Intraaneurysmal Embolization Using Guglielmi Detachable Coils for Cerebral Aneurysms: Selection of Embolization Technique Related to the Aneurysmal Neck Diameter.

We performed intraaneurysmal embolization using Guglielmi detachable coils (GDCs) for cerebral aneurysms, and we report here on the selection of an embolization technique based on the aneurysmal neck diameter. Intraaneurysmal embolization was attempted on 47 patients (48 aneurysms), aged between 33 and 89 years (mean 65.5 years), from March 1997 to March 2001.In this series, we considered the wide-necked aneurysm as an aneurysm with a neck diameter of 4 mm or more, and/or with a neck-to-fundus ratio of greater than 1.0. In 8 wide-necked aneurysms, neck plasty was performed employing a balloon or stent-assisted technique to prevent coil protrusion into the parent artery. Forty-seven cases who could undergo intra-aneurysmal embolization were classified into the following groups: 1) small aneurysm (<10 mm)/small neck (<4 mm) (S/S group): 26 aneurysms; 2) small aneurysm/wide neck (S/W group): 18 aneurysms; 3) large aneurysm (10-25 mm): 2 aneurysms; and 4) giant aneurysm (>25 mm): 2 aneurysms. Complete occlusion (95-100%) was achieved immediately after coil embolization in 19 aneurysms (73%) of the S/S group and in 12 aneurysms (63%) of the S/W group.In 1 of the 2 large aneurysms, complete occlusion was achieved, and dome filling was observed in the other. This dome filling was also noticed in both giant aneurysms. Balloon-assisted technique was performed in seven aneurysms with wide necked leading to complete occlusion in 6 aneurysms. Follow-up angiography over a mean period of 13 months confirmed the complete occlusion in these 6 aneurysms. The use of the stent-assisted technique for large aneurysms produced complete occlusion, and the parent artery was preserved. During the 2-year follow-up period, no coil compaction was observed. The complications included aneurysm rupture during the procedure in 2 patients and occlusion of the peripheral arteries in 2 patients, but no permanent neurological deficits related to coil embolization were observed.It is very likely that the conventional embolization techniques can achieve complete occlusion for small aneurysms with small necks. For wide-necked aneurysms, however, neck plasty using a balloon or stent provides satisfactory therapeutic results.