Grant: Operating Grant

A cerebral aneurysm is an abnormal bulge or "ballooning" of the wall of an artery of the brain. An estimated 600000 Canadians have a cerebral aneurysm. About 3000 will suffer rupture from their aneurysm per year, with potentially catastrophic outcome. Most people (2/3) will die or suffer permanent disabilities; 50% of survivors will experience considerable neuropsychological dysfunction. Endovascular embolization is a minimally invasive procedure used to treat aneurysms. This involves making a small hole in a groin artery and driving a small tube up to the brain aneurysm under X-Ray guidance. Through the tube, small platinum coils or stents (metallic mesh tubes) are deposited in or near the aneurysm to cause the aneurysm to clot off. Although well-tolerated by patients, the biggest problem is that the aneurysm are not always completely healed, with as high as 20-40% recurrence rate. Even though nearly 15 years have elapsed since the initial clinical trial that led to approval of the platinum coil for treatment of brain aneurysms, important shortcomings remain that have negative impact on patient care. Radiofrequency ablation (RFA) is a widely used medical procedure that generates heat at the end of a probe. The heat generated induces endothelial injury. Mechanisms of recurrences are still poorly understood, but we have shown that they relate to inhibition of endothelial invasion of the blood clot that forms in the aneurysm after coil occlusion. We believe that RFA could be used to promote complete healing. RFA can be performed under image guidance, and could likely be readily combined with ET of aneurysms to improve results. In recent pilot experiments, we have found that aneurysms heal better when ET is combined with RFA. However, we need to examine and understand the basic underlying changes occurring in the blood vessels as a result of using RFA before we can translate it to the treatment of aneurysms.