title: Cerebral haemodynamics during thoracic- and thoracoabdominal aortic aneurysm repair.
abstract: OBJECTIVE
  To investigate cerebral haemodynamics during operations for thoracic and thoracoabdominal aortic aneurysms.
  
  
  METHODS
  Prospective clinical study.
  
  
  METHODS
  10 patients operated on consecutively with resection for thoracic (5) or thoracoabdominal aortic (5) aneurysms.
  
  
  METHODS
  Blood flow velocity of the middle cerebral artery was measured through a temporal approach using a TC Doppler with a 2 MHz probe. Recordings were made during induction of anaesthesia and performed continuously before, during and after cross-clamping of the aorta.
  
  
  RESULTS
  Following 10 min. of aortic cross-clamping blood flow velocity of the middle cerebral artery increased from 44 to 55 cm/s (p < 0.01). A further increase to 69 cm/s (p < 0.01) was observed 5 min after declamping. The pulsatility index averaged 0.74 increasing to 1.21 (p < 0.05) at clamping and 0.87 (p < 0.05) after declamping.
  
  
  CONCLUSIONS
  There was an increased blood flow velocity of the middle cerebral artery during cross-clamping of the descending thoracic aorta in patients operated on for thoracic and thoracoabdominal aortic aneurysms. This increase in cerebral blood flow and blood volume could explain the acute increase in cerebrospinal fluid pressure observed during cross-clamping of the thoracic aorta.
authors.affiliation: Department of Surgery, University Hospital of Trondheim, Norway.
authors.forename: O D
authors.initials: OD
authors.lastname: Saether
authors.forename: R
authors.initials: R
authors.lastname: Juul
authors.forename: P
authors.initials: P
authors.lastname: Aadahl
authors.forename: T
authors.initials: T
authors.lastname: Strømholm
authors.forename: H O
authors.initials: HO
authors.lastname: Myhre
mesh_terms: D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000601:surgery*; D017545:Aortic Aneurysm, Thoracic / Q000601:surgery*; D001783:Blood Flow Velocity; D001794:Blood Pressure; D001810:Blood Volume; D002315:Cardiopulmonary Bypass; D002536:Cerebral Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015170:Cerebrospinal Fluid Pressure; D002560:Cerebrovascular Circulation; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011673:Pulsatile Flow; D018608:Ultrasonography, Doppler