[Current State of the Flow Diverter in Endovascular Treatment]

Since Pipeline Flex(Covidien/Medtronic)was approved in April 2015, flow diverter(FD)treatment has started in Japan. Three kinds of FDs(Pipeline, FRED and Surpass)are available now, and we have been able to treat a variety of aneurysms, including those that are giant-sized and located posterior circulation, which had been difficult to treat safely before the appearance of the FD. In addition, indications for FDs have been expanding with increasing evidence. However, there are some challenges that need to be overcome. First, thromboembolic complications due to high metallic amounts in FD must be considered. The long duration of antiplatelet therapy must be continued to reduce thromboembolic complications, but the precise required-duration of this therapy has not yet been determined. Second, FD treatment requires a few months before an aneurysmal cure is achieved. Therefore, there is a possibility of an aneurysmal rupture after FD deployment. In addition, there are some kinds of aneurysms for which FD treatment is less effective, such as aneurysms with a large branch vessel. In this review, I describe the details of each FD and the current state of FD, based on the evidence.