Long-term safety and efficacy of distal aneurysm treatment with flow diversion in the M2 segment of the middle cerebral artery and beyond

Abstract

BackgroundIndications for flow diversion stent (FDS) treatment are expanding. However, there is still a lack of evidence for the long-term outcome in distally located aneurysms in the M2 segment of the middle cerebral artery (MCA) and beyond.MethodsConsecutive subjects (from June 2013 to August 2020) with MCA aneurysms in the M2 segment or beyond treated with FDS were reviewed retrospectively. The primary endpoints for clinical safety were the absence of mortality, stroke event, re-rupture of the aneurysm, and worsening of clinical symptoms. The primary endpoint for treatment efficacy was complete/near-complete occlusion at follow-up after 12 months.Results23 patients were identified: 7 aneurysms were located in the M2 segment of the MCA, 4 in the M2-M3 bifurcation, 2 in M3, 3 in M3-4 branching, and 2 in M4; 5 aneurysms were located in M2 with extension into the M1-M2 bifurcation. 13 aneurysms were of fusiform morphology, 8 sacculofusiform, and 2 saccular. 16 aneurysms were of highly suspected dissecting etiology. The median diameter of the parent vessel was 2.1 mm proximally and 2 mm distally. The median time of the follow-up was 30 months (range 16 months to 6 years). Complete/near complete occlusion was observed in 14/20 patients (70%) and one stable remodeling (5%) was seen at 12 months. 22 patients (95.6%) had an excellent clinical outcome (mRS 0–1) at 6 months. Technical challenges associated with the deployment of FDS occurred in 8.7% of cases. Severe complications, intraparenchymal hemorrhage and re-rupture of the aneurysm occurred in 2 patients (8.7%).ConclusionFlow diversion of distally located aneurysms is technically feasible with low morbidity and mortality.

Safety and Efficacy of the FRED Jr Flow Re-Direction Endoluminal Device for Intracranial Aneurysms: Retrospective Multicenter Experience With Emphasis on Midterm Results

“…The densely braided mesh of a flow diversion stent delivered at the aneurysm base decreases the blood flow into the aneurysm and induces thrombus formation within the aneurysm sac while maintaining adequate blood flow through the parent artery and the covered vessel branches (5). The development of smaller flow diverters like Flow Re-Direction Endoluminal Device Jr (FRED Jr; MicroVention, Tustin, California), which can be delivered into small-caliber (<3 mm diameter) vessels, enabled the expansion of indications for flow diversion stent treatment in smaller parent vessels (2,6). However, there is only a limited number of studies evaluating flow diverter devices specifically developed for smaller arteries (2,7).…”

Cerebral revascularization for the management of complex middle cerebral artery aneurysm: A case series

“…Recently, flow diversion devices have been reported as an alternative endovascular treatment for complex MCA aneurysms. Cimflova et al (28) reported that the complete/near-complete occlusion rate was 70% in consecutive subjects with 23 MCA aneurysms. Potentially severe periprocedural or postprocedural events occurred in 17.4% of the patients and severe complications (intraparenchymal hemorrhage and rerupture of the aneurysm) occurred in half of those patients (8.7%), which was consistent with previous studies (29,30).…”

Distal Flow Diversion with Anti-Thrombotically Coated and Bare Metal Low-Profile Flow Diverters—A Comparison

“…Contrary to that, Salem et al found that MCA-bifurcation aneurysms are treatable with much lower complication rates, the outcomes of their study being comparable to other, well consented FD locations [ 45 ]. Cimflova and coworkers contributed their experience with less than 9% significant complications after FD implantation in the MCA distal to the M1 segment [ 46 ].…”