title: Successful removal of cryptic arteriovenous malformation located at the upper ventral pons via subtemporal transtentorial approach.
abstract: BACKGROUND
  Lesions located at the ventral portion of the brain stem are still difficult to access surgically. We report herein a case of ventral pontine cryptic arteriovenous malformation that was successfully removed via a subtemporal-transtentorial approach.
  
  
  METHODS
  An 18-year-old female patient experienced repetitive hemorrhagic attacks leading to a massive pontine hemorrhage with several neurologic deficits. Since angiography and magnetic resonance imaging failed to delineate the hemorrhagic origin, a combination of multiple approaches was initially attempted. The subtemporal-transtentorial approach made it possible to obtain an adequate operative view in this case. An angioma observed at the septum of the multilocular hematoma was totally removed. Pathologic examination of the resected specimen revealed it to be an arteriovenous malformation. Postoperatively, the patient showed unexpectedly good recovery despite the original massive pontine hemorrhage.
  
  
  CONCLUSIONS
  Several surgical approaches to the ventral pons have been proposed in the literature. While the subtemporal-transtentorial approach was useful in our patient, multiple routes should be considered to access a massive lesion of unknown extent at the ventral pons. The unexpected recovery observed in our patient suggests that surgery is an option in the treatment of this type of lesion.
authors.affiliation: Department of Neurosurgery, Showa General Hospital, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nagata
authors.forename: H
authors.initials: H
authors.lastname: Nikaido
authors.forename: T
authors.initials: T
authors.lastname: Mori
mesh_terms: D000293:Adolescent; D001165:Arteriovenous Malformations / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery*; D002533:Cerebral Angiography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D011149:Pons / Q000503:physiopathology* / Q000601:surgery*