Background A technique for stent-assisted coil embolization of a bilobed wide-necked saccular aneurysm of the anterior inferior cerebellar artery (AICA) with the AICA arising from the dome of the aneurysm is described.

Clinical presentation A middle-aged patient was referred for treatment of a bilobed saccular aneurysm identified on a CT angiogram performed for a subarachnoid hemorrhage which occurred 20 days prior to presentation. A diagnostic angiogram showed a bilobed wide-necked saccular aneurysm at the AICA origin with the AICA arising from the dome of the aneurysm and also supplying the territory of the posterior inferior cerebellar artery. The therapeutic procedure involved trans-aneurysmal cannulation of the AICA with the microcatheter left in situ. Another microcatheter was maneuvered into the larger dome of the aneurysm. A stent was then deployed in the basilar artery, jailing the previous microcatheter in the aneurysm. Helical Guglielmi detachable coils were deployed in the aneurysm resulting in complete occlusion of the aneurysm with preservation of the AICA.

Conclusions It is important to preserve a normal branch arising from the dome of an aneurysm although it is technically demanding and a relative limitation. This case report describes a technique of coiling a bilobed aneurysm with a vital branch arising from the dome, with preservation of the branch and complete occlusion of the aneurysm using two microcatheters and a stent. This expands the repertoire of endovascular treatment of complex aneurysms.