Endovascular surgery for the internal carotid artery aneurysm arising near the dural ring

We report our experiences with internal carotid artery (ICA) aneurysm arising near the dural ring in 13 patients (15 aneurysms) treated by endosaccular embolization using Guglielmi detachable coil (GDC). Patients ranged in age from 44 to 79 years old (average 58 years) and were all female except one male. Fourteen aneurysms were asymptomatic and 1 presented with subarachnoid hemorrhage (Hunt and Kosnik grade IV). The aneurysm was less than 5 mm in diameter in 5, between 5 mm and 12 mm in 7, more than 12 mm in 3. In GDC treatment, it was not always easy to navigate the microcatheter into the aneurysm due to the curve of the carotid siphon, position of the neck, and the projection of the dome of the aneurysm. In these instances, preshaping the tip of the catheter with steam was very helpful. During the insertion of GDC, remodelling of the ICA was performed using the assist balloon in most cases. Total obliteration was obtained in 10, and more than 95% obliteration was possible in 4 aneuryms. In one aneurysm, stable placement of the microcatheter was impossible and embolization was abandoned. Complication was encountered only in this left-handed patient, who developed a temporary motor aphasia and left arm weakness due to a small cerebral infarction in the right frontal lobe. A possible cause of this event was ischemia due to prolonged manipulation of microcatheters, and repeated inflation and deflation of the assistant balloon in the ICA with poor collaterals. Remodelling technique seemed to be extremely useful but should be carefully applied. In summary, endosaccular embolization may be considered as a less invasive alternative for this aneurysm, considering the relative difficulty in surgical clipping due to its complex anatomical location.