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.