title: Intraoperative conversion from endoscopic to microscopic approach for the management of sellar pathology: incidence and rationale in a contemporary series.
abstract: BACKGROUND
  The endoscopic transsphenoidal approach has become widely used for pituitary and extended skull base operations. Intraoperative conversion to a microscopic approach may be an important option in selected cases. We aim to characterize the operative situations in which such conversion occurred and facilitated the procedure.
  
  
  METHODS
  From April 2008 through August 2009, 148 planned endoscopic transsphenoidal approaches were performed. All cases were retrospectively reviewed to identify those patients converted to a microscopic approach. Clinical and operative characteristics, reasons for conversion, and patient outcomes were reviewed.
  
  
  RESULTS
  Of the 148 endoscopic cases, conversion was undertaken in 27 (18%). Ten patients (37%) had undergone previous transsphenoidal surgery. Reasons for conversion in nonreoperation cases were atypical nasal anatomy (6 patients), acromegaly with distorted anatomy (5 patients), desire for binocular vision (3 patients), complex sphenoid sinus anatomy and difficulty visualizing sella/midline (2 patients), and obstructive mucosal bleeding (1 patient). Of the 10 reoperation procedures, conversions occurred in 3 patients with Cushing's disease and 2 with acromegaly. The primary reasons for conversion in reoperations were scarring with loss of anatomic landmarks (4 patients), mucosal bleeding (2 patients), acromegaly with distorted anatomy (2 patients), technical problem with visualization (1 patient), and desire for binocular surgery (1 patient).
  
  
  CONCLUSIONS
  Although endoscopic transsphenoidal surgery provides superior visualization in most patients, conversion to a microscopic or endoscopic-assisted approach may provide essential visualization in selected patients. This may be especially true in patients undergoing reoperation and patients with acromegaly or Cushing's disease. Trainees learning the endoscopic transsphenoidal approach should become familiar with the benefits and limitations of the various transsphenoidal approaches.
authors.affiliation: Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA. gzada@usc.edu
authors.forename: Gabriel
authors.initials: G
authors.lastname: Zada
authors.forename: Lance S
authors.initials: LS
authors.lastname: Governale
authors.forename: Edward R
authors.initials: ER
authors.lastname: Laws
mesh_terms: D000172:Acromegaly / Q000473:pathology / Q000601:surgery; D004724:Endoscopy / Q000379:methods* / Q000592:standards; D005260:Female; D006801:Humans; D015994:Incidence; D007431:Intraoperative Complications / Q000209:etiology / Q000517:prevention & control; D007432:Intraoperative Period; D008297:Male; D008866:Microsurgery / Q000379:methods* / Q000592:standards; D009296:Nasal Cavity / Q000033:anatomy & histology / Q000601:surgery; D019635:Neurosurgical Procedures / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D047748:Pituitary ACTH Hypersecretion / Q000473:pathology / Q000601:surgery; D010911:Pituitary Neoplasms / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies; D012658:Sella Turcica / Q000473:pathology / Q000601:surgery*; D019292:Skull Base Neoplasms / Q000473:pathology / Q000601:surgery*; D013100:Sphenoid Bone / Q000473:pathology / Q000601:surgery; D013101:Sphenoid Sinus / Q000033:anatomy & histology / Q000473:pathology / Q000601:surgery; D016896:Treatment Outcome