Introduction Distal circulation wide necked aneurysms had been treated for a long time by the means of microsurgery. Recent breakthrough in endovascular technology, appearance of a broad variety of intracranial stents and flow-diverting devices, turned endovascular surgical neuroradiology into the first line of treatment for said pathology in several institutions. Nowadays exist two standard approaches for endovascular treatment of distal aneurysms with the first one being an implantation of flow-diverting device and stent assisted coil embolization (SAC) as the second one.

Materials and methods 1567 patients with cerebral aneurysms underwent treatment in our department since January 2011. Among them, 116 patients had distal circulation aneurysms. Twenty-four patients were treated with flow-diverter implantation, the devices were as follows: Pipeline (n-5), Pipeline Flex (n-11) Pipeline Shield (n-1), FRED (n-4), Fred jr (n-1) P64 (n-2). 92 patients were treated by stent-assisted coil embolization. Among them 81 patient were treated by low-profile stent-assisted coil embolization with LVIS jr. 11 patients were treated by stent-assisted coil embolization with Enterprise (n-6), Solitaire AB (n-4) and Leo (n-1) We defined localization of an aneurysm in distal circulation for aneurysms beyond the circle of Willis. Rates of technical issues, intraoperative complications, morbidity and mortality and recanalization (Raymond and Roy scale) were assessed for either group.

Results Among patients treated by FD 2 (8,3%) had major complications that led to dependent outcome in one case and to mortality in other one. Among patients treated by SAC 2 (1.7%) had major complications that led to dependent outcome. However the difference between groups by initial analysis did not meet statistical significance (p=0.46). The rate of combined Raymond and Roy class 1+2 recanalization did not vary significantly between groups (p=0.46) and consisted 20.5% (5 pts) for FD and 29% (34 pts) for SAC. Nevertheless, true recanalization rate for FD was significantly lower (p=0.0275) and consisted 4.1% (1 pt) vs 25% (30 pts) for SAC.

Conclusion While either method allows for safe occlusion of an aneurysm with a similar complication rate, flow diversion provides higher rate of total occlusion, but combined near total (Raymound and Roy 2) and total occlusion rate does not vary among groups. Morbidity and mortality in either group didn’t exceed the rate stated by the literature. Keeping in mind, that low-profile stent-assisted coil embolization provides immediate occlusion in comparison with long-term occlusion by FD we can suggest, that both methods are suitable but the decision should be based on individual risk of aneurysm rupture for each patient.

Disclosures D. Kislitsin: None. A. Gorbatykh: None. R. Kiselev: None. A. Moskalev: None. K. Orlov: None.