Endoscopic transsphenoidal pituitary surgery: various surgical techniques and recommended steps for procedural transition.

Various techniques in pituitary endoscopy are reviewed in the attempt to assemble the transitional steps necessary to take a neurosurgeon from traditional microscopic transsphenoidal surgery to endoscopic endonasal pituitary surgery. The senior author's (HDJ) experiences of endonasal endoscopy in more than 200 operations as well as the reports in the literature on pituitary endoscopy are reviewed. Two distinct advantages that an endoscope has over an operating microscope are its ability to visualize through a narrow surgical corridor and its ability to provide angled, close-up views. An endoscope can be used to assist the operating microscope (endoscope-assisted microsurgery). Endoscopy can also be used for endonasal retractor placement when microscopic surgery is preferred (endoscopic sphenoidotomy). When endonasal endoscopy is chosen, the surgical approach can be made with a deep-transseptal, a paraseptal, a middle turbinectomy or a middle meatal approach (endonasal transsphenoidal endoscopy). Endonasal endoscopy can be performed via either one or two nostrils. Working-channel endoscopy can be performed for restricted purposes. When a neurosurgeon desires to adopt endoscopy into pituitary surgery, the author recommends endoscope-assisted microsurgery as the first step followed by endoscopic sphenoidotomy as a combined effort between an endoscopic rhinologist and the neurosurgeon as the next step leading finally to endonasal pituitary endoscopy. Various methods of transsphenoidal endoscopy and the authors' recommendations for transitional steps are reported based on the authors' personal experience and literature review.