A blood flow diversion device to treat an aneurysm at a bifurcation artery, the blood flow diversion device having a plurality of legs that anchors the blood flow diversion device onto a parent artery of the bifurcation artery, and a plurality of branches that extends from the plurality of legs. The plurality of branches includes a plurality of upstream branches positioned above the plurality of legs to lie on a upstream portion of an aneurysm entrance of the aneurysm and divert the blood flow towards children arteries of the bifurcation artery, and a plurality of downstream branches positioned above the plurality of upstream branches to extend within an internal volume of the aneurysm and promote thrombosis formation in the internal volume.
