Safety and efficacy of low profile flow diverter stents for intracranial aneurysms in small parent vessels: systematic review and meta-analysis

Background This meta-analysis aims to evaluate the clinical and angiographic outcomes of low profile flow diverters (FDs) used in treating intracranial aneurysms in small parent vessels (≤3.5 mm). Methods A systematic review was conducted using Medline, Scopus, and Web of Science databases from inception to October 2024. Studies reporting clinical and angiographic outcomes for Silk Vista Baby, Flow Re-direction Endoluminal Device Junior (FRED Jr), and p48 MW Flow Modulation Device were included. Favorable outcomes were defined as those reported directly in studies or as a modified Rankin Scale score of 0–2. Results 33 studies involving 998 patients with 1049 aneurysms were analyzed. Favorable neurological outcomes were reported in 94% of cases overall, with unruptured aneurysms achieving better outcomes (97.1%) than ruptured aneurysms (80%). Procedure related complications were observed in 15.7% of cases, with a lower rate in unruptured aneurysms (12.7%) compared with ruptured aneurysms (20%). Complete or near complete occlusion was achieved in 79.5% of aneurysms from 28 studies, with similar rates for both unruptured (73.6%, from 14 studies) and ruptured (74%, from 13 studies) aneurysms. Among devices, the FRED Jr showed the highest favorable outcome rate (97.6%), while the p48 MW device had the highest complication rate (17.2%). Adjunctive coiling did not significantly affect neurological outcomes but was associated with a slightly lower complication rate (12.1%). Conclusion Low profile FDs demonstrated high rates of favorable neurological outcomes in small parent vessel aneurysms, particularly in unruptured cases. These FDs achieved acceptable rates of adequate aneurysm occlusion and complications.