You are one of the few neurosurgical specialists, who combines a very deep and thorough training in endovascular methods as well as in open brain surgery. Could you speak about what kind of patients benefit most from such rare and the superior expertise? - Dr. P. Roc Chen, MD. At this point the cerebrovascular neurosurgery developed into a very complicated cross-role, at this point. Open vascular surgery has been performed for several decades and the techniques at this point are very refined. We are able to treat a lot of complex cerebrovascular diseases very successfully. However, over the last 20 to 30 years, the entire endovascular field developed from almost nothing into extremely robust subspecialty. What is one of the most meaningful things about endovascular neurosurgery is that it is bringing very attractive, less complicated post-procedure recovery time, patients are more comfortable with recovery, they tolerate procedures easier, and also fundamentally we want to bring down to the minimum the risk of a procedure. I don't think we can call endovascular neurosurgery a "minimal risk", but at the same time we do see the difference in terms of recovery between open cerebrovascular surgery and endovascular neurosurgery. So at this point both subspecialties are developing in conjunction together and able to provide patients different options in terms of treatment and treatment modalities. The most meaningful thing is that, as things progress, we've seen the combination of two types of treatment modalities to give us the best choice to give a patient most beneficial result, and give the best outcome, least risk, and as times goes on, it would be much better. When surgeons have better background and are capable to handle extremely complicated open surgery and also able to handle quite sophisticated endovascular treatment - typically, they're able to be less biased to provide patients with a good recommendation and also give them what potentially is the overall best treatment option. For patient with cerebrovascular disease that will be the one of the best choice to see this physician [who can do both endovascular and open brain surgery].