title: The transnasal transclival approach for clivus chordoma.
abstract: BACKGROUND
  We present our experience using a standardized transnasal transclival approach (TTA) for endoscopic removal of chordomas of the clivus.
  
  
  METHODS
  13 patients with clival chordoma (CC) underwent tumor resection. Patients were operated by a surgical team consisting of a rhinosurgeon and a neurosurgeon. All patients underwent postoperative proton radiotherapy. Residual tumor was left in situations where radical removal would have entailed an increased risk of neurological deficits.
  
  
  RESULTS
  Radical or near total removal of CC was accomplished in 12/13 patients. Intraoperative MRI (IMRI) was used in 4/13 CC patients. A watertight dural seal presented as the main challenge specifically for tumor extensions resulting in large dural defects.
  
  
  CONCLUSIONS
  The TTA provides an elegant alternative to classical approaches to clival lesions especially for midline tumor locations. For large tumors iMRI is of significant help. Dural reconstruction of large defects emerged as the greatest challenge of this technique even for experienced endoscopic surgeons.
authors.affiliation: Department of Otorhinolaryngology Head and Neck Surgery, University Hospital Zurich, Zurich, Switzerland. David.Holzmann@usz.ch
authors.forename: D
authors.initials: D
authors.lastname: Holzmann
authors.forename: R
authors.initials: R
authors.lastname: Reisch
authors.forename: N
authors.initials: N
authors.lastname: Krayenbühl
authors.forename: E
authors.initials: E
authors.lastname: Hug
authors.forename: R L
authors.initials: RL
authors.lastname: Bernays
mesh_terms: D000328:Adult; D000368:Aged; D002817:Chordoma / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D003388:Cranial Fossa, Posterior / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D057605:Natural Orifice Endoscopic Surgery / Q000379:methods*; D019292:Skull Base Neoplasms / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*