title: Distinct trends of pulsatility found at the necks of ruptured and unruptured aneurysms.
abstract: BACKGROUND
  Aneurysm hemodynamics has been shown to be an important factor in aneurysm growth and rupture. Although pulsatility is essential for blood flow and vascular wall function, studies of pulsatile flow properties in brain aneurysm disease are limited.
  
  
  OBJECTIVE
  To investigate differences in pulsatility within a group of ruptured and unruptured aneurysms by implementing patient-specific pulsatile flow simulation.
  
  
  METHODS
  41 of 311 internal carotid artery aneurysms were selected from an aneurysm database (29 unruptured and 12 ruptured) and used for patient-specific hemodynamic simulations of pulsatile flow. Flow pulsatility changes in ruptured and unruptured groups were analyzed by comparing different components of blood flow. Pulsatility index (PI) was used to quantify the pulsatility of blood flow in each group at the aneurysm neck, body, dome, and parent artery.
  
  
  RESULTS
  Within the parent artery, PI did not significantly differ between ruptured and unruptured groups (0.58). Within unruptured aneurysms, values of PI similar to that of the parent artery were found (0.61). Trends of significantly higher PI (1.99) were found within ruptured aneurysms (p<0.001). These differences were localized at the aneurysm neck, where PI in ruptured (1.93) and unruptured (0.59) aneurysms was significantly different (p<0.001).
  
  
  CONCLUSIONS
  A trend towards a lower PI, similar to that in the parent artery, was found in unruptured aneurysms, while ruptured aneurysms followed a trend of higher pulsatility. The difference was significant at the aneurysm neck, indicating that pulsatility and this location may be important aspects of aneurysm rupture and a useful predictor of the risk of aneurysm rupture.
authors: Division of Interventional Neuroradiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
authors: Jordan
authors: J
authors: Patti
authors: Fernando
authors: F
authors: Viñuela
authors: Aichi
authors: A
authors: Chien
mesh_terms: D000328:Adult; D000368:Aged; D017542:Aneurysm, Ruptured / Q000175:diagnosis / Q000503:physiopathology*; D001783:Blood Flow Velocity / Q000502:physiology; D002340:Carotid Artery Diseases / Q000175:diagnosis / Q000503:physiopathology*; D016208:Databases, Factual / Q000639:trends*; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011673:Pulsatile Flow / Q000502:physiology*
keywords: Aneurysm; Blood Flow