Endosaccular Coil Embolization of Large Unruptured Intracranial Aneurysms

• Published in: Nōshotchū no geka Vol. 41; no. 2; pp. 102 - 109
• Main Authors: OISHI, Hidenori, YAMAMOTO, Munetaka, NONAKA, Senshu, SUGA, Yasuo, SHIMIZU, Takashi, YOSHIDA, Kensaku, MITSUHASHI, Takashi, ARAI, Hajime
• Format: Journal Article
• Language: English; Japanese
• Published: The Japanese Society on Surgery for Cerebral Stroke 2013; Japanese Society on Surgery for Cerebral Stroke
• Subjects: endosaccular coil embolization; endovascular therapy; large unruptured intracranial aneurysms
• ISSN: 0914-5508; 1880-4683
• DOI: 10.2335/scs.41.102

We retrospectively studied the endosaccular coil embolization of 88 patients with 89 large (maximum diameter ≥10 mm) unruptured intracranial aneurysms (UIAs). The mean aneurysm and neck size were 12.7 ±2.9 mm and 5.7±1.8 mm, respectively. Frequent locations were the paraclinoid segment of the internal carotid artery and posterior communicating artery in the anterior circulation and the basilar artery bifurcation in the posterior circulation. Twenty-one aneurysms (23.6%) presented with the clinical symptoms due to the mass effect. All of the procedures were completed. Embolization techniques used were conventional (simple, balloon-assisted, or double-catheter) techniques in 66 aneurysms and the stent-assisted technique in 23 aneurysms. Overall immediate anatomical outcomes showed complete occlusion (CO) in 50.6%, residual neck (RN) in 29.2%, and residual aneurysm (RA) in 20.2%. Overall radiological follow-up results of the 71 aneurysms showed unchanged in 26.8%, improved in 11.3%, minor recurrence in 22.5%, and major recurrence in 39.4%. The final anatomical outcomes of the aneurysms radiologically followed up were CO in 47.9%, RN in 31.0%, and RA in 21.1%. The stent-assisted technique improved the immediate anatomical outcomes and decreased the risk of recurrence in the short term compared with the conventional techniques. Procedure-related complications occurred in 15.9% of the aneurysms. Four aneurysms (4.5%) had ischemic complications, and two aneurysms (2.2%) had hemorrhagic complications. Only four patients had clinical worsening of the mRS of >1 at the latest clinical follow-up. The permanent morbidity and mortality rates were 3.4% and 1.1%, respectively. The mean clinical follow-up period after endovascular therapy was 34.9±2.9 months (13 days–9.54 years). No patients suffered from aneurysmal subarachnoid hemorrhage (SAH) during the clinical follow-up periods. Permanent clinical worsening of the mass effect occurred in three patients with visual symptoms. Two aneurysms showed transient asymptomatic perianeurysmal edema that improved after administration of steroid therapy. Basilar artery dissection and renal artery injury due to the migration of the femoral sheath guidewire occurred once in each case. Twenty-one aneurysms (23.6%) underwent endosaccular coil re-embolization without any complications. No patients underwent surgical clipping or parent artery scarification. The mean duration between the initial treatment and the first re-embolization was 18.2 months (0.5–48.4 months). Endosaccular coil embolization of the large UIAs is effective and safe. But recurrence and aneurysm growth after endosaccular coil embolization are significant concerns, and patients with visual symptoms may be candidates for parent artery occlusion or surgical clipping.