title: Operative Learning Curve After Transition to Endoscopic Transsphenoidal Pituitary Surgery.
abstract: BACKGROUND
  No clear consensus yet defines the endpoints for operative learning curves in the transition to minimally invasive endoscopic techniques. This retrospective review of our first 202 patients who underwent endoscopic pituitary resection examines the statistical learning curve related to operative times-a measure of our surgical team's efficiency and complication rate, a reflection of surgical skill and maturity.
  
  
  METHODS
  Retrospective chart review included patient demographic data, tumor type, operative time, complications, and follow-up. During the 5-year study period, surgeries were performed by an otolaryngology-neurosurgery team. Statistical analysis by Pearson's correlation delineated a learning curve for operative time and complications.
  
  
  RESULTS
  Our learning curve showed comparable plateaus: 120 cases (48% males, 52% females) for operative time (mean, 134 minutes; range, 62-307 minutes) and 100 cases for incidence of cerebrospinal fluid (CSF) leak. The risk of CSF leak declined significantly with the surgeon's increasing experience. Complication rates were as follows: temporary nasal obstruction, 9.9%; CSF leak, 8.4%; postoperative epistaxis, 7%; sinusitis, 4.5%; septal osteomyelitis, 2.4%; postoperative sellar hematoma, 1.5%; anosmia, 0.5%; and septal perforation, 0.5%. The overall CSF leak rate included 5.5% intraoperative and 2.9% postoperative; most cases resolved with a lumbar drain. Four patients (2%) underwent postoperative surgical repair and lumbar drainage.
  
  
  CONCLUSIONS
  Our learning curve-defined endpoints for 2 measures, operative time and complication rates, support improved outcomes for reduced CSF leaks, the most common complication, with increasing operative experience. We will continue to examine the implications related to safety, efficacy, and the need for subspecialization in this minimally invasive surgery.
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA; Brain Tumor Center, University of Cincinnati Gardner Neuroscience Institute, Cincinnati, Ohio, USA.
authors.forename: Tasneem
authors.initials: T
authors.lastname: Shikary
authors.affiliation: Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA; Brain Tumor Center, University of Cincinnati Gardner Neuroscience Institute, Cincinnati, Ohio, USA; Mayfield Brain and Spine, Cincinnati, Ohio, USA.
authors.forename: Norberto
authors.initials: N
authors.lastname: Andaluz
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA; Center for Epidemiology and Biostatistics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
authors.forename: Jareen
authors.initials: J
authors.lastname: Meinzen-Derr
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA; Brain Tumor Center, University of Cincinnati Gardner Neuroscience Institute, Cincinnati, Ohio, USA.
authors.forename: Collin
authors.initials: C
authors.lastname: Edwards
authors.affiliation: Department of Neurological Surgery, University of California, San Francisco, California, USA.
authors.forename: Philip
authors.initials: P
authors.lastname: Theodosopoulos
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA; Brain Tumor Center, University of Cincinnati Gardner Neuroscience Institute, Cincinnati, Ohio, USA. Electronic address: zimmerli@ucmail.uc.edu.
authors.forename: Lee A
authors.initials: LA
authors.lastname: Zimmer
mesh_terms: D000328:Adult; D002983:Clinical Competence / Q000592:standards; D005260:Female; D006801:Humans; D059032:Learning Curve; D007902:Length of Stay; D008297:Male; D044583:Neuroendoscopy / Q000009:adverse effects / Q000193:education* / Q000592:standards; D061646:Operative Time; D000072220:Otolaryngologists / Q000592:standards; D010900:Pituitary Diseases / Q000601:surgery*; D010902:Pituitary Gland / Q000601:surgery; D011183:Postoperative Complications / Q000209:etiology; D012189:Retrospective Studies
keywords: Endoscopic surgery; Pituitary tumor; Skull base; Sphenoid