Brain aneurysms result in subarachnoid hemorrhage, one of the most devastating forms of stroke. Subarachnoid hemorrhage (SAH) mostly from rupturing of brain aneurysms is related to greater fatality than the other forms of strokes. Case fatality of SAH ranges between about 30 to 70% with an average of approximately 50%. Even if patients survive, only a small number have a good outcome. An estimation of the annual risk of SAH from an incidentally found brain aneurysms is an important step in order to make an appropriate management plan for a patient with a brain aneurysm, because the risk of SAH and risk of treatment need to be compared. Past clinical studies clearly showed that a larger aneurysm size was an independent risk factor of aneurysm rupturing. However, the risk of SAH from a small growing aneurysm remains unknown. Drs. Tateshima and Viñuela's awarded project will investigate how a small brain aneurysm grows.
A Novel Research Approach in a Rat Brain Aneurysm Model. Rat brain aneurysms are induced by unilateral carotid ligation and feeding a special diet which contains 0.2% beta-aminopropionitril and 8% sodium chloride. It takes approximately 3 months for a small brain aneurysm to be developed in the rat brain artery, and it grows for several months or some aneurysms even rupture. Rat brain aneurysms in various maturing and growth stages will be obtained in this project. Dr Tateshima and colleagues will perform micro-CT angiography of the rat brain aneurysms and will harvest the specimens. They will compare the alteration of histology, molecular-biology and hemodynamic pattern of the brain aneurysms during the process of their growth. This research will help to make an appropriate clinical decision in the management of a patient with a small aneurysm that shows some morphological change.
