Endoscopic skull base surgery I: a new animal model for pituitary surgery

Endoscopy has emerged as a new means to perform minimally invasive surgery of the skull base. Specifically, endoscopic techniques and instruments can be used to safely and effectively approach and resect tumors of the pituitary gland in humans. No animal model currently exists to serve as a template upon which to refine and develop endoscopic surgical technique in this region of the anatomy. We operated on two purpose-bred Hampshire-Yorkshire-Duroc hybrid swine to demonstrate the application of endoscopy to pituitary surgery. Based upon similar anatomical relationships in humans and swine between the oropharynx, nasopharynx, and skull base, we used a transoral, transpalatal approach to access the vomer of the swine. Under endoscopic exposure, we resected the vomer, entered the sphenoid sinus, and then resected the sphenoid septum, sella turcica, and adenohypophysis. Clear visualization of the pituitary, hypophyseal stalk, cavernous sinuses, and carotid prominences was achieved and documented with digital photography. Benefits and limitations of the technique were noted. These results have pertinent implications both for the study of the surgical anatomy of the swine craniofacial skeleton, and for future development of endoscopic surgical manipulation of the skull base.