FRED X flow diversion stent for intracranial aneurysms: a systematic review and meta-analysis

The Flow Re-Direction Endoluminal Device X (FRED^TM-X, MicroVention, Inc., Terumo Corporation, USA), introduces a dual-layer structure and antithrombotic surface technology, designed to address the limitations of earlier devices in reducing material thrombogenicity and promoting better vessel endothelialization for brain aneurysm. Herein, we present the first systematic review and meta-analysis summarizing available literature to reach a consensus regarding the safety and effectiveness of FRED^TM-X.

A literature search was performed in four electronic databases, PubMed/MEDLINE, Embase, Google Scholar, and Web of Science, for studies that evaluated FRED-X in managing intracranial aneurysms. Proportions were pooled employing the inverse variance method, and binary outcomes were analyzed using odds ratio (OR) and 95% confidence interval (CI). The primary outcome was an aneurysm occlusion at the final follow-up.

Eight studies involving 480 patients and 531 aneurysms were included. Most patients were female (81.5%), with a mean age of 56.2 years. Most aneurysms were unruptured (84.1%, 95%CI = 66% - 96.5%) and located in the anterior circulation (86.7%, 95%CI = 75.9% - 94.8%), primarily in the internal carotid artery (64.2%). Procedural data showed a mean procedure time of 68.2 (SD = 38.1) minutes and a fluoroscopy time of 23.5 (SD = 11.7) minutes. The mean aneurysm size was 6.4 mm (SD = 5.1). In-stent stenosis occurred in 1.2% of cases. Adequate occlusion was achieved in 85.9% (95%CI = 79% - 91.8%) of patients at the last follow-up. Symptomatic complications occurred in 4% (95%CI = 0.7% - 9%) of patients, and the overall mortality rate was 0.34% (95%CI = 0.0% - 1.7%).

The FRED-X flow diverter is safe and effective in treating intracranial aneurysms. It has low complication rates, minimal in-stent stenosis, and efficient procedural metrics. Long-term studies must confirm its durability and potential for broader applications.