2017 年 11 巻 3 号 p. 124-132
Objective: An outline and the results of clinical trials of flow diverters in Japan are reported.Subjects and Methods: There have been three flow diverters that have been evaluated by clinical trials in Japan: Pipeline, Surpass, and FRED. Since the clinical trials of Surpass and FRED are in progress as of January 2016, this report primarily focuses on Pipeline, which was approved for clinical use in April 2015 for the treatment of unruptured or chronic ruptured large/giant intracranial aneurysms.Results: The Japanese clinical trial of Pipeline was performed at four facilities by registering 22 patients, with 22 aneurysms. The procedure was completed in 21 (95.5%) of the 22 patients. The achievement rate of “complete occlusion of the target intracranial aneurysm and 50% or less stenosis of the parent artery” 180 days after the procedure, which was the primary endpoint, was 61.9%. “Severe ipsilateral stroke or neurologic death” within 180 days after the procedure, which was a major secondary endpoint, occurred in two patients (9.1%), and both events were subarachnoid hemorrhage due to rupture of the target aneurysm.Conclusion: The flow diverter is undoubtedly a revolutionary device in the treatment of large/giant intracranial aneurysms, but the results of the clinical trials in Japan were not satisfactory compared with previous reports. Therefore, the devices should be used carefully by comparing the safety and efficacy with those of existing endovascular treatment techniques including stent-assisted coil embolization and direct surgery in individual patients.