What are some of the examples of vascular problems in the brain that are most amenable to the combination of endovascular approach and open surgery? Dr. P. Roc Chen, MD. Cerebrovascular surgery, including brain aneurysms, which is one of the diseases that are not well-known by everyone, but when you have brain aneurysm rupture, it tends to have a high mortality. Second condition is called arteriovenous malformation - the artery and vein have a wrong connection with a short circuit shunting, and also have a so-called occlusive disease, which is a carotid stenosis, which is known as a cause of ischemic strokes. In all of these diseases you would see the benefit of a combination of endovascular and open brain surgery treatments. For example, in brain aneurysm treatment, traditionally, open surgery is the only option, and over the last 20-some years it developed into so-called coil embolization - we use the catheter to treat these patients. And we see in the European trial and also in a trial from this country, data that suggest that some patients with brain aneurysm rupture do benefit from endovascular treatment a little bit better than from open surgery in their first few years of recovery [after brain aneurysm rupture]. We also, at our own institution, prospectively follow up a group of brain aneurysm patients over the last few years. We see that combined endovascular and open surgery to assess high-grade patients, which means patients have a very poor neurological status when they come in with the aneurysm rupture, when they are treated with combined endovascular and open surgery, and also leaning more towards endovascular treatment, their outcome is better than when done by a traditionally dominant open brain surgery. We show that data recently, it is just being presented in the Congress of Neurological Surgeons annual meeting. At the same time, if you look at the carotid disease, in the 1980s - 90s, clinical trials showed the strong benefit of open surgery carotid endarterectomy to prevent stroke. That is very clear benefit, this is Class One data. However, over the last 10+ years, the endovascular procedure with balloon angioplasty and stenting for the carotid disease has gradually turned to be more popular in this country, and in Europe. However, for a period of time we didn't know whether endovascular technique is as good as surgery. Recent trial, so-called CREST, randomized two groups of patients to open surgery versus endovascular balloon angioplasty and stenting. And it demonstrated that there is no significant difference from statistical standpoint. The true meaning of this is that we now have more options with patients with the same type of disease that we treat with open surgery or endovascularly. They all have a different potential procedure-related risk and complications. If we focus on each patient individually and analyze them to choose the best treatment modality, we can bring the overall risk to treat this carotid disease much better. So in that way that we are able to bring down the potential procedure risks. That ultimately benefits the patient!