Effects of flow diversion stents on rabbits' wide necked aneurysms and branches

Objective To observe the effects of flow diversion stents on rabbits' aneurysms and branches.Method 30 New Zealand white rabbits with wide necked aneurysm were randomly divided equally into three groups.In group A and B,flow diversion stents were implanted into parent vessel with metal coverage 30%～35% and 45%～ 50%,respectively.Angiography was performed at 4 weeks after stent implantation.After 3 months all animals were euthanized for pathological examination after angiography.In group C,animals were only performed for angiography without any stent implanted after grouped and at 3 months,and then animals were euthanized for pathological examination after angiography.Results Immediately after stents placement,90% and 70% aneurysms' necks covered by stents successful in group A and B,respectively.The contrast retention in aneurysms were 88.7% and 100%,respectively.intravenous digital subtraction angiography showed that 77.8% and 85.7% aneurysms were completely occluded at 4 weeks fogow -up,respectively.Artery digital subtraction angiography showed that 71.4% and 85.7% aneurysms were occluded at 3 months follow- up,respectively.All branches covered by stents were patency at angiography follow - up.Pathologic analysis showed that the dome of embolized aneurysms was full filled with thrombus and neointimas at neck and parent vessel were found.In group C,mean aneurysm dimensions were not significantly changed in angiography after grouped and before sacrificed at 3 months( P ＞ 0.05).Conclusions The flow diversion stents are effective in the treatment of wide necked aneurysms with preservation of adjacent branch vessels in angiography. Key words: Flow diversion stent; Metal coverage; Intracranial aneurysm; Branch vessel; Rabbit