Floor plan - 2013 Annual Meeting - American Association for Hand ...

Evaluation of Cortical Reorganization in Facial Transplantation
Institution where the work was prepared: University of Pittsburgh, Pittsburgh, PA, USA
Kia M. McLean, MD; Mario G. Solari; Justin M. Sacks; Anjey Su; Vijay S. Gorantla; Jignesh V. Unadkat; Stefan
Schneeberger; George E. Carvell; Daniel J. Simons; W.P. Andrew Lee; University of Pittsburgh Medical Center
INTRODUCTION:
Facial transplantation must provide effective functional outcome in order to be widely accepted as a reconstructive option.
Understanding cortical reorganization, the brain's functional compensation for injury, could be the key to optimizing functional outcome
in facial transplantation. The specific aims of this study were to establish a functional face transplant model in the rat and perform a
comprehensive analysis of functional recovery and cortical reorganization.
METHODS:
We performed 5 syngeneic and 5 allogeneic functional hemifacial transplants with appositions of donor and recipient infraorbital nerves
and facial nerve branches. Allogeneic transplants were given 15 mg/kg/day of cyclosporine for immunosuppression. As a control 5 syngeneic
hemifacial transplants without nerve appositions were performed. Electromyography (EMG) was completed 12 weeks
post–transplant. Sensory regeneration, cortical reintegration and reorganization were studied at 20 weeks post-transplant through stimulation
of the whiskers and microelectrode output recording from the somatosensory cortex.
RESULTS:
All experimental transplants showed clinical evidence of motor recovery by movement of the whiskers at 24 days (syngeneic) and 32
days (allogeneic) post-transplant respectively, while control animals did not exhibit return of whisker movement. All experimental animals
showed presence of conduction potentials on EMG 12 weeks post-transplant, while no electrical activity was elicited in control animals
(p < .001). Stimulation of whiskers elicited a specific regional response and directional sensitivity of cells in the somatosensory cortex.
Histology of the somatosensory cortex with cytochrome oxidase and horseradish peroxidase staining confirmed cortical reorganization.
CONCLUSION:
We have established a functional model for face transplantation in the rat. This is the first model for cortical reorganization in composite
tissue transplantation. Motor nerve recovery was confirmed clinically and physiologically. The sensory pathway in each whisker was
traced to the corresponding region of the somatosensory cortex, quantified, and visualized by histology. This is the first electrophysiological
and histological evidence of cortical reorganization in face transplantation.
Le Fort I Osteotomy with Interpositional Free Fibula Flap for Maxillary Augmentation
Institution where the work was prepared: R Adams Cowley Shock Trauma Center, Baltimore, MD, USA
Rachel Bluebond-Langner, MD; Lisa Witkin; Eduardo D. Rodriguez; R Adams Cowley Shock Trauma Center
INTRODUCTION:
Severe maxillary deficiency results in functional compromise including altered mastication, speech abnormalities, as well as cosmetic
deformities. Historically this has been treated in one of three ways: augmentation with non-vascularized bone grafts, Le Fort I osteotomy
with interpositional bone graft or LeFort I osteotomy with distraction osteogenesis. We present a novel technique, Lefort I osteotomy
with interpostional vascularized bone flap, which is particularly useful in patients who have failed augmentation with conventional
techniques.
MATERIALS/METHODS:
Six patients with maxillary hypoplasia underwent Le Fort I osteotomy with interpositional osteoseptocutaneous fibula flaps.
Osteotomies were made to contour the fibula which was then secured between the down-fractured maxilla and the stable zygomaticomaxillary,
pterygomaxillary and nasomaxillary buttresses. Data collected included age, gender, mechanism of injury, maxillary
advancement operative procedures.
RESULTS:
Maxillary retrusion was due to trauma (n=3), cancer (n=1), chronic maxillary atrophy (n=1) and Crouzon's (n=1). There were 3 females
and 4 males with an average age of 40. Four patients had prior attempts at maxillary advancement or augmentation including onlay
bone grafts, Lefort III advancement without bone grafting and distraction osteogenesis. The average skin flap area was 33.7 cm2 and
average bone flap length was 13.7 cm. All flaps survived with no donor site complications. Simultaneous vestibuloplasty was performed
in 3 patients using the fibula skin paddle. Average maxillary advancement was 3mm. One has had complete dental restoration including
endosseous implants and a fixed prosthesis. The remaining five are in the process. Average follow up was 9 months.
DISCUSSION:
Classically, non vascularized bone graft is used to bridge the gap between the osteotomized maxilla and stable bone. The advantages
of vascularized bone flaps over non-vascularized bone grafts include transfer of viable bone with significantly less resorption over time
and long term osseous integration of implants. Augmentation with a fibula flap has been performed however to our knowledge there
are no reports of the use of the fibula osteoseptocutaneous flap as an interpositional material following LeFort I osteotomy for treatment
of severely atrophic maxillas. This technique allows simultaneous repositioning of the maxillary alveolus between stable skeletal
buttresses, augmentation of the midface and creation of a vestibule. Furthermore, the maxillary muscosa is left intact obviating the need
for debulking and skin grafting when endosseous implants are placed.
184