title: Endonasal microscopic removal of clival chordomas.
abstract: BACKGROUND
  Clival chordomas have traditionally been removed using a variety of anterior and lateral skull base approaches. Herein, we evaluate the outcomes of patients who underwent an extended endonasal transsphenoidal removal of a clival chordoma.
  
  
  METHODS
  All consecutive patients with a clival chordoma treated using an endonasal microscope approach were identified. In 8 cases, frameless surgical navigation was used, and in 4 cases, endoscopic assistance was used. Patients treated with prior radiotherapy were excluded.
  
  
  RESULTS
  Over 5 years, 18 procedures were performed on 14 patients (7 females; mean age, 47 years). Patients were followed from 3 to 58 months (median, 20 months). Mean tumor diameter was 32 +/- 17 mm; 7 (50%) patients had intradural extension. Postoperative MRIs after the initial operation showed gross total, near-total (>90%), and subtotal resection in 43%, 43%, and 14% of patients, respectively. Use of the endoscope was associated with gross total or near-total tumor removal in 4 of 4 cases. Tumor regrowth occurred in 2 (14%) cases 10 and 12 months after the initial surgery and before radiotherapy. Two patients had multiple operations, in one as a planned staged operation, and in the other, 3 additional debulkings were performed despite an initial gross total removal. Nine patients, all with CS invasion, had subsequent stereotactic radiation. Of 10 patients with cranial neuropathy, 80% improved or resolved including 75% and 67% of sixth and fifth CN palsies, respectively. Complications included one each of adrenal insufficiency and chemical meningitis. There were no CSF leaks or new neurological deficits.
  
  
  CONCLUSIONS
  In this small series with relatively short follow-up, endonasal microscopic removal of clival chordomas proved safe and elfective with gross total or near-total removal in 86% of patients and improvement of cranial neuropathy in 80% of patients. Endoscopy for aiding tumor removal and assessing completeness of resection, as well as surgical navigation, are recommended for all cases.
authors.affiliation: Division of Neurosurgery, University of California at Los Angeles David Geffen School of Medicine, Los Angeles, CA 90095, USA.
authors.forename: Nasrin
authors.initials: N
authors.lastname: Fatemi
authors.forename: Joshua R
authors.initials: JR
authors.lastname: Dusick
authors.forename: Alessandra A
authors.initials: AA
authors.lastname: Gorgulho
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Mattozo
authors.forename: Parham
authors.initials: P
authors.lastname: Moftakhar
authors.forename: Antonio A F
authors.initials: AA
authors.lastname: De Salles
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Kelly
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002817:Chordoma / Q000601:surgery*; D015331:Cohort Studies; D003388:Cranial Fossa, Posterior; D004724:Endoscopy; D005260:Female; D006801:Humans; D008297:Male; D008866:Microsurgery; D008875:Middle Aged; D038361:Neuronavigation; D012189:Retrospective Studies; D019292:Skull Base Neoplasms / Q000601:surgery*; D016896:Treatment Outcome