Safety and effect of pipeline flex embolization device for complex unruptured intracranial aneurysms

To investigate the safety and short-term effect of Pipeline Flex devices in the treatment of complex unruptured intracranial aneurysms, a retrospective study was performed for patients with complex unruptured intracranial aneurysms who were treated with the Pipeline Flex embolization device (PED Flex device) combined with or without coiling. The clinical, endovascular, and follow-up data were analyzed. One hundred and thirty-one patients with 159 complex unruptured cerebral aneurysms were treated with the PED Flex device, with 144 Flex devices deployed. Periprocedural complications occurred in four patients, resulting in the complication rate of 3.1%, including ischemic complications in three patients (2.3%) and hemorrhagic complication in one (0.8%). At discharge, the mRS was 0 in 101 (77.1%) patients, 1 in 25 (19.1%), 2 in four (3.1%), and 4 in one (0.8%), with the good prognosis rate (mRS 0-2) of 99.2%. Clinical follow-up was carried out in 87 (66.4%) patients 3-42 months after the procedure, with the mRS of 0 in 78 (89.7%), 1 in five (5.7%), 2 in three (3.4%), and 4 in one (1.1%). No significant (P = 0.16) difference existed in the mRS at discharge compared with that at clinical follow-up. Angiographic follow-up was performed in 61 (46.7%) patients with 80 (50.3%) aneurysms at 3-40 months, with the OKM grade of D in 57 (71.3%) aneurysms, C in eight (10%), and B in 15 (18.8%). Asymptomatic instent stenosis occurred in four patients (6.6%). In conclusion: The treatment of complex intracranial aneurysms with the Pipeline Flex embolization device may be safe and effective, with a high complete occlusion rate, a decreased complication rate, and a good prognosis rate at medium follow-up.