The Source for Neurovascular News and Education

June 02, 2020


One-year outcomes of the SAFE trial suggest the indications for use could be expanded.


The FRED and FRED Jr flow diverters (MicroVention) appear to be just as effective as other flow diverters for the treatment of intracranial aneurysms and may even offer a safety benefit. These are the main findings of the Safety and efficacy Analysis of FRED Embolic device in aneurysm treatment (SAFE) trial 1-year update, published online recently ahead of print in the Journal of NeuroInterventional Surgery.

“FRED and FRED Jr represent a new generation of flow diverter with a specific design (stent-in-stent),” lead author Laurent Pierot, MD (Hôpital Maison-Blanche, Reims, France) told Neurovascular Exchange in an email.

“This design enhances the navigability of the device, especially in tortuous anatomy and apposition of the device to the arterial wall, a key point in achieving aneurysm occlusion,” the investigators write.


High Degree of Efficacy

For the SAFE trial, Pierot and colleagues prospectively evaluated outcomes of 103 patients with unruptured and recanalized aneurysms located in the anterior circulation treated with FRED and FRED Jr at one of 13 French interventional neuroradiology centers. Aneurysms were located in the supraclinoid internal carotid artery (ICA) in 71 patients (68.9%), cavernous ICA in 15 (14.6%), anterior cerebral or anterior communicating artery in nine (8.7%), and middle cerebral artery in nine (7.8%). Most aneurysms (68.9%) were small (< 10 mm).

The cumulative 1-year mortality rate was 1.9% and the cumulative 1-year morbidity rate was 2.9%. One of the two deaths that occurred was related to cancer.

One-year anatomical results were available for 93.9% of patients and suggest a high degree of efficacy.


One-Year Anatomical Results


6 Months

(n = 95)

1 Year

(n = 90)

Complete Occlusion



Neck Remnant



Aneurysm Remnant




Pierot described the low morbidity and mortality outcomes as a “good surprise,” with data that compare positively with other devices. “The safety is better compared to first-generation devices. This is probably not exclusively related to the device, but also to the fact that the participating teams are now more familiar with the technique of flow diversion,” he speculated.

Efficacy rates appear to be similar to those obtained with other devices, he noted.

“Typical indications for flow diversion are large and giant aneurysms, [especially] those located on the ICA,” said Pierot. “With the good safety [demonstrated with] the device, indications can be enlarged to smaller aneurysms and, with the FRED Jr, to aneurysms located on smaller vessels or more distally,” he concluded.





Pierot L, Spelle L, Berge J, et al. SAFE study (Safety and efficacy Analysis of FRED Embolic device in aneurysm treatment): 1-year clinical and anatomical results. J NeuroIntervent Surg. 2018;Epub ahead of print.



  • The SAFE study was funded by MicroVention Europe.
  • Pierot reports being a consultant for Balt, MicroVention, Neuravi, and Penumbra.