[Relationship between characteristic geometry and risk of rupture in cerebral saccular aneurysm].

OBJECTIVE: To explore the relationship between the characteristic geometry and the risk of rupture in cerebral saccular aneurysm. METHODS: The clinical features of 473 cerebral saccular aneurysm patients with complete materials of cerebral angiography, 426 with ruptured aneurysm and 47 with unruptured aneurysm, were analyzed retrospectively. The relation of depth, neck width, and aspect ratio (AR) of aneurysms to the risk of rupture were analyzed. RESULTS: The mean depth, neck width, and the AR of the patients with ruptured aneurysm were (5.9+/-3.0) mm, (3.0+/-1.2) mm, and (2.1+/-0.9), all significantly lower than those of the unruptured aneurysm patients [(8.0+/-4.2) mm, (4.8+/-2.4) mm, and (1.7+/-0.6) respectively, all P<0.01]. CONCLUSION: AR is not correlated with the location of aneurysms, but reflects the geometrical and hemodynamic features of cerebral saccular aneurysms very well. High AR may be useful in predicting imminent aneurysmal rupture. But by now, no definitive AR level is accepted in discriminating between unruptured and ruptured aneurysms.