogenic differentiation of mesenchymal stem cells. When transplanted as acellular scaffolds, their chemical properties promote recruitment of osteoprogenitor cells, vascular invasion, and bone formation. Interestingly, in their study, Lazarou et al achieved satisfactory bone formation DISCUSSION

Reconstruction of Punitive Ear Amputations in Uganda: A Unique Surgical Burden of Disease.

AbstractOver the course of 12 months, a plastic surgical team from Paris, France, undertook 2 intensive ear reconstruction missions with plastic surgeons from the CoRSU Rehabilitation Hospital in Uganda. A cohort of over 30 adult women was assessed having been subjected to ear amputations by members of the Lords Resistance Army in Northern Uganda in the 1990s. The patients were identified, mobilized, and transferred to Kampala for surgery by a charitable arm of the Watoto Church, known as Living Hope. The surgical team performed 15 ear reconstruction cases during the first 1-week mission and 16 ear reconstruction cases during the second 1-week mission. All cases were reconstructed successfully using the 2-stage autologous auricular reconstruction method advocated by the senior author (FF). Local skin was used to cover the costal cartilage framework in the first stage without need for temporo-parietal fascial flaps. Technical challenges included the older age of patients and ossified costal cartilage, high prevalence of HIV positivity, bilateral amputation, and difficulty of surgical follow-up. The main modifications to standard practice were routine pre-op testing of the costal cartilage, pre-op viral load and CD4 count screening in HIV-positive patients, simultaneous bilateral first-stage ear reconstruction, prolonged hospital stay, and implementation of routine surgical counting procedures.

81B: MITIGATING RADIATION-INDUCED SKIN INJURY: PREVENTING ANGIOSTASIS VIA TOPICAL CXCR3 SILENCING

Methods: A novel, skin-only murine model of radiation injury was employed. Mice were exposed to 20gy immediately followed by local cutaneous delivery of CXCR3 siRNA with an agarose-based delivery matrix. Reapplication of siRNA complex occurred at days 7, 14, and 21. Tissue oxygenation was evaluated at days 0, 7, 14, 21 and 28. CXCR3 and angiogenic/angiostatic mediators (VEGF, SDF-1, CXCL9-11) were evaluated at the mRNA and protein levels (RT-PCR and ELISA). Lung, liver, and spleen homogenates evaluated off target effects.

Alloderm as a Topical Gene Therapy Matrix To Improve Graft Vascularity

INTRODUCTION: Alloderm acellular dermal matrix is widely used for structural or dermal replacement purposes. Given its highly biocompatible quality, its infection resistance, and its potential to vascularize, we explored the possibility of Alloderm to function as a siRNA delivery matrix. Specifically, we sought to improve Alloderm vascularization by siRNA mediated inhibition of Prolyl hydroxylase domain-2 (PHD2), a cytoplasmic protein that regulates the HIF-1α pathway of angiogenic factor upregulation and neovascularization.

Chemical Delay of Flaps through Endogenous Stem Cell Therapy

INTRODUCTION: Alloderm acellular dermal matrix is widely used for structural or dermal replacement purposes. Given its highly biocompatible quality, its infection resistance, and its potential to vascularize, we explored the possibility of Alloderm to function as a siRNA delivery matrix. Specifically, we sought to improve Alloderm vascularization by siRNA mediated inhibition of Prolyl hydroxylase domain-2 (PHD2), a cytoplasmic protein that regulates the HIF-1α pathway of angiogenic factor upregulation and neovascularization.