Low-angled microcatheter approach for coil embolization of the anterior choroidal artery aneurysm

Thromboembolic complication is a serious concern following coil embolization for aneurysms involving the anterior choroidal artery (AChA). To minimize this complication and to improve packing density, we present a technical concept of coil embolization. We attempted packing of the aneurysmal sac by lowering the microcatheter approach angle into an aneurysm to secure AChA origin as well as to improve coil packing density of the aneurysm. This technical concept involves approaching the aneurysm sac with an adjusted shaping of the microcatheter tip to achieve the effect which was not obtained when the microcatheter approach angle into the aneurysm sac was high (ae<yen>90A degrees). We evaluated immediate angiographic outcome by the Raymond classification, coil packing density, and follow-up results (modified Rankin Scale (mRS) and recurrence) in seven aneurysms involving AChA in six patients. We achieved immediate angiographic outcome of the Raymond classes I or II with 31% mean packing density. The AChA origin was preserved without any procedure-related complication. There was neither clinical event (mRS = 0) nor aneurysm recurrence confirmed on the source image of magnetic resonance angiography during 6-9 months follow-up. The technical concept of low-angled microcatheter approach can be useful to improve coil packing density and to secure AChA origin when AChA arises near the aneurysm.