Aneurysm Inclination Angle as the Predisposing Factor for the Occurrence of Rupture

Introduction Natural course of aneurysms that occur on blood vessels of the brain singles out the need for understanding the mechanism of the occurrence of aneurysm wall rupture and identification of anatomic characteristics as predictive factors for hemorrhage to occur.

Aim In this study, we comparatively present results of our researches and experimental models on animals.

Material and Methods We made a comparative analysis of anatomical characteristics of blood vessels of the brain and aneurysms obtained on the basis of digital subtraction angiography and intraoperative finding. In this article, we review recent research in the anatomic characteristics of intracranial aneurysms and parent blood vessels.

Results We present a series of 185 aneurysms (ruptured and unruptured) dissected at the Neurosurgical Clinic of Clinical Center of Serbia in Belgrade. Inclination angle may be considered as the vital predisposing factor for intracranial aneurysm rupture. In aneurysms that ruptured, it was 139.748 ± 27.242 degrees, while in unruptured aneurysms it was considerably smaller and amounted to 100.882 ± 22.001 degrees (p < 0.01).

Conclusion Inclination angle may be regarded as the vital predisposing factor because it differs considerably in unruptured and ruptured aneurysms. Aneurysms with blood stream angle smaller than 115 degrees have very small probability of rupture, while blood stream angle bigger than 150 degrees presents a high risk of rupture.

Keywords intracranial aneurysm; inclination angle; rupture