Biomedical Engineering Analysis of the Rupture Risk of Cerebral Aneurysms: Flow Comparison of Three Small Pre-ruptured Versus Six Large Unruptured Cases

A. Kamoda, Takanobu Yagi, A. Sato, Y. Qian, Kiyotaka Iwasaki, Mitsuo Umezu, T. Akutsu, H. Takao, Y. Murayama

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


A relationship between blood flows in cerebral aneurysms and their rupture remains obscure. In clinical practice, the size of aneurysms is one of the important factors for determining a strategy of treatment, but in our database three small aneurysms became ruptured during follow-up. Here, we aim to study their pre-ruptured hemodynamics, and differentiate them with those of six large unruptured aneurysms. All the aneurysms occurred in internal carotid artery, and their mean sizes were 6 and 10.8 mm for pre-ruptured and unruptured cases, respectively. We reproduced their replica as a patient-specific elastic model using clinical images obtained by digital subtraction angiography and a series of rapid prototyping techniques. Flows were reproduced in vitro using a cerebral flow simulator, and visualized by Time-resolved Particle Image Velocimetry. All pre-ruptured cases showed the collision of an incoming flow at a distal neck, and formed a prominent jet stream directing towards the aneurismal head. In contrast, none of unruptured aneurysms had such a marked impingement, and their flows were most likely characterized by swirling patterns. All unruptured cases occurred in a twisted vessel, or carotid siphon, whereas pre-ruptured ones were located downstream whose geometries consisted of a simple curvature. These findings suggest that internal carotid artery has a regional dependency of the risk of aneurismal rupture. Furthermore, the presence of jet streams for smallsized aneurysms may be a substantial indicator of the rupture and immediate treatments.

Original languageEnglish
Title of host publicationIFMBE Proceedings
Number of pages4
Publication statusPublished - 2009
Event13th International Conference on Biomedical Engineering, ICBME 2008 -
Duration: 2008 Dec 32008 Dec 6


Other13th International Conference on Biomedical Engineering, ICBME 2008



  • cerebral aneurysm
  • hemodynamics
  • PIV
  • rupture

ASJC Scopus subject areas

  • Biomedical Engineering
  • Bioengineering

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