title: Expanded endonasal approach: a fully endoscopic completely transnasal resection of a skull base arteriovenous malformation.
abstract: OBJECTIVE
  Vascular lesions with an intraosseus nidus involving the skull base are uncommon and challenging [Gianoli GJ, Amedee RG Vascular malformation of the sphenoid sinus. Ear Nose Throat J. 70:373-375;(1991), Malik GM, Mahmood A, Mehta BA Dural arteriovenous malformation of the skull base with intraosseous vascular nidus. Report of two cases. J. Neurosurg 81:620-623;(1994)]. We present a pediatric patient, with a life-threatening arteriovenous malformation (AVM) of the sphenoid sinus, clivus, and ventral skull base, who failed routine multimodality management of AVMs. An entirely transsphenoidal fully endoscopic resection was used to resect this ventral cranial base AVM with an intraosseus nidus located in the clivus.
  
  
  METHODS
  A 4-year-old female presented with recurrent, life-threatening hemorrhages from a clival and ventral skull base AVM of the entire clivus and ventral skull base. The patient had been temporized from the age of 2-4 years with multiple internal and external carotid arterial particulate and alcohol embolizations, including both external and internal carotid artery embolizations, intracranial ligation of the right internal carotid artery, and gamma knife irradiation. Despite these multiple interventions, the patient had persistent, life-threatening hemorrhages from arterial recanalization and recruitment requiring intubation, tracheostomy, and nasopharyngeal packing.
  
  
  METHODS
  The patient underwent a three-stage surgical intervention to resect the AVM. An open subfrontal approach, as the first procedure, provided minimal access to the feeding vessels and was therefore aborted. A two-stage image-guided fully endoscopic approach via a sublabial midface approach without external incisions was performed. Postoperative angiography revealed minimal residual shunting in the pharynx and cavernous sinus. The patient has been free of significant hemorrhages over the past three years.
  
  
  CONCLUSIONS
  Technological advances in endoscopic surgery and image guidance are now allowing for purely endoscopic surgical treatment of previously unresectable lesions with acceptable morbidity. We report the successful and safe resection of a ventral cranial base AVM via a fully endoscopic approach. This paper reports the first AVM with a purely intraosseus nidus of the ventral skull base and demonstrates the ability to deal with complex ventral skull base lesions using a fully endoscopic transsphenoidal technique.
authors.affiliation: Department of Otolaryngology, University of Pittsburgh School of Medicine, UPMC Presbyterian University Hospital, Pittsburgh, PA 15213, USA. kassamab@upmc.edu
authors.forename: Amin B
authors.initials: AB
authors.lastname: Kassam
authors.forename: Ajith J
authors.initials: AJ
authors.lastname: Thomas
authors.forename: Lee A
authors.initials: LA
authors.lastname: Zimmer
authors.forename: Carl H
authors.initials: CH
authors.lastname: Snyderman
authors.forename: Ricardo L
authors.initials: RL
authors.lastname: Carrau
authors.forename: Arlan
authors.initials: A
authors.lastname: Mintz
authors.forename: Michael
authors.initials: M
authors.lastname: Horowitz
mesh_terms: D002533:Cerebral Angiography; D002675:Child, Preschool; D004724:Endoscopy; D004844:Epistaxis / Q000209:etiology / Q000601:surgery; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D009296:Nasal Cavity / Q000601:surgery*; D019635:Neurosurgical Procedures; D011182:Postoperative Care; D019291:Skull Base / Q000601:surgery*; D014057:Tomography, X-Ray Computed