Microsurgery
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Two hundred free flaps for reconstructing the head and neck regions in 192 patients with non-oncological pathology were studied. Pathological entities included Romberg's disease, hemifacial microsomia, acquired facial palsy, trauma, and burn sequelae. Indications for selecting a specific free flap for reconstructing each case, details of anastomoses, reexploration, flap success, operative time, length of hospitalization, and complications were studied. ⋯ There were no major complications and no deaths in the study group. The patients were followed for at least 1 year in all cases. It is concluded that free flaps are safe and reliable procedures for reconstructing complex head and neck non-oncological defects.
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The goal of this study was to determine the functional axonal anatomy of a termino-lateral neurorrhaphy (TLN). We hypothesize that axons populating a TLN must relinquish functional connections with their original targets prior to establishing new connections via the TLN. Two-month-old F344 rats underwent a TLN between the left peroneal nerve and a nerve graft tunneled to the contralateral hindlimb. ⋯ Left peroneal nerve stimulation proximal to the TLN site resulted in bilateral extensor digitorum longus (EDL) and tibialis anterior (TA) muscle contractions, with significantly lower forces on the side reinnervated by TLN. Evoked EMGs demonstrated that the right and left hindlimb musculature were electrically discontinuous following TLN. These data support our hypothesis that axons can form functional connections via a TLN, but they must first relinquish functional connections with their original targets.
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The mechanism of end-to-side neurorrhaphy is believed to be by collateral sprouting, although evidence for this is lacking. This study validates whether axonal sprouting originates from the donor intact nerve by collateral sprouting with the use of a fluorescent double-labeling technique. End-to-side neurorrhaphy was performed on adult female Sprague-Dawley rats. ⋯ Double-labeling neurons, however, were seen in animals treated with end-to-side neurorrhaphy whether or not perineurotomy was performed. These results demonstrate that one parent nerve fiber can emanate another axon by collateral sprouting following end-to-side neurorrhaphy. We hypothesize that the causes of collateral sprouting might result from "switching signals" and/or "switching factors."
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Traditionally, the mouse nonvascularized skin graft has been widely used in organ transplant research. There are, however, several limitations with this model, the main one being the different immune response of vascularized vs. nonvascularized grafts. We have recently developed a vascularized, orthotopic ear transplant model in mice. ⋯ In summary, this study illustrates that it is technically possible to transplant a mouse ear graft. The main advantage of this model is that it is a vascularized graft that can be visibly observed and easily biopsied, thus allowing for good correlation between gross and histological findings after transplantation. We plan to use this model further to study in detail the rejection patterns in an allograft and xenograft setting.