Sheep hemifacial and auricular transplantation models: an anatomic study.

Abstract

Currently, only a few large animal models, including swine, dog, and nonhuman primate, are described for composite face transplantation studies and the literature lacks reports on the large animal model of composite auricular transplantation. Large animal models offer better understanding of the immunological mechanisms and major histocompatibility complex characterization and, for this reason, are preferred to the small animal models for the assessment of new immunosuppressive tolerance induction protocols. Thus, the aim of this study was to demonstrate feasibility of dissection and exploration of vascular territories of the hemifacial and auricle transplantation models in the sheep cadavers. Ten cadaver sheep heads were studied. The vascular territories of the composite hemifacial flap and composite auricle flap were defined by anatomical dissection. Methylene blue staining and laser-assisted indocyanine green angiography using SPY Elite System were used for vascular territories assessment. The dissection of cadaver sheep heads confirmed that the hemifacial flap and auricle flap can be raised on the same pedicle consisting of the common carotid artery and jugular vein. An adequate vascular network was observed in the flaps after injection of methylene blue dye via the arterial pedicle. Laser-assisted indocyanine green angiography identified vascular territories of the hemifacial and auricular vascular network. We described a new hemifacial and an auricular transplantation models in the sheep cadavers and have confirmed presence of the adequate vascular network as demonstrated by the laser-assisted angiography. This study introduces 2 new large animal models into the armamentarium of vascular composite allotransplantation.