title: Tuber cinereum proximity to critical major arteries: a morphometric imaging analysis relevant to endoscopic third ventriculostomy.
abstract: BACKGROUND
  Arterial bleeding in the interpeduncular fossa is a dreaded complication of endoscopic third ventriculostomy (ETV). When the "safe zone" of the tuber cinereum (TC) is fenestrated, the basilar artery tip (BT) or its branches may be encountered below the third ventriclular floor. Major arterial injuries might be avoided by careful preoperative planning. We aimed to establish previously unavailable normal magnetic resonance imaging (MRI) and MR angiographic (MRA) morphometry and configuration of the BT and posterior cerebral artery P1 segments relative to the TC.
  
  
  METHODS
  We analyzed images of 82 patients with non-dilated ventricles (mean Evans' index 0.26), and lying in a neutral head position (mean cervico-medullary angle 141°). We cross-referenced axial MRAs with sagittal MRIs to measure distances of BT and P1 segments from the TC, and to classify the location of the BT in the interpeduncular and suprasellar cisterns. We correlated the sagittal areas of these cisterns and patients' ages with the TC-to-artery distances using regression analysis.
  
  
  RESULTS
  The BT, right P1 and left P1 segments were a mean 4.9 mm, 5.5 mm, and 5.7 mm respectively from the TC. Seventy-four percent of BTs were anterior to the mammillary bodies. These distances and locations did not correlate with age (mean 53 years) or size of basal cisterns.
  
  
  CONCLUSIONS
  The normal BT and P1 segments are anatomically close to the TC and potentially at risk during ETV in adults of all ages. The new morphometric data presented, along with cross-referencing of preoperative multiplanar images, could help reduce vascular complications during ETV.
authors.affiliation: Section of Neuroradiology, Addenbrooke's Hospital, Cambridge, UK.
authors.forename: Avril
authors.initials: A
authors.lastname: Horsburgh
authors.forename: Tomasz
authors.initials: T
authors.lastname: Matys
authors.forename: Ramez W
authors.initials: RW
authors.lastname: Kirollos
authors.forename: Tarik F
authors.initials: TF
authors.lastname: Massoud
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001158:Arteries / Q000601:surgery; D004724:Endoscopy / Q000379:methods; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000473:pathology / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D020542:Third Ventricle / Q000098:blood supply / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome; D014371:Tuber Cinereum / Q000098:blood supply / Q000473:pathology / Q000601:surgery*; D014696:Ventriculostomy / Q000379:methods; D055815:Young Adult