System for computational estimation of cerebral aneurysm risk of rupture.

Decision-making by neurosurgeons regarding the surgical procedures to be undertaken in patients suffering from cerebral aneurysms is currently aided by data from the medical clinic and indices based on purely geometrical aspects of the pathology, for example, the measure of the openness of the artery adjacent to the aneurysm, as well as the depth of the aneurysmal sac. These indices are calculated from patient medical images (MRI, CT angiography, among others), having no functional or physical argument beyond medical studies based on statistical data to support their use. On the other hand, and in a complementary manner, computational modeling and numerical simulation bring out the physics behind the bloodstream and even the stress experimented by the various layers that make up the walls of blood vessels and the aneurysm as a result of the action of blood pressure on the endothelium. With information obtained from these models and from computer simulators it is possible to provide physicians with additional indexes associated with hemodynamic and structural factors, the latter being able to take into account the existing damage on the walls of vessels and aneurysms. 

Impact

Surgical procedures are of high complexity, high costs and, in some cases, with still doubtful benefits to the patient. Moreover, in certain situations, complications of the original pathological condition might arise or even new pathological situations can be generated. The computational estimation (at very low cost) of the risk of aneurysm rupture contributes to decrease the number of medical procedures to be performed by incorporating indices that take into account functional aspects of the severity of a given aneurysm.

Methodologies for testing the computer system

Medical images and clinical data of patients who suffered any cerebrovascular event associated with aneurysms will be provided by neurosurgeons associated with INCT- MACC and belonging to the Department of Neurosurgery, Transplant Hospital of São Paulo Euryclides Jesus Zerbini (former Brigadier Hospital). This information will be incorporated into a database along with the morphological, structural and hemodynamic indices of risk of rupture and correlated via data mining techniques to data of occurrence of rupture.

Specifications and results to be provided by the computer system

• 3D Reconstruction of a high degree of precision and anatomically detailed of cerebral the patient’s arterial tree and aneurysms.
• Full details of blood flow in arteries and aneurysms, along with information on pressure and flow fields in every point of the spatial domain over the entire cardiac cycle.
• Full details of stress state and of existing damage in the endothelium of vessels and aneurysms, as well as in the tissues that make up these structures.
• Index of risk of aneurysm rupture based on the functional aspects of the blood circulation and structural behavior of vessel and aneurysm walls.