Aneurysm geometry in predicting the risk of rupture. A review of the literature.

The management of unruptured aneurysms (UAs), whose incidence is increasing, is still a controversial issue. Many studies have been investigating the link between the geometry of the aneurysm and the risk of future rupture in order to bring forth a clear decision plan. The different estimators studied are the aneurysm's geometry and hemodynamic features on one hand, and the patient's clinical characteristics on the other. We reviewed the literature while focusing on the different geometrical parameters that have been used in estimating the future risk of rupture. These include mainly the size ratio (SR), the aspect ratio, the non-sphericity index (NI), the undulation index (UI), and the vessel aneurysm inclination angle (AA), to name a few.