Functional Validation of a New Alginate-based Hydrogel Scaffold Combined with Mesenchymal Stem Cells in a Rat Hard Palate Cleft Model.

BACKGROUND: One of the major difficulties in cleft palate repair is the requirement for several surgical procedures and autologous bone grafting to form a bony bridge across the cleft defect. Engineered tissue, composed of a biomaterial scaffold and multipotent stem cells, may be a useful alternative for minimizing the non-negligible risk of donor site morbidity. The present study was designed to confirm the healing and osteogenic properties of a novel alginate-based hydrogel in palate repair. METHODS: Matrix constructs, seeded with allogeneic bone marrow-derived mesenchymal stem cells (BM-MSCs) or not, were incorporated into a surgically created, critical-sized cleft palate defect in the rat. Control with no scaffold was also tested. Bone formation was assessed using microcomputed tomography at weeks 2, 4, 8, and 12 and a histologic analysis at week 12. RESULTS: At 12 weeks, the proportion of bone filling associated with the use of hydrogel scaffold alone did not differ significantly from the values observed in the scaffold-free experiment (61.01% ± 5.288% versus 36.91% ± 5.132%; p = 0.1620). The addition of BM-MSCs stimulated bone formation not only at the margin of the defect but also in the center of the implant. CONCLUSIONS: In a relevant in vivo model of cleft palate in the rat, we confirmed the alginate-based hydrogel's biocompatibility and real advantages for tissue healing. Addition of BM-MSCs stimulated bone formation in the center of the implant, demonstrating the new biomaterial's potential for use as a bone substitute grafting material for cleft palate repair.

Intraosseous microdialysis for bone free flap monitoring in head and neck reconstructive surgery: A prospective pilot study.

BACKGROUND: Although some researchers have positioned microdialysis catheters in the soft tissue surrounding bone, the results did not accurately reflect bone metabolism. The present study's objective was to establish the feasibility of microdialysis with a catheter positioned directly in bone. METHODS: Thirty-four patients (19 males, 15 females; median age: 59) were included in a prospective, nonrandomized clinical trial in the Department of Maxillofacial Surgery at Amiens-Picardie University Hospital (Amiens, France). Fibula or iliac crest free flaps were used in reconstructive head and neck surgery (for cancer, osteoradionecrosis, trauma, or ameloblastoma) and monitored with microdialysis catheters positioned in a hole drilled into the bone. Glucose, lactate, pyruvate, and glycerol concentrations were analyzed for 5 days. RESULTS: All catheters were positioned successfully, and thrombosis did not occur during the monitoring. In two patients, an increase in the lactate concentration and a glucose level close to 0 were associated with signs of flap necrosis, with removal on Days 9 and 50. In viable flaps, the mean glucose level was 2.02 mmol/L, the mean lactate level was 8.36 mmol/L, and the mean lactate/pyruvate ratio was 53. Forty percent of the glucose values were below 1 mmol/L, and 50% of the lactate/pyruvate ratio values were above 50-suggesting a specific metabolic pattern because these values would be considered as alert values in soft tissue. CONCLUSION: Monitoring bone free flaps with intraosseous microdialysis is feasible. This technique specifically assesses bone viability, and further studies are now necessary to define the alert values in bone.

Vascular anatomy of the free fibula flap including the lateral head of the soleus muscle applied to maxillo-mandibular reconstruction.

PURPOSE: Initially described by Baudet in 1982, the fibula flap including the lateral head of the soleus muscle allows a one-stage reconstruction for large maxillo-mandibular defects. The aim of this study was to evaluate the number of muscular branches destined to the soleus muscle and their distance from the origin of the fibular artery, to assess the vascular anatomy of the free fibula flap including the lateral head of the soleus muscle applied to maxillo-mandibular reconstruction. METHODS: We performed a cadaveric anatomic study on ten lower limbs, and a CT angiography anatomic study on 38 legs. The number of soleus branches originating from the fibular artery, and the distance between the origin of the fibular artery and each of the identified branches were measured. RESULTS: The number of soleus branches destined to the lateral head of the soleus muscle is variable, with in our study 1-3 branches found. Soleus branches destined to the lateral head of the soleus muscle emerged at a distance ranging between 0 and 2.9 cm (mean value = 1.82 cm) from the origin of the fibular artery in 40% of cases, between 3 and 5.9 cm (mean value = 4.27 cm) from the origin of the fibular artery in 37% of cases, and was at a distance of 6 cm or more (mean value = 6.93 cm) from the origin of the fibular artery in 20% of cases. CONCLUSIONS: An origin of the soleus vessels in close proximity to the origin of the fibular artery represents the main limitation of this flap, the length of the remaining fibular pedicle making it difficult to achieve secure anastomosis in the cervical area. The vascular distribution of the proximal part of the lateral head of the soleus muscle being segmental, it is possible to lengthen the flap pedicle ligating the most proximal soleus branches originating from the fibular artery.

Face graft? Extrapolation of facial allotransplantation to children.

The possibility to imagine a vascularized composite allotransplantation for disfigured children is felt more critical than for adults non on technical point of view but in terms of indications and justifications. The question is not about surgery. It is related to the pathologies themselves for which transplant could be suitable. Moreover the procurement of face transplant will be more difficult because of immunologic criteria but also age and phototype. Specificity of the newborn malformative face is usually not only a question of tissue defect. It is reasonably not an indication for VCA. It should be added that nothing is known about the future of transplantation in terms of duration but also morbidities due to immunosuppression. Indications are rather negative. To rise the question of VCA for children has a double benefit. The first is to point out that surgical innovation often arise from a non imaginable or non imagined clinical situation. The second is the question of VCA in newborn regarding the tolerance.

Infant Odontogenic Myxoma: a specific entity.

INTRODUCTION: In children, and specifically in infants, odontogenic myxomas are extremely rare. In infants, myxoma seems to display mostly the same clinical, radiological and pathological characteristics. This paper presents a series of odontogenic myxomas in infant patients. MATERIALS AND METHODS: Four infant patients were included in this retrospective study. The clinical, radiological and pathological presentation was characterized and the treatment analysed. RESULTS: All patients presented with a rapidly evolving paranasal swelling. CT-scan showed a maxillary homogeneous unilocular and intraosseous tumour. In all cases, pathological examination revealed a loose myxoid stroma within stellate and spindle shaped cells. All patients underwent conservative surgery through a vestibular approach. CONCLUSION: This patient series and a review of the literature demonstrates that odontogenic myxoma is specific in infant. We propose the name of Infant Odontogenic Myxoma for this entity.

Midface osteotomies lines: evolution by Paul Tessier, the second Tessier classification.

The Tessier collection is an inheritance of a whole career of a surgeon and a life dedicated to cranio-facial malformations. It is a good opportunity to analyse some particular points of the surgical work of Paul Tessier, in particular to understand how the midface advancement procedures were made up and thought out. Medical files, pictures, X-rays and drawings help us to describe step by step the different types of midface osteotomies done by Paul Tessier, from TESSIER I to TESSIER VII osteotomies. The author describes the reason for the surgical lines and their modifications justified by all those files and by Tessier's personal annotations. Based on a single clinical case, Tessier experimented with new surgical procedures, firstly on skulls and dissection then the proposed surgery, the experience of the surgery and the post-operative result for each patient made him decide to change lines and procedures. At each step, the modification was done to improve stability, aesthetics, or to do the procedure in an easier way. Difficulties and mistakes were always new lessons for further patients.