Endoscopic pituitary surgery: an in vivo model for transnasal transsphenoidal hypophysectomy

The transseptal transsphenoidal approach to surgical intervention of the pituitary gland has been described for decades. Its gradual acceptance as the standard of therapy is indicative of general trends toward less invasive means of managing intracranial surgical disease. The evolution of the technique has coincided with advances in medical technology, including the introductions of intraoperative fluoroscopy and operative microscopy. Current progress in the field of endoscopy promises to further this evolution: endoscopic telescopes and instruments have improved on the optical and technical limitations of the microscope and require an even less invasive approach to the sella. To test the benefits and limitations of the endoscope in performing transnasal transsphenoidal hypophysectomy in an in vivo model, we operated on two live anesthetized pigs using 4.0-mm 0- and 30-degree 18-cm long endoscopes. The long lengths of the pig snouts precluded a transnasal approach to the sella; however, we were able to use the endoscopes to explore the sphenoid sinus, sella turcica, and parasellar regions via a transoral exposure. Digital images of the relevant skull base anatomy were captured. The benefits and limitations of the technique were noted and compared with our experience with microscopy in transsphenoidal hypophysectomy in humans.