Treatment of experimental aneurysms with an embolic-containing device and liquid embolic agent: feasibility and angiographic and histological results.

OBJECTIVE: To assess the feasibility and analyze angiographic and histological results of experimental aneurysms treated with an embolic-containing device (ECD) and to test a liquid embolic agent (LEA), N-butyl cyanoacrylate. METHODS: Four experimental large bifurcation aneurysms and 1 large sidewall aneurysm were created in 5 dogs. These venous pouch aneurysms were occluded endosaccularly with an ECD and N-butyl cyanoacrylate. Angiographic and/or histopathological data were analyzed at 1 day (bifurcation), 1 week (bifurcation), 4 months (sidewall), 6 months (bifurcation), and 12 months (bifurcation). RESULTS: Aneurysm dimensions were 16 to 18 mm in length, 6 to 8 mm in width, and a neck measuring 6 to 8 mm. Immediately after the procedure, 2 of 4 bifurcation aneurysms were 100% occluded. In one case, glue had spilled into the parent artery. One occluded aneurysm recanalized at 6 months. One occluded aneurysm remained closed at 12 months. Histopathological analysis of the 6- and 12-month specimens showed adherence of glue to the aneurysm wall, no appreciable inflammatory response to the ECD, and aneurysm wall fibrosis with adventitial chronic inflammation. The aneurysm necks were covered by neointima with the presence of endothelialization. CONCLUSION: Within the limitations of this experimental study, treatment of large, wide-necked aneurysms with the ECD and LEA may be feasible. Suboptimal technique and ECD geometry can cause leakage of LEA into the parent vessel or incomplete apposition of the ECD/glue to the aneurysm wall. However, the ECD and glue injection technique did achieve complete occlusion in 1 aneurysm that persisted 1 year later. The histopathological findings in this instance are moderately encouraging. Further investigations of an ECD with N-butyl cyanoacrylate or another LEA are warranted.