You frequently deal with and specialize in is carotid artery occlusive disease. Dr. P. Roc Chen, MD. What happens in such situation is a build-up of atherosclerotic plaque at the bifurcation of carotid artery or other segments, and then eventually, at some point, it restricts the normal blood flow to the carotid artery and to the brain, and also there is a risk that some fragments of atherosclerotic plaque will rupture, travel to the brain vessels, and cause a stroke by lodging in one of the small arteries of the brain. How do you approach carotid artery occlusive disease? What are the nuances from your practice for such patients? Carotid disease is probably the best studied cerebrovascular disease in the entire neurosurgery field. And we know that open surgery, so-called carotid endarterectomy, meaning that when you have a plaque in the carotid artery beyond certain percentage, typically saying that beyond 70% occlusion, asymptomatic or symptomatic. Many patients had recent stroke or recent transient ischemic attack, TIA. Patients with even 60% carotid stenosis will benefit from the surgical treatment. Plaque in carotid artery will break and create some fragments. They break off, causing distal brain vessel ischemic stroke by blocking the artery. Surgery is well known to reduce risk in two years, about 26% of reduction of stroke risk compared to medical treatment. Obviously, the study was done in 90s. However, these days the endovascular technique - balloon angioplasty and stenting - also provides a great result and long-term results, in fact, many clinical trials showed one consistent thing: Long-term, open surgery and endovascular treatment results are quite similar. The recurrence rate is similar, about 5% risk in the long run. A little bit more debate still remains about How to choose patients to do endovascular treatment versus open surgery? As I mentioned before, we try to assess patients individually. At the same time, I do think that general guideline is - at this point, high surgical risk patients - and that's been studied quite well now - patients with high surgical risk do benefit from endovascular treatment, particularly if they had carotid endarterectomy and stenosis recurred at same side, where surgery was done previously. If patients had a radiation to the neck for whatever reason - had cancer in the neck had a radiation, and later developed carotid stenosis. Endovascular carotid stenting is beneficial for those patients, while surgery is much more troublesome for them. If patients after surgery had some nerve palsy and the vocal cord dysfunction, or have a poor cardiac function, endovascular stenting is also better. We must make sure these patients are able to survive for a long time, but at the same time they have relatively poor function and could not necessarily tolerate the anesthesia quite well. Extremely obese patients also benefit from endovascular approach. In addition to those indications, endovascular methods work well for tandem lesions, meaning a stenosis in the neck artery and also a narrowing in the brain part of a vessel. In that scenario, open surgery can only fix one narrowing at the same time. But if you do endovascular procedure - stenting and balloon angioplasty - often you can fix them both. So, these are general guidelines and perspective on how to approach carotid artery disease treatment. But I do think that each individual patient should be analyzed, assessed by the surgeon and multidisciplinary team to get the best treatment option for the patient.