Endovascular coil embolization of large and giant aneurysms is technically difficult for anatomical reasons, particularly when the neck is wide. The Enterprise and Neuroform stents are specially designed to treat wide-necked aneurysms.
We retrospectively analyzed 38 patients (41 treatments) with large (maximum diameter ≥ 10 mm) aneurysms treated with endovascular coil embolization, and divided them into two groups: patients treated after (27 patients, 29 treatments) and before (11 patients, 12 treatments) the intracranial stents were approved in Japan. In the 29 treatments after the stent approval, 9 aneurysms were treated with the balloon-assisted technique; 3, with the double catheter technique; and 14, with the stentassisted technique. Immediate radiological outcomes showed complete occlusion (CO) in 27.6% of the aneurysms, neck remnant (NR) in 27.6%, and body filling (BF) in 44.8%. Early radiological follow-up (3-12 months) showed CO in 54.5% of the aneurysms, and late follow-up (>12 months) showed CO in 75.0%. Twelve of 14 aneurysms (85.7%) treated with the stent-assisted technique showed no change or improved radiological findings in the follow-up studies. In the group of patients treated before the stent approval, immediate radiological outcomes showed CO in 25.0% of the aneurysms, NR in 33.3%, and BF in 41.7%. The radiological follow-up showed no CO' NRs were seen in approximately 40%.
In summary, adjunct techniques, especially stent-assisted techniques, are frequently used to treat large aneurysms. Although the immediate radiological outcome was not satisfactory, follow-up studies showed favorable radiological results in many cases, especially those in which the stent was used in the treatment. The overall radiological outcomes of the patients treated after the approval of the stent were obviously better than those of patients treated before the stents were approved.