title: Complete loop of the posterior cerebral artery with ruptured aneurysm at the origin of the medial posterior choroidal artery. A case report.
abstract: BACKGROUND
  Anatomical anomalies of the PCA are unusual and their association with an aneurysm is exceptional. A unique case of a complete loop of the posterior cerebral artery associated with a ruptured aneurysm is presented.
  
  
  METHODS
  A 69-year-old woman with a subarachnoid hemorrhage in World Federation of Neurosurgical Societies grade IV was diagnosed with a loop of the right PCA with an aneurysm at the apex of the loop. At surgery, the aneurysm was found to arise at the origin of the MPChA and it was clipped. Three months later, after improving to Glasgow Outcome Scale 3, the patient died of unrelated cause.
  
  
  CONCLUSIONS
  To our knowledge, a complete loop of the PCA associated with an aneurysm at the origin of the MPChA has never been described. Microneurosurgical approach via subtemporal craniotomy was safe and effective in displaying the anomalous anatomy and allowing perfect clipping of the aneurysm.
authors.affiliation: Section of Neurosurgery, Department of Neurological, Neurosurgical and Behavioural Sciences, University of Siena, 53100 Siena, Italy. mmkk@fmu.ac.jp
authors.forename: Vitaliano F
authors.initials: VF
authors.lastname: Muzii
authors.forename: Reza
authors.initials: R
authors.lastname: Dashti
authors.forename: Stefano
authors.initials: S
authors.lastname: Toninelli
authors.forename: Juha
authors.initials: J
authors.lastname: Hernesniemi
mesh_terms: D000368:Aged; D020785:Central Nervous System Vascular Malformations / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D002532:Intracranial Aneurysm / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D008636:Mesencephalon / Q000098:blood supply; D019635:Neurosurgical Procedures / Q000295:instrumentation / Q000379:methods*; D020769:Posterior Cerebral Artery / Q000002:abnormalities* / Q000473:pathology* / Q000601:surgery; D013345:Subarachnoid Hemorrhage / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D013525:Surgical Instruments; D016896:Treatment Outcome