Endovascular management of spontaneous delayed migration of the flow-diverter stent

Spontaneous delayed migration of the flow-diverter stent (FD) is an unusual complication that can be fatal. The purpose of this study is to report our experience and review the literature for the management of delayed FD migration. Between November 2013 and June 2017, 122 patients treated by FD at our institution were enrolled. We also performed a comprehensive review of the literature. Six patients (4.9%) were found to have spontaneous delayed migration of their FD. The device migrated proximally in 4 patients and distally in 2 patients. One patient had temporal lobe infarction due to stent migration, and another had subarachnoid haemorrhage (SAH). Three patients were treated with a 2nd or 3rd FD, while 2 were treated with stent-assisted coiling, and one was treated with sacrifice of the parent internal carotid artery. According to our results and the literature, the prevalence rate of delayed FD migration ranges from 2.2% to 4.9%, and the mortality and morbidity rate of delayed FD migration is 40%. Neuro-interventionalists should be aware of this complication and be familiar with risk factors, preventive methods and treatment options. If there is any concern regarding the size or position of the FD, early imaging follow-up and endovascular treatment should be indicated.