<International Circulation>:  What are the risks of treatment with the clot retriever in patients with cerebral infarction?

Prof. Lutsep: There certainly are potential risks but they have been low in the trials. One risk is that despite efforts to prevent pieces of debris from going downstream and affecting other vessels， sometimes that can happen and a piece of a clot can cause a vessel occlusion further down in the vascular bed. There are ways to reduce it from happening by blocking flow proximally to encourage the emboli to be pulled out rather than going in the wrong direction. Another risk is that as these devices are placed in the vessel they can pull on the vessel and can cause it to tear in some cases and that may or may not have consequences. What we worry about is that sometimes it can tear enough that the vessel can leak and cause a hemorrhage.